Research You Can Use – Further refinements in sport drinks

When new sports science information is published that might be pertinent to the game, I like to alert the coaches because new data typically is published in a place that is advantageous to the author (promotion and tenure considerations), but not in a place where the information will impact the athletes and coaches. A recent study adds further data in the ongoing study of nutrition and physical performance. In the July issue of Medicine & Science in Sports & Exercise, the research team at James Madison University headed by Dr. Mike Saunders reported evidence that consuming a modest amount of protein in a sport drink during exercise increases endurance, reduce muscle damage, and enhances recovery. I have reported on similar findings for Soccer Journal, but this project had better experimental controls that make it more applicable to the practicing athlete.

Fifteen male cyclists completed a stationary ride to exhaustion while drinking either a conventional carbohydrate sports drink (Gatorade®) or a drink containing carbohydrate and protein in a 4:1 ratio (Accelerade®). The following day, the cyclists completed a second ride to exhaustion at a higher intensity, this time without drinking anything. Muscle damage (from serum CPK levels) was measured before the second ride and performance on both rides was determined (how long it took them to reach exhaustion). When reviewing articles that compare two products, ethical disclosure requires that the researchers declare whether they or this project has received money from one of the manufacturers to sponsor research. Dr Saunders and colleagues received no money from either product to conduct this study. You may have noticed that Soccer Journal has had advertisements for Accelerade® in the past.

On average, the subjects were able to cycle 29% longer in the first ride and 40% longer in the second ride when given the carb:protein drink. In addition, muscle damage (CPK levels) were 83% less when using the carb:protein drink.

According to Dr. Saunders, director of the Human Performance Laboratory at James Madison University, “This study provides further confirmation of the value of adding protein to a conventional carbohydrate-electrolyte sports drink. Our results suggest that athletes in all sports where endurance and recovery are critical would benefit from a protein-containing sports drink.”

Just how the addition of protein to a drink aids subsequent performance is not well understood. It is known that simply adding more carbohydrate to a conventional sport drink does not make it more effective. There seems to be a special interaction between carbohydrate and protein, but determining the specific nature of this mechanism will require further study. An increasing body of work suggests that carb:protein drinks work; the question is how they work.

There are two thoughts about how the addition of protein to a sports drink might reduce exercise-related muscle damage. The protein may raise amino acid levels in the blood. Elevated levels of blood amino acids have been shown to reduce muscle protein breakdown. The protein in the sports drink might also be used for energy during extended exercise, resulting in less breakdown of muscle protein as a source of energy that can occur when muscle glycogen levels are severely depleted.

Now, some might say that the carb:protein drink was successful because it had more calories than the carb alone drink, but I seriously doubt that the few extra calories as protein would lead to a 40% improvement in performance the next day. The math could be done…the extra calories needed for the next ride is far more than the extra calories added by the protein in the drink.

One of the problems faced in soccer is the short recovery periods between matches. Soccer is not scheduled as rigidly as is football. In scholastic or collegiate seasons, games could be played with 1-2 days rest. Club tournaments can have multiple games in the same day, so preparation for the next match really does begin right after the one just finished. You can’t rely on the players to make the best decisions regarding preparation during a short recovery window. One of my main mantras on recovery between matches or practices involves food choices and when the right choices are to be eaten after exercise. And if you aren’t paying attention to this 2nd most critical factor in performance (after physical training) and your opponent is, then your team is going into matches at a competitive disadvantage. I know of teams who, through booster clubs, have an ‘assistant coach for nutrition’ whose responsibility it is to make sure the players make proper food choices…these folks aren’t low carb types either! Parents and boosters may choose a low carb diet, but that would not be helpful for competitive athletes.

The interesting part of this project was that the diet after the first ride was standardized so the added work the next day was not due to eating lots more carbohydrate. The authors suggest that reduced muscle damage could at least partly explain why the cyclists given the carb:protein sports drink on day one were able to perform so much better than their counterparts on day two. This particular result has important implications for athletes who train hard every day, like your players do.

At this time, Accelerade is the only sports drink on the market containing the 4:1 ratio of carbohydrate and protein that has proven so effective in the new study and in previous studies. It should be used in the same way as a conventional sports drink. Players should consume 4-6 ounces every 12-15 minutes throughout each practice and game and an additional 8-12 ounces immediately after practices and games to further boost recovery