Good For You: Chocolate Milk

Consuming a small amount of protein immediately before or after regular resistance training leads to greater gains in muscle gain and strength, according to a research analysis published in the American Journal of Clinical Nutrition.

Led by Naomi Cermak, Ph.D., of the Maastricht University Medical Centre in the Netherlands, a team of researchers looked at studies on protein supplementation during weeks-long resistance-training programs. Their interest was to see if regular supplementation has the same benefit over time that one-time pre- or post-workout supplementation has been found to confer, namely, greater muscle resynthesis after exercise. Better post-workout resynthesis indicates more of a muscle-building effect from resistance training.

Cermak looked at 22 studies involving a total of 680 subjects. The studies they looked at lasted an average of 12 weeks, with an average of three resistance-training sessions per week. The subjects included young (age 23 or younger) and older (age 50 or older) subjects, and people new to resistance training as well as athletes who regularly did resistance training.

The results overwhelmingly supported protein supplementation. Young subjects had about an extra kilogram increase in fat-free mass over control groups who did the same resistance training but consumed a placebo rather than protein supplement. This was true even though all of the subjects ate more than enough protein in their regular diets to meet basic bodily needs.

The results were perhaps even more striking in older subjects – an average 38 per cent greater increase in fat-free mass and 33 per cent greater increase in one-rep leg-press strength for those in the protein groups compared to the control groups. As Cermak points out, increases in fat-free mass and muscular strength are especially meaningful at ages when people tend to lose muscle mass and, therefore, functional capacity. For older distance runners, maintaining muscle mass is a key part of preserving stride length.

Cermak told Runner’s World that her findings are pertinent to runners who include regular resistance training to supplement their primary activity of running. The average amount of protein consumed on training days in the studies Cermak analysed was 42 grams, or about 710 kilojoules of protein; this included protein eaten during normal meals. Cermak recommends chocolate milk as an easy-to-consume, real-world protein supplement. A cup of low-fat chocolate milk contains about 795 kilojoules and contains 8 grams of protein.


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