It’s well established… physical activity requires strong, healthy muscles. When people exercise on a regular basis, their muscles experience a continuous cycle of muscle breakdown (during exercise), remodeling and growth,especially with weight-training and weight lifting.
Athletes have long used methods to enhance the cycle of physiologic responses to increase muscle growth. The use of high-quality, high-protein beverages and supplements during and after exercise has become well accepted and popular. Dairy-based whey proteins being are a favorite.
Several studies have shown and documented beneficial effects of protein supplement consumption.
The effect of the essential amino acid – leucine naturally present in these products as part of the protein’s typical amino acid profile is very important.
Two reports, published in the September 2011 issue of The American Journal of Clinical Nutrition report the results of two independent studies conducted to understand better how amino acids influence protein synthesis in athletes.
According to the ASN researchers “These studies, and others like them, help us understand and apply something we all inherently know: the human body works in a complex, yet completely logical way! It makes good sense that consuming a food containing high-quality protein during and/or immediately following exercise would help muscles get stronger. Muscle strength doesn’t just happen on its own; our muscles need to be both encouraged with exercise and nourished. Now we have even more scientific proof for this common-sense concept.”
In the first study, researchers from McMaster University investigated whether post exercise muscle protein synthesis is different when a large, single dose of whey protein (25 grams) is consumed immediately after activity compared with when smaller doses (2.5 grams) are consumed 10 times over an extended period. The idea with the small “protein shots” was to mimic how another milk protein, casein, is digested.
Participants were 8 men; (mean age: 22 years) performed 8 sets of 8-10 repetitions on a leg-extension machine; each subject participated in both dietary treatment regimens. In the second study with researchers from the US Army Research Institute of Environmental Medicine, active-duty military personnel (7 men and 1 woman; mean age: 24 years) consumed a high-protein beverage (10 grams protein providing essential amino acids) containing 1.87 or 3.5 g leucine while exercising on a stationary bicycle. In both studies, post exercise muscle protein synthesis was evaluated.
Consuming the large dose of whey protein immediately after exercise increased muscle protein synthesis more than when periodic smaller doses of protein were consumed. In the second study, muscle protein synthesis was 33% greater after consumption of the leucine-enriched protein beverage than after the lower-leucine supplement drink.
The researchers concluded that muscle metabolism after exercise can be effectively managed using proper dietary supplementation.
In consideration of the most beneficial timing of protein intake, immediate post exercise consumption appears to be the best. Leucine may play an especially important role in stimulating muscle growth in the post activity recovery period.
Story Source: American Society for Nutrition
Journal References: “Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise” American Journal of Clinical Nutrition, 2011;
“Leucine-enriched essential amino acid supplementation during moderate steady state exercise enhances post exercise muscle protein synthesis” American Journal of Clinical Nutrition, 2011;
American Society for Nutrition (2011, August 18) “Muscle-building effect of protein beverages for athletes investigated”
This article is for informational and educational purposes only, and is not intended to provide medical advice, diagnosis or treatment. Contact your doctor or healthcare professional for medical and nutritional consultation.