(3) in 1996 with supporting evidence for the muscle pump theory, based on differences in forearm blood flow above or below the heart during simulated exercise. They found that rhythmic cuff inflations, which mimicked the muscle pump, caused an immediate 60% increase in blood flow when the arm was below the heart, but no apparent increase when the arm was above. Since cuff inflations were the same in either case, these results indicate that the muscle pump – aided by a greater pressure when the arm was below the heart – was the driving force for the increased blood flow. In addition, voluntary handgrip exercises elicited a greater blood flow than did cuff inflations alone, suggesting that voluntary exercise activates multiple factors, which act in concert with the muscle pump to further increase blood …show more content…
had more participants and these participants were human. One may question whether the muscle pump’s effects were not seen in Hamann et al.’s study, not because they don’t exist, but because the conditions were not appropriate. The skeletal muscle had to overcome pharmaceutically enhanced vasodilation, which was much greater than what is physiologically normal. Furthermore, as mentioned by the authors, blood flow stimulated by adenosine may have been too high to allow enough time for the muscle pump to respond adequately. The fact that the dogs were only engaging in “moderate exercise” (running 3 miles/hour), also begs the question of whether an effect may have been detected at higher exercise