Resistance and aerobic training in older men: effects on VO2 peak and the capillary supply to skeletal muscle

Hepple, R. T., S. L. M. Mackinnon, J. M. Goodman, S. G. Thomas, and M. J. Plyley. Resistance and aerobic training in oldermen: effects onO_{2 peak} and thecapillary supply to skeletal muscle. J. Appl.Physiol. 82(4): 1305-1310, 1997.Both aerobic training (AT) and resistance training (RT) may increase aerobic power(O_{2 peak}) in theolder population; however, the role of changes in the capillary supplyin this response has not been evaluated. Twenty healthymen (age 65-74 yr) engaged in either 9 wk of lower body RTfollowed by 9 wk of AT on a cycle ergometer (RTAT group) or 18 wk of AT on a cycle ergometer (ATAT group). RT was performedthree times per week and consisted of three sets of four exercises at6-12 repetitions maximum. AT was performed threetimes per week for 30 min at 60-70% heart ratereserve. O_{2 peak} was increasedafter both RT and AT (P < 0.05).Biopsies (vastus lateralis) revealed that the number of capillaries per fiber perimeter length was increased after both AT and RT(P < 0.05), paralleling the changesin O_{2 peak}, whereascapillary density was increased only after AT(P < 0.01). These results, and thefinding of a significant correlation between the change in capillarysupply and O_{2 peak}(r = 0.52), suggest the possibility that similar mechanisms may be involved in the increase ofO_{2 peak} afterhigh-intensity RT and AT in the older population.