Endurox, Myoplex, Accelerade — the grocery store touts all sorts of fancy sounding protein energy shakes, drinks and mixes that promise to aid recovery and keep you performing at your best. But exercise scientists may have identified a better option for endurance athletes looking to optimize their game: the humble chocolate milk.
In a recent study in the Journal of Strength and Conditioning Research, researchers found that athletes who consumed chocolate milk (which contains a mix of carbohydrates and proteins) immediately after exercise performed better in a later exercise session than those who had a carbohydrate-only drink.
“There may be an advantage to consuming carbohydrate and protein together,” said Michael Saunders, an exercise physiologist at James Madison University in Virginia who was not involved in the study. Athletes have known for the last 30 years that consuming carbs after exercise can help them perform better the next time they train or race. This is one of a number of recent studies that suggest a small amount of protein can further boost performance.
To conduct the study, researchers at the University of Texas, Austin (UT) had ten trained cyclists and triathletes — five men and five women — come into the lab after fasting overnight. They cycled for an hour and a half at a high intensity and then drank one of three different beverages: chocolate milk, a carb-only drink with the same number of calories or a zero-calorie placebo. All drinks were designed to taste identical so athletes couldn’t identify which beverage they were drinking. After recovering for four hours, the athletes had to cycle 40 kilometers as fast as they could. Researchers chose the 40-kilometer time trial to most closely simulate a sporting event, said co-author John Ivy, a UT exercise scientist.
Athletes repeated the whole procedure three times, at least a week apart, so that everyone had a chance to perform with each of the three beverages. Researchers found that athletes who drank chocolate milk completed the 40-kilometers 7 minutes faster, on average, than when they drank either the carb-only drink or the placebo (a typical finish time was 80 minutes).
Multiple studies on protein-laden exercise drinks have shown similar results, particularly in athletes who complete intense training sessions on the same day. “When performances are less intense or done a day apart, the benefit seems to be less pronounced,” said lead author Lisa Ferguson-Stegall, an exercise physiologist now at the University of Minnesota Medical School.
But exactly how protein boosts performance is still under debate. Some studies have suggested that the additional protein reduces damage to the muscle or lowers the inflammatory response to a hard bout of exercise. The UT researchers didn’t find any difference in damage or inflammation — but they did notice an increase in protein synthesis in athletes who drank the chocolate milk.
According to Ferguson-Stegall, the body’s exaggerated protein production could provide more energy for activity. Alternatively, more protein could slow down the emptying of nutrients in the stomach, acting as a sort of time-release capsule and providing a steadier stream of fuel.
The specific kinds of proteins in chocolate milk may also have some performance-boosting benefits, according to Ferguson-Stegall. Chocolate milk contains two different types: whey, which the body breaks down quickly, and casein, which the body digests more slowly.
“It’s a nice mix of different rates of proteins being absorbed and being used by the body,” said Ferguson-Stegall. In addition to this protein-mix, the extra burst of energy from the added sugar makes chocolate milk an even better option than plain milk. And these benefits far outweigh the potential perks of chocolate or caffeine (commercial chocolate milk contains negligible amounts cocoa and caffeine).
While the study tested elite athletes who are used to hours of daily training, Ferguson-Stegall sees broader implications for the finding.
“You don’t have to be a highly trained athlete to benefit from this,” said Ferguson-Stegall. Whether you’re a recreational jogger or a weekend warrior, she said, drinking chocolate milk is a widely accessible, cheap and effective way to recover from exercise.
Saunders, however, warned that the average person should not try to emulate the diet of elites. “It’s really a myth that you need to eat like an athlete,” he said.
While elite athletes may often consume a 500-calorie energy drink after a training session, “if you’re somebody who’s going to the gym and jogging for two miles on a treadmill, you don’t want to consume a 500-calorie drink of anything,” Saunders said. He recommends that people only partially replenish the calories lost during exercise, focusing instead on drinking water to stay hydrated.