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This podcast is about hormones and aging, and specifically, how much hormones affect body composition as you get older.

In it, I’ll go through the most important hormones as they relate to body composition, how they change as we get older, and what we can do to maintain optimal hormone profiles relevant to our age.

There’s no question that we can’t maintain as optimal a hormone profile at 45 as we can at 25, but as you’ll learn here, we can still maintain good enough hormones to gain muscle, lose fat, stay lean and fit, and feel great.

The idea that our hormones crate as we get older and make it impossible to get and stay fit is very discouraging to many people. The good news is that’s mostly untrue. If we’re willing to do a few things consistently and do them well, we can keep our hormones in very healthy and effective ranges.

Listen to this podcast to learn about hormones and how they affect body composition, especially as we age.


0:00 – Pre-order my new fitness book now for a chance to win over $12,000 in splendid swag: 

5:08 – These hormones most affect body composition

5:53 – How do these hormones affect body comp?

6:37 – Leptin

7:01 – Ghrelin

8:27 – Testosterone and estrogen

12:01 – Hormones do negatively affect body composition as we get older if we don’t do anything to mitigate the changes

12:31 – How do we prevent our hormones from affecting us negatively?

13:46 – Leptin

14:20 – Ghrelin

14:54 – Growth hormone

16:05 – What effect does training have?

16:40 – Testosterone

17:57 – Do you need high levels of testosterone to get and stay in great shape?

20:01 – Estrogen

Mentioned on the Show:

Pre-order my new fitness book now for a chance to win over $12,000 in splendid swag: 

What did you think of this episode? Have anything else to share? Let me know in the comments below!


For decades now, most doctors have recommended cardio over strength training because they believed it produced more health benefits, stress to the body less, and it was more popular among the public. We now know though that strength training has multiple major advantages over cardio, and if you had to pick just one kind of exercise, it should.

Strength training. That said, there are good reasons to include cardio in your exercise routine as well. First, as the term implies, cardio boosts the health and the function of your cardiovascular system. For instance, while cardio and strength training are. About equally effective for reducing blood pressure.

Research shows that doing both reduces blood pressure the most. Additionally, cardio but not strength training helps keep your arteries flexible and responsive to changes in blood flow. And that’s why studies show that people who do the most cardio have these splt arteries, and that is crucial for maintaining healthy blood pressure.

And minimizing stress on your heart and blood vessels. Another circulatory downside to aging is the reduction of the capillary health and density of your muscles and other tissues. And studies show that cardio can significantly increase capillary density, which is the number of capillaries in an area of the body in muscle tissue, in just a.

Weeks cardio also burns substantially more calories per unit of time than strength training does. And that of course can help you lose fat faster and help you keep it off more effectively. Cardio is great for, uh, body composition maintenance for that reason. And when you combine strength training, And cardio together.

And when you combine them, especially in the way that I teach in my new book, muscle for Life, which you can learn about at Muscle for Life, muscle f o r life You can maximize fat loss without hindering. Muscle or strength gain. So the takeaway here is with moderate, sustainable and effective doses of strength training and cardiovascular exercise, you can build a body that looks, feels, and functions like a well-oiled machine and cardio’s easier to incorporate into your fitness regimen than.

Think too. In fact, in Muscle for Life, I share three simple principles that allow you to enjoy most of the benefits cardio has to offer with none of the potential downsides. And again, you can learn all about that book as well as the now it’s over $13,000 of Cool goodies, fitness goodies that I’m giving away to people who pre-order the book at Muscle for Life

Hello and welcome to Muscle for Life. I’m Mike Matthews. Thank you for joining me today. And if you haven’t already, please do take a moment to subscribe to the show in whatever app you are listening to me in so you don’t miss any new episodes. And it helps me because it boosts the ranking of the show in the various charts.

So this episode is going to be about hormones and aging, and specifically, how much do hormones affect body composition? As you get older, and this is a question I’ve been asked many times over the years, and I think I’ve touched on it here and there tangentially, but I have not produced a podcast like this an in-depth discussion where I will go through the most important hormones as they relate to body composition and how things change as we get older and what we can do to maintain optic.

Hormone profiles relevant to our age, of course, unless we are willing to use drugs we cannot maintain as optimal of a hormone profile at 45 as we can at 20 or 25. But as you will learn in this podcast, we can still maintain good enough hormones to build muscle, to gain strength, to lose fat, to sta lean, to feel great.

Many people incorrectly think that as we get older, our hormones. Crater and that makes it almost impossible to get and stay fit or get and stay very fit. And that is very discouraging to many people I know. I’ve heard from many of them over the years, and the good news is that is mostly untrue. If we are willing to do a few things consistently and do them well, we can keep our hormones in.

Very healthy ranges, very effective Ranges. Ranges that again, allow us to build muscle, get strong, lose fat, stay lean, and almost as effectively as when we were in our twenties. That has been shown in a number of studies. That is not just my opinion. All right, so let’s start this discussion with, uh, a quick list of the hormones that most affect our body composition.

They are leptin, grelin, insulin growth hormone, and the sex hormones, testosterone and. Estrogen. So as we get older, the levels of these hormones change, and many people, uh, many men in particular are fixated on testosterone. Many women are most concerned with estrogen, and those are very important hormones, but, The other hormones that I mentioned, they also play a large role in the negative experiences that many people have as they get older.

If they don’t do the handful of things that I’m gonna share with you in this episode. So let’s talk about these hormones and how they affect body composition. Research shows that as we get older, circulating levels of insulin go up, for example, and then insulin sensitivity decreases. So our cells, they don’t respond to insulin’s signals as well as they did when we were younger.

And together those changes can make us more likely to gain fat, and particularly abdominal fat can make us, uh, more biologically inclined. Toward fat storage. Of course, you can’t, uh, meaningfully increase your body fat levels without a calorie surplus. But when you are in a calorie surplus, how much of that surplus is stored as fat versus burned off or processed in other ways?

um, leptin, that’s a hormone that’s produced by fat cells that regulates a number of things, hunger, metabolic rate, appetite, feelings of motivation, body weight, very important hormone. And studies show that as we get older, we become less sensitive to leptin, which of course can make it easier to overeat and to burn less energy.

And of course that can make it easier to get fatter over time. Now ghrelin is a hormone that stimulates hunger. And so lower levels of ghrelin would be generally preferable for body composition because less hunger means less overeating. And of course that means less fat gain. And studies show that levels of ghrelin tend to decline as we get older and under normal dieting circumstances, that would be helpful, that would be good, uh, at least for body composition.

But, Ghrelin also stimulates growth hormone secretion. And as growth hormone decreases, age-related muscle loss can increase, uh, fat burning can decrease because growth hormone stimulates fat mobilization. It stimulates the release of fatty acids from fat cells to to burn. Uh, for energy. And so generally the lower your growth hormone levels are, the worse it is for your body composition.

And speaking of growth hormone research also shows that GH levels generally decline as we get older, irrespective of ghrelin. So this is kind of a one two punch. And again, that can. Muscle mass, or it can negatively impact muscle growth. It can negatively impact fat burning, which of course then makes it easier to gain fat to get fatter.

And last, we have the two hormones that most people are most concerned about as they get older. Testosterone and estrogen and testosterone is highest in males during their teens and their twenties. And after that, research shows that testosterone tends to. Decline slowly at about a rate of 1% per year, and testosterone deserves a lot of the attention that it gets.

Of course, this is mostly with men because it does play a very important role in muscle building in. Strength gain in fat loss. And that’s why research shows that declining testosterone levels, uh, are associated with decreased muscle mass, decreased strength, increased body fatness, and especially in the form of visceral fat, fat over your organs, which is particularly dangerous to your health.

Now, estrogen is. Another sex hormone. And that one is responsible for feminine things for the development and regulation of the female reproductive system. Uh, female secondary sex characteristics. And many people don’t know that light testosterone, estrogen does play a key role in building muscle and.

Losing fat. It is one of the reasons why women can gain muscle and lose fat fairly effectively about as effectively as men when you look at it in terms of percentage of body weight. So men can gain an absolute amount of muscle, uh, faster than women on average. So your average guy is going to gain a pound of muscle.

Faster than your average gal. But when you look at muscle gain over the course of one year, two years, three years, and so on, and you look at it relative to body weight and you look at the rate of muscle gain relative to body weight, men and women are comparable in that regard. Of course, men can gain a lot more total muscle and a lot more total strength, uh, but when you’re looking at it, Related to body weight, women can gain muscle pretty effectively and estrogen, high levels of estrogen are a big reason for that because estrogen improves insulin sensitivity, it stabilizes blood sugar levels.

That, of course, has positive effects on nutrient. Use being able to take the amino acids, for example, that you eat and then turn them into muscle tissue. Research shows that estrogen reduces fat storage in the lower body in the abdomen, and it increases concentrations of a compound called. A M P activated protein kinase, A M P K, and that boosts fat burning throughout the body, and estrogen also increases muscle growth.

It increases recovery, post-workout recovery. It decreases muscle soreness after training your muscles. And in women estrogen levels, they fluctuate, uh, throughout each month. And during menopause though, which is around the age of 50, for most women, estrogen levels drop dramatically as do progesterone, testosterone, follicle stimulating hormone luteinizing hormones.

So a lot of these hormones, a lot of these sex hormones, they drop and they. Up significantly. And studies show that that results in a decreased metabolic rate. It, it results in increased fat storage and primarily from decreased insulin sensitivity. So again, our body simply can’t process the food that we eat as effectively as when insulin sensitivity was higher, and it can result in loss of muscle mass.

And so, , if we don’t do anything to prevent a lot of those things that I just shared with you, then the hormonal changes that take place as we get older do significantly impact our body composition and of course, in a negative way. And if that goes on for too long, that of course impairs mobility. It increases morbidity.

It increases mortality. It increases the chances of us getting sick or dying. It decreases quality of life. If we intervene with effective diet and effective exercise, our hormones are far less likely to impact our body composition negatively and our health negatively as we get older. Multiple studies show that doing regular resistance training workouts, for example, and.

Lowering your body fat levels to a healthy range. You don’t have to be shredded, let’s just say somewhere around maybe 15% as a guy or 25% as a gal, that, or those two things that can greatly increase insulin sensitivity. And that’s true even if you are in your golden years. For example, in one study conducted by scientists at University of Maryland, a school of medicine, 35, middle-aged and older men, followed a calorie controlled diet for nine months.

And with the intention of losing a half of a pound to about one pound of body weight per week, and at the end of the study, the men had lost nearly 20 pounds and seen huge increases in insulin sensitivity. And again, generally speaking, the higher our insulin sensitivity levels are, the better our bodies can use the food that we eat for things other than fat storage, like muscle repair and muscle growth.

Now let’s look at leptin Studies show that doing some physical exercise, just being physically active, that could be resistance training, it could be cardio, could be both. That physical activity is an effective way to improve leptin levels and to improve leptin sensitivity, which again has positive.

Effects on appetite, uh, on body weight, on metabolic rate, on quite a few things that have direct effects on body composition. And as we are talking, appetite and hunger. Let’s also look at ghrelin and if we remember, lower levels of ghrelin generally means less hunger. But if they get too low, that can be negative because of how it decreases growth hormone production.

And studies show that exercise is also a great way to increase ghrelin levels to a healthy range. Again, as we get older, ghrelin levels tend to fall, but they tend to fall too far. And so by bringing ground levels back up into a healthy range, that helps our metabolism work more effect. Now what about growth hormone?

Well, research shows that when we are younger, we can greatly increase growth hormone levels by training and particularly by doing intense training. Studies show that the higher the intensity, the more growth hormone is produced, but that effect diminishes as we get older and we can’t do much. That specifically, however, there are things we can do to minimize the negative effects of lower growth hormone levels.

For example, research shows that GH levels are significantly higher in lean elderly people than overweight elderly people. And that was looked at following aerobic exercise. They’re looking at the the response to exercise. And so by just maintaining a healthy body composition, a healthy body fat percentage, again, Below 20% in men, uh, 15%, between 10 and 15% is, is really optimal.

And in women below 30%, but somewhere between 20 and 25 is probably optimal. By just doing that, we can maintain significantly higher levels of growth hormone. Especially when we are training regularly. And speaking of training, that’s a great way of counteracting some of the negative effects of lower growth hormone levels.

If we train to build muscle to get strong, to stay lean, don’t have to be shredded, but just. Stay healthily lean, and if we do those things, of course, primarily with resistance training, that’s what it takes to, to gain muscle, to gain strength. Then we are working directly against muscle loss and strength loss and fat gain, which again, are side effects or potential side effects when growth hormone levels are.

Now with testosterone, many people think that aging alone is responsible for declining testosterone levels and that it is inevitable, but that is simply not true. Research shows that lifestyle factors are equally, if not more causative as aging itself. For example, there are a handful of things that many people experience as they get older.

That can greatly depress testosterone levels like weight gain, sedentary living, so not exercising, not being physically active anymore. Chronic illness, the use of various medications, uh, not sleeping enough, uh, consuming alcohol. And so testosterone doesn’t just automatically bottom out because we get. , if we do some things to keep it under control, if we avoid the handful of things I just mentioned, research shows that we can maintain very healthy levels of testosterone as we get older, and the most effective ways are staying lean, uh, training our muscles regularly.

So regular resistance training, particularly intense resistance training and maintaining good sleep hygiene, those things. Are the 20% that give you 80% of the results. And another thing that is nice to know is research shows that we don’t need stellar, uh, top shelf testosterone levels to get and stay in Great.

Shape the natural variance in people’s anabolic hormone levels. Just doesn’t influence muscle building and fat loss nearly as much as many people would have you believe. Now, if you are using exogenous hormones, if you are injecting testosterone, for example, and you are increasing your testosterone levels to super physiological ranges above and beyond.

What is ever seen naturally. Yeah. That has a big effect on muscle building, and I’m not recommending that, but it does, it has negative side effects as well. And again, I, it’s, it’s not something that I ever recommend, but if we’re talking about a natural range of, let’s say 300 to maybe a thousand or so nanograms per dec.

That’s how testosterone is often measured. Then there is not a big difference between, let’s say four to 506 to 700 or even 800. There will be a difference primarily in energy levels and sex drive. The person with the higher testosterone levels will notice a bit more of those things than the person with lower testosterone levels, but the person with lower, not low, but just lower four to 500 is perfectly healthy.

Uh, for, for a man at any age really, but particularly a middle-aged man and beyond that man is not going to have symptoms of low testosterone. They’re not going to have low energy, low mood, low sex drive, uh, low response to training. They’re going to feel good. They’re going to be able to gain plenty of muscle, plenty of strength, lose plenty of fat, and they’re gonna be able to do those things.

In particular, those body composition things. About as effectively, if you look at it in, in terms of rate and relative to body weight as the person with much higher testosterone levels, and the story is more or less the same for estrogen and women, at least until they reach menopause. If they don’t do the things that I just mentioned for men, then the decline will be more precipitous.

But if they do, they can maintain healthy and effective levels of estrogen. Of course, again, They reach menopause and then there are unavoidable changes that occur. But that does not mean that women cannot get into great shape and stay in great shape after menopause. They absolutely can. That has been shown in a number of studies.

For example, one study that was conducted with post-menopausal women found that in 16 weeks they gain. A significant amount of muscle. They decreased their body fat percentage by almost 7% in an absolute sense, not in a relative sense. So if they started at an average of 35, they ended at an average of 28, for example, and they gained a lot of leg strength.

Which some of that is going to be related to just getting good at the exercise, but not all of it. I mean, it was a 41% increase on average, and they also saw a 27% increase in average bench press strength, and they were only training three times per week. And so to summarize everything we have discussed here, yes, our hormone levels do change as we get older and they change negatively.

They don’t change for the better. However, if we exercise regularly, if we train our muscles regularly, If we maintain a healthy body fat level, a healthy body composition, we can mitigate a lot of that downward shift. And in some cases, as I mentioned, it’s actually an upward shift, like in the case of insulin, for example.

But the most important hormones related to body composition, they are generally moving downward as we get older. If we don’t engineer our lifestyle to support our hormone, And of course that is not to say that we can become entirely ageless, that we can maintain the same hormone levels, the same hormone profile at 55 as when we were 25.

No, there are some hormones that will decrease as we get older, regardless of what we do. Growth, growth, hormone, testosterone, estrogen, for example. But that does not mean that we are destined to become frail, fat and unhealthy. It just means that our physiology is not as conducive to being jacked and ripped as when we were younger.

We could draw many analogies. But let’s look at gardening and let’s look at soil. And if you have really good soil, for example, it is going to have a very specific composition in terms of minerals and organic matter and clay versus sand versus, well, I don’t know that much about soil. Maybe silt is another one.

And if you have a lot of. The right minerals and a lot of the right organic matter and a great composition, like a lot of clay is good. For example, I know that because I’m in Ocala, Florida, which has very good soil, and so when you have great soil, it is easier to grow great plants, but as soil becomes less rich with nutrients and as the composition shifts more towards sand, for example, it becomes harder to grow.

Great. But just because your soil shifts from great to good doesn’t mean that you can’t grow great plants anymore. It just means that it’s harder. It just means that you’re going to have to pay attention to the details more, and it’s going to take more time. You’re gonna have to be more patient. And the same is true of our hormones.

When we were younger, we had great soil for growing great muscles and losing great amounts of fat. And as we get older, the soil. It doesn’t have to go to shit. It just, in most of us, is no longer great per se at let’s say 50, like it was at 20 or 25. But it still can be good. And with good soil, you can still grow great muscles and you can still have a great body composition.

It’s just a bit. Harder, you have to pay a bit more attention to energy balance, for example, to macronutrient balance, to sleep hygiene, you have to be more patient because it takes longer, uh, to, to some degree to gain muscle and strength and it can take longer to lose fat, particularly the stubborn fat in the lower abdomen region in guise and in the hips and thighs.

Gals and you have to give a bit more importance to recovery. You can’t train as intensely as frequently as when you were younger, but if you’re willing to calibrate your diet and your exercise accordingly, you still can get great results. Well, I hope you liked this episode. I hope you found it helpful, and if you did subscribe to the show because it makes sure that you don’t miss new episodes.

And it also helps me because it increases the rankings of the show a little bit, which of course then makes it a little bit more easily found by other people who may like it just as much as you. And if you didn’t like something about this episode or about the show in general, or if you have. Ideas or suggestions or just feedback to share.

Shoot me an email, mike muscle for, muscle f o r and let me know what I could do better or just, uh, what your thoughts are about maybe what you’d like to see me do in the future. I read everything myself. I’m always looking for new ideas and constructive feedback. So thanks again for listening to this episode, and I hope to hear from you.

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