The following is an advocacy article for Chocolate Milk as a recovery aid for athletes. It’s a guest piece by my friend and colleague Peter Curcio, a registered dietitian, trainer, and Olympic weightlifter. I really like that he isn’t just another dietitian. Because he also competes in the sport of weightlifting (lucky for me, as a member of my team) his ideas stem from both a place of research AND practical experience.
It is nearly impossible to arrive at conclusions that are both useful and nuanced without experience in both. If only research, then you lose sight of what is important on the platform, field, court, etc – too many researches have no clue at all. However, if you have only “real-world” experience, then you develop a profound blindness to subtly. (See my article on Coaches as Scientists to get a broader view of what I’m talking about.)
Peter’s got both sides … that and a powerful appetite for chocolate chip protein pancakes! (Seriously, it’s unreal.)
Make sure that you leave a comment and I’ll get him to answer any questions you’ve got.
For Strength Athletes, Milk Mustaches Are More Than Just Cool
By: Peter Curcio, RD, USAW
For every athlete (and, let’s face it, we’re all athletes in one form or another), strength is all about recovery. Literally. After an intense workout or training session, muscles need to be replenished with nutrients to help them not only refuel but grow bigger and stronger. Chocolate milk is a great way to facilitate this process.
For several years, scientists have looked at chocolate milk in the context of endurance athletes (e.g. cyclists, long-distance runners) undergoing varying intensities of training to see what effect chocolate milk has on increasing the rate of glycogen repletion following the workout.
Glycogen is your body’s fuel, sort of like gasoline in a car. More specifically, it’s the storageform of glucose (most commonly called “sugar” or “carbohydrate”), and it’s found predominantly in muscles and the liver. When you exercise, your body breaks down glycogen like a madman, freeing up glucose to be used by your muscles. When the gas tank in your muscles starts to get low, more glucose is pulled in from the bloodstream.
This would be all fine and dandy, except that if muscles started monopolizing the glucose in the bloodstream, you could experience some potential lightheadedness and the shakes. You might even get a little crabby (I know I sometimes do, according to my lovely girlfriend). That’s called low blood sugar (or hypoglycemia). Fortunately, your liver immediately kicks into gear, breaking down its own glycogen to keep blood sugar relatively stable.
In other words, your body uses glucose for energy, and its stored in the form of glycogen primarily in muscle and the liver. When your muscles start to use up all their glucose and begin to siphon it from the blood, the liver uses its own glucose to maintain equilibrium.
At the end of an intense workout, glycogen levels (i.e. the “gas tank”) can be very low. For optimal recovery, athletes need to get more glucose! The easiest way is through a beverage, which is substantial enough to give the body what it needs without leaving behind any uncomfortable “full” feeling that might occur after eating a full meal.
Simple, Yet Effective
At this point, many of you may be asking yourself, “Why chocolate milk? Why not just regular milk?” It all comes down to sugar. A cup of chocolate milk has about 28 grams of sugar compared to 13 grams in regular milk. The extra sugar is a plus in this context (i.e. post-workout) since it can easily be used by the body to replenish both muscle and liver glycogen.
Now, many of you reading this prefer to get down with the heavy stuff, and you may be wondering why I’m going on and on about endurance athletes. It turns out that although it may not be as significant, glycogen depletion happens when you’re lifting weights, too.
Think of it this way: your muscles (and your brain!) have to work hard to lift heavy weights up and then put them down again. They’re tearing through glucose like it’s going out of style. Train hard enough and for a long enough time and you’ll definitely feel your fuel gauge go from “Full” to “Half-Full” or even lower. Given that, getting a form of carbohydrate into your system soon after working out is important to kick start the biological equivalent of refilling your gas tank.
Save The Best For Last: Protein
Milk contains two types of protein, casein and whey. You may recognize these as the primary components in a variety of protein powders. They are both considered to be complete proteins, containing in the proper proportions all the essential amino acids (the building blocks of proteins) that the body cannot make and must get from food. They are also very highly bioavailable,making them easy for the body to digest and absorb.
Whey is considered a fast protein. In other words, it just about flies through your stomach and into your intestines where it can be digested, absorbed, and shuttled off to the muscles that need it. Casein, on the other hand, is a slower-acting protein. It tends to clump up and hang out in the acidic environment of the stomach, making its transit time to the intestine a bit longer when compared to whey.
Fortunately, the combination of a fast and a slow protein allows for more efficient utilization (i.e. more protein is accessible by your body for a longer period of time). In fact, this seems to be another shining feature of milk. Since the proteins in milk are not broken down into their constituent amino acids ahead of time like you see in some protein powders (e.g. whey hydrolysate), the body actually has to spend some time doing the work of digesting them.
This is actually a good thing, despite being contrary to what many of you have read. It’s generally been thought that delivering hydrolyzed protein – a technical name for protein that has been broken down into its individual amino acids – directly after training would garner the greatest increase in muscle recovery and growth, since it’s easier for the body to absorb. While this is true – amino acids and small protein fragments called peptides do in fact get absorbed more quickly than a “whole” milk protein – they are also processed just as rapidly. In other words, muscles have only a brief amount of time to receive the influx of amino acids from the bloodstream before they are broken down further and whisked away to the kidneys to be excreted.
To sum up, milk supplies not only a high-quality protein but one that is in its whole form, which the body can utilize – and reap the maximum benefit from – over a longer period of time.
Some Other Considerations
The fat content in milk also seems to help extend this window of opportunity. Generally speaking, fat, like casein protein, is more slowly released from the stomach and into the intestines. That’s why a meal higher in fat seems to sit in your stomach for a long time. Fat and protein both help to slow down the rate of digestion. In fact, many dietitians recommend mixed meals (containing a little bit each of carbohydrate, protein, and fat) for exactly this reason. In the context of post-training recovery, having a little bit of fat in your chocolate milk may actually help give the body that extra bit of time it needs to utilize as much protein as possible.
In fact, one research study by Elliot and colleagues showed that between two isocaloric servings – meaning they both had the same calories – of fat-free and whole milk, the extra fat in whole milk resulted in more protein being retained by the body. This was despite the fact that there was less protein in the whole milk!
As you can see, the value of chocolate milk lies in the properties of its inherent macronutrients (carbohydrates, protein, and fat) as well as its practical applications. It’s relatively affordable, tastes pretty darn good, and is a convenient post-workout recovery beverage that won’t leave a heavy feeling in your stomach. If you have problems with lactose, there are even lactose-free varieties of chocolate milk out there, and even enzymes that are available to help break up lactose and make it easier on your digestive system.
Although it may not be for everyone, chocolate milk works. And, for many, it’s an alternative worth checking out.
- Aragon A. An Objective Comparison of Chocolate Milk and Surge Recovery [Internet]. [cited 2011 Sep 8];Available from: http://www.bodyrecomposition.com/muscle-gain/an-objective-comparison-of-chocolate-milk-and-surge-recovery.html
- Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrère B. Slow and fast dietary proteins differently modulate postprandial protein accretion. [Internet]. 1997 Dec; http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=25140&tool=pmcentrez&rendertype=abstract
- Elliot T a, Cree MG, Sanford AP, Wolfe RR, Tipton KD. Milk ingestion stimulates net muscle protein synthesis following resistance exercise. Medicine and science in sports and exercise. 2006 Apr;38(4):667–74.
- Farnfield MM, Trenerry C, Carey K a, Cameron-Smith D. Plasma amino acid response after ingestion of different whey protein fractions. International journal of food sciences and nutrition. 2008 May;60(September):1–11.
- Karp JR, Johnston JD, Tecklenburg S, Mickleborough TD, Fly AD, Stager JM. Chocolate milk as a post-exercise recovery aid. International journal of sport nutrition and exercise metabolism. 2006 Feb;16(1):78–91.
- Lacroix M, Bos C, Léonil J, Airinei G, Luengo C, Daré S, et al. Compared with casein or total milk protein, digestion of milk soluble proteins is too rapid to sustain the anabolic postprandial amino acid requirement. The American journal of clinical nutrition. 2006 Nov;84(5):1070–9.
- Roy BD. Milk: the new sports drink? A Review. Journal of the International Society of Sports Nutrition. 2008 Jan;5(Table 1):15. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=25140&tool=pmcentrez&rendertype=abstract