By Dr. Chantal Charo. Ever thought about drinking chocolate milk instead of whey protein post workout shake? Dr. John Ivy’s group from the University of Texas Austin have shown several benefits of drinking chocolate milk (CM) post workout for both casual and professional athletes. Dr. Ivy said that “The advantages for the study participants were more muscle and less fat, improved times while working out and overall better physical shape than peers who consumed sports beverages that just contained carbohydrates.” Why chocolate milk? Here’s a brief background explaining how the timing and composition of nutrients significantly 
influences exercise recovery. Why do you replenish with a “post work out meal” made of whey protein and a fruit after working out? Immediate post workout carbohydrate refeeds replenish the stores of muscle glycogen that has been depleted following heavy training and improve performance. Ingestion of protein post workout also improves recovery from heavy lifting. When it comes to Chocolate milk (CM), it recently been investigated as a potential post workout beverage that improves exercise recovery because of its carbohydrate to protein ratio and composition. Furthermore, CM has good taste, is cheap and is widely available making it a convenient alternative to popular alternative post workout recovery beverages such as whey protein. At least 2 published studies have reporter that post exercise consumption of CM was associated with improved peak tork and overall superior performance during subsequent workouts, compared to carbohydrates alone. Sarcolemnal disruption markers such as creatine kinase and myoglobin, impaired performance in subsequent training sessions and muscle soreness are significantly reduced whereas, muscle function is improved .In sports that require endurance, such as cycling, studies reported an increase in endurance of 54% in cyclists who drank CM post cycling session as compared to cyclists who drank commercially available recovery drinks such as Gatorade. Another study by Dr. Ivy’s group compared CM to commercial recovery drinks, and has concluded that chocolate milk drinkers had twice the improvement in maximal O2 uptake after four and a half weeks of cycling.
The carbohydrate composition of CM is sucrose, lactose and fructose corn syrup., whereas CM protein contains 778mg of the amino acid leucine, which plays a key role in de novo muscle synthesis. Several studies assessed the effect of CM on the protein metabolic response and found an increase in net balance of the amino acids they assessed. Chocolate milk is a good source of electrolytes, providing many of the same electrolytes that are added to commercial recovery drinks (calcium, potassium, sodium and magnesium) along with fluids to help rehydrate after strenuous exercise. Some research suggests that athlete rehydration and replenishment of electrolytes lost during sweat, is greater when CM is the beverage ingested, compared to commercially available recovery beverages. This is most likely due to milk’s 
essential electrolyte content and energy density. These essentials include potassium, sodium, magnesium and calcium. The loss of calcium is of particular concern since research suggests rigorous exercise may cause substantial calcium loss, which could increase the risk of stress fractures.
How do you incorporate CM in your diet? To meet the current recommendations for post-exercise carbohydrate intake a 165 lbs or 75-kg male would need to consume 2 to 3.5 cups of low fat CM. The amounts of carbohydrates and proteins contained in these volumes of low fat chocolate milk vary by brand, however on average, the carbohydrate content is 70 to 84 g and the protein content varies from 19 to 30 g.
References
- Thomas K, Morris P, Stevenson E: Improved endurance capacity following chocolate milk consumption compared with 2 commercially available sport drinks Appl Physiol Nutr Metab 2009, 34:78-82.
- Wojcik JR, Walberg-Rankin J, Smith LL, Gwazdauskas FC: Comparison of carbohydrate and milk-based beverages on muscle damage and glycogen following exercise Int J Sport Nutr Exerc Metab 2001, 11:406-419.14.
- Cockburn E, Hayes PR, French DN: Acute milk-based protein-CHO supplementation attenuates exercise-induced muscle damage. Appl Physiol Nutr Metab2008, 33:775-83.
- Watson P, Love TD, Maughan RJ, Shirreffs SM.. A comparison of the effects of milk and a carbohydrate electrolyte drink on the restoration of fluid balance and exercise capacity in a hot, humid environment. European Journal of Applied Physiology. 2008;104:633-642.
