What governs skeletal muscle VO2max? New evidence.

摘要: Recent investigations into the determinants of skeletal muscle maximal oxygen consumption (VO2) have provided further evidence regarding role O2 supply and demand in governing exercise metabolism. Specifically, four studies utilizing both animal human models are highlighted here: 1) diffusive component was examined exercising canine gastrocnemius by a rightward shift dissociation curve while maintaining delivery constant; 2) peripheral central components studying quadriceps muscle, already recognized to very high mass specific delivery, under conditions increased (hyperoxia) reduced availability (hypoxia); 3) intracellular PO2 progressive increase lactate efflux from submaximal effort; finally 4) itself as determinant mitochondrial consumption. In summary, these illustrate importance diffusion gradient blood cell; that even functionally isolated trained highest recorded metabolic rates can be increasing supply; constant during graded is therefore unrelated efflux; only hyperoxia does approaching limits, shown disproportionate for change VO2max.