Chocolate Milk: The New Sports Drink?
Study Shows Chocolate Milk May Help Athletic Performance
WebMD News Archive
Feb. 24, 2006 -- During a 2004 Summer Olympics awash in controversies over
steroids and supplements, one sportswriter wryly noticed that top American
swimmer Michael Phelps was playing it safe -- he preferred to drink Carnation
Instant Breakfast between races.
Now it appears that the six-time gold medalist may have been onto something.
A new study shows that plain old chocolate milk may be as good -- or better --
than sports drinks like Gatorade at helping athletes recover from strenuous
The study, published in the International Journal of Sport Nutrition and
Exercise Metabolism, was small in scale; it was partially funded by the
dairy industry. But dietitians say the study should help to counter the notion
that high-tech, expensive supplements are better than whole foods when it comes
to athletic performance. They also note that milk contains key nutrients, such
as calcium and vitamin D, in quantities that sports drinks can't match.
"[Milk] is a sports drink 'plus,'" Keith Ayoob, EdD, a registered
dietitian and associate professor of pediatrics at the Albert Einstein College
of Medicine, tells WebMD. "It will supply you with things you need whether
or not you're working out."
The study builds on findings that intense endurance exercise reduces the
muscles' supply of stored glucose, or glycogen, a key source of fuel for
exercise. To maximize glycogen replacement, the American College of Sports
Medicine and the American Dietetic Association recommend taking in a serving of
carbohydrates within 30 minutes after a long and vigorous workout.
Milk vs. Sports Drinks
Common sports drinks such as Gatorade supply those carbs, as well as fluids
and electrolytes lost through sweat. However, more recent research suggests
that adding protein to the mix may further hasten recovery. Hence the new wave
of drinks such as Endurox R4 that include protein as well as higher doses of
In the study, nine male cyclists rode until their muscles were depleted of
energy, then rested four hours and biked again until exhaustion. During the
rest period, the cyclists drank low-fat chocolate milk, Gatorade, or Endurox
R4. During a second round of exercise, the cyclists who drank the chocolate
milk were able to bike about 50% longer than those who drank Endurox, and about
as long as those who drank the Gatorade.
The findings suggest that chocolate milk has an optimal ratio of
carbohydrates to protein to help refuel tired muscles, researcher Joel M.
Stager, PhD, Indiana University kinesiology professor, tells WebMD.
But the most puzzling result of the study, experts say, was why Endurox --
which has the same carb-to-protein ratio as the chocolate milk -- fared so
poorly. Researcher Jeanne D. Johnston, MA, tells WebMD it may have to do with
the different composition of the sugars in the milk. Another theory is that the
sugars in the milk may be better absorbed in the gut than those in the
Edward F. Coyle, PhD, a researcher on exercise and hydration at the
University of Texas, tells WebMD the trial would have been stronger if the
researchers had also tested the effect of flavored water or another dummy
The study was partly funded by the Dairy and Nutrition Council, an industry
group. Coyle says that the study's reliance on industry funding is not unusual
in the world of sports research, as federal funding for such research is hard
to come by.