Chocolate Milk and Exercise Recovery

In February 2006, The International Journal of Sport Nutrition & Exercise Metabolism published a study indicating that chocolate milk was as good or better than commercial carbohydrate and protein-based sports drinks at helping athletes recover from strenuous exercise. Since then, the “conventional wisdom” in the endurance sports is that chocolate milk is the best post-workout supplement.

The study compared chocolate milk to two other sports drinks – a “carbohydrate replacement” drink (Endurox R4) and “fluid replacement” drink (Gatorade), and the methodology was pretty straightforward. The researchers had nine highly-trained male cyclists exercise to glycogen depletion at which point they discontinued all exercise and ingested equal amounts of either chocolate milk, Gatorade, or Endurox R4. The test subjects took another “dosing” two hours later and then rested for an additional four hours.

After the rest period was over, the nine test subjects “cycled to exhaustion” at a 70% VO2 max level. The researchers measured both time to exhaustion and total work performed during this ride and took blood samples immediately afterward.

The results were quite interesting. The chocolate milk and Gatorade subjects had significantly greater time to exhaustion levels than the Endurox R4 subjects. This was particularly unexpected given that chocolate milk and Endurox R4 had virtually identical levels of protein, carbohydrates, and electrolytes. And although Gatorade had no protein whatsoever, it seemed to enhance endurance recovery levels much better than Endurox R4.

By far the key factor in the case of chocolate milk might be something which is often considered to be a pariah among recovery supplements – namely fat content. The only significant difference between chocolate milk and Endurox R4 seemed to be the level of fat. Chocolate milk had almost four times the amount of fat than Endurox R4. And Gatorade, of course, had no fat at all. In fact, the researchers concluded accordingly:

The greater fat content of the chocolate milk may have increased circulating free fatty acids in the blood, delaying glycogen depletion and allowing for an increased time to exhaustion. Alternatively, the fat content of the chocolate milk may have delayed glycogen resynthesis and decreased time to exhaustion due to a decreased gastric emptying rate and a consequent decreased carbohydrate absorption rate. It is possible that the use of non-fat chocolate milk may have yielded an increased time to exhaustion compared to FR.

So the jury is still not out on whether or not fat consumption was the factor key to endurance recovery in this scenario. However, it’s high time that the endurance sports community (and the general public as well) pays more attention to the role that fat plays in exercise recovery – as well as in maintaining optimal health overall.

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