Abstract
The SRT, DRT, and MT of older men (OA) who have experienced a life style of chronic physical activity were compared to those of nonactive men of similar age (ONA), and also to active (YA) and nonactive young men (YNA). Although activity level and age were significant factors, most of the activity level-by-age interaction in all but DRT was attributed to the slower performance of the ONAs. At least in this study, a life style of physical activity appeared to play a more dominant role in determining SRT, DRT, and MT than age. The hypothesis that most of the slowing of responses in the aged is attributable to CNS processing rather than MT decrements is repudiated, since MT results paralleled those of SRT and DRT.