Listening to NPR the other morning on my way to class, I heard an interesting story about athletic recovery following endurance training. Instead of the typical carbohydrate-electrolyte beverages or water being handed to marathon runners after a race, they’re receiving chocolate milk! Although the entire nation seems to be up in arms about the sugar-overloaded milk products provided to children in elementary and middle schools, there is increasing evidence that athletes gain tremendous benefits in terms of endurance and muscle recovery from consuming these drinks post-race. Marathon runners are constantly “looking for the one drink that will help them feel better so they can run again” (Aubrey), and milk provides essential nutrients lacking from Gatorade and water alone.
In physiology, we learned that it’s the amount of calcium present in the post-ganglionic neuron at the neuromuscular junction, as well as its rate of replenishment, providing muscular endurance as opposed to the quantity of ATP or mitochondria in the skeletal muscle cells. If this is such a well-known fact, why haven’t we seen star athletes sweating out milk droplets in national campaigns sponsored by the American Dairy Association? Granted it doesn’t sound that appealing to gulp down a pint of milk as you sweat it out on the field in the mid-day sun (please allow me to reference Anchorman by stating that “milk was a bad choice”), the effects are more pronounced after strenuous exercise in preparation for the next workout. “Activity of caspase-3, the cysteine protease responsible for cleavage of the actomyosin protein in skeletal muscle” (Lunn) is reduced in subjects consuming milk post-exercise, according to a study published in Medicine & Science in Sports & Exercise. Overall, compared to consumption of a carbohydrate-only beverage following endurance exercise, consuming fat-free chocolate milk “significantly increased skeletal muscle protein synthesis, attenuated whole body proteolysis, and suppressed or maintained molecular activity of protein breakdown during recovery” (Lunn).
Although these findings may not translate as well during aerobic exercise, their impact on athletic training regimes could provide a significant advantage to lactose-tolerant athletes. They’ve also demonstrated that “compounds in cocoa inhibit the activity of the pancreatic lipase enzyme” (Aubrey), which prevents it from breaking down fat for transport and storage within the body. Endurance athletes usually have trouble consuming enough calories, but there’s a potential application for this finding to combat the childhood obesity epidemic. As long as the excess sugar and fat calories are taken out of chocolate milk, its consumption could help children receive the protein and calcium their developing bodies need without all the added calories. Not that anyone really needed an excuse to drink delicious, creamy chocolate milk, but this research sounds pretty appetizing to me.
References:
Aubrey, Allison. “What’s to Love and Loathe about Chocolate Milk?” The Salk: NPR. Web. Nov. 21, 2011. http://www.npr.org/blogs/thesalt/2011/11/21/142517141/whats-to-love-and-loathe-about-chocolate-milk Accessed: Nov. 22, 2011.
Lunn, W.R. et al. “Chocolate Milk & Endurance Exercise Recovery: Protein Balance, Glycogen & Performance.” Medicine & Science in Sports & Exercise. Web. Sept. 7, 2011. http://www.ncbi.nlm.nih.gov/pubmed/21904247 Accessed: Nov. 22, 2011.
It’s true that more athletes are turning to chocolate milk as a choice recovery beverage. But again, what makes milk better then commercial sports drinks? Like Erin explained, the endurance and ability of a muscle to contract efficiently is dependent on the amount of glycogen available in the muscle’s stores. It is from these stores that muscles derive the energy needed for contraction and is the reason for fatigue as glycogen stores are depleted (1). Once sufficiently decreased, the stores must been resynthesized before the muscle can contract efficiently, a process which can be influenced by the type, amount, and timing of nutrient intake (2). Taking this into account, studies have shown that consuming carbohydrates immediately after exercise can increase the rate of glycogen synthesis (2). Adding protein to the mix also has a positive effect on the rate of resynthesis and can decrease recovery time significantly (2).
ReplyDeleteSo how does chocolate milk hold up against sports drinks? Recent studies comparing the endurance capacities between of individuals who consumed chocolate milk with individuals who consumed sports drinks found significant differences. Thomas et al, who compared the endurance capacity of cyclist when they consumed chocolate milk to their performance when they consumed one of two sports drinks (carbohydrate or fluid replacement drink), found that individuals were able to cycle 51-43% longer when they consumed chocolate milk (2). Studies conducted by Karp et al produced similar results and found that cyclists who consumed chocolate milk had significantly greater time to exhaust and were able to exert a greater total amount of work during the endurance exercise then cyclists who used a carbohydrate or fluid replacement drink (1).
Still, before everyone starts dumping out their Gatorade and filling their jugs with milk, this may not be the best choice for everyone. These studies were conducted using athletes who needed to compete the next day and so needed to ‘jump start’ the recovery process. Taking that into account, consuming chocolate milk may not be a good choice for an individual wanting to loose weight. Individuals need to determine the reasons and goals for their exercise regime and whether it is to ‘get in shape’ or ‘compete like Lance Armstrong.’ One should always research and reflect on their own personal interests before jumping into the latest craze.
Karp, J., Johnston, J., Tecklenburg, S., Mickleborough, T., Fly, A., & Stager, J. (2006). Chocolate milk as a post-exercise recovery aid. International Journal Of Sport Nutrition And Exercise Metabolism, 16(1), 78-91
Thomas, K., Morris, P., & Stevenson, E. (2009). Improved endurance capacity following chocolate milk consumption compared with 2 commercially available sport drinks. Applied Physiology, Nutrition, And Metabolism = Physiologie Appliquée, Nutrition Et Métabolisme, 34(1), 78-82.
I find this interesting. I went on the internet to do some research. I found that the first reported use of chocolate milk during exercise was in the 2004 Summer Olympics by American swimmer Micheal Phelps. He was drinkin Carnation Instant Breakfast between races.
ReplyDeleteI think it is important to emphasize that drinking excess chocolate milk is ok when you are recovering from strenuous exercise. As stated previously, milk has higher levels of calcium and vitamin D that energy drinks do not have. It is important to remember that milk has a lot of sugar in it as well and so if you are just consuming large amounts that you are not burning these calories, it will be stored as fatty acids in your adipose tissue.
I think consuming milk is better than consuming energy drinks. It is more natural and it is cheaper as well. This means it is more likely that your family will spend money on milk versus energy drinks.
I also think milk might help you relax and that might also help with your recovery versus having an energy drink that will have caffeine in it and could prevent you from relaxing.
http://www.cbsnews.com/stories/2006/02/24/health/webmd/main1342839.shtml
Karp, J. International Journal of Sport Nutrition and Exercise Metabolism, 2006; (16: 78-91). "Nutrition and athletic performance -- Position of the American Dietetic Association, Dietitians of Canada, and the American College of Sports Medicine,"
While I myself happen to LOVE chocolate milk, I think it could be important to point out that while the calcium and vitamin D content in milk IS beneficial to those looking to relax or recover, all natural milk would be beneficial AND have less possibility of side effects. Some dairies inject their cows with recombinant Bovine Growth Hormone. This hormone boosts milk production but subsequently inflames the udders. This new problem is addressed by antibiotics, which can be found in trace amounts in marketed milk products. So before you drink a nice big glass and then go for a jog - you might wanna check what's in it first.
ReplyDeleteLee, Jean, and Randy Wei. "Milk, Doing Your Body Good?" The Journal of Young Investigators :: JYI.org. University of California at Berkeley, Sept. 2002. Web. 01 Dec. 2011. <http://www.jyi.org/volumes/volume6/issue3/features/lee_and_wei.htm