The Hidden Factor Hindering Your Muscle Growth

STACK Expert Jim Carpentier explains the harmful effects of the stress hormone cortisol and enumerates several steps athletes can take to combat them.

When your body is under stress, the stress hormone cortisol is released. While it confers some benefits, such as adaptation to stress and reduced inflammation, cortisol, left unchecked, is like an unblocked linebacker going for the quarterback. Over time it can weaken your immune system, limit muscle gains and even cause your muscles to break down.

RELATED: Cortisol: The Hormone Inhibiting Your Workout Gains

Athletes seeking to maximize size and strength need a defensive strategy to manage and minimize cortisol's catabolic (muscle tissue breakdown) effects.

The Basics

The Hidden Factor Hindering Your Muscle Growth

The body's adrenal glands naturally release cortisol in response to physical, emotional and psychological stress. Its primary role is to help mobilize the body's energy. According to Edmund R. Burke, Ph.D., author of Optimal Muscle Recovery, it does this by speeding up protein breakdown in the muscles and diverting amino acids that synthesize protein from the muscles to the liver. "That is why individuals involved in strength training may experience a decrease in muscle mass if they do not take the necessary steps to reduce the release of cortisol and rebuild muscle protein," he says.

Excessive cortisol is also associated with sleep deprivation, overtraining, dehydration, and skipping meals (especially breakfast).

RELATED: The One Thing You Need to Do to Build Muscle

Here are some guidelines to effectively control cortisol levels and optimally create an anabolic (muscle-repairing and muscle-building) environment:

Exercise to lower stress and simultaneously build muscle

Dave Tuttle, author of 50 Ways to Build Muscle Fast, writes that, "[t]oo much worrying can literally make you sick. Muscle growth, of course, requires a healthy immune system. When anabolic forces predominate in the body, growth is maximized. When stress rears its ugly head, however, the body responds by releasing the catabolic hormone cortisol." He adds that stress can reduce muscle growth or even stop it altogether, and that exercise is among the ways to decrease stress and anger. The right amount of exercise is key for stress reduction and building muscle.

RELATED: 5 Things That Happen When You Work Out for Too Long

Prevent overtraining

Tired Athlete

High-intensity weight training is like the proverbial two-edged sword. When performed in moderation with sufficient recovery, it indeed lowers mental stress—releasing mood-boosting endorphins—while also building muscle. Overdoing weight training, especially when it is combined with aerobic exercise, sports practices and games, however, is counterproductive, causing fatigue, muscle and joint inflammation, and continuous muscle breakdown, nullifying muscle building.

The remedy: Perform short and infrequent workouts that boost strength and increase overall ability for other physical activities, as advocated by Ellington Darden, Ph.D., author of The New High Intensity Training. "It takes very little high-intensity training to stimulate growth. Never do more exercise when you can get better results from less," he adds.

Other strategies to prevent overtraining include workouts under an hour, high-intensity full-body workouts just two or three times a week on non-consecutive days, and low-intensity active recovery activities on non-lifting days (e.g., taking a Yoga class, doing brisk walking or low-impact/low intensity swimming or bicycling). In other words, practice moderation and balance.

Sleep less and lose muscle

Poor Sleep

Athletes and non-athletes alike often don't realize that muscles don't grow the weight room, but rather during periods of deep sleep. At least 8 to 9 hours of complete recovery following high-intensity workouts is optimal for muscle repair and growth to occur. "One night of poor sleep and you already disrupt your cortisol production. Miss as little as two hours of sleep for three nights and you increase your cortisol levels by 50 per cent," says Shawn Talbott, Ph.D., author of The Cortisol Connection. The reason: The body reads sleep deprivation as stress and elevates cortisol to deal with it.

Stay hydrated

Hydration for Athletes

Water is an essential yet frequently overlooked promoter of muscle function and growth—muscles are about 75 per cent water. Thus, keeping a water bottle handy throughout the day and drinking about 2 liters (6-8 glasses)—and also consuming water-based foods such as fruits and vegetables—helps your muscles look fuller and keeps cortisol levels down. Also note: the hotter summer months increase the need for adequate hydration to replace water lost from perspiration. Be aware that even slight dehydration increases cortisol levels, impacting exercise and sports performance, according to a University of Barcelona study. How to tell if you're hydrated? A general gauge is urine color. It should be clear or light yellow.

Avoid skipping meals


Recall what happens when you're sleep deprived: Cortisol levels rise and muscle gains drop. These same things result when you deprive yourself of muscle-building meals during the day and for longer hours overnight during sleep! Klaus Arndt and Judd Biasiotto, Ph. D., authors of Anabolic Training, suggest making a muscle-building breakfast comprising protein and complex carbohydrates a priority after being in a catabolic state while sleeping eight hours—the longest period of time going without food. "Only with a fresh supply of nutrients can your system continue to regenerate and build muscle," he says.

Bottom line: If you seek more muscle, heading to the gym without breakfast is just as contraindicated as shortening overnight sleep to allow time for exercise before school or work.

In addition, don't skimp on calories after breakfast so you stay in the anabolic mode. Consuming at least five to six smaller meals per day (spaced about two to three hours apart) consisting of complex carbohydrates and high-quality protein helps continually fuel muscles between workouts while keeping catabolic cortisol away. And be sure to have a higher carbohydrate to protein ratio meal immediately after a workout (e.g., banana and chocolate milk) to optimally boost recovery and rebuild muscle tissue for growth.

Vitamins and minerals conquer stress


Consuming a balanced diet containing ample amounts of vitamin- and mineral-rich carbohydrates, protein, and beneficial fats is not only required for building and repairing muscle following strength training, but also for lowering cortisol-induced stress. Asheville, North Carolina-based chiropractor and health and wellness writer Dr. Tracey Roizman, D.C., advises consuming vitamins B, C and D and magnesium-rich foods and beverages to fight stress and diminish cortisol. And, here's a great way to get both vitamin D and a natural dose of the anabolic hormone testosterone: Perform workouts outdoors in sunlight! Testosterone is also released from vitamin D, the "sunshine" vitamin.


  • Burke, Edmund R., Ph.D., Optimal Muscle Recovery. (Avery Publishing, 1999), pp. 40-41.
  • Tuttle, Dave, 50 Ways to Build Muscle Fast. (Avery Publishing, 2000), pp. 103, 155.
  • Darden, Ellington, Ph.D., The New High-Intensity Training. (Rodale, Inc., 2004), p. 90.
  • Lesley Rotchford, "The Secret to Middle Management," Shape Magazine,  January/February 2016. p. 86.
  • Journal of the American College of Nutrition, April 2012, p. 31.
  • Biasiotto, Judd, Ph.D. and Arndt, Klaus, Anabolic Training. (Solaris Corp, 1996), pp. 21-22.
  • Tracey Roizman, D.C., "Vitamins That Help Balance Cortisol," (August 27, 2013).

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