Are You Losing Muscle Because Of Cortisol?

Shaun McEwan
Written By: Shaun McEwan
February 9th, 2009
Updated: June 13th, 2020
Categories: Articles Nutrition
149.4K Reads
Ever wondered why all those hours in the gym is failing to bring you results? Well it's probably got something to do with Cortisol.

Ever wondered why all those hours in the gym is failing to bring you results? Well it’s probably got something to do with Cortisol and after reading this article you should have an understanding of exactly what this hormone does and what you can do to minimise its negative effects.

What is Cortisol?

Cortisol if often referred to as the ‘Stress Hormone’ as although it is produced naturally throughout the day it is released in greater amounts as a response to stress. The adrenal gland is where Cortisol is produced and released by the body in varied levels throughout the day. Cortisol levels are generally higher in the mornings and lower at night time as the amount of Cortisol released drops throughout the day unless of course the body releases more Cortisol as a reaction to Stress.

Benefits Of Cortisol:

Some of the benefits from this hormone include increasing short term memory and helping the liver to remove toxins from the body. The immune system works with the hormone to regulate the blood sugar levels with the body.

Disadvantages Of Cortisol:

Disadvantages include raised blood pressure and lower bone density. This will not be an issue with normal amounts of Cortisol production. It is only when higher amounts of Cortisol are produced by the body usually in relation to stress that these factors become an issue.

How Does Cortisol Affect my Training?

Gaining Muscle:

Push Up

Now we all know that testosterone helps us to build muscle, well Cortisol does the opposite! It is a catabolic hormone that reduces protein synthesis and prevents tissue growth.

It is after about 1 hour of lifting when testosterone levels begin to drop and Cortisol levels begin to rise. This of course is a bad combination and is why any good muscle building routine can be completed in under an hour. You should have a good warm up and complete your stretches in your own time but as soon as you hit the weights, that’s it – Stay focused… No chatting… Just lift and get your workout routine done in under an hour to prevent the effects of Cortisol from stopping your gains!

Burning Fat:

Too much cardiovascular exercise will cause Cortisol levels to increase and as we know Cortisol will eat away at your muscle fibres and reverse the effects of your training.

Firstly let’s just remember the difference between losing weight and losing fat. The truth is you’re not going to look much better unless its fat you’re burning…. And quite often it’s not! If it were true that cardio just burns fat then you could just get on your bike and cycle all day every day and get ripped. But we all know it’s not that easy, overtraining causes the body to use muscle for fuel and to try and hold on to body fat instead of burning it.

Too much cardiovascular exercise will cause Cortisol levels to increase and as we know Cortisol will eat away at your muscle fibres and reverse the effects of your training. So remember sometimes less is more and limiting cardio sessions to 4-5 per week will be more effective than running for hours every day.

How to Control Your Cortisol Levels

1. Keep Your Weight Training Workouts Less Than 1 Hour

  • As stated already, if you workout for longer than 1 hour your testosterone levels will drop and Cortisol levels will rise therefore preventing muscle growth! Keep your workouts short and intense!

2. Limit Your Cardio

  • Too much cardio causes more Cortisol to be released by the body so don’t over-do it on the treadmill and remember any cardio should be combined with a good diet.

3. Nutrition

  • Try to eat at least 5-6 small meals each day as it has been found that eating more frequently helps to control Cortisol levels keeping them lower than if you were eating larger meals less frequently. The most important meals are breakfast and your Post Workout meal. Make sure you eat in the morning as Cortisol levels are shown to be higher at this time and maintaining a proper diet including protein, carbs and essential fats help to control Cortisol levels.
  • A good post workout shake should include around 40-50g of protein (view protein powders) and 50-70g of simple carbs (dextrose) that will provide an insulin spike – this helps to clear Cortisol levels and keep up those muscle gains!

4. Relax

  • Well this is a simple one in theory, as I’ve mentioned Cortisol levels are proven to rise dramatically due to the body reacting to stress. Try to chill out and not to let things stress you out!.... take a nice walk… have a bath… read a book, whatever helps you to relax and relieve the stress.

5. Sleep

  • 8 Hours sleep is ideal but try to get at least 7! Remember muscle doesn’t grow whilst you’re in the gym – it grows when you’re resting. Cortisol levels are at a low and growth hormones are at a high when sleeping so make sure you’re getting enough of it!

6. Limit Caffeine Intake

  • Cortisol levels can be elevated due to the stimulating effect of caffeine and it has been shown that as little as 2-3 cups per day can cause Cortisol levels to rise.
Posted on: Sun, 07/08/2018 - 05:10

I use Brands chicken essence in asia, swear by it for recovery

Posted on: Thu, 06/26/2014 - 19:09

I noticed you didn't site one study or reference for some of the "facts" you threw out there like eating 5-6 small meals a day is best. I happen to believe that's total bullshit. Do you expect the reader to just believe everything you say?

Posted on: Wed, 01/08/2014 - 15:40

Another BS article on cortisol.

Doesn't anybody do any research on a subject before writing on it?

Nope. They just act like a parrot, repeating what they have heard before.

Thank you for that post, Colin.

I do a full-body workout, and it takes me about an hour and forty-five minutes to do it.

I keep a log on my progress, and I'm on track with normal gains.

Posted on: Thu, 05/15/2014 - 11:54

Could you please post a scientific link to where I can find information supporting your views? I want to learn more about this subject and don't want to rely just on personal experiences because of course, everyone is different and effects aren't always visible or obvious.

Colin Vettori
Posted on: Mon, 12/02/2013 - 20:18

If you actually look at the studies, acute elevations of cortisol levels while resistance training have little effect on hypertrophy. Dr Stuart Phillips debunks this in his study . And as Dr Layne Norton points out 'He actually shows that acute cortisol increases were MORE closely associated with anabolism than testosterone or GH. Thus effectively demonstrating that short term fluctuations in hormones may not be anabolic and short term increases in cortisol not only aren't catabolic but that they are indicative of a GOOD training session'.To say you can't train for longer than 1hr because the cortisol boogeyman is going to come and get you is just BRO SCIENCE. As long as you have your nutrition on point, you'll be fine well past 1hr. I have made some of my greatest gains after I stopped limiting my workouts to 1hr.

Posted on: Thu, 08/29/2013 - 21:15

Good, informative article, but I do have a question. Why do my cardio workouts turn me into the angriest man alive!? Could imbalanced cortisol levels have something to do with it? It's weird because I don't feel the least bit mad after a good, solid, T-raising weights workout & you'd think that would be causing it. But it's only when I do cardio. My infinitely understanding Wife says it's because I have OCD & the overheating of my body aggrevates it. My trainer just says it's because I'm a weird person (lol). All I know is that on the cardio only days, I feel really good afterward, but the least little thing will make a shouting, hollering, Hulk of a guy that I don't want to be.

Any constructive advise would be greatly appreciated. :)

Posted on: Sat, 06/22/2013 - 09:39

my name is Kieron im 22 from England. I weigh about 10st 4lbs but I firmly believe that I have trouble with my cortisol levels after reading and studying this articale. I first started training in the gym when I was 17 and only weighed about 7st at the time but then more frequentlly my muscles were decreasing/deflating even though I was using the correct techniques lifting the right weights in the gym and eating more proteins. Then I randomly started massaging ice gel into my arms which somehow stimulated my muscle tissues and fibres and made feel quite big, but it only worked for a few days so which meant I had to apply ice gel nearly every other day to my affected muscle area. It was only 3 years ago that when I was actually going to the gym more that I started to feel that I was getting a bit bigger and seeing a bit of results but then after I broke my ankle playing football a year later so I had to have an op on it to fit a titanium plate in my ankle which meant I was injected with morphine and anthestics. Since then I have simply found it impossible to gain any inch of muscle on any part of my body which has made me angry, depressed and frustrated. After which I had simply giving up on trying improve my physique and quit the gym. But after reading this articale it has hopefully shed a bit of light on my problem and would like to know that can I build the physique I have always dreamt of? And if so how can I reduce my cortisol/catabolic levels for good to achieve my dream physique especially if any supplements work too?

Posted on: Sun, 11/18/2012 - 06:33

How I eat after gym. My wheat 70 kg.

Posted on: Thu, 01/12/2012 - 14:22

I really enjoyed this article, but would like the option to save it in favourite articles or something, do you think Muscle and Strength could make that possible for me lol???

Posted on: Sat, 10/15/2011 - 16:52

I cut out coffee / caffeine about a year ago in an effort to regulate my cortisol levels, since it's particularly tied to belly fat. My weight training takes about an hour, 4 days per week, but I'm wondering if it's ok to do 20-30min cardio afterwards. That's what has been recommended to me, for all the various reasons that post-lifting cardio is beneficial, but does the body then consider that to be a 90min work out? Or is that 1-hour mark only for actually lifting weights?


M&S Team Badge
Posted on: Sun, 10/16/2011 - 14:24

The one hour guideline is for weight training and muscle building.

Posted on: Mon, 06/20/2011 - 13:22

Your post is based on truth but takes a biased opinion on the negative effects of cortisol.
It is true that it is a catabolic hormone but it is also essential, even in body building. It is responisble for MPB (Muscle Protein Breakdown) but by doing this increases the overall rate of Muscle Protein Turnover, which gets rid of old Proteins and helps the body replace them with fesh Amino Acids.
As long as the Amino Acids are availiable (through diet) cortisol alone should not be enough to prevent muscle growth.
It is about keeping your body in a NET Anabolic State. As long as the rate of Muscle Protein Synthesis is greater than Muscle Protein Breakdown (through good diet) the body remains Anabolic.

I'm not arguing your post, just explaining that Cortisol is not all that bad and it is essential for our body's to work properly.

Posted on: Sat, 05/07/2011 - 11:02

I do training every for more than an hour and my body hasnt got much muscle on it beeing doing it for 20 years I have a stress problem that triggers sometimes in the morning. Wake up at 3 in the morning. I think to much gym dont give my brain enough rest and also to much training to much because I am an active worker in tennis during the day
Do you think I am overtraining plus being active on the tennis court?

Posted on: Mon, 06/15/2015 - 16:00

I think you are in the beginning stages of adrenal fatigue. I started by waking up at 3 am every morning- except by diarrhea. It only progressed so now I am Addison's. Get into an endocrinologist now before you lose your adrenal.

Posted on: Fri, 04/15/2011 - 03:04

Runs? I though we were on to Cortisol effects? why the jump to LBM?

Posted on: Sat, 11/20/2010 - 13:48

This is very difficult to read but i am proof of it's truth.

I'm one of the many Runners torn between Distance Running and bulking via Weight Training. Needless to say, my 30+miles/week and 3 days tossing Weights were counterproductive and very frustrating. Frustrating at my mass results; my runs were great!

So, I'm having to shave about 15miles/week down. I'll still run; but instead of running for 2 hours on Saturday mornings with my 4 weekday runs, i'm doing harder/shorter bursts.

I hope to see a return on investment over the next few months. I am going to miss losing myself in my Runs though. Argh!! -Michael

Mikey Guns
Posted on: Sun, 10/16/2011 - 13:43

My experience is that doing short hard intervals, particularly if you've been off awhile or changed your routine, stimulates more cortisol release and insomnia. Once I get used to the particular difficulty level of the new interval, the physiological response seems to revert to normal. When I crank it up to the next level, I take a cortisol blocker for a week or two then I'm okay without the supplement until the next increase in intensity. Be warned that a number of the so-called cortisol blockers which are oriented toward weight loss (the newest marketing hustle for these products) are loaded with caffeine, which isn't going to help if you're fighting insomnia.

Some literature seems to suggest that C and glutamine are helpful for cortisol control issues for serious athletes. But to my knowledge there are no control group studies that prove that conclusively.

Posted on: Thu, 11/03/2011 - 11:18

Which cortisol blockers do you use?

Posted on: Sat, 09/11/2010 - 23:34

If caffeine causes cortisol levels to rise then is it counter-productive to take pre-workout supplements with a lot of caffeine? I know caffeine will help power you through your workout but how much is too much? I know Jack3d has a smaller amount of caffeine then many other PWO supplements, but will it negatively effect my gains in the hour that I have to work out?


M&S Team Badge
Posted on: Mon, 09/13/2010 - 10:25

Hi Brandon,

Hard training and a proper diet will never let you down. With these 2 aspects nailed down, I would continue using a pre-workout with caffeine if it is benefiting you. I would simply watch the amount of caffeine you are taking in the rest of the day.

With many things in the realm of lifting, the importance of a minor issue tends to become overblown by members on both sides of the fence. Caffeine does impact cortisol, but will not impact you in any noticeable way if you work hard and eat properly, and aren't overdoing it. The body will respond to the demands of training, and if the raw materials are there, it will grow.

Posted on: Fri, 08/06/2010 - 16:50

Great article Shaun. I've struggle with cortisol and lack of sleep for years. Both from work and insomnia. Nothing is more important to the body and mind that good nutrition and good sleep. Thanks for the great information.