Resistance and aerobic training in older men: effects on VO2peak and the capillary supply to skeletal muscle.
Both aerobic training (AT) and resistance training (RT) may increase aerobic power (VO2peak) in the older population; however, the role of changes in the capillary supply in this response has not been evaluated. Twenty healthy men (age 65-74 yr) engaged in either 9 wk of lower body RT followed by 9 wk of AT on a cycle ergometer (RT-->AT group) or 18 wk of AT on a cycle ergometer (AT-->AT group). RT was performed three times per week and consisted of three sets of four exercises at 6-12 repetitions maximum. AT was performed three times per week for 30 min at 60-70% heart rate reserve. VO2peak was increased after 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 changes in VO2peak, whereas capillary density was increased only after AT (P < 0.01). These results, and the finding of a significant correlation between the change in capillary supply and VO2peak (r = 0.52), suggest the possibility that similar mechanisms may be involved in the increase of VO2peak after high-intensity RT and AT in the older population.
Hepple
R T
RT
Department of Physiology, University of Toronto, Ontario, Canada.
Mackinnon
S L
SL
Goodman
J M
JM
Thomas
S G
SG
Plyley
M J
MJ
D000368:Aged; D015308:Anaerobic Threshold / Q000502:physiology; D002196:Capillaries / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D006801:Humans; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000502:physiology; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D014891:Weight Lifting