It lurks inside. A hormone that hates your muscles and wants you to be fat.

This catabolic criminal is called cortisol, a hormone that rises with emotional, mental and physical stresses. And if this criminal isn’t stopped, the only thing that gets arrested is your development.

 Any type of stress can increase cortisol in your system, even weight training. As you strength-train, homroncortisol levels increase and the protein in your muscles is reduced. Even worse is overtraining, since overworking your muscles can actually cause muscle breakdown.
     “Think of cortisol as borrowing protein from the muscles,” says Emily Cooper, MD, a family and sports-medicine physician who heads Seattle Performance Medicine. “The problem occurs with athletes who never pay back the loan.”

What Is Cortisol?

Produced by the adrenal cortex, the steroid hormone cortisol (aka the stress hormone) is necessary for proper metabolic function, helping to control carbohydrate metabolism, cardiovascular function and inflammation. Problems occur when cortisol elevates beyond normal levels. Too much cortisol can lead to muscle breakdown, bone mass loss, weight gain and increased abdominal fat.
     Rising cortisol levels can cause muscle-tissue breakdown, as the protein released has its amino acids converted into glucose for energy. Cortisol also inhibits the synthesis of new protein, meaning no new muscle is being built.

Controlling Cortisol

Here are some key ways to help control cortisol.

Do not overtrain. Workouts should be completed within an hour, remembering to add intensity gradually. Symptoms of overtraining include muscle soreness, fatigue, moodiness and insomnia.

Rest your body between workout days. Do not work the same muscle groups multiple days in a row. “It takes about 48 hours for the body to recover from a heavy strength-training session,” explains Cooper. “If you work out within 24 hours of the initial session, the body stays in the muscle-breakdown stage.”

Watch your diet. “Overtraining is a nutritional deposit shortage,” states Cooper. She suggests eating multiple meals of high-quality protein, complex carbohydrates, fruits and veggies, monounsaturated fats and essential fatty acids. An article in Nutrition Research showed that restricting calories by 50% raised cortisol by 38%.

Get plenty of sleep. Make sure you get in eight hours per night.

Spike insulin levels post-workout. “Insulin interferes with cortisol and may enhance cortisol clearance from the body,” says Rehan Jalali, president of the Supplement Research Foundation. “Consuming a high-glycemic-index carbohydrate and protein drink after a work-out may help minimize excessive cortisol levels.”

Relax and avoid additional stressors. Minimize stresses in your life, such as job and family difficulties. Try learning breathing techniques, such as those taught in yoga.

Cortisol Blockers: An Action Plan

The following can help you in the battle against the stress hormone.

Phosphatidylserine (PS) This phospholipid is the supplement that’s best known for reducing cortisol. Studies have shown that PS can reduce cortisol levels by 20% or more. Take from 300–800 mg total of PS twice per day, before exercise and bedtime. The bedtime dose is important since weight?lifters can have higher levels of cortisol during sleep.

Vitamin C Studies have shown that vitamin C may lower cortisol and modulate stress. Take 1,000 mg per day in multiple doses before exercise, post-workout and at bedtime.

ZMA Zinc is involved in more than 100 enzymatic reactions so insufficient amounts of zinc can interfere with resting metabolism rate. Follow label recommendations and use before training and bedtime.

Epimedium (horny goat weed) Known for boosting sex drive, this herb is thought to work through modulation of cortisol, allowing enhanced exercise recovery. Take two or three times daily for a dosage of 250–1,000 mg total.

Magnolia Bark The Chinese have long used this herb to relieve stress and enhance energy. Take 250–750 mg of extract standardized to 1–2% honokiol and magnolol.
     As research continues, other supplements may be suggested, including Ginkgo biloba, DHEA, vitamin A and green tea.

And of course testing and monitoring your cortisol levels is key.