The results of this study make for an interesting comparison with research that demonstrates lack of blood vessel dilation in muscles to be a root cause of age-related loss of muscle mass, or sarcopenia: researchers "have determined that moderately and temporarily restricting the flow of blood through muscles - a practice adopted by bodybuilders who noticed that it made light weights feel heavier - can be combined with low-level resistance exercise training to produce muscle-mass increases in older men. ... investigators studied changes in the thigh muscles of seven older men (average age 70) when they performed four minutes of low-resistance leg extension exercises both with and without inflatable cuffs that reduced blood flow out of the muscles. Muscle protein synthesis was measured in each of the men by monitoring changes in a chemical tracer infused into the bloodstream. In addition, a series of biopsies yielded muscle samples that were analyzed to track alterations in biochemical pathways critical to muscle growth. ... We saw that when we put the cuffs on, they responded similarly to young people doing traditional high-intensity resistance exercise."