by Kevin Watanabe
You have heard it from everyone—the television, your doctor, even your mother—drink your milk! Now research is giving you good reason to bring milk with you to the gym.
In addition to being cheaper than many commercial sports drinks, low fat and nonfat milk has several beneficial qualities that may make it appealing to athletes:
- Milk naturally contains electrolytes that are lost through sweat during intense exercise. Researchers believe this may be one reason why athletes stay better hydrated when they drink milk instead of plain water.
- Milk contains carbohydrate to replace lost energy stores and protein that the body can readily use to rebuild muscle. The combination of the two nutrients may also help the body to take in the energy more readily.
- Milk also contains calcium—an essential mineral that many Americans do not get enough of through diet.
Milk for Strength Training
At least two studies have shown positive gains for athletes who are doing resistance training. One study, led by Sarah Wilkinson, tracked the rate of muscle building in eight athletes during two trials in which they consumed either nonfat milk or a soy protein drink with an equal amount of protein. The study found greater muscle protein gains in athletes during the milk trial than in the soy trial. The authors say this difference may be due to the specific types of proteins in milk, particularly the mix of whey, which is quickly absorbed, and casein, which is slowly absorbed.
A larger crossover study in the American Journal of Clinical Nutrition compared nonfat milk to a soymilk drink that contained an equal amount of protein. The study found that both fast-twitch muscle and slow-twitch muscle area increased greatest in the milk group. The significant increase in fat-free mass could be beneficial for both strength training and endurance athletes.
Milk for Endurance Athletes
Several studies have compared the effects of milk and carbohydrate replacement beverages on recovery for cyclists. Two similarly designed crossover studies found better recovery in cyclists who drank low-fat chocolate milk after a workout than in those who consumed a carbohydrate replacement beverage. The cyclists in both studies took one of the drinks immediately after exercise and again at two hours of rest. They then cycled to exhaustion four hours after the first bout of exercise. The average time to exhaustion was more than 50% greater in the chocolate milk trial than in the trial with the carbohydrate replacement drink. Both studies used chocolate flavored nonfat milk to increase palatability.
Milk as a Sports Drink
The research on possible performance gains from milk is promising. Even though all of the research on milk as a performance enhancing aid has been on adult males, it seems that it can be beneficial to all athletes. Nancy Clark, a registered dietitian and board certified specialist in sports dietetics, recommends milk to both endurance and strength training athletes as long as they are not lactose intolerant. She says, “milk is far more than just protein for building/repairing muscles. It’s also a fluid that replaces sweat losses, as well as a source of sodium, potassium and other electrolytes.” She adds that everyone needs calcium and vitamin D. Indeed, the National Health and Nutrition Examination Survey shows that men and women of all ages do not get the recommended levels of calcium. So despite the lack of research on groups other than adult males, a glass of low-fat or nonfat milk after exercise may benefit all.
Besides being a registered dietitian, Kevin is also informally trained as a motorcycle mechanic and judo instructor. He spends his free time helping with Tufts judo club and hanging out with his wife. Kevin is a grateful recipient of perfect grace.