Courtesy of Daniel L. Carl, Ph.D.
Chocolate Milk – it’s hard to believe that those two simple words are stand alone in our great sport. Chocolate Milk. OK, so what do we know about chocolate milk? Why is Chocolate Milk relevant in the sport of swimming? Is it a fad? Is it simply cool and tastes great so we like it? Or is there some real physiological value behind one of the greatest beverages known to mankind. Let’s take a closer look.
We know that following an intense swim practice we drive down our muscle glycogen stores. And we know that the capacity of stored glycogen is limited to about 2 hours’ worth of work. Therefore, if we do not replace or fully recover our glycogen stores at an adequate rate, in theory, we will have a successive decline in storage and ultimately a failure in our ability to train or perform.
Well, back in the 80s research showed that ingestion of a high concentration of CHO accelerated the rate of return of glycogen stores if ingested during the first 2 hours following exercise. This acceleration was also seen during the subsequent 2 hours.
This was followed up in the early 90’s with research on a combination of CHO vs PRO vs a CHO-PRO mixture and the results indicated that the CHO-PRO mixture produced even faster recovery of the glycogen stores. So over the next decade, high concentrations of CHO along with Protein supplementation became commonplace in an effort to accelerate recovery. Ultimately the theory became that a combination of CHO and PRO typically at a ratio of 4:1 was the quickest and most efficient approach to recovery.
Fast forward to 2006 and our swimming friends at Indiana University. As it was told to me one day while they were sitting around in a lab meeting discussing the role of various proteins and combinations to enhance recovery, one of the participants remarked that the chocolate milk they were drinking contained the same ratio of CHO:PRO as being recommended in the expensive supplemental recovery drinks. Therefore it should work, right? Well, they tested it and yes, simply using a commercially available CM drink worked in accelerating recovery. Since then CM has been studied extensively in various forms and for the most part with success.
Now in fairness to all of the research, there have been reports that indicate that CM is not any more effective than regular CHO ingestion. In actuality, the research is pretty split on whether or not PRO, in general, is truly beneficial. And it should be noted that adding PRO to a CHO beverage will not improve performance. So please do not make the mistake of ingesting PRO during competition or practice. Its perceived benefits are in post-swimming recovery.
So, is CM beneficial as a post swimming workout recovery drink? There is plenty of research in support of CM along with some not so favorable. However, with regard to recovery CM has not been shown to be detrimental. Simply not any more advantageous. Therefore, I suggest drink up, do so as close to the completion swimming practice as you can, and always remember to eat healthy, well-balanced meals.
Suggested Reference Readings
Ivy JL, Katz AL, Cutler CL et al. Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion.
J Appl Physiol (1985). 1988 Apr;64(4):1480-5.
Zawadzki KM, Yaspelkis BB, Ivy JI. Carbohydrate-protein complex increases the rate of muscle glycogen storage after exercise. J Appl Physiol. 1992;72:1854–9.
Karp JR, Johnston JD, Tecklenburg S et al. Chocolate Milk as a Post-Exercise Recovery Aid. Int J Sport Nutr Exerc Metab. 2006, 16, 78-91
Daniel L. Carl Ph.D. Bio
Dan Carl is an Associate Professor of Exercise Physiology in the Department of Rehabilitation, Exercise and Nutrition Sciences at the University of Cincinnati. Dr. Carl also works as a Senior Coach and consultant with the Cincinnati Marlins and as head coach at Sycamore HS. Prior to his 13 years in Cincinnati, Dr. Carl worked 14 years as a Division I coach at Miami Univ., Univ. of Delaware, Ohio State Univ. and Valparaiso University.