There’s no doubt that men have an easier time building lean body mass than women. One explanation is hormonal differences, especially differences in testosterone production. Testosterone is the main anabolic hormone that stimulates muscle growth. It exerts its effects primarily by increasing muscle protein synthesis.
Men get most of their testosterone from Leydig cells in their testicles that produce it. Even though women lack testicles, their adrenal glands produce testosterone but far less than men produce. In fact, men produce about 15 to 20 times more testosterone relative to women. What role does testosterone play in muscle development in women and how can women hope to build lean body mass with such low levels of testosterone?
Testosterone – The Master Hormone for Building Lean Body Mass
Testosterone not only boosts muscle protein synthesis directly – it has indirect effects by its interactions with other anabolic hormones like growth hormone. It also influences neurons that innervate muscle fibers, boosting their ability to generate force and grow larger. There’s little doubt that testosterone plays an important role in muscle growth and development. Yet, many women are still able to build strength and muscle mass through weight training that emphasizes progressive overload. How does this come about?
Testosterone Response in Women
As mentioned, women have some testosterone circulating in their bloodstream, thanks to their adrenal glands, but their levels are lower than a man’s. The amount of testosterone a woman has circulating in her bloodstream varies with her menstrual cycle and the time of day. Testosterone levels are usually higher around the time a woman ovulates and in the early morning hours. Some women have a condition called polycystic ovary disease where they produce more testosterone. These women typically have an easier time building muscle relative to women without this condition.
Research shows that men experience a rise in testosterone levels after strength-training and after high-intensity cardiovascular exercise. The amount of testosterone released is related to the intensity of the exercise. Some research shows that women also experience a slight rise in testosterone after an intense workout. Other studies show no change. If women do get a boost in testosterone after a high-intensity workout, it’s not as pronounced as in men. On the other hand, some studies suggest that women who resistance train regularly have an increase in free testosterone. Free testosterone is testosterone not bound to a protein carrier and the form that has biological activity. On the other hand, long periods of endurance exercise like long-distance running suppresses testosterone production in both men and women.
So How Do Women Build Lean Body Mass?
As you can see, women are at a disadvantage from a hormonal standpoint, at least in terms of testosterone, when it comes to building strength and muscle mass. Fortunately, other hormones like growth hormone have anabolic activity, and women have higher growth hormone levels than men naturally. In addition, resistance training enhances the activity of growth hormone in women.
To get these benefits you’ll need to lift heavy to fatigue the muscle. Muscle endurance workouts don’t have the same growth hormone stimulating benefits. Likewise, high-intensity, short duration aerobic exercise that causes a build-up of lactate raises growth hormone levels. Growth hormone has other benefits as well – it helps with tissue repair and recovery and boosts fat burning.
What Does This Mean?
Women have a more difficult time building lean body mass because they have less free testosterone to boost muscle growth. On the other hand, they have the benefits of growth hormone, another anabolic hormone. So, if you want to enhance your lean body mass and become stronger, maximize growth hormone release by doing high-intensity exercise and lifting heavy. Growth hormone is also released during the deep stages of sleep, so get seven to eight hours of sleep each night to support muscle growth. Both growth hormone and testosterone declines with age. That’s why it’s important to maintain the intensity of your workouts while still allowing adequate rest and recovery time.
The Bottom Line?
Take advantage of growth hormone and try to maximize it if you want to get leaner while increasing lean body mass. Lift hard and don’t skimp on sleep and you’ll keep growth hormone working for you.
Am J Physiol Endocrinol Metab. 2006 Dec;291(6):E1177-87.
Science Daily. “Varying Weight Training Intensity Increases Growth Hormone in Women”
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Essentials of Strength Training and Conditioning. Baechle and Earle. Second edition. 2000.
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