Research Roundup #17: The Most Scientific Way to Bulk, Lowering Blood Pressure With Exercise, and Training According to Muscle Fiber Type

It’s estimated that there are over 2+ million scientific papers published each year, and this firehose only seems to intensify.

Even if you narrow your focus to fitness research, it would take several lifetimes to unravel the hairball of studies on nutrition, training, supplementation, and related fields.

This is why my team and I spend thousands of hours each year dissecting and describing scientific studies in articles, podcasts, and books and using the results to formulate our 100% all-natural sports supplements and inform our coaching services. 

And while the principles of proper eating and exercising are simple and somewhat immutable, reviewing new research can reinforce or reshape how we eat, train, and live for the better. 

Thus, each week, I’m going to share three scientific studies on diet, exercise, supplementation, mindset, and lifestyle that will help you gain muscle and strength, lose fat, perform and feel better, live longer, and get and stay healthier. 

This week, you’ll learn how to bulk (according to science), the best type of exercise for lowering blood pressure, and whether you should tailor your training to your muscle fiber type. 

Table of Contents

• 7 steps to the perfect bulking diet, according to science.
• A combination of cardio and weightlifting is best at lowering blood pressure.
• Should you follow a weightlifting program based on your muscle fiber type?

7 steps to the perfect bulking diet, according to science.

Source: “Nutrition Recommendations for Bodybuilders in the Off-Season: A Narrative Review” published on June 26, 2019 in Sports (Basel).

From “dirty bulking” to drinking a gallon of milk a day to following a ketogenic diet to recomping, there are just as many theories about the best diet for muscle gain as there are about the best diet for fat loss. 

That’s why a team of researchers led by fitness coach Juma Iraki conducted this narrative review. 

In it, they analyzed all of the current evidence regarding the best dieting strategies for maximizing muscle gain and minimizing fat gain. 

Here are the highlights:

• Calories: Consume up to 20% more calories than you burn, which is ~19-to-22 calories per pound of body weight per day for most people. If you’re a beginner or intermediate weightlifter, a 10-to-20% calorie surplus will likely result in maximum muscle gain, but aiming toward the top end of this range will result in more fat gain. If you’re advanced, a 5-to-10% calorie surplus is more fitting because consuming more won’t accelerate muscle gain further, but will cause more fat gain.

Sticking to these calorie recommendations should increase a beginner or intermediate weightlifter’s body weight by ~0.25-to-0.5% per week, and an advanced trainee’s body weight by ~0.25% per week.

• Protein: Consume ~0.7-to-1 gram of protein per pound of body weight per day from high-quality sources such as lean meats, dairy, whey protein powder, casein protein powder, and pea protein powder, targeting the top end of this range to optimize muscle growth. If you struggle to control your appetite while bulking, eating up to 2 grams of protein per pound of body weight per day and less carbs and fat may help you minimize fat gain.
• Fat: Consume ~0.2-to-0.7 grams of fat per pound of body weight per day, prioritizing high-quality fats such as omega-3 and omega-6. Eating more than this at the expense of protein or carbohydrates is likely to diminish muscle gain.
• Carbohydrates: Once you’ve allotted your calories to protein and fat, get the remainder of your daily calories from carbs. This normally means consuming ~1.4-to-2.3 grams of carbs per pound of body weight per day. (The researchers don’t state this explicitly, but they also imply that if you need to increase your calorie intake, the extra calories should largely come from carbs.)
• Nutrient Timing: Divide your daily protein intake into multiple meals, each containing ~0.2-to-0.3 grams of protein per pound of body weight, which is ~30-to-40 grams per meal for most people. Consuming a protein-rich meal in the 1-to-2 hours before and after training and before bed may offer a small benefit. 

Pre- and post-workout carbs and fat have little bearing on performance or results, so consume them according to your preferences.

• Performance supplements: Take 3 grams of creatine and 3-to-5 grams of beta-alanine daily at a time that suits you. Take 8 grams of citrulline malate and 2.5-to-2.7 milligrams of caffeine per kilogram of body weight an hour before training (this is slightly lower than most studies recommend, so if you go with this advice and don’t feel a benefit, bump it up to 3-to-6 milligrams per kilogram of body weight). Avoid caffeine within 3-to-9 hours of bedtime or it may hinder your sleep.
• Dietary supplements: Following a flexible dieting approach minimizes your risk of nutrient deficiencies, though taking a multivitamin is a good failsafe. Since most western diets lack omega-3 fatty acids, supplementing with 2-to-3 grams of fish oil (EPA and DHA) may confer several additional health benefits.

These recommendations are far from exhaustive, but lay out everything you need to optimize your bulk.

That said, if you’d like even more in-depth advice about dieting for muscle growth, including exactly how many calories, how much of each macronutrient, and which foods you should eat to reach your fitness goals, take the Legion Diet Quiz.

Or, if you’d like more specific advice about what supplements you should take for your budget, circumstances, and goals, then take the Legion Supplement Finder Quiz.

TL;DR: To maximize muscle growth during a bulk, eat up to 20% more calories than you burn, ~0.7-to-1 grams of protein, ~0.2-to-0.7 grams of fat, and ~1.4-to-2.3 grams of carbs per pound of body weight per day.

A combination of cardio and weightlifting is best at lowering blood pressure.

Source: “Comparative effectiveness of aerobic, resistance, and combined training on cardiovascular disease risk factors: A randomized controlled trial” published on January 7, 2019 in PLoS ONE.

Hypertension, or high blood pressure, is one of the leading risk factors for mortality worldwide. Thus, keeping your blood pressure levels in an optimum range is a hallmark of health, fitness, and longevity.

Most everyone knows that working out is one of the best ways to accomplish this, but what kind of exercise is most effective? 

Some say you should emphasize cardio since pretty much every study since the 60s says cardio reduces blood pressure significantly. 

Others say that weightlifting provides all the health benefits of cardio and also helps you build muscle, which is vital for maintaining metabolic health and keeping “lifestyle” diseases like heart disease, osteoporosis, and type 2 diabetes at bay. (Oh, and it makes you look good.)

Who’s right?

That’s what researchers at the University of Illinois wanted to puzzle out when they divided 69 overweight, sedentary, middle-aged and elderly men and women with high blood pressure into four groups: 

1. Group one lifted weights for an hour three days per week.
2. Group two did cardio for an hour three days per week.
3. Group three did 30 minutes of cardio and 30 minutes of weightlifting three days per week.
4. Group four did no exercise (the control group).

After eight weeks, the only group that experienced a significant decrease in blood pressure was the cardio+weightlifting group, whose diastolic (when your heart is relaxed) and systolic (when your heart is contracting) blood pressure both dropped ~4 mmHg. The weightlifting-only group didn’t experience any drop in average blood pressure, and the cardio-only group experienced a small, insignificant drop in blood pressure.

(This is a little odd in that several other studies have found that weightlifting and cardio alone can reduce blood pressure, thus it’s possible this would have been the case in this study as well if it had lasted longer.)

The cardio+weightlifting group gained the most muscle (~1.8 lb) and almost the same amount of strength as the weightlifting-only group (the weightlifting-only group’s leg press one-rep max strength increased by ~28 lb, whereas the cardio+weightlifting group’s increased by ~24 lb). They also improved their VO2 max (a proxy of cardiovascular fitness) by ~16%, which wasn’t too far behind the cardio-only group, who increased their VO2 max by ~25%.

To better understand the effects of each program, the researchers also ran the results through an algorithm to estimate the overall “cumulative benefit” of each exercise protocol.

When they analyzed the data, they found that “the combined group [cardio + weightlifting] experienced more cumulative benefits across all cardiovascular outcomes . . .”

In other words, combining cardio and weightlifting improved blood pressure and the overall cardiovascular health of these people more than weightlifting or cardio alone. 

An earlier meta-analysis conducted by scientists at the University of Connecticut also supports these findings. In that study, researchers analyzed 68 studies that examined how combining cardio and weightlifting affected blood pressure. Once again, they concluded that “The potential BP [blood pressure] lowering effects from CET [cardio + weightlifting] are equal to or greater than aerobic exercise among adults with hypertension.”

The takeaway, then, is that any exercise improves your heart health, but combining weightlifting and cardio is optimal. And if you want to boost your cardiovascular and metabolic health, here’s what I recommend in my fitness book for absolute beginners, Muscle for Life:

• Do three-to-five strength training workouts per week.
• Do one-to-three hours of low-to-moderate-intensity cardio per week.

(Or if you aren’t sure if Muscle for Life is right for you or if another training program might be a better fit for your circumstances and goals, then take Legion Strength Training Quiz, and in less than a minute, you’ll know the perfect strength training program for you. Click here to check it out.)

TL;DR: Any exercise lowers your risk of hypertension, but a combination of weightlifting and cardio is best. 

Should you follow a weightlifting program based on your muscle fiber type?

Source: “Do the anatomical and physiological properties of a muscle determine its adaptive response to different loading protocols?” published on April 27, 2020 in Physiological Reports.

Generally speaking, you can lump muscle fibers into two categories: type I and type II.

Type I fibers contract slowly, are resistant to fatigue, and have a limited potential for growth, which is why they’re often referred to as slow twitch muscle fibers. 

Type II fibers contract quickly, produce more power, and have a much greater potential for muscle growth than type I fibers, but fatigue more rapidly, which is why they’re referred to as fast twitch muscle fibers.

Most people’s muscles are split about 50/50 between fast- and slow-twitch fibers. That said, some muscles tend to be more slow- (calves) or fast- (shoulders) twitch than others, and your exact ratio of slow to fast twitch fibers is heavily influenced by your genetics.

Some research suggests that you may be able to gain more muscle and strength by fine-tuning your strength training program based on your muscle fiber type instead of following a more generic program. The way this generally looks in practice is that people who are more type I dominant should emphasize higher reps and lighter weights, and people who are more type II dominant should emphasize lower reps and heavier weights.

That’s the theory, but other scientists aren’t convinced. 

For example, one of the most comprehensive reviews on muscle growth to date, published in The Journal of Strength and Conditioning Research, concluded that “ . . . a fiber-type prescription with respect to repetition range has not been borne out by research.”

To hammer out this hemming and hawing, scientists at CUNY Lehman College conducted this study.

They had 26 young untrained men perform 4 sets of calf raises twice per week (2 sets of standing calf raises and 2 sets of seated calf raises). They had everyone train one leg with light weights and 20-to-30 reps per set, and one the other leg with heavier weights and 6-to-10 reps per set.

The researchers chose to investigate the calves because the two muscles that make up the calves—the soleus and gastrocnemius—are composed of different fiber types. 

Specifically, the soleus is predominantly composed of type I fibers (~80%), whereas the gastrocnemius generally has a similar composition of both fiber types. 

If the “train-according-to-your-fiber-type” theory holds true, you’d expect these two muscles to respond differently to higher or lower training intensities.

For instance, if you trained your calves with light weights in a high rep range, you’d expect more growth in the gastrocnemius and less in the soleus. And if you trained your calves with heavy weights in a low rep range, you’d expect a greater response in the soleus than the gastrocnemius. 

After 8 weeks the researchers used ultrasound to measure how much the participants’ calves had grown and found that everyone’s calves had increased in size by a similar amount (8-to-14%). The participants gained about the same amount of strength in both legs, too.

All in all, this study adds to the previous research that shows training according to your fiber type is mostly a waste of time. 

That said, the researchers uncovered another wrinkle that’s more useful. 

The researchers noticed that while everyone’s calves grew to a similar degree, there were large individual differences in how participants responded to the different rep ranges.

For some people, high-rep training led to more calf muscle growth, whereas for others low-rep training was better, and for the rest it didn’t seem to matter (their calves grew equally well regardless of what rep range they used).

What should we make of all this?

By my lights, this is yet another reason to train your muscles using a variety of rep ranges and intensities, which is how I train and what I recommend in my programs for men and women. As a general rule, it’s probably best to do about 80% of your sets in the ~4-to-10 rep range and about 20% using higher or lower reps. 

There are a few ways to implement this concept in your training: 

• Switch to higher reps if you’ve been using lower reps, or vice versa, and see how your body responds. For instance, if you’ve mostly been training in the ~3-to-5-rep range, give 6-to-10 reps a whirl for a few months.
• Try using different rep ranges for lagging muscle groups. This is the same as the first method, except you only mix up your intensity for the body parts you’re most keen to grow. 
• Follow a periodized strength training program that involves rotating through a variety of rep ranges and intensities over several months, so that you get the best of both worlds. This is the most scientifically supported method and one of the key components of my Beyond Bigger Leaner Stronger program.

(Again, if you aren’t sure if Beyond Bigger Leaner Stronger is right for you or if another training program might be a better fit for your circumstances and goals, then take Legion Strength Training Quiz, and in less than a minute, you’ll know the perfect strength training program for you. Click here to check it out.)

TL;DR: Don’t bother trying to tailor your training program to your muscle fiber type. Instead, focus on training all of your muscle groups with a variety of intensities and rep ranges.