Turn on your TV, page through the sports section of your local paper, or pick up any men’s magazine and you’re bound to see an ad describing the symptoms of low testosterone and how to fix it. While some medical conditions might require hormone replacement therapy, there’s a great deal you can do to maintain your testosterone levels.

“We can’t completely stop the natural aging process,” says Dr. Nicholas Ratamess, PhD in the Department of Health and Exercise Science at the College of New Jersey. Testosterone levels peak in adolescence and early adulthood then begin a slow decline of one to three percent per year as you roll into your mid-30s. The brain controls testosterone production and generally maintains normal serum values anywhere from 300-1000 ng/dL depending on your age and health status. While most of the press regarding testosterone focuses on muscle mass and sexual function, aging research clearly illustrates this hormone’s critical role in maintaining energy levels, mood, body fat, bone strength, and cardiovascular health over a man’s life.

Five keys to maintenance

• Maintain a healthy weight and a healthy waist size.

A recent study in the European Journal of Endocrinology followed 2396 men between the ages of 40 and 79 across Europe for almost five years. During that period, researchers gathered resting hormone levels along with details on changes in age, height, weight, waist circumference, medical conditions, medication usage, tobacco and alcohol use and physical activity levels. Then, they compared these variables with changes in testosterone levels. Other than age, body weight had the biggest impact on a man’s testosterone levels. “Weight gain was associated with suppression of testosterone,” reports EM Camacho, the primary investigator of the study. However, the news wasn’t all bad. “Losing five percent of weight was associated with a significant increase in testosterone, which increased further with additional weight loss,” Camacho adds.

“There’s a clear link between increasing body fat and low testosterone in men,” says Dr. Todd Schroeder, PhD. and Director of USC’s Clinical Exercise Research Center. As body weight and obesity increase, the hypothalamus secretes less of a hormone called gonadotropin releasing hormone (GTRH) resulting in changes in the production and secretion of testosterone. This problem is compounded by the impact of “fat cells producing leptin which directly suppresses testosterone production”, says Ratamess. As body fat increases, more leptin is secreted into the bloodstream. Over time, leptin resistance may occur resulting in further suppression of testosterone production. Data from the Massachusetts Male Ageing Study dramatically illustrates the impact of weight in that an increase of eight to 11 pounds reduces testosterone levels in men equivalent to 10 years of aging. Keep in mind that we are talking about increases in adipose tissue, not muscle.

Besides regularly looking at the scale, it’s also important to keep an eye on your waist size. Harvard Men’s Health Watch reports, “a four-inch increase in waist size increases a man's odds of having a low testosterone level by 75 percent.” Supporting this is a study by Dr. Johan Sartberg and his colleagues, who reported on the association between waist size and testosterone levels in 1548 men between the ages of 25 and 84. They found the lowest levels of testosterone in men with the largest waists, even after adjusting for age, overall body fat and lifestyle factors like physical activity and smoking. A good rule of thumb is your waist size should be about half your height, so, if you’re 6 feet tall, or 72 inches, you should shoot for maintaining your waist size at 36 inches.

• Get up and move

Whether you’re lifting heavy things, taking a walk or going for a bike ride, getting up and moving is key. “Long-term strength training does not appear to change resting totals and free testosterone,” says Jakob L. Vingren, PhD, CSCS, and Assistant Professor at the University of North Texas. Exercise is a key component in maintaining your weight along with your muscular strength and endurance over your lifetime. While acute elevations of testosterone occur during and immediately after an exercise session, this doesn’t result in an increase in resting levels. Changes are the result of shifts in fluid volume, not large scale testosterone secretion, but are important because “increases in these hormones are optimal for maximizing skeletal muscle anabolism and hypertrophy,” says Schroeder.

While resting testosterone levels do not increase with chronic exercise, “resistance training has been shown to up-regulate androgen receptor content for a few days following a workout,” says Ratamess. This enhances muscle cell’s sensitivity to testosterone enabling protein synthesis to continue to occur. “Increasing androgen receptors enables us to do better with less and maintain muscle mass and strength” says Schroeder.

• Get adequate rest.

Chronic sleep deprivation increases your chances of developing cancer, diabetes, depression, high blood pressure, heart disease, and now low testosterone. Researchers at the University of Chicago examined the impact of one week of sleep deprivation (subjects slept five hours/night) in ten healthy young men (average age = 24.3 years) and found a 10-15 percent decrease in their testosterone levels. “Chronic sleep curtailment is endemic in modern societies” and “the majority of daily testosterone release occurs in men during sleep,” adds Rachel Leproult, PhD, one of the authors of the study. However in addition to not replenishing circulating testosterone, lack of sleep also significantly increases the level of cortisol in the human body. While this hormone is essential for initiating fight or flight responses by stimulating glucose production and fat burning, it also increases protein catabolism. More importantly, chronically elevated levels suppress testosterone production.

• Manage your stress.

Researchers out of the University of Berkeley report that psychological stress impacts testosterone levels in two ways. First, spikes in cortisol suppress testosterone production at the testes. Then, to make a bad problem worse, stress hormones signal the hypothalamus to release Gonadotropin Inhibiting Hormone, further curtailing sex hormone production. Robert Josephs, PhD, Professor of Clinical Psychology at the University of Texas at Austin, says, “The hormonal axes that regulate testosterone levels and cortisol levels are antagonistic." As poorly managed stress levels increase, cortisol increases and testosterone decreases. Josephs adds, “effects of cortisol in both men and women are reversed when stress levels go down."

• Eat a healthy diet.

Skip the processed foods and shoot for high quality proteins (lean meats, nuts, eggs), lots of veggies, complex carbohydrates and healthy fats like olive oil and avocados. “Eating healthy is simple, but it’s not easy,” says Dr. Bryant Stamford PhD, Professor of Kinesiology and Integrative Physiology at Hanover College. To stay on track, make sure to plan your meals--including snacks. That way you know what you’re going to eat and you’ll always have it on hand when you need it. Keeping a diet diary is another strategy you can employ to track what you eat. Thanks to all the diet diary apps out there, it’s easier now than ever.
Recipe for peak values

Testosterone plays a huge role in a man’s health over a lifetime. In addition to maintaining muscle mass and sexual function, it plays a key role in sustaining your mood, bone density and even cardiovascular heath. To summarize our recommendations, “for the aging male to preserve testosterone, he needs lots of exercise, lots of good food, and lots of good sleep,” Stamford says.

References
1. Phone Interview 6/14 with Dr. Nicholas Ratamess PhD. in the Department of Health and Exercise Science at the College of New Jersey.
2. Camacho EM, Huhtaniemi IT, O'Neill TW, Finn JD, Pye SR, Lee DM, Tajar A, Bartfai G,Boonen S, Casanueva FF, Forti G, Giwercman A, Han TS, Kula K, Keevil B, Lean ME, Pendleton N, Punab M, Vanderschueren D, Wu FC; EMAS Group. Age-associated changes in hypothalamic-pituitary-testicular function in middle-aged and older men are modified by weight change and lifestyle factors: longitudinal results from the European Male Ageing Study. Eur J Endocrinol. 168(3):445-5, Feb 2013.
3. Phone Interview 6/14 with Dr. Todd Schroeder ,PhD. and Director of USC’s Clinical Exercise Research Center.
4. Travison TG, Araujo AB, Kupelian V, O’Donnell AB, and McKinlay JB. The Relative Contributions of Aging, Health, and Lifestyle Factors to Serum Testosterone Decline in Men. The Journal of Clinical Endocrinology & Metabolism. 92(2),545-555, February 1, 2007.
5. Harvards Men’s Health Watch. March 2011.
6. Svartberg Johan, von Mühlen Denise, Sundsfjord Johan, Jorde Rolf. Waist Circumference and Testosterone Levels in Community Dwelling Men. The Tromsø Study. European Journal of Epidemiology, 19(7): 657-664, July 2004.
7. http://www.nlm.nih.gov/medlineplus/ency/article/003707.htm
8. Vingren JL, Kraemer WJ, Ratamess NA, Anderson JM, Volek JS, and Maresh C. M. Testosterone Physiology in Resistance Exercise and Training – The Up-Stream Regulatory Elements. Sports Medicine; 40(12),1037-53,2010.
9. Leproult R and Cauter EV. Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men. JAMA; 305(21):2173-2174,2011.
10. http://www.berkeley.edu/news/media/releases/2009/06/15_stress.shtml
11. Phone Interview on 6/14 with Dr. Bryant Stamford PhD, Professor of Kinesiology and Integrative Physiology at Hanover College.