For centuries, scientists, coaches, and athletes have argued about the best loading strategy for increasing muscle growth. Conventional wisdom is that muscles grow best in response to time under tension. A McMaster University study led by Nicholas Burd found that low-load, high-volume resistance exercise was more effective for stimulating muscle protein synthesis than high-load, low volume exercise. On different days, test subjects performed knee extensions to failure using loads of 90 percent or 30 percent of 1-rep maximum.
The scientists used sophisticated methods to measure muscle protein synthesis from muscle biopsies taken during recovery. The high-rep, low-load workout stimulated protein synthesis the most. While the study has important implications for athletes, we need more research to support this training method. (PLoS ONE online)