This article is an excerpt from the new third editions of Bigger Leaner Stronger and Thinner Leaner Stronger, my bestselling fitness books for men and women.
In this age, which believes that there is a short cut to everything, the greatest lesson to be learned is that the most difficult way is, in the long run, the easiest.
Supplements aren’t nearly as important as some people would have you believe. The right ones can help speed up your results, but even then, they’re supplementary, not vital.
So the first thing you need to know is you don’t need supplements. Absolutely none are necessary for reaching your health and fitness goals.
That said, you should consider including several supplements in your regimen because sound scientific research has proven they can help you build muscle and lose fat faster, boost workout performance and postworkout recovery, and improve your general health and well-being.
For instance, research shows that creatine, beta-alanine, and citrulline absolutely can help you gain muscle and strength faster, synephrine and yohimbine can help you burn more fat, and vitamin D and fish oil can improve your health and well-being in many ways.
On the other hand, a number of popular supplements you’ve probably heard of or even tried are proven duds.
For example, branched-chain amino acids are often claimed to increase muscle growth, but a growing body of evidence shows they don’t.
Garcinia cambogia is one of the (if not the) most popular weight loss supplements of all time, but several studies show that while it may work in rats, it’s a complete flop in humans.
The same goes for the go-to supplement for boosting testosterone, Tribulus terrestris—it simply doesn’t work, period.
It would take an entire book to break down everything you see on the shelves of your local supplement store, so instead, I want to focus on the six types of supplements that are going to be most beneficial for you:
- Protein powder
- Fish oil
- Vitamin D
- Fat burner
- Muscle builder
With these six supplements, you can positively and significantly impact just about every meaningful aspect of your physiology, including muscle growth, fat loss, inflammation, heart health, mood, brain and gut health, insulin sensitivity, energy levels, immunity, and more.
We’re going to review each of these types of supplements broadly in this chapter, and then, in chapter 30, talk specifics (products and protocols).
Table of Contents
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Let’s start at the top.
Whey and casein and soy, oh my!
The selection of protein powders on the market can be overwhelming. There are dozens of popular brands and scores of popular products.
Which should you buy, and why?
Should you choose an animal-based protein powder like whey, casein, or egg? Or maybe a plant-based protein powder like rice, soy, hemp, or pea will be best for you? Or a blend, maybe?
Well, a good protein powder meets a few criteria:
1. It doesn’t have to taste like a milkshake, but it should taste good and mix well.
If you have to choke it down, you’re going to have trouble sticking with it.
2. It should have a good macronutrient profile.
It should provide the most protein for the fewest calories and be as low in carbs and fat as possible.
3. It should have a good amino acid profile and be absorbed well by the body.
This determines how useful it really is for our purposes.
4. It should be affordable and offer good value in terms of cost per serving.
I also believe it’s beneficial to choose a protein powder that doesn’t contain artificial sweeteners, food dyes, or other junk, simply because it helps reduce our overall exposure to these chemicals, which may not be as entirely harmless as we’ve been told.
There are several types of protein powders that pass this test. Let’s learn a bit about each (as well as two popular choices that don’t pass the test).
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The Scoop on Whey Protein
Whey protein is Grand Poobah of protein powders, and for good reason.
It provides you with a lot of protein per dollar, it tastes good, and its amino acid profile is particularly suited to muscle building.
What is it, though, and what makes it special?
Whey is a translucent liquid that’s left over after curdling and straining milk to make cheese. It used to be considered a worthless byproduct of dairy processing, but eventually its high-protein content was discovered.
Scientists also discovered that whey is rich in the amino acid leucine, which plays a vital role in stimulating protein synthesis. This put whey at the top of the list for bodybuilders.
What’s more, whey is quickly digested, which means it causes a dramatic spike in amino acids in the blood when eaten. This makes it ideal for postworkout supplementation, and research suggests it may stimulate more immediate muscle growth than slower-burning proteins like casein or egg.
In short, whey is an excellent all-around choice for protein supplementation. What type of whey protein should you buy, though? You have three to choose from:
1. Whey concentrate
Whey concentrate is the least processed form of whey protein. It ranges from 25 to 80 percent protein by weight, depending on the quality, and contains dietary fat and lactose.
2. Whey isolate
Whey isolate is a form of whey protein processed to remove the fat and lactose. It’s at least 90 percent protein by weight.
3. Whey hydrolysate
Whey hydrolysate is whey protein (concentrate or isolate, but usually isolate) specially processed to be more easily digested and absorbed.
Whey isolate and hydrolysate are often marketed as superior to whey concentrate in all respects, but this isn’t true. Isolate and hydrolysate do have advantages—more protein by weight, no lactose, better mixability and digestibility, and some would say better taste—but as far as bottom-line results go, whey concentrate works just fine.
That said, choosing the cheapest whey you can find, which will always be a concentrate, isn’t always a good idea. A quality whey concentrate is somewhere around 80 percent protein by weight, but inferior concentrates can be as low as 25 percent protein by weight.
The general rule with whey protein is you’ll get what you pay for. If a product costs a lot less than the going rate for whey, it’s probably because it’s made with low-quality ingredients.
High prices aren’t always indicative of high quality, however.
Disreputable supplement companies will often add small amounts of whey isolate and hydrolysate to a base of low-quality concentrate to create a “blend,” and then call special attention in their packaging and advertising to just the isolate and hydrolysate.
To protect yourself as a consumer, always check ingredient lists, serving sizes, and amounts of protein per serving before buying a protein powder.
First, look at the ingredients list because ingredients are listed in descending order according to predominance by weight. This means there’s more of the first ingredient than the second, more of the second than the third, and so on.
Therefore, if a protein powder bills itself as a whey isolate but has whey concentrate as the first ingredient, it contains more whey concentrate than anything else and may in fact be mostly concentrate and contain very little isolate.
Worse are “whey” protein powders that list milk protein (a very cheap alternative) before any form of whey.
You should also look at the amount of protein per scoop relative to the scoop size, because a large discrepancy between the two is a red flag that something isn’t right.
For instance, if a serving weighs 40 grams but contains just 22 grams of protein, don’t buy the product unless you know that the other 18 grams consist of stuff you want.
A high-quality whey protein is easy to spot:
1. Whey concentrate, isolate, or hydrolysate is the very first ingredient.
If you see anything other than one of those three ingredients in the number one spot, find another product.
2. The serving size is relatively close to the amount of protein per serving.
It’ll never match because even the “cleanest” protein powders have sweeteners, flavoring, and other minor but requisite ingredients in addition to the protein powder itself.
The Scoop on Casein Protein
Like whey, casein protein comes from milk. Unlike whey, however, casein digests slowly, resulting in a steadier, more gradual release of amino acids into the blood.
There’s an ongoing debate as to whether whey or casein is better for gaining muscle, but here’s what most reputable experts agree on:
- Whey’s rapid digestion and abundance of leucine makes it a great choice for postworkout nutrition.
- Casein may or may not be as good for postworkout nutrition as whey.
- Casein is just as good as whey for general supplementation needs.
- You can speed up muscle recovery by having 30 to 40 grams of a slow-burning protein like casein (or low-fat cottage cheese or Greek or Icelandic yogurt) before bed.
As far as types of casein protein go, you have two choices:
- Calcium caseinate
- Micellar casein
Calcium caseinate is a form of casein processed to improve mixability.
Micellar casein is a higher quality form produced in a way that preserves the small bundles of protein (micelles) that are responsible for its slow-digesting properties and often destroyed during traditional manufacturing processes.
This is why research shows that micellar casein is digested slower than calcium caseinate, making it especially beneficial for prebed use.
Similar to whey, when buying a casein protein, you should look at the amount of protein per scoop relative to the scoop size, because a large discrepancy indicates something isn’t right.
The Scoop on Egg Protein
Did you know that you can buy egg protein powder? Many people don’t, but you can, and it’s perfectly viable for two reasons:
1. It has a high biological value, or BV.
This is a measurement of how efficiently the protein is absorbed and utilized by your body.
As you can imagine, high-BV proteins are best for building muscle, and animal research suggests that egg protein is as effective as whey protein for this purpose.
Human research also shows that egg is highly effective at stimulating protein synthesis.
2. It has very little fat and carbohydrate.
Egg protein powder is made from egg white, so it’s naturally more or less carb- and fat-free. That means more macros for your food!
As far as types of egg protein go, you can choose powdered or liquid; either is fine.
Also, in case you’re wondering, egg protein contains no cholesterol, so you can supplement with it in addition to any whole eggs you eat (if that’s something you’re concerned about).
The Scoop on Soy Protein
While studies show that soy is an all-round effective source of protein, it’s also a source of ongoing controversy, and especially among men.
According to some research, soy foods can have feminizing effects in men due to estrogen-like molecules in soybeans called isoflavones.
According to other studies, however, neither soy nor isoflavones can alter fertility or male hormones at normal levels of intake.
What gives, then? There isn’t a simple answer just yet.
For instance, research shows that these effects can vary depending on the presence or absence of certain intestinal bacteria. These bacteria, which are present in 30 to 50 percent of people, metabolize an isoflavone in soy called daidzein into an estrogen-like hormone called equol, which can affect the body.
This is why a study conducted by scientists at Peking University found that when equol-producing men ate high amounts of soy food for three days, their testosterone levels dropped and estrogen levels rose.
Another interesting twist can be found in a study conducted by scientists at Sungkyunkwan University, which found that in a high-estrogen environment, isoflavones suppressed estrogen production, and in a low-estrogen environment, they increased estrogen production.
So, the bottom line here is while soy is technically a good source of protein, eating too much of it may negatively impact your hormone profile, so why bother? There are plenty of other choices, including plant-based ones like rice and pea.
The Scoop on Rice Protein
You may not think much of the protein found in rice or even know it contained any protein, but it makes for quite the protein powder.
Rice protein has a high BV of about 80 percent (similar to beef’s) and a robust amino acid profile very similar to soy’s, which is why research shows that it’s an effective muscle builder.
It also has a mild taste and pleasant texture and mouthfeel, making it an all-around winner for plant-based protein supplementation.
As far as forms go, rice protein isolate is really the only game in town. If you want to make it even better, you can mix it with the next option.
The Scoop on Pea Protein
Pea protein is the real unsung hero of plant proteins. I mean, when’s the last time you heard a meathead say that he’s eating a lot of peas to help bulk up?
Well, he could because pea protein has a high BV (about the same as rice’s) and, like whey, a large amount of leucine. That’s why studies show that pea protein is indeed effective in promoting muscle gain.
Pea protein is often combined with rice protein because they taste great together and have complimentary amino acid profiles, combining into something chemically similar to whey. In fact, this mix is often referred to as the “vegan’s whey.”
Pea protein powder comes in two forms:
- Pea protein concentrate
- Pea protein isolate
Both pea protein concentrate and isolate are created by drying and grounding peas into a fine flour, mixing it with water, and removing the fiber and starch, leaving mostly protein with a smattering of vitamins and minerals.
Whether the final product is considered a concentrate or isolate just depends on how much of the nonprotein elements are removed. Pea protein isolate needs to be 90-plus percent protein by weight, whereas pea protein concentrate can be anywhere from 70 to 90 percent protein by weight.
This is why I prefer isolate over concentrate (less carbohydrate and fat).
The Scoop on Hemp Protein
Hemp protein is highly nutritious but only about 30 to 50 percent protein by weight, which means it comes with quite a bit of carbs and fat.
Furthermore, hemp protein isn’t absorbed nearly as well as soy, rice, or pea protein and is lower in essential amino acids, making it even less useful as a protein supplement.
That’s why I look at hemp protein powder more as a whole food than a protein supplement, and why I don’t recommend it purely for protein supplementation.
The Scoop on Collagen Protein
Collagen protein is all the rage at the moment, thanks mostly to slick marketers and prominent diet and health influencers.
Unfortunately, it doesn’t even deserve a spot on the stage, let alone the spotlight.
As you know, the amount of essential amino acids a protein provides is very important, especially for improving body composition.
Collagen protein scores very low in this regard because while it’s abundant in the amino acids glycine, proline, hydroxyproline, and alanine, it’s low in the essential amino acids leucine, isoleucine, and valine, which are most related to muscle building.
It’s also low in sulphur, which is involved in a number of bodily functions such as blood flow, energy production, and protecting cells from oxidative damage.
One thing collagen protein does have going for it, however, is the high amount of glycine, which can improve the quality of your skin, hair, and nails. That said, glycine is dirt cheap, and you can buy it alone (and in bulk) if you want to supplement with it.
Fish oil is exactly what it sounds like: oil obtained from fish. Popular sources of fish oil are salmon, herring, mackerel, sardines, and anchovies.
The reason fish oil supplements exist is they’re a very good source of two nutrients mentioned earlier in this book: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
We recall that EPA and DHA are known as omega-3 fatty acids and that our bodies can’t produce them, which is why they’re also known as essential fatty acids.
Unfortunately, studies show that the average person’s diet provides just one-tenth of the EPA and DHA needed to preserve health and prevent disease. This is a serious concern because studies show that inadequate EPA and DHA intake can increase the risk of a number of health conditions, including heart disease, Alzheimer’s, and cancer.
Thus, when EPA and DHA intake is too low, increasing it can benefit you in many ways, including:
- Improved mood (lower levels of depression, anxiety, and stress)
- Better cognitive performance (memory, attention, and reaction time)
- Reduced muscle and joint soreness
- Improved fat loss
- Prevention of fat gain
- Faster muscle gain
Fatty fish isn’t the only way to get more EPA and DHA in your diet. Grass-fed meat, free-range eggs, and vegetable oils are other options, but none are ideal.
Omega-3 levels are much lower in meat and eggs than fish, and vegetable oils don’t contain EPA and DHA but instead the fatty acid alpha-linolenic acid (ALA), which the body then converts into EPA and DHA.
Research shows that this conversion process is very inefficient, however, so you would have to eat large amounts of ALA regularly to supply your body with enough EPA and DHA. This is why vegans often have omega-3 fatty acid deficiencies.
There are three forms of fish oil supplements on the market today:
- Ethyl ester
- Reesterified triglyceride
A triglyceride is a molecule that consists of three fatty acids and one molecule of glycerol, a colorless, odorless substance found in fats and oils. The triglyceride form of fish oil is its natural (unprocessed) state.
An ethyl ester fish oil is created by processing natural triglycerides to replace the glycerol molecules with ethanol (alcohol). This removes impurities and increases the amount of EPA and DHA in the oil.
The reesterified triglyceride form is similar to the natural form and is created by using enzymes to convert the ethyl ester oil back into triglyceride oil.
Of these three forms, you’d probably assume that a natural triglyceride supplement is your best choice. Not necessarily.
While natural triglyceride fish oils are absorbed well by the body, they can have much higher levels of contaminants than ethyl ester and reesterified triglyceride oils (due to the low level of processing).
Furthermore, natural triglyceride fish oils are lower in EPA and DHA per gram than ethyl ester and reesterified triglyceride oils, which means you have to take more to achieve the desired results. This can be expensive both in terms of dollars and calories.
Ethyl ester fish oils are the most popular, but that’s not because they’re the best. They’re just the cheapest to produce, which comes with significant downsides.
First, studies show that this form of fish oil isn’t absorbed well by the body. It also releases ethanol (alcohol), which needs to be processed by the liver. This can cause various side effects, including burping, flu-like symptoms, upset stomach, strange tastes in your mouth, and skin rash.
Ethyl ester fish oils also oxidize (go bad) more quickly and easily than triglyceride oils.
As you can tell, I’m no fan of ethyl ester fish oils and don’t recommend them.
In case you’re wondering how to tell whether a fish oil is an ethyl ester product, check the label. If it doesn’t specifically state the form of the oil, assume it’s ethyl ester. Companies that pay more for the superior, more expensive triglyceride forms call it out in their marketing to increase salability.
And that leaves reesterified triglyceride oil, which is becoming the “gold standard” of fish oil supplements for several reasons:
- High bioavailability
- High concentrations of EPA and DHA
- Low levels of toxins and pollutants
- Resistance to oxidation
- None of the alcohol-related side effects associated with ethyl ester oils
Not many companies sell reesterified triglyceride oils because they’re the most expensive to produce, but I think they’re well worth the premium.
Not too long ago, vitamin D was simply known as the “bone vitamin,” and even today many physicians still believe it’s essential only for bone health.
Recent research shows otherwise, though. Nearly every type of tissue and cell in the body has vitamin D receptors, including your heart, brain, and even fat cells, and vitamin D plays a vital role in a large number of physiological processes.
Furthermore, studies show that vitamin D also regulates genes that control immune function, metabolism, and even cell growth and development.
This is why insufficient vitamin D levels is associated with an increased risk of many types of disease, including osteoporosis, heart disease, stroke, some cancers, type 1 diabetes, multiple sclerosis, tuberculosis, and even the flu.
Our bodies can’t produce enough vitamin D to maintain adequate levels, either, so we have to obtain it from diet, sun exposure, or supplementation.
There are small amounts of vitamin D in various foods like beef liver, cheese, and egg yolks, which have anywhere from 10 to 60 IU (international units) per ounce, and slightly larger amounts in fatty fish like salmon, tuna, and mackerel, which have anywhere from 50 to 150 IU per ounce. Cod liver oil is by far the best food source with over 1,300 IU per tablespoon.
Vitamin D is also added to various “fortified” foods like milk, breakfast cereals, orange juice, and margarine, but getting enough vitamin D through these foods alone isn’t feasible if you’re trying to follow a sensible meal plan.
When our skin is exposed to UVB rays, which are emitted by the sun, they interact with a form of cholesterol in the body to produce vitamin D. The more skin that’s exposed to the sun, and the stronger the sun’s rays, the more vitamin D you produce.
For instance, research shows that with 25 percent of our skin exposed, our bodies can produce upwards of 400 IU of vitamin D in just three to six minutes of exposure to the 12 p.m. Florida summer sun.
Depending on your diet and latitude, that means you’d need to spend anywhere from 15 to 60 minutes sunbathing per day to maintain sufficient levels. And you might be simply out of luck in the winter.
All this is why I prefer vitamin D supplementation. It’s cheap, effective, and gives you maximum flexibility in your diet.
Our bodies need a variety of vitamins and minerals to support all the vital growth and repair processes that keep us alive and functioning.
Ideally, we’d get everything we need from the food we eat, but due to the nature of the average Western diet, most people tend to be deficient in a number of key nutrients.
For example, according to research conducted by scientists at Colorado State University and published in 2005, at least half the US population failed to meet the recommended dietary allowance (RDA) for vitamin B-6, vitamin A, magnesium, calcium, and zinc, and 33 percent of the population didn’t meet the RDA for folate.
A more recent study conducted by scientists at Tufts University and published in 2017 found that more than 30 percent of the US population was deficient in calcium, magnesium, and vitamins A, C, D, and E.
Research also shows that average vitamin K intake levels may be suboptimal as well.
Enter the multivitamin supplement. The idea of taking a supplement that can plug any nutritional holes in our diets and mitigate the harmful effects of some of our less-than-healthy habits is great in theory, but most multivitamins fall short of this mark (let alone surpass it).
Instead of doing the hard work of determining optimal dosages of the essential vitamins and minerals for their target publics, most supplement companies go with premade formulations provided by manufacturers.
These products are often stuffed with all kinds of micronutrients, regardless of whether we need to supplement with them or not, and in unjustifiably high or low dosages. This is why many multivitamins provide an overabundance of vitamins and minerals that most people aren’t deficient in and little or none of what they need most.
For instance, many multivitamins contain large amounts of the microminerals manganese, molybdenum, and boron and vitamins C, E, and A, despite the fact that most people eating halfway decent diets already get plenty of these nutrients and don’t need to supplement with them.
In contrast, a good example of something important lacking in most multivitamins is vitamin K, a group of vitamins that plays an important role in bone growth and repair, blood vessel function, cancer prevention, joint health, and more.
And if a multivitamin does include vitamin K, it’s almost always a small dose of a form that’s present in large amounts in whole foods, known as vitamin K1.
The form that should be included is vitamin K2, which offers unique health benefits and is much harder to obtain from diet alone. Why is K2 rarely found in multivitamins? Because it’s expensive, of course.
Furthermore, many multivitamins provide potentially dangerous superdoses of certain vitamins and minerals.
For example, the amount of vitamin E in many multivitamins can be harmful to your health. Vitamin E is an antioxidant, meaning it helps protect against oxidative damage, and it’s often overdosed on the assumption that more antioxidants is always better. This is why both it and vitamin C (another antioxidant) are usually included in multivitamins in sky-high amounts.
Not all antioxidants are similar, however, and regular supplementation of vitamin E above 400 IU per day is now suspected to increase the risk of all-cause mortality (death from all causes).
To make matters worse, very few multivitamins contain anything worthwhile in addition to the vitamins and minerals.
Call me cynical, but am I supposed to get excited over a 100 milligram “proprietary blend” of fruit and vegetable powders? Some probiotics that are undoubtedly dead and, even if they weren’t, wouldn’t do anything anyway? A few enzymes or amino acids that I don’t need to supplement with? Herbs that purport to help “detox” my body (which no supplement can do)?
So, in the final analysis, I’d rather people just eat a healthy amount and variety of fruit and vegetables than waste money and pin false hopes on a multivitamin that’s very unlikely to benefit them in any meaningful way.
I probably don’t need to say this by now, but I’m going to do it anyway:
No amount of weight loss pills and powders are going to make you lean.
Trust me. If you’re trying to lose fat, pill popping, even to excess, is not going to be enough. There just aren’t any safe, natural “fat-burning” compounds powerful enough to cause meaningful weight reduction on their own.
Furthermore, you shouldn’t be surprised at this point to learn that most weight loss supplements on the market, including some of the most popular ones, are flops.
- According to a meta-analysis conducted by scientists at the University of Exeter, the best you can hope for with Garcinia cambogia is a few extra pounds of weight loss over a few months, and even that is less likely than no additional weight loss whatsoever.
- According to another meta-analysis conducted by the same scientists, green coffee extract may be able to help you lose weight slightly faster only when taken in high enough doses, but the scientific jury is still out and the case isn’t looking good.
- Conjugated linoleic acid (CLA) is a bit of a mystery as studies show it can help some people lose fat, fail to help others, and even cause fat gain in some cases.
How? Why? What will it do for you? Nobody can say yet.
- Animal research shows that raspberry ketones have anti-obesity effects in mice, but we have no valid human research to see how they affect us.
Now the good news:
If you know how to drive fat loss with proper dieting and exercise, there are a few supplements that can accelerate the process.
Based on my experience with my own body and having worked with thousands of people, I feel comfortable saying that a proper fat loss supplementation routine can increase fat loss by about 30 to 50 percent with few if any side effects.
That is, if you can lose 1 pound of fat per week through proper diet and exercise (and you can), you can lose 1.3 to 1.5 pounds of fat per week by adding the right supplements into the mix.
Another big benefit of taking the right fat loss supplements is that they’re especially effective for reducing “stubborn fat,” which is belly and lower-back fat for most men.
What are these “right” supplements, how do they work, and how can we use them safely and effectively?
Let’s find out, starting with everyone’s favorite.
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Caffeine does a lot more than give you an energy high.
Studies show that it also:
- Decreases perceived effort (makes exercise feel easier)
- Makes you more resistant to fatigue
- Increases power output
- Increases muscle endurance
- Increases strength
- Increases anaerobic performance
- Boosts fat loss
Caffeine can also reverse the muscle weakness many people experience when they train in the morning.
Most of caffeine’s benefits are a byproduct of its ability to increase the amount of catecholamines (chemicals that trigger fat burning) in your blood, which also raises your basal metabolic rate.
For instance, research shows that in most people, a relatively small dosage of 200 milligrams of caffeine increases BMR by about 7 percent for three hours. If you have caffeine two or three times per day, then, this can add up to an additional 150 to 200 calories burned.
You should also know that your body begins building a tolerance to caffeine almost immediately, and the higher your tolerance is, the less effective caffeine will be for enhancing performance and fat loss.
Therefore, if you want to get the biggest performance boost out of caffeine, use it just a few days per week before your most difficult workouts (I usually have some before my workouts that involve barbell squatting and deadlifting).
And to get the most fat loss out of caffeine, use it daily for two to three weeks, and then take a week off to “reset” your tolerance and preserve its effectiveness.
Yohimbine is a compound obtained from the bark of the Pausinystalia yohimbe tree, and several studies show that it can speed up fat loss.
Like caffeine, it does this by stimulating the production of catecholamines, but unlike caffeine, it can also help you burn more “stubborn fat.”
“Stubborn fat?” you might be wondering.
Yep, some fat cells are far more difficult to shrink than others. This isn’t a genetic curse. It’s simply a physiological mechanism your body uses to defend against low body fat levels.
To trigger fat burning, your body releases catecholamines into your blood, which then “attach” to receptors on fat cells. This causes the release (mobilization) of the energy stored within those cells for use.
Fat cells have two types of receptors for catecholamines: alpha- and beta-receptors. To keep this simple, beta-receptors generally speed up fat mobilization, whereas alpha-receptors hinder it. (The physiology is more complex than this, but we don’t need to go deeper for our purposes here.)
Thus, the more alpha-receptors a fat cell has, the more “resistant” it is to being mobilized by catecholamines. On the other hand, the more beta-receptors a fat cell has, the more “receptive” it is to the fat-mobilizing molecules.
As you’ve probably guessed, the areas of your body that get lean quickly have a lot of fat cells rich in beta-receptors, and the areas that take their sweet time leaning out have a large amount of fat cells rich in alpha-receptors.
Another problem with these stubborn fat deposits relates to blood flow.
You may have noticed that fat in areas of your body like the lower stomach and back is slightly colder to the touch than fat in other areas of your body, like the arms or chest.
This is due to less blood flowing through these cooler areas, and less blood flow means fewer catecholamines, which means even slower fat loss.
So we have two things working against us here: large amounts of fat cells that don’t respond well to catecholamines and reduced blood flow that keeps the catecholamines away.
This is why you can steadily lose weight with almost all the fat seeming to come from parts of your body that are already fairly lean.
For instance, it’s common for men to lose fat from their arms, shoulders, and chest while their stomach and lower back remain relatively unchanged.
Thus, once you approach about 10 percent body fat, every bit of “stubborn” fat you lose can have a noticeable impact on your physique. At this point, losing just a pound or two of fat from the “right places” can do a lot more in the mirror than several pounds from areas of your body that are already defined.
Now, what does yohimbine have to do with all this?
Studies show that it can speed up stubborn fat loss by attaching itself to, and more or less deactivating, the alpha-receptors on fat cells.
In other words, yohimbine prevents your fat cells’ alpha-receptors from putting the brakes on fat burning.
There’s a catch, however. Elevated insulin levels completely negate yohimbine’s fat loss benefits. That means it’s strictly for use while exercising in a fasted state.
Synephrine is a compound found primarily in the bitter orange fruit, which is why it’s often referred to by that name.
It’s chemically similar to the ephedrine and pseudoephedrine found in many over-the-counter cold and allergy medications as well as weight loss and energy supplements that contain ma huang.
Consequently, synephrine stimulates the nervous system and increases BMR, and increases the thermic effect of food (the energy cost of digesting and processing what you eat).
There’s also evidence that, like yohimbine, synephrine blocks the alpha-receptors on fat cells, which means that it too can speed up stubborn fat loss.
I haven’t been to a supplement store in some time now, but the last time I was at one, I figured I’d take a look at the fancy stuff they keep locked up in the back.
(If it’s behind lock and key, it must be good, right?)
As usual, the cabinet was packed full of loud, shiny bottles that claimed to contain revolutionary natural muscle builders. The names always get me.
There was a time when I would buy supplements like these and hope they worked. I know better now. Here’s the truth:
Most supplements that claim to aid in muscle building do absolutely nothing. And that’s particularly true of three of the most popular “muscle builders” on the market:
- Testosterone boosters
- Growth hormone boosters
Fortunately, research shows that you can accelerate muscle gain with supplementation, and three of your best options are creatine, beta-alanine, and citrulline.
Let’s talk about both the bad and good in more detail.
Branched-Chain Amino Acids (BCAAs)
BCAAs are a group of three essential amino acids:
As you know, leucine directly stimulates protein synthesis. Isoleucine also stimulates it weakly and improves glucose metabolism and uptake in the muscles. Valine doesn’t seem to do much of anything for muscle tissue compared to leucine and isoleucine.
BCAA supplements aren’t top sellers because they work wonders in the body but rather because they’re easy to sell. For example, a number of studies seem to show several impressive benefits, “everyone” into fitness seems to drink them, and they make for some mighty delicious water.
If I wanted to sell you BCAAs, I could point to research that suggests they improve immune function, diminish fatigue, minimize exercise-induced muscle damage, and enhance postworkout muscle growth.
What I wouldn’t tell you, however, is the bulk of this research doesn’t directly apply to the average healthy, physically active person following a sensible workout routine and high-protein diet.
First off, studies commonly cited as evidence of the muscle-related benefits of BCAA supplementation were done with people who didn’t eat enough protein.
For example, one study used by supplement companies to move a lot of BCAA powders was conducted by scientists at the Center for the Study and Research of Aerospace Medicine.
It examined the effects of BCAA supplementation on a group of wrestlers in a calorie deficit, and after three weeks, found that the wrestlers who supplemented with 52 grams of BCAAs per day preserved more muscle and lost a bit more fat than the ones who didn’t.
If that’s all you were told, you might start reaching for your wallet. Before you do, however, you should know the rest of the story: these wrestlers weighed about 150 pounds on average and were eating a paltry 80ish grams of protein per day.
As you learned earlier in this book, that’s about half as much protein as these athletes should’ve been eating, so all this study really tells us is BCAA supplementation might mitigate muscle loss when restricting both calories and protein intake. And who knows what to think on the additional fat loss, as there’s no plausible mechanism whereby BCAAs can impact this. Color me unimpressed.
Other studies showing various muscle-related benefits of BCAA supplementation are almost always hampered by a lack of dietary controls and low protein intakes. And in almost all cases, the people are exercising in a fasted state, which affects the muscles and body differently than when exercise is done in a fed state.
I think an argument could be made for athletes training several hours per day possibly benefitting from BCAA supplementation, but for the rest of us, it’s far more sizzle than steak. We can get all the branched-chain amino acids we need to recover from our training and build muscle from the food we’re eating as a regular part of our diets.
In fact, research even suggests BCAAs obtained through food are more conducive to muscle growth than amino acid drinks.
Finally, a recent review of BCAA research that was conducted by scientists at the University of Arkansas found that BCAA supplementation either has no effect on muscle growth or may even decrease it.
Thus, the researchers concluded that “the claim that consumption of dietary BCAAs stimulates muscle protein synthesis or produces an anabolic response in human subjects is unwarranted.”
With testosterone levels on the decline here in the West, natural testosterone boosters have quickly become one of the biggest sellers for supplement companies.
If we’re to believe even half the claims made to sell them, they’re basically natural alternatives to steroids that will quickly transform us into muscle-bound alpha males who make the ladies swoon and fellas tremble.
Too bad they’re all completely worthless. Yes, all, and yes, worthless.
Most of these products don’t just contain ingredients not proven to work, they contain stuff proven to not work. And in the rare case where they contain an ingredient or two shown to have positive hormonal effects, the changes are too small to make any kind of difference in the gym.
For example, three of the most popular ingredients in these supplements are the herb Tribulus terrestris, the mineral supplement ZMA, and the amino acid D-aspartic acid.
Multiple studies have shown Tribulus terrestris has no effect on testosterone levels, body composition, or exercise performance. There’s absolutely no question at this point that Tribulus is a dud as far as testosterone boosting and muscle building go.
ZMA is a combination of zinc, magnesium, and vitamin B6, and its story is about the same.
Studies show that unless you’re quite deficient in zinc, ZMA won’t increase your testosterone levels, and if you are deficient, you don’t need to supplement with ZMA per se—you simply need to increase your zinc intake.
Thus, it’s disingenuous to call zinc a “testosterone booster” because it won’t boost anything for most people, and when it does, it’s not raising the absolute ceiling of natural testosterone production—it’s simply eliminating a micronutrient deficiency that was suppressing testosterone production.
D-aspartic acid is the most promising of the trio, but that isn’t saying much.
When research published in 2009 showed that D-aspartic acid could increase testosterone levels in both humans and rats, supplement companies had a field day.
Bottles flew off the shelves, and D-aspartic acid was being heralded as the next creatine.
Well, several studies on it have been published since then, and they lend some much-needed perspective.
We don’t need to wade through the physiology here, but what you need to know is yes, D-aspartic acid can increase testosterone production, but its effects are generally small, unreliable, and temporary.
If a relatively insignificant and temporary increase in testosterone production sounds “better than nothing,” allow me to continue.
Let’s say you saw a 20 percent increase in natural testosterone production with D-aspartic acid, or any kind of testosterone booster for that matter. That sounds pretty good, right?
It would be as far as efficacy goes, but it wouldn’t mean anything as far as strength and muscle gain go.
That’s because studies show that relatively small fluctuations in testosterone levels have little to no effect on body composition and performance. The effects only become pronounced when testosterone levels exceed the top end of what’s naturally achievable, and the only way to do that is with drugs.
For example, a study conducted by scientists at McMaster University had 56 young, resistance-trained men lift weights five days per week and follow a standard bodybuilding diet.
After 12 weeks, researchers found that exercise-induced spikes in anabolic hormones like testosterone, growth hormone, and insulin-like growth factor 1 (IGF-1) varied widely in magnitude but had no effect on muscle or strength gain.
In other words, some guys responded more “anabolically” to the training than others, but this didn’t translate into more muscle or strength.
Another study worth reviewing was conducted by scientists at Charles R. Drew University of Medicine and Science, who used drugs to manipulate the testosterone levels of 61 young, healthy men.
After 20 weeks, the researchers found a dose-dependent relationship between testosterone and leg strength and power, meaning that higher testosterone levels meant more strength and power, but the effects weren’t significant until testosterone levels exceeded the top of the natural range by about 20 to 30 percent.
And just to gain more clarity on the matter, let’s review a bit of steroid research.
An extensive study conducted by scientists at Maastricht University involved an in-depth review of the steroid literature, and found that muscle gain in people lifting weights on steroids ranged from 4.5 to 11 pounds over the short term (less than 10 weeks), and the largest amount gained was 15.5 pounds of muscle in 6 weeks.
So, if skyrocketing your testosterone with anabolic steroids doesn’t necessarily mean gaining “shocking” amounts of muscle, what do you think a pitifully weak natural testosterone booster could possibly accomplish?
Do yourself a favor and just skip these products. And skip the companies that sell them because they know everything we’ve just discussed yet still offer testosterone boosters to make a quick buck.
Growth Hormone Booster
Growth hormone boosters are just more of the same BS.
Most contain a mixture of amino acids and herbs with the occasional oddball “toss-ins,” and most have no effect on growth hormone production whatsoever. And those that do aren’t effective enough to make any real difference.
Take the amino acid gamma aminobutyric acid (GABA), which is in many growth hormone supplements.
Research shows it can indeed increase postexercise growth hormone levels, but this small and temporary boost won’t impact muscle growth.
Another bestseller is deer antler velvet, used in Traditional Chinese medicine for various preventive health purposes.
It may have some valid applications, but hormone optimization and muscle building are not on the list. Studies clearly show that deer antler velvet doesn’t increase testosterone or growth hormone levels or enhance muscle or strength gain.
Mucuna pruriens is another example of a flop found in many growth hormone supplements. The active ingredient in this bean—L-DOPA—can help reduce symptoms of Parkinson’s disease and may improve sperm quality, but there’s no good evidence it can raise testosterone or growth hormone levels to a meaningful degree.
So, skip any natural supplement that claims to impact growth hormone production. You’re not missing out on anything.
Of all the workout supplements on the market today, creatine stands out as one of the absolute best.
It’s the most well-researched molecule in all of sports nutrition—the subject of hundreds of scientific studies—and the benefits are clear:
- It helps you build muscle faster.
- It helps you get stronger faster.
- It improves anaerobic endurance.
- It improves muscle recovery.
And the best part is it does all these things naturally and safely.
What is it, though, and how does it work?
Creatine is a molecule produced in the body and found in foods like meat, eggs, and fish. It’s composed of the amino acids L-arginine, glycine, and L-methionine and is present in almost all cells, where it acts as an “energy reserve.”
When you supplement with creatine, your total body creatine stores increase, with most going to your muscle cells. And what do you think happens when your muscle cells have significantly higher levels of readily available energy? You got it. Performance is enhanced.
Creatine also enhances muscle growth by increasing the amount of water in muscle cells. This makes muscles bigger, of course, but it also positively impacts nitrogen balance (a measure of nitrogen intake minus nitrogen loss, with a positive balance indicating muscle gain) and the expression of certain genes related to muscle building.
Other research suggests that creatine also has anticatabolic effects, which further helps with muscle gain.
Many people shy away from creatine because they’ve heard it makes you bloated. This used to be a problem years ago, but it has become a nonissue today since processing methods have improved. You shouldn’t notice any difference in subcutaneous (underneath the skin) water levels when you supplement with creatine.
Creatine comes in many forms, including creatine monohydrate, creatine ethyl ester, buffered creatine, and others.
We could discuss them one by one, but here’s all you really need to know: go with powdered creatine monohydrate. It’s the most researched form by which all others are judged, and it’s the best bang for your buck.
Beta-alanine is an amino acid that our body combines with the essential amino acid L-histidine to form a compound molecule called carnosine, which is stored in your muscles and brain.
Carnosine does a number of things in the body, including helping regulate acidity levels in our muscles.
When a muscle contracts repeatedly, it becomes more and more acidic. This, in turn, impairs its ability to continue contracting, until eventually it can no longer contract at all. This is one of the ways muscles become fatigued.
Carnosine counteracts this by reducing muscle acidity, thereby increasing the amount of work the muscles can do before becoming fatigued.
This is why a meta-analysis conducted by scientists at Nottingham Trent University found that beta-alanine supplementation results in a slight improvement in endurance when exercise duration is between 60 and 240 seconds.
Several studies also show that beta-alanine can enhance muscle growth.
Scientists aren’t sure why just yet, but people who supplement with beta-alanine seem to gain more muscle than those who don’t. This effect doesn’t appear to be merely a byproduct of improved workout performance, either.
L-citrulline is an amino acid that plays a key role in the urea cycle, the process whereby the body eliminates toxic byproducts of digesting protein and generating cellular energy.
It’s called the urea cycle because these waste products are converted into a substance called urea, which is expelled from the body through urine and sweat.
And in case you’re wondering, the “L-” refers to the structure of the amino acid and denotes that it can be used to create proteins (the other type of amino acid is the “D-” form, which is found in cells but not in proteins).
L-citrulline is a popular workout supplement because it can improve both your resistance and endurance training and boost nitric oxide production.
For example, in one study conducted by scientists at the University of Córdoba, people who supplemented with 8 grams of L-citrulline before their chest workouts increased the number of reps they could do by 52 percent and experienced significantly less postworkout muscle soreness.
In another study conducted by scientists at the Biological and Medical Magnetic Resonance Center, 6 grams of L-citrulline per day increased cellular energy production during exercise by 34 percent, resulting in a greater capacity for physical output and intensity.
When you supplement with L-citrulline, your kidneys convert it into another amino acid, L-arginine, and this increases nitric oxide production.
Nitric oxide is a gas produced by the body that widens blood vessels and improves blood flow. By raising nitric oxide production, you can improve exercise performance, lower blood pressure, and even harden erections (an easy way to impress your significant other!).
Ironically, supplementing with L-citrulline accomplishes this better than L-arginine itself because it’s absorbed better by the body.
There are two widely available forms of citrulline to choose from:
- Citrulline malate
The only difference between these two forms is L-citrulline is the pure amino acid, and citrulline malate is L-citrulline combined with malic acid, a natural substance found in many fruits.
There isn’t much human research available on the potential benefits of supplementing with malic acid, but it has been shown to improve endurance in animal studies. It may offer cardiovascular benefits as well.
Thus, I recommend citrulline malate over L-citrulline for two reasons:
- It’s the form used in most studies that found performance benefits.
- There’s a fair chance malic acid confers additional health and performance benefits.
In other words, there’s no downside to citrulline malate, and it may be superior to L-citrulline.
I wish someone would have taught me what you’ve just learned back when I started training.
It would’ve saved me who knows how much time and money I wasted researching and buying worthless pills and powders.
I hope you’ve found this information not only helpful but relieving, because let’s face it: supplementation is a complex and overwhelming subject, and it’s all too easy to wind up with cabinets full of expensive bottles and bags of stuff that delivers minimal if any bottom-line results.
If you follow the advice in this chapter, you’re not going to be one of these people, because you now know the absolute best choices for gaining more muscle and strength, losing more fat, and improving and maintaining health and vitality.
I should also mention that just because I didn’t bring up something here doesn’t mean it has no merits. It just means it’s not one of the 20 percent of supplements that will provide 80 percent of the benefits we’re most after.
If you want to learn more about the science of supplementation and how you can further optimize your mental and physical health and performance, head over to the supplements category of my blog at www.biggerleanerstronger.com/supplements.
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- Supplements aren’t nearly as important as some people would have you believe. The right ones, however, can help speed up your results.
- A good protein powder meets a few criteria:
It doesn’t have to taste like a milkshake, but it should taste good and mix well.
It should provide the most protein for the fewest calories and be as low in carbs and fat as possible.
It should have a good amino acid profile and be absorbed well by the body.
It should be affordable and offer good value in terms of cost per serving.
- Whey protein provides you with a lot of protein per dollar, tastes good, and its amino acid profile is particularly suited to muscle building.
- Whey isolate and hydrolysate do have advantages—more protein by weight, no lactose, better mixability and digestibility, and some would say better taste—but as far as bottom-line results go, whey concentrate works just fine.
- A high-quality whey protein is easy to spot:
Whey concentrate, isolate, or hydrolysate is the first ingredient.
The serving size is relatively close to the amount of protein per serving.
- When buying a casein protein, you should look at the amount of protein per scoop relative to the scoop size.
- While soy is technically a good source of protein, eating too much of it may negatively impact your hormone profile, so why bother? There are plenty of other choices, including plant-based ones like rice and pea.
- Rice and pea protein are effective muscle builders.
- Hemp protein isn’t absorbed nearly as well as soy, rice, or pea protein and is lower in essential amino acids.
- Collagen protein is low in the essential amino acids leucine, isoleucine, and valine, which are most related to muscle building.
- Fish oil is a very good source eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
- When EPA and DHA intake is too low, increasing it can benefit you in many ways, including improved mood (lower levels of depression, anxiety, and stress), better cognitive performance (memory, attention, and reaction time), reduced muscle and joint soreness, improved fat loss, prevention of fat gain, and faster muscle gain.
- Reesterified triglyceride oil is becoming the “gold standard” of fish oil supplements.
- Insufficient vitamin D levels is associated with an increased risk of many types of disease, including osteoporosis, heart disease, stroke, some cancers, type 1 diabetes, multiple sclerosis, tuberculosis, and even the flu.
- Our bodies can’t produce enough vitamin D to maintain adequate levels, so we have to obtain it from diet, sun exposure, or supplementation.
- Ideally, we’d get all the nutrition we need from the food we eat, but due to the nature of the average Western diet, most people tend to be deficient in a number of key nutrients.
- The idea of taking a supplement that can plug any nutritional holes in our diets and mitigate the harmful effects of some of our less-than-healthy habits is great in theory, but most multivitamins fall short of this mark (let alone surpass it).
- I’d rather people just eat a healthy amount and variety of fruit and vegetables than waste money and pin false hopes on a multivitamin that’s very unlikely to benefit them in any meaningful way.
- No amount of weight loss pills and powders are going to make you lean.
- Most weight loss supplements on the market, including some of the most popular ones, are flops.
- A proper fat loss supplementation routine can increase fat loss by about 30 to 50 percent with few if any side effects.
- Another big benefit of taking the right fat loss supplements is that they’re especially effective for reducing “stubborn fat,” which is belly and lower-back fat for most men.
- Caffeine decreases perceived effort (makes exercise feel easier), makes you more resistant to fatigue, increases power output, muscle endurance, strength, and anaerobic performance, and boosts fat loss.
- Caffeine can also reverse the muscle weakness many people experience when they train in the morning.
- Your body begins building a tolerance to caffeine almost immediately, and the higher your tolerance is, the less effective caffeine will be for enhancing performance and fat loss.
- If you want to get the biggest performance boost out of caffeine, use it just a few days per week before your most difficult workouts (I usually have some before my workouts that involve barbell squatting and deadlifting).
- To get the most fat loss out of caffeine, use it daily for two to three weeks, and then take a week off to “reset” your tolerance and preserve its effectiveness.
- Stubborn fat refers to fat cells that are far more difficult to shrink than others. This is why you can steadily lose weight with almost all the fat seeming to come from parts of your body that are already fairly lean.
- Once you approach about 10 percent body fat, every bit of “stubborn” fat you lose can have a noticeable impact on your physique.
- Yohimbine prevents your fat cells’ alpha-receptors from putting the brakes on fat burning.
- Elevated insulin levels completely negate yohimbine’s fat loss benefits. That means it’s strictly for use while exercising in a fasted state.
- Synephrine stimulates the nervous system and increases BMR and the thermic effect of food (the energy cost of digesting and processing what you eat).
- Synephrine also blocks the alpha-receptors on fat cells, which means that it too can speed up stubborn fat loss.
- We can get all the branched-chain amino acids we need from the food we’re eating as a regular part of our diets.
- BCAAs obtained through food are more conducive to muscle growth than amino acid drinks.
- Creatine helps you build muscle and get stronger faster and improves both anaerobic endurance and muscle recovery.
- Many people shy away from creatine because they’ve heard it makes you bloated. This used to be a problem years ago, but it has become a nonissue today.
- Go with powdered creatine monohydrate. It’s the best bang for your buck.
- Beta-alanine can improve endurance and enhance muscle growth.
- L-citrulline can improve both your resistance and endurance training and boost nitric oxide production.
- By raising nitric oxide production, you can improve exercise performance, lower blood pressure, and even harden erections.
- I recommend citrulline malate over L-citrulline.
This article is an excerpt from the new third editions of Bigger Leaner Stronger and Thinner Leaner Stronger, my bestselling fitness books for men and women, which are currently on sale for just 99 cents.
+ Scientific References
- X, T., J, L., W, D., P, L., L, L., C, L., Y, Z., J, H., & D, L. (2013). The cardioprotective effects of citric Acid and L-malic Acid on myocardial ischemia/reperfusion injury. Evidence-Based Complementary and Alternative Medicine : ECAM, 2013. https://doi.org/10.1155/2013/820695
- JL, W., QP, W., JM, H., R, C., M, C., & JB, T. (2007). Effects of L-malate on physical stamina and activities of enzymes related to the malate-aspartate shuttle in liver of mice. Physiological Research, 56(2), 213–220. https://doi.org/10.33549/PHYSIOLRES.930937
- R, B., A, S., JA, T., & A, P. (2012). The effect of nitric-oxide-related supplements on human performance. Sports Medicine (Auckland, N.Z.), 42(2), 99–117. https://doi.org/10.2165/11596860-000000000-00000
- D, P.-J., E, B., & RR, W. (2004). Potential ergogenic effects of arginine and creatine supplementation. The Journal of Nutrition, 134(10 Suppl). https://doi.org/10.1093/JN/134.10.2888S
- E, C., P, C., & L, C. (2007). Citrulline and the gut. Current Opinion in Clinical Nutrition and Metabolic Care, 10(5), 620–626. https://doi.org/10.1097/MCO.0B013E32829FB38D
- D, B., JP, M., B, G., S, C.-G., ME, L. G., & PJ, C. (2002). Citrulline/malate promotes aerobic energy production in human exercising muscle. British Journal of Sports Medicine, 36(4), 282–289. https://doi.org/10.1136/BJSM.36.4.282
- J, P.-G., & PM, J. (2010). Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. Journal of Strength and Conditioning Research, 24(5), 1215–1222. https://doi.org/10.1519/JSC.0B013E3181CB28E0
- Smith, A. E., Walter, A. A., Graef, J. L., Kendall, K. L., Moon, J. R., Lockwood, C. M., Fukuda, D. H., Beck, T. W., Cramer, J. T., & Stout, J. R. (2009). Effects of β-alanine supplementation and high-intensity interval training on endurance performance and body composition in men; a double-blind trial. Journal of the International Society of Sports Nutrition, 6, 5. https://doi.org/10.1186/1550-2783-6-5
- RM, H., B, S., G, B., RC, H., & C, S. (2012). Effects of β-alanine supplementation on exercise performance: a meta-analysis. Amino Acids, 43(1), 25–37. https://doi.org/10.1007/S00726-011-1200-Z
- JR, H., G, L., JR, S., MW, H., N, S., P, R., DS, M., DH, F., I, S., E, C., & I, O. (2015). β-Alanine ingestion increases muscle carnosine content and combat specific performance in soldiers. Amino Acids, 47(3), 627–636. https://doi.org/10.1007/S00726-014-1896-7
- W, A., & GJ, V. (2009). Exercise and fatigue. Sports Medicine (Auckland, N.Z.), 39(5), 389–422. https://doi.org/10.2165/00007256-200939050-00005
- FC, T., CC, C., & PL, K. (2014). Contribution of creatine to protein homeostasis in athletes after endurance and sprint running. European Journal of Nutrition, 53(1), 61–71. https://doi.org/10.1007/S00394-013-0498-6
- G, P., S, M., D, M., KE, Y., & MA, T. (2001). Effects of acute creatine monohydrate supplementation on leucine kinetics and mixed-muscle protein synthesis. Journal of Applied Physiology (Bethesda, Md. : 1985), 91(3), 1041–1047. https://doi.org/10.1152/JAPPL.2001.91.3.1041
- A, S., NJ, Y., R, S., S, M., & MA, T. (2008). Global and targeted gene expression and protein content in skeletal muscle of young men following short-term creatine monohydrate supplementation. Physiological Genomics, 32(2), 219–228. https://doi.org/10.1152/PHYSIOLGENOMICS.00157.2007
- MD, D., AJ, A., R, M., DE, B., DO, J., & L, S. (2011). AMPK and substrate availability regulate creatine transport in cultured cardiomyocytes. American Journal of Physiology. Endocrinology and Metabolism, 300(5). https://doi.org/10.1152/AJPENDO.00554.2010
- GJ, G., C, B., JH, V., S, K., JH, W., & LH, van den B. (2005). Few adverse effects of long-term creatine supplementation in a placebo-controlled trial. International Journal of Sports Medicine, 26(4), 307–313. https://doi.org/10.1055/S-2004-817917
- RA, B., CH, P., KF, V., AJ, S., LR, S., & R, C. (2010). Effect of short-term creatine supplementation on markers of skeletal muscle damage after strenuous contractile activity. European Journal of Applied Physiology, 108(5), 945–955. https://doi.org/10.1007/S00421-009-1305-1
- JM, E., JR, S., GA, M., NJ, S., KA, I., AN, G., & R, G. (2005). Effect of creatine phosphate supplementation on anaerobic working capacity and body weight after two and six days of loading in men and women. Journal of Strength and Conditioning Research, 19(4), 756–763. https://doi.org/10.1519/R-16924.1
- JS, V., NA, R., MR, R., AL, G., DN, F., MM, M., TP, S., MJ, S., K, H., & WJ, K. (2004). The effects of creatine supplementation on muscular performance and body composition responses to short-term resistance training overreaching. European Journal of Applied Physiology, 91(5–6), 628–637. https://doi.org/10.1007/S00421-003-1031-Z
- JD, B. (2003). Effect of creatine supplementation on body composition and performance: a meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism, 13(2), 198–226. https://doi.org/10.1123/IJSNEM.13.2.198
- R, K., A, E., A, M., PN, P., N, R., H, W., L, T., R, V. der G., & AJ, L. (2004). Mucuna pruriens in Parkinson’s disease: a double blind clinical and pharmacological study. Journal of Neurology, Neurosurgery, and Psychiatry, 75(12), 1672–1677. https://doi.org/10.1136/JNNP.2003.028761
- HM, C., JM, S., & JV, C. (2003). Effect of deer velvet on sexual function in men and their partners: a double-blind, placebo-controlled study. Archives of Sexual Behavior, 32(3), 271–278. https://doi.org/10.1023/A:1023469702627
- ME, P., JF, Y., SC, M., & SE, B. (2008). Growth hormone isoform responses to GABA ingestion at rest and after exercise. Medicine and Science in Sports and Exercise, 40(1), 104–110. https://doi.org/10.1249/MSS.0B013E318158B518
- DW, W., & SM, P. (2012). Associations of exercise-induced hormone profiles and gains in strength and hypertrophy in a large cohort after weight training. European Journal of Applied Physiology, 112(7), 2693–2702. https://doi.org/10.1007/S00421-011-2246-Z
- DS, W., & B, L. (2013). D-aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained men. Nutrition Research (New York, N.Y.), 33(10), 803–810. https://doi.org/10.1016/J.NUTRES.2013.07.010
- Topo, E., Soricelli, A., D’Aniello, A., Ronsini, S., & D’Aniello, G. (2009). The role and molecular mechanism of D-aspartic acid in the release and synthesis of LH and testosterone in humans and rats. Reproductive Biology and Endocrinology : RB&E, 7, 120. https://doi.org/10.1186/1477-7827-7-120
- K, K., MK, P., H, G., J, M., & W, S. (2009). Serum testosterone and urinary excretion of steroid hormone metabolites after administration of a high-dose zinc supplement. European Journal of Clinical Nutrition, 63(1), 65–70. https://doi.org/10.1038/SJ.EJCN.1602899
- C, S., N, B., C, E., E, S., & M, S. (2008). Short term impact of Tribulus terrestris intake on doping control analysis of endogenous steroids. Forensic Science International, 178(1). https://doi.org/10.1016/J.FORSCIINT.2008.01.003
- RR, W. (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition, 14(1). https://doi.org/10.1186/S12970-017-0184-9
- JJ, H., CM, L., & JR, S. (2010). Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein. Nutrition & Metabolism, 7. https://doi.org/10.1186/1743-7075-7-51
- A, M., AX, B., E, de K., B, R., H, L., & CY, G. (1997). Combined effects of caloric restriction and branched-chain amino acid supplementation on body composition and exercise performance in elite wrestlers. International Journal of Sports Medicine, 18(1), 47–55. https://doi.org/10.1055/S-2007-972594
- PC, C. (2006). Branched-chain amino acids and immunity. The Journal of Nutrition, 136(1 Suppl). https://doi.org/10.1093/JN/136.1.288S
- MA, S., DM, B., & DE, M. (1984). Regulation of valine metabolism in man: a stable isotope study. The American Journal of Clinical Nutrition, 40(6), 1224–1234. https://doi.org/10.1093/AJCN/40.6.1224
- M, D., QW, S., MJ, Z., & SP, F. (2007). Leucine stimulates mammalian target of rapamycin signaling in C2C12 myoblasts in part through inhibition of adenosine monophosphate-activated protein kinase. Journal of Animal Science, 85(4), 919–927. https://doi.org/10.2527/JAS.2006-342
- CM, B., JC, M., JM, M., AG, M., JW, O., CM, T., CM, W., & VG, W. (1988). Activities of octopamine and synephrine stereoisomers on alpha-adrenoceptors. British Journal of Pharmacology, 93(2), 417–429. https://doi.org/10.1111/J.1476-5381.1988.TB11449.X
- S, H., KR, F., G, C., N, L., S, P.-C., & DB, A. (2006). Citrus aurantium and synephrine alkaloids in the treatment of overweight and obesity: an update. Obesity Reviews : An Official Journal of the International Association for the Study of Obesity, 7(1), 79–88. https://doi.org/10.1111/J.1467-789X.2006.00195.X
- BC, N., K, P., KE, S., & LC, S. (2007). Mass spectrometric determination of the predominant adrenergic protoalkaloids in bitter orange (Citrus aurantium). Journal of Agricultural and Food Chemistry, 55(24), 9769–9775. https://doi.org/10.1021/JF072030S
- J, G., M, T., M, B., D, R., M, G., & M, L. (1988). Alpha 2-antagonist compounds and lipid mobilization: evidence for a lipid mobilizing effect of oral yohimbine in healthy male volunteers. European Journal of Clinical Investigation, 18(6), 587–594. https://doi.org/10.1111/J.1365-2362.1988.TB01272.X
- M J Millan, A Newman-Tancredi, V Audinot, D Cussac, F Lejeune, J P Nicolas, F Cogé, J P Galizzi, J A Boutin, J M Rivet, A Dekeyne, & A Gobert. (n.d.). Agonist and antagonist actions of yohimbine as compared to fluparoxan at alpha(2)-adrenergic receptors (AR)s, serotonin (5-HT)(1A), 5-HT(1B), 5-HT(1D) and dopamine D(2) and D(3) receptors. Significance for the modulation of frontocortical monoaminergic transmission and depressive states - PubMed. Retrieved August 31, 2021, from https://pubmed.ncbi.nlm.nih.gov/10611634/
- KN, M., F, K., & KN, F. (2012). Marked resistance of femoral adipose tissue blood flow and lipolysis to adrenaline in vivo. Diabetologia, 55(11), 3029–3037. https://doi.org/10.1007/S00125-012-2676-0
- AD, S. (1993). Structure, function, and regulation of adrenergic receptors. Protein Science : A Publication of the Protein Society, 2(8), 1198–1209. https://doi.org/10.1002/PRO.5560020802
- RJ, L. (1979). Direct binding studies of adrenergic receptors: biochemical, physiologic, and clinical implications. Annals of Internal Medicine, 91(3), 450–458. https://doi.org/10.7326/0003-4819-91-3-450
- SM, O. (2006). Yohimbine: the effects on body composition and exercise performance in soccer players. Research in Sports Medicine (Print), 14(4), 289–299. https://doi.org/10.1080/15438620600987106
- Robertson, D., Wade, D., Workman, R., Woosley, R. L., & Oates, J. A. (1981). Tolerance to the humoral and hemodynamic effects of caffeine in man. Journal of Clinical Investigation, 67(4), 1111. https://doi.org/10.1172/JCI110124
- KJ, A., B, Z.-M., P, P., K, A., & E, J. (1980). Caffeine and coffee: their influence on metabolic rate and substrate utilization in normal weight and obese individuals. The American Journal of Clinical Nutrition, 33(5), 989–997. https://doi.org/10.1093/AJCN/33.5.989
- R, M.-R., J, G. P., Á, L.-S., JF, O., & VE, F.-E. (2012). Caffeine ingestion reverses the circadian rhythm effects on neuromuscular performance in highly resistance-trained men. PloS One, 7(4). https://doi.org/10.1371/JOURNAL.PONE.0033807
- A, A., S, T., S, C., P, H., L, B., & J, M. (1990). Caffeine: a double-blind, placebo-controlled study of its thermogenic, metabolic, and cardiovascular effects in healthy volunteers. The American Journal of Clinical Nutrition, 51(5), 759–767. https://doi.org/10.1093/AJCN/51.5.759
- VL, D. S., FR, M., NE, Z., F, G.-R., MJ, D., & L, G.-F. (2015). Effects of acute caffeine ingestion on resistance training performance and perceptual responses during repeated sets to failure. The Journal of Sports Medicine and Physical Fitness, 55(5), 383–389. https://pubmed.ncbi.nlm.nih.gov/26068323/
- TA, A., RL, R., & K, F. (2008). Effect of caffeine ingestion on one-repetition maximum muscular strength. European Journal of Applied Physiology, 102(2), 127–132. https://doi.org/10.1007/S00421-007-0557-X
- DL, R., & ND, C. (2016). Effect of Coffee and Caffeine Ingestion on Resistance Exercise Performance. Journal of Strength and Conditioning Research, 30(10), 2892–2900. https://doi.org/10.1519/JSC.0000000000001382
- CA, F., NM, A., J, S. J., CF, B., JD, de A. C., & WC, F. (2018). Performance of muscle strength and fatigue tolerance in young trained women supplemented with caffeine. The Journal of Sports Medicine and Physical Fitness, 58(3), 249–255. https://doi.org/10.23736/S0022-4707.17.06615-4
- TW, B., TJ, H., RJ, S., GO, J., DJ, H., JW, C., & MH, M. (2006). The acute effects of a caffeine-containing supplement on strength, muscular endurance, and anaerobic capabilities. Journal of Strength and Conditioning Research, 20(3), 506–510. https://doi.org/10.1519/18285.1
- M, D., & PM, S. (2005). Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis. Scandinavian Journal of Medicine & Science in Sports, 15(2), 69–78. https://doi.org/10.1111/J.1600-0838.2005.00445.X
- C, M., Y, S., M, H., S, I., T, T., & H, O. (2005). Anti-obese action of raspberry ketone. Life Sciences, 77(2), 194–204. https://doi.org/10.1016/J.LFS.2004.12.029
- AC, W., AC, B., RN, C., Z, Z., & DA, S. (2007). The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain. International Journal of Obesity (2005), 31(3), 481–487. https://doi.org/10.1038/SJ.IJO.0803437
- I, O., R, T., & E, E. (2011). The use of green coffee extract as a weight loss supplement: a systematic review and meta-analysis of randomised clinical trials. Gastroenterology Research and Practice, 2011. https://doi.org/10.1155/2011/382852
- I, O., SK, H., R, P., B, W., & E, E. (2011). The Use of Garcinia Extract (Hydroxycitric Acid) as a Weight loss Supplement: A Systematic Review and Meta-Analysis of Randomised Clinical Trials. Journal of Obesity, 2011. https://doi.org/10.1155/2011/509038
- ER, M., R, P.-B., D, D., RA, R., LJ, A., & E, G. (2005). Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Annals of Internal Medicine, 142(1). https://doi.org/10.7326/0003-4819-142-1-200501040-00110
- GK, S. (2017). Vitamins K1 and K2: The Emerging Group of Vitamins Required for Human Health. Journal of Nutrition and Metabolism, 2017. https://doi.org/10.1155/2017/6254836
- AT, E., & SL, B. (2008). Vitamin K intake and atherosclerosis. Current Opinion in Lipidology, 19(1), 39–42. https://doi.org/10.1097/MOL.0B013E3282F1C57F
- JB, B., BB, F., VL, F., CM, W., & SH, Z. (2017). Impact of Frequency of Multi-Vitamin/Multi-Mineral Supplement Intake on Nutritional Adequacy and Nutrient Deficiencies in U.S. Adults. Nutrients, 9(8). https://doi.org/10.3390/NU9080849
- L, C., SB, E., A, S., N, M., S, L., BA, W., JH, O., & J, B.-M. (2005). Origins and evolution of the Western diet: health implications for the 21st century. The American Journal of Clinical Nutrition, 81(2), 341–354. https://doi.org/10.1093/AJCN.81.2.341
- V, T., A, B., EL, P., O, E., SQ, W., & AC, H. (2010). Estimated equivalency of vitamin D production from natural sun exposure versus oral vitamin D supplementation across seasons at two US latitudes. Journal of the American Academy of Dermatology, 62(6), 929.e1-929.e9. https://doi.org/10.1016/J.JAAD.2009.07.028
- MF, H. (2004). Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. The American Journal of Clinical Nutrition, 79(3), 362–371. https://doi.org/10.1093/AJCN/79.3.362
- B, D.-H., A, M., JP, B., S, B., P, B., GE, F., RG, J., P, L., J, M.-T., & N, Y. (2010). IOF position statement: vitamin D recommendations for older adults. Osteoporosis International : A Journal Established as Result of Cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA, 21(7), 1151–1154. https://doi.org/10.1007/S00198-010-1285-3
- Wacker, M., & Holick, M. F. (2013). Vitamin D—Effects on Skeletal and Extraskeletal Health and the Need for Supplementation. Nutrients, 5(1), 111. https://doi.org/10.3390/NU5010111
- JH, S., Y, I., & T, M. (1997). Oxidative stability of docosahexaenoic acid-containing oils in the form of phospholipids, triacylglycerols, and ethyl esters. Bioscience, Biotechnology, and Biochemistry, 61(12), 2085–2088. https://doi.org/10.1271/BBB.61.2085
- J, D., & HO, B. (1979). Haemostatic function and platelet polyunsaturated fatty acids in Eskimos. Lancet (London, England), 2(8140), 433–435. https://doi.org/10.1016/S0140-6736(79)91490-9
- J, N., JP, S., G, K., M, M., C, von S., & A, H. (2011). Enhanced increase of omega-3 index in response to long-term n-3 fatty acid supplementation from triacylglycerides versus ethyl esters. European Journal of Clinical Nutrition, 65(2), 247–254. https://doi.org/10.1038/EJCN.2010.239
- J, D., P, M., JM, M., I, A., & EB, S. (2010). Bioavailability of marine n-3 fatty acid formulations. Prostaglandins, Leukotrienes, and Essential Fatty Acids, 83(3), 137–141. https://doi.org/10.1016/J.PLEFA.2010.06.007
- MS, R., Z, L.-W., PN, A., TA, S., NE, A., & TJ, K. (2005). Long-chain n-3 polyunsaturated fatty acids in plasma in British meat-eating, vegetarian, and vegan men. The American Journal of Clinical Nutrition, 82(2), 327–334. https://doi.org/10.1093/AJCN.82.2.327
- H, P., SK, P., V, D., & L, B. (2011). Omega-3 fatty acids and metabolic syndrome: effects and emerging mechanisms of action. Progress in Lipid Research, 50(4), 372–387. https://doi.org/10.1016/J.PLIPRES.2011.06.003
- Eric N Ponnampalam, Neil J Mann, & Andrew J Sinclair. (n.d.). Effect of feeding systems on omega-3 fatty acids, conjugated linoleic acid and trans fatty acids in Australian beef cuts: potential impact on human health - PubMed. Retrieved August 31, 2021, from https://pubmed.ncbi.nlm.nih.gov/16500874/
- GI, S., P, A., DN, R., BS, M., D, R., MJ, R., & B, M. (2011). Omega-3 polyunsaturated fatty acids augment the muscle protein anabolic response to hyperinsulinaemia-hyperaminoacidaemia in healthy young and middle-aged men and women. Clinical Science (London, England : 1979), 121(6), 267–278. https://doi.org/10.1042/CS20100597
- JD, B., & PR, H. (2009). Anti-obesity effects of long-chain omega-3 polyunsaturated fatty acids. Obesity Reviews : An Official Journal of the International Association for the Study of Obesity, 10(6), 648–659. https://doi.org/10.1111/J.1467-789X.2009.00584.X
- C, C., J, D., P, R., JM, A., & F, L. (1997). Effect of dietary fish oil on body fat mass and basal fat oxidation in healthy adults. International Journal of Obesity and Related Metabolic Disorders : Journal of the International Association for the Study of Obesity, 21(8), 637–643. https://doi.org/10.1038/SJ.IJO.0800451
- RJ, G., & J, K. (2007). A meta-analysis of the analgesic effects of omega-3 polyunsaturated fatty acid supplementation for inflammatory joint pain. Pain, 129(1–2), 210–223. https://doi.org/10.1016/J.PAIN.2007.01.020
- S, K., MP, van B., M, O., WM, V., D, K., & LJ, L. (2004). Dietary intake of fatty acids and fish in relation to cognitive performance at middle age. Neurology, 62(2), 275–280. https://doi.org/10.1212/01.WNL.0000103860.75218.A5
- G, P., NA, G., H, B., G, H., AM, R., & D, H.-P. (2006). Omega-3 fatty acids and mood disorders. The American Journal of Psychiatry, 163(6), 969–978. https://doi.org/10.1176/AJP.2006.163.6.969
- D, S., R, B., & SA, M. (2012). Omega-3 fatty acids EPA and DHA: health benefits throughout life. Advances in Nutrition (Bethesda, Md.), 3(1), 1–7. https://doi.org/10.3945/AN.111.000893
- PM, K.-E., DS, T., S, Y.-P., P, H., K, M., V, F., RL, H., G, Z., & TD, E. (2000). Polyunsaturated fatty acids in the food chain in the United States. The American Journal of Clinical Nutrition, 71(1 Suppl). https://doi.org/10.1093/AJCN/71.1.179S
- Kabil, O., Vitvitsky, V., & Banerjee, R. (2014). Sulfur as a Signaling Nutrient Through Hydrogen Sulfide. Annual Review of Nutrition, 34, 171. https://doi.org/10.1146/ANNUREV-NUTR-071813-105654
- Eastoe, J. E. (1955). The amino acid composition of mammalian collagen and gelatin. Biochemical Journal, 61(4), 589. https://doi.org/10.1042/BJ0610589
- JD, H., J, N., & G, L. (2010). Evaluating the quality of protein from hemp seed (Cannabis sativa L.) products through the use of the protein digestibility-corrected amino acid score method. Journal of Agricultural and Food Chemistry, 58(22), 11801–11807. https://doi.org/10.1021/JF102636B
- Babault, N., Païzis, C., Deley, G., Guérin-Deremaux, L., Saniez, M.-H., Lefranc-Millot, C., & Allaert, F. A. (2015). Pea proteins oral supplementation promotes muscle thickness gains during resistance training: a double-blind, randomized, Placebo-controlled clinical trial vs. Whey protein. Journal of the International Society of Sports Nutrition 2015 12:1, 12(1), 1–9. https://doi.org/10.1186/S12970-014-0064-5
- F, M., ME, P., D, T., S, B., R, B., & S, M. (2001). The influence of the albumin fraction on the bioavailability and postprandial utilization of pea protein given selectively to humans. The Journal of Nutrition, 131(6), 1706–1713. https://doi.org/10.1093/JN/131.6.1706
- JM, J., RP, L., JM, W., M, P., EO, D. S., SM, W., DS, K., JE, D., & R, J. (2013). The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance. Nutrition Journal, 12(1). https://doi.org/10.1186/1475-2891-12-86
- CS, H., HS, K., HJ, L., SH, L., YS, K., TB, C., HG, H., & KO, H. (2006). Isoflavone metabolites and their in vitro dual functions: they can act as an estrogenic agonist or antagonist depending on the estrogen concentration. The Journal of Steroid Biochemistry and Molecular Biology, 101(4–5), 246–253. https://doi.org/10.1016/J.JSBMB.2006.06.020
- Baohua Liu, Liqiang Qin, Aiping Liu, Yuhui Shi, & Peiyu Wang. (n.d.). [Equol-producing phenotype and in relation to serum sex hormones among healthy adults in Beijing] - PubMed. Retrieved August 31, 2021, from https://pubmed.ncbi.nlm.nih.gov/22279666/
- CL, F., C, A., WK, T., A, G., T, J., K, W., SM, S., SS, L., & JW, L. (2005). High concordance of daidzein-metabolizing phenotypes in individuals measured 1 to 3 years apart. The British Journal of Nutrition, 94(6), 873–876. https://doi.org/10.1079/BJN20051565
- LK, B., BL, M., BL, D., JW, L., & AM, D. (2010). Soy protein isolates of varying isoflavone content do not adversely affect semen quality in healthy young men. Fertility and Sterility, 94(5), 1717–1722. https://doi.org/10.1016/J.FERTNSTERT.2009.08.055
- JE, C., TL, T., SM, S., & R, H. (2008). Soy food and isoflavone intake in relation to semen quality parameters among men from an infertility clinic. Human Reproduction (Oxford, England), 23(11), 2584–2590. https://doi.org/10.1093/HUMREP/DEN243
- JE, T., DR, M., GW, K., MA, T., & SM, P. (2009). Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. Journal of Applied Physiology (Bethesda, Md. : 1985), 107(3), 987–992. https://doi.org/10.1152/JAPPLPHYSIOL.00076.2009
- S, van V., EL, S., S, A. S., JW, B., DW, W., SK, S., AV, U., Z, L., SA, P., CM, P., DR, M., & NA, B. (2017). Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men. The American Journal of Clinical Nutrition, 106(6), 1401–1412. https://doi.org/10.3945/AJCN.117.159855
- R, M., B, S., M, U., M, F., A, M., Y, M., M, K., & M, S. (2017). Dietary egg-white protein increases body protein mass and reduces body fat mass through an acceleration of hepatic β-oxidation in rats. The British Journal of Nutrition, 118(6), 423–430. https://doi.org/10.1017/S0007114517002306
- PT, R., B, G., B, P., M, B., GA, W., AP, G., JM, S., & LJ, V. L. (2012). Protein ingestion before sleep improves postexercise overnight recovery. Medicine and Science in Sports and Exercise, 44(8), 1560–1569. https://doi.org/10.1249/MSS.0B013E31824CC363
- KD, T., TA, E., MG, C., SE, W., AP, S., & RR, W. (2004). Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise. Medicine and Science in Sports and Exercise, 36(12), 2073–2081. https://doi.org/10.1249/01.MSS.0000147582.99810.C5
- Hoffman, J. R., & Falvo, M. J. (2004). Protein – Which is Best? Journal of Sports Science & Medicine, 3(3), 118. /pmc/articles/PMC3905294/
- Thomson, R. L., & Buckley, J. D. (2011). Protein hydrolysates and tissue repair. Nutrition Research Reviews, 24(2), 191–197. https://doi.org/10.1017/S0954422411000084
- M, D., Y, B., C, G.-R., P, G., J, F., P, C., O, B., & B, B. (2001). The digestion rate of protein is an independent regulating factor of postprandial protein retention. American Journal of Physiology. Endocrinology and Metabolism, 280(2). https://doi.org/10.1152/AJPENDO.2001.280.2.E340
- Y, B., M, D., P, G., MP, V., JL, M., & B, B. (1997). Slow and fast dietary proteins differently modulate postprandial protein accretion. Proceedings of the National Academy of Sciences of the United States of America, 94(26), 14930–14935. https://doi.org/10.1073/PNAS.94.26.14930
- LE, N., GJ, W., DK, L., CJ, M., & PJ, G. (2012). Leucine content of dietary proteins is a determinant of postprandial skeletal muscle protein synthesis in adult rats. Nutrition & Metabolism, 9(1). https://doi.org/10.1186/1743-7075-9-67
- S, R., CJ, R., C, J., RP, W., RA, M., & SM, M.-G. (2007). The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players. Journal of Strength and Conditioning Research, 21(2), 348–353. https://doi.org/10.1519/R-18395.1
- SB, H., DB, A., JR, V., A, P., D, G., & C, N. (1998). Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial. JAMA, 280(18), 1596–1600. https://doi.org/10.1001/JAMA.280.18.1596
- RR, W. (2017). Branched-chain amino acids and muscle protein synthesis in humans: myth or reality? Journal of the International Society of Sports Nutrition, 14(1). https://doi.org/10.1186/S12970-017-0184-9
- JD, B. (2003). Effect of creatine supplementation on body composition and performance: a meta-analysis. International Journal of Sport Nutrition and Exercise Metabolism, 13(2), 198–226. https://doi.org/10.1123/IJSNEM.13.2.198