Are your hormones affecting your muscle gain?

Struggling to gain muscle? Could your hormones be to blame? The answer lies in this blog.

We often take our hormones for granted and don’t think about them until something isn’t quite right. But we should give them more praise.  

A healthy hormone system enables us to stay in shape and conduct our daily activities. And that system is essential for people trying to gain muscle. 

It can be frustrating to dedicate time and effort to your physique and not see the desired results. You might have tried changing your diet or your training plan. But have you considered that your hormones could be the culprit?  

How do hormones affect muscle growth?  

Hormones are vital in regulating your metabolism (the internal process that governs our energy and processes our food intake).  

During and after a workout, the body is flooded with different hormones. These are either anabolic (hormones that use energy) or catabolic (hormones that release energy). Only the muscles stimulated during this exercise are subject to the effects of these hormones [1].  

For muscle growth, you need more anabolic hormones than catabolic hormones. 

Anabolic hormones for muscle growth include: 

Anabolic hormones enable muscles to grow through a process known as anabolism (when energy is used to construct molecules from smaller units).  

Catabolic hormones (such as cortisol) do the opposite and inhibit muscle growth through processes that break down molecules to release energy (like when digesting food).  

If there is a higher level of catabolic hormones than anabolic hormones in the body, you will begin to lose muscle mass. Therefore, hormonal disruptions (like a thyroid disorder) can affect these processes, your overall metabolism, and muscle gain [2].  

If you’re concerned about a hormone imbalance or want to find out your baseline levels, a blood test such as our Ultimate Performance Blood Test can give you insight.  

Hormones that affect muscle growth

It is clear that both anabolic and catabolic hormones are important to consider in the process of building muscle, but which ones are key, and how do you make sure you have the right levels?

Can testosterone affect muscle growth?

Testosterone is primarily produced by the testicles (and the ovaries in women). Testosterone regulates muscle mass, strength, fat distribution, libido, and bone mass [3], making it one of the most important hormones for bodybuilding.  

Bodybuilders sometimes use testosterone supplements to enhance their physique and muscle-building capability. However, using anabolic steroids like testosterone has been banned in sports competitions as it may give an unfair advantage and potentially cause long-term adverse health effects

Natural techniques that you can use in the gym to help boost your testosterone levels include: 

  • Keeping workouts shorter than 60 minutes 
  • Doing multiple sets of each exercise  
  • Including compound exercises (exercises that use more than one muscle group, such as squats)  
  • Working out your legs - stimulates your largest muscles and therefore produces more testosterone [1] 


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How does growth hormone (GH) affect muscle growth?

Growth hormone (GH) helps to: 

  • Build skeletal muscle tissue 
  • Develop body strength 
  • Eliminate body fat 

GH production declines with age, and the less GH you produce, the more body fat you accumulate [4], which is why it may be harder to lose weight as you age.  

Your body releases GH during its REM cycles of sleep and uses this time to repair any damaged muscle cells. Therefore, improving your quality of sleep may, in turn, help your workout efforts.  

Exercise (in particular, compound movements that use multiple joints, for example, squats or bench presses) also releases GH. The more muscle fibres you use, the more GH your body will create.  

Try to shorten your workouts (approximately 30-40 minutes), as the quicker, more intense duration produces a higher hormone output. 

How does insulin affect muscle growth?

Insulin is responsible for storing the product of food breakdowns in the muscles and liver. As another anabolic hormone, it moves amino acids into your muscle cells to help repair tissue.  

Insulin can have positive impacts on your muscles but could also become a burden if you have excess body fat. The production of insulin is heavily influenced by diet and exercise, so it can be something that you control. However, training can increase your body’s sensitivity to insulin, which is why it’s always so hard to lose the last bit of fat.  

Once you’ve lost some weight, your body shifts into survival mode and tries to protect the remaining fat and muscle it needs to function. To combat this, try eating healthy fats that insulin is less sensitive to. 

Healthy fats include: 

  • Fish 
  • Nuts 
  • Coconut oil 
  • Avocados 

How can insulin-like growth factors affect muscle growth?

Insulin-like growth factors (IGFs) are produced in the liver in response to the growth hormones - if GH levels rise, so do IGFs.  

As the name suggests, IGFs stimulate muscle growth. They increase lean body mass, helping you to burn fat, increasing your physical endurance, and accelerating your recovery time [5].  

Your IGF levels peak during puberty and gradually decrease with age. Exercise is the best natural method of increasing your IGF levels. We recommend either High-Intensity Interval Training (HIIT) or resistance training. Improving your sleep quality and avoiding alcohol can also benefit your IGF levels. 

How does cortisol affect muscle growth? 

Cortisol is the main catabolic hormone that can affect muscle growth. Cortisol is triggered by physical and emotional stress. It can start to break down your muscles when your blood sugar is low (people who enjoy endurance sports may have experienced its effects). But how can you minimise cortisol when training?  

The answer is simple - try to avoid lengthy cardio sessions. Unfortunately, exercises that cause GH to release, such as using heavy weights and large muscle groups, also stimulate high cortisol levels. But when completed in short-term durations, the cortisol can be helpful as muscles need to break down slightly to grow.  

Find a good balance to ensure you are not overtraining.  


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How to ensure your hormones aren’t affecting your muscle gain 

To summarise, you should try to minimise your catabolic hormone release by keeping the duration of your workouts shorter and making sure you are not excessively stressing your muscles.  

Aim to stimulate your anabolic hormones for muscle growth through weight training and HIIT cardio workouts.  

Ensure you also are fuelling your body right. Certain foods can affect your hormones. 

Top diet tips for your hormones include:  

  • Eating fewer carbs – can increase your growth hormone. 
  • Eating carbs before or during your workout – can minimise cortisol levels 
  • Fasting – when done safely, this can increase GH levels 
  • Eating protein after a workout – can keep your testosterone levels high 
  • Sipping a sports drink throughout your workout – helps to keep your glucose levels up 

Aside from diet and training movements, other less obvious factors could influence your hormone production and progress. So, we’ve put together some extra top tips to keep your hormones balanced when training. 

Top tips to enhance hormone production 

  1. Complete aerobic and anaerobic exercises on separate days as they each have distinct effects on the body - it is counterintuitive to do them in proximity and risk inflammation or high cortisol levels. 
  2. Try to get good quality sleep, as not only would you feel well-rested and ready to combat any workout, but your GH levels are stimulated during deep sleep. 
  3. Do weight training in the evenings rather than early morning for the best gains. Your cortisol levels tend to be at their highest soon after you have woken up. 

Other factors could be affecting your hormone production, such as health conditions. If you are struggling to gain muscle, then a health check such as our Ultimate Performance Blood Test or our Male Hormone Blood test could help you to determine any underlying conditions that may be affecting your progress.  

We also have more information on sports performance, from diet to supplements in our sports performance guide



  1. Speck, C. (2019) Master Your Hormones to Maximise Muscle Growth. [online] Fit Plan. Available at: [Accessed 08/06/20]. 
  2. Marcin, A. (2019) Catabolism vs Anabolism: What's the Difference? [online] Healthline. Available at: [Accessed 08/06/20]. 
  3. Wein, H. (2013) Understanding How Testosterone Affects Men. [online] National Institutes of Health. Available at:,estradiol%2C%20a%20form%20of%20estrogen. [Accessed 08/06/20]. 
  4. Rogers, P. (2020) How to Stimulate Hormones for Bodybuilding. [online] Very Well Fit. Available at: [Accessed: 03/06/20]. 
  5. Eriksson, A. (2020) Growth And Longevity: The Enigma And Potential Of IGF-1. [online] Breaking Muscle. Available at:,and%20accelerates%20recovery%20from%20injuries. [Accessed 08/06/20]. 


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