Determinants of maximal instantaneous muscle power in women aged 50-75 years

The present study aimed at analysing the age- related decline in maximal muscle power (W) in 52 sedentary healthy women aged between 50 and 75 years to determine whether force or velocity is the major de- terminant. Maximal muscle power was estimated from two types of vertical jumps, squatting (SJ) and counter- movement (CmJ), performed on a force platform. It was obtained by measuring the vertical force (Fopt) applied to the body centre of gravity and calculating the corre- sponding vertical velocity (vopt). An age-related decline in absolute W was statistically signi®cant in all the conditions examined and in both peak W and average power (W) values. The decrease in vopt was also statistically significant. Also Fopt declined but this reduction was not statistically significant with the exception of the average value in CmJ. Not surprisingly the highest W were obtained in CmJ, and the difference in power production between the two types of jump showed an age-related decrement only in W. The main finding of the study was the demonstration that vopt was the critical determinant of the age-related decline in W in healthy elderly women.