Exercise and Testosterone

This article comes from www.WebMD.com, May 2014.The author examines the ways that working out can help improve testosterone levels for men whose levels are not so low as to require medical intervention.

One of the points they mention, but do not explain, is that being overweight or obese can cause serious drops in T levels. This happens because fat cells both produce estrogen and have estrogen receptors, and the more estrogen one has, the less effective one's testosterone will be in relation.

If you want to serious improve your overall hormone levels, lose the bodyfat - do not accept it when doctors tell you 18% is healthy - it's borderline obese. And don't trust body mass index (BMI) to be a good indicator, either. You can have a BMI of 24-25 and still have 20% bodyfat.

For most men who are not athletes or competing in strength events, 12-15% bodfat is a good goal. 

One other point - the author mentions that weight training provides more return on investment for increasing T levels, but he didn't mention that long sessions of steady-state cardio can actually increase estrogen levels and reduce T levels. The best evidence of this is that endurance athletes, such as professional cyclists, are 20-50% below normal in their T levels during a 3-week race such as the Tour de France.

Does Working Out Affect Testosterone Levels?

By Eric Metcalf, MPH
WebMD Feature
Reviewed by Brunilda Nazario, MD

If you’re a man with low testosterone, exercise may help.

Doctors and fitness professionals still have a lot to learn about exercise and its effects on testosterone. Several factors besides your workout are involved.

But one thing is clear: You need to make exercise a habit in order to get the benefits.

After exercise, testosterone levels rise -- but not for long.  

"Sometimes it’s 15 minutes after exercise that testosterone is elevated. Sometimes it can be up to an hour,” says Todd Schroeder, PhD, who studies exercise and hormones in older men at the University of Southern California.

It's not yet clear what health effects, if any, these temporary boosts may have. Of course, exercise has many other well-known health perks.

For men who have low testosterone, exercise alone probably won’t raise their levels enough to make a difference in how they feel, says endocrinologist Scott Isaacs, MD, of Emory University. But he says for men whose testosterone level is on the borderline between normal and low, “I think it’s going to have a much more potent effect.”

4 Factors That Matter

Your weight, age, fitness level, and the timing of your workout all matter.

1. Your weight: Isaacs treats men with low testosterone. He sees obesity as a big part of the problem. If you’re overweight, exercise can improve your testosterone levels by helping you shed pounds, says Isaacs, the author of Hormonal Balance: How to Lose Weight By Understanding Your Hormones and Metabolism.

2. Your age: Older men seem to get less of a post-exercise boost in testosterone, Schroeder says -- though this needs more research. Still, exercise offers many other health benefits for older men, including bone and muscle health and better balance.

3. When you exercise: Your testosterone levels vary throughout the day. Levels are typically highest in the morning and lowest in the afternoon. Research has found that strength-training workouts may have a bigger effect on testosterone in the evening. As a result, the brief boost from your exercise session might be even bigger if you schedule it after work instead of early in the morning, Isaacs says.

4. Your fitness level: Not in great shape? If you start exercising, you maybe get a bigger, though still brief, boost in testosterone than a man who's already in good shape. But after a few weeks, your body gets used to the challenge. Eventually, you'll get a lower hormone response from the same workout, Schroeder says. 

All Types of Exercise Count

Endurance training and resistance training (such as weight lifting) both boost testosterone levels briefly, Schroeder says.

Lifting weights or doing other strength-training workouts has a bigger effect on your testosterone, Schroeder says. He says the following strategies will give you an even bigger boost in testosterone from your strength training workouts, which is backed up by research. 

• Use more muscles. (For instance, a full-body workout affects this hormone more than doing one exercise, such as biceps curls.)
• Lift heavier weights rather than doing many reps of light weights.
• Have shorter rest periods during your workout.

Still, you should build an overall exercise plan that also includes cardio and flexibility training, so you're helping your overall health.

Overdoing it, though, could backfire. Elite athletes (and amateurs who overtrain), can see a drop their testosterone level, which is a sign that they’re doing harm to their bodies. In these cases, they tend to have low testosterone and high cortisol, a stress hormone, Schroeder says. He notes that a rise in cortisol can be linked to a fall in testosterone. 

Signs of overtraining include:

• Excessive soreness
• Trouble recovering from workouts
• Trouble sleeping
• Losses in performance and strength

Give yourself enough time to rest between workouts, and eat healthfully to help your body recover after workouts.

Isaacs discloses that he is on the speaker’s bureau for Abbott Laboratories, which markets a testosterone replacement product. Schroeder reports no disclosures.