Role of central circulatory factors in the fat-free mass-maximal aerobic capacity relation across age

Abstract

Fat-free mass (FFM) (primarily skeletal muscle mass) is related to maximal aerobic capacity among healthy humans across the adult age range. The basis for this physiological association is assumed to be a direct relation between skeletal muscle mass and its capacity to consume oxygen. We tested the alternative hypothesis that FFM exerts its influence on maximal aerobic capacity in part via an association with central circulatory function. To do so, we analyzed data from 103 healthy sedentary adults aged 18–75 yr. FFM was strongly and positively related to maximal oxygen consumption ( r = 0.80, P < 0.001). FFM was also strongly and positively related to supine resting levels of blood volume ( r = 0.79, P < 0.001) and stroke volume ( r = 0.75, P < 0.001). Statistically controlling for the collective influences of blood volume and stroke volume abolished the tight relation between FFM and maximal oxygen consumption ( r = 0.12, not significant). These results indicate that 1) FFM may be an important physiological determinant of blood volume and stroke volume among healthy sedentary adult humans of varying age; and 2) this relation between FFM and central circulatory function appears to represent the primary physiological basis for the strong association between FFM and maximal aerobic capacity in this population. Our findings suggest that sarcopenia (loss of skeletal muscle mass with aging) may contribute to the age-related decline in maximal aerobic capacity primarily via reductions in blood volume and stroke volume rather than a direct effect on the oxygen-consuming potential of muscle per se.

Adverse effects of coexistence of sarcopenia and metabolic syndrome in Japanese women

“…On the other hand, skeletal muscle mass directly affects to individual VO 2 max level regardless of upper and lower extremity exercise, 44 and sarcopenia is associated with age-related loss of VO 2 max among healthy people across the adult age range. 45 It is not understood how the interaction of sarcopenia and MetS causes further decreases in the age-related loss of cardiorespiratory fitness or muscle power. The results of this study showed that the effect of the interaction between sarcopenia and MetS on VO 2 max was not significant.…”

Age‐related decreases in basal limb blood flow in humans: time course, determinants and habitual exercise effects

“…For example, the impact of sarcopenia (decrease in muscle mass and quality with advancing age) historically has been restricted to skeletal muscle function and performance (Evans, 1995). We demonstrated recently that sarcopenia also probably contributes to the age-associated decline in maximal aerobic capacity via reductions in plasma and blood volumes (Hunt et al 1998). The present findings indicate another influence of this process on cardiovascular function in the ageing human: contributing to a decrease in basal limb blood flow and vascular conductance.…”

“…We can only speculate on the mechanisms involved in the age-related decline in limb vascular conductance. Muscle sympathetic vasoconstrictor nerve activity (MSNA) increases markedly with advancing age in both sedentary and physically active men (Sundlof & Wallin, 1978;Ng et al 1994;Davy et al 1998). In this regard, we have previously reported a significant inverse relation between basal wholelimb vascular conductance and MSNA in young and older healthy men (Dinenno et al 1999); statistically accounting for the age-associated increase in MSNA abolished the significance of the age differences in basal femoral blood flow and vascular conductance.…”

Modelling the influence of fat-free mass and physical activity on the decline in maximal oxygen uptake with age in older humans

“…In addition, Hagberg et al (1985) examined the haemodynamic responses of master athletes, young athletes and older sedentary subjects during both submaximal and maximal exercise and found that the maximal arteriovenous oxygen difference was lower in sedentary older subjects than in the other subject groups. Furthermore, there is recent evidence to suggest that central circulatory function is related to FFM insofar as there is a strong correlation between both blood volume and stroke volume and FFM (Hunt et al 1998). …”