Human Growth Hormone & Insulin-Like Growth Factor - Building Muscle & Burning Fat

by Dr. David Minkoff January 27, 2022 6 min read

Human Growth Hormone & Insulin-Like Growth Factor - Building Muscle & Burning Fat

Growth Hormone (GH or HGH) is a key hormone that helps us build muscle and burn fat.

Your muscles are made of cells that have been fused together into muscle fibers. And on the outside of these fibers are things called satellite cells.

When you work out you damage cells in the muscle fibers. To fix this, your body releases Growth Hormone, Growth Factors (other hormones) and Testosterone. These tell the satellite cells to start replicating to both repair and replace damaged cells in the muscle, and also to add more cells, increasing the muscle fibers in size.

As the cells require essential amino acids to replicate, the growth hormones tell the cells to take in the essential amino acids you consumed. 

This is something we obviously want. 

But GH does more than this. It also helps regulate your metabolism in conjunction with your thyroid. It stimulates the uptake of amino acids throughout your body to repair bones, ligaments, tendons and, really, most every cell in the body. 

It’s even been called the “anti-aging” hormone as, if it’s low, raising it can bring one’s overall body health back to earlier, “younger” levels, “reversing” aging to a degree.

But it also stimulates the release of something else very important for fat burning, a hormone called Insulin-Like Growth Factor (IGF), and it’s primary job is the releasing of energy for use between meals.

Now, we already know about the hormone glucagon. When you haven’t eaten in a while, and your blood sugar levels go down, glucagon is released to tell your liver and muscles to release stored sugar called glycogen. 

And when all this stored sugar is used up, if you still haven’t eaten, then glucagon says to start burning body fat for energy. 

And we want this.

Well, IGF does much the same thing as glucagon.

But… unlike glucagon, which only goes into action when blood sugar levels drop, IGF is mainly released when Growth Hormone is released, and only on an empty stomach.

So, if we put attention on lowering our overall insulin levels, which releases glucagon, while raising our growth hormone levels, we get not just one, but two fat-burning hormones working for us.

IGF also regulates cell growth, particularly nerve cells, which we especially need if we’re putting our body through hell while working out.

So let’s look at what raises and lowers these hormones, and how to get the most out of them.

What Raises And Lowers Growth Hormone And IGF

As far as releasing them there are four key things: resistance training, amino acids, fasting, and sleep.

First, when we work out we damage our muscles and this releases GH to build them back up. 

But it was found that maximum production occurred when we did not work our muscles to full muscle failure, but just before. 

Now, going past muscle failure may stimulate the release of more GH, IGF and Testosterone than going to just before muscle failure. But this would also release more cortisol, which works against GH, IGF and Testosterone. 

So work your muscles hard, but don’t kill them.

Carrying on, we see an increase in growth hormone during the workout and then a drop right after it. 

Then we see GH and IGF come to life at night, usually during the first 2-3 hours of deep sleep, and then again surge about 15-18 hours after the initial workout, whether you work out again the next day or not. 

This is because GH is produced in little spurts.

Beyond this, just the consuming of protein causes the body to release GH to get the cells to take in the amino acids, even when not working out. 

This is one reason some people on keto have a harder time gaining muscle. Yes, they’re off sugars, but they’re not giving their body enough of what it needs to build — protein, amino acids — both to build muscle, but also to build the enzymes that actually burn body fat, something else GH induces.

Then there is fasting.

Fasting, Growth Hormone And Autophagy

When we’re in a fasted state our insulin levels go very low and glucagon is released. 

And when we do this for some time glucagon simulates a process called autophagy. This is where the body starts doing a bit of spring cleaning among the cells, getting rid of the old ones and making new ones to replace them, cleaning out toxins, and much more.

During this, GH is released to instruct the cells to take up amino acids to repair or replace old cells, which also releases IGF and so we see fat-burning for energy here as well.

In fact, one study found that 3 days into a fast GH levels increased over 300% and another study showed a 1250% increase 1 week in. 

But while those can be nice to do to clean out the old cells, you don’t have to fast for the body to produce GH or lose fat.

The last point is sleep.

Deep Sleep Is The Most Important Time For Release Of Growth Hormone, IGF And Fat Burning

Sleep is one of the most important things when working out or doing exercise of any kind. It’s when your body has a chance to rebuild. It’s also when most of your fat-burning occurs.

This is because during the first 2 or so hours of sleep we get a significant release of GH and IGF. 

It’s almost a mini-autophagy, really. Growth hormone goes out, detox of cells occurs, old cells are removed, repaired or replaced, injuries healed, especially the microscopically tiny injuries you never see, but which build up over time into strange aches if not allowed to heal nightly. 

Sleep is the most important factor in building muscle and losing fat. Beyond the amino acids and nutrients necessary to actually. 

If building muscle comes from repairing injured tissue, it won’t happen without growth hormone. 

If the first 2-3 hours of sleep are the main time your body burns fat due to the release of IGF, then if you’re not getting good sleep you’re going to have a very hard time losing fat no matter what you do.

Okay, so what lowers it? A few things.

What Lowers Growth Hormone And IGF

As we saw above, first is sleep. If you want higher levels of GH and IGF, greater lean muscle and less fat — get good sleep. 

When we don’t it’s not just the GH and IGF we lose, lack of sleep stimulates Cortisol release, the hormone there to get you through the day when you’re tired and which also… prevents fat loss or muscle growth.

Next, the amount of body fat you have is directly related to your GH production. 

Not only does more GH lead to less body fat, but reversely, the more body fat you have… the less GH is produced. 

And the less body fat you have, the more GH is produced. 

So the more we get our health under control and lower body fat levels, the more we raise GH levels.

And then of course we have our friends processed sugar and insulin. 

When our blood sugar is high, our insulin is high. And as GH is also a fat-burning hormone, it gets suppressed by insulin. 

So if you have a bunch of processed sugar right before or after a workout, we get spiked insulin and a suppression of GH and IGF. 

And, as too high insulin can make you tired, it can make workouts, and the recuperation afterwards, not so fun (this is less so if you’re young, but it will catch up with you).

But that processed sugar and insulin also raise cortisol levels, which further prevent GH & IGF release. 

So if you have a sugary meal before bed, you’re raising insulin and cortisol levels and lowering GH and IGF production. Now instead of fat burning, you’re going to have fat building while you sleep.

Not what we want. 

So, Take your PerfectAmino, workout normally, get a good nights sleep each day and never work out the day after a bad night’s sleep, eat generally healthy and stay way from processed sugars. 

If you did only that for 3-6 months your Growth Hormone and IGF levels would naturally raise. 

I hope that helps.