Exercise-training-induced changes in metabolic capacity with age: the role of central cardiovascular plasticity.
Although aging is typically associated with a decline in maximal oxygen consumption (VO2max), young and old subjects, of similar initial muscle metabolic capacity, increased quadriceps VO2max equally when this small muscle mass was trained in isolation. As it is unclear if this preserved exercise-induced plasticity with age is still evident with centrally challenging whole body exercise, we assessed maximal exercise responses in 13 young (24 ± 2 years) and 13 old (60 ± 3 years) males, matched for cycling VO2max (3.82 ± 0.66 and 3.69 ± 0.30 L min(-1), respectively), both before and after 8 weeks of high aerobic intensity cycle exercise training. As a consequence of the training both young and old significantly improved VO2max (13 ± 6 vs. 6 ± 7 %) and maximal power output (20 ± 6 vs. 10 ± 6 %, respectively) from baseline, however, the young exhibited a significantly larger increase than the old. Similarly, independently assessed maximal cardiac output (Q max) tended to increase more in the young (16 ± 14 %) than in the old (11 ± 12 %), with no change in a-vO2 difference in either group. Further examination of the components of Q max provided additional evidence of reduced exercise-induced plasticity in both maximal heart rate (young -3 %, old 0 %) and stroke volume (young 19 ± 15, old 11 ± 11 %) in the old. In combination, these findings imply that limited central cardiovascular plasticity may be responsible, at least in part, for the attenuated response to whole body exercise training with increasing age.
Department of Circulation and Medical Imaging, Faculty of Medicine, The Norwegian University of Science and Technology, Prinsesse Kristinas gt. 3, 7006, Trondheim, Norway, eivind.wang@ntnu.no.
Eivind
E
Wang
Morten Svendsen
MS
Næss
Jan
J
Hoff
Tobias Lie
TL
Albert
Quan
Q
Pham
Russell S
RS
Richardson
Jan
J
Helgerud
D000328:Adult; D000375:Aging / Q000502:physiology*; D002319:Cardiovascular System / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005500:Follow-Up Studies; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D055815:Young Adult