Drinking water to stay hydrated is usually associated with images of sweltering heat and long bouts of endurance. However, as the rain signals the beginning of fall and the upcoming winter storms, athletes need to stay hydrated to optimize their strength, not just their endurance.
A 2008 study out of the University of Connecticut’s Human Performance Laboratory examined healthy, resistance trained males in 3 different states; hydrated, slightly dehydrated (signaled by a loss of 2.5% body weight in water), and dehydrated (loss of 5%). The study found that the dehydrated individuals had higher levels of cortisol, a hormone that is a marker for stress, and lower levels of testosterone, a hormone responsible for much of the growth in strength and muscle size after exercise. Such detriments were even greater among individuals in the more dehydrated state.
So these trained males’ response to lifting weights was normal; an increase in stress hormones, particularly cortisol. This catabolic environment from the stress of exercise is normally balanced by an increase in testosterone, a marker of the anabolic process that allows the body to respond to the stimulus of resistance training. These normal responses were both negatively affected by even a slightly dehydrated condition.
For you power athletes (see Sparta Point 12/31/08), such as anyone not involved in cross country, you do not need to be drinking water for endurance or cramping (see Sparta Point 2/17/10). But water will help you reap more benefits from a set of sprints or lifting.
Go ahead; tip your glass of water more often, about half an ounce for every pound of body weight. It is one of the cheapest ways to improve hormone levels without testing positive.