Limitations to Maximal Oxygen Uptake
- 117 Downloads
An increase in exercise capacity depends on the magnitude of increase in maximum aerobic capacity. Central and peripheral factors may limit oxygen uptake. Central oxygen delivery depends on cardiac output and maximal arterial oxygen content. Peripheral extraction of the delivered oxygen is expressed as a-v̅ O2. With increasing intensities of exercise, the respiratory system may become limiting in some trained individuals. Most studies have shown a higher stroke volume in maximal as well as submaximal exercise in the trained vs untrained individuals A variety of peripheral factors determine vascular tone. Maximal oxygen uptake depends on all components of the oxygen transporting system, but stroke volume appears to be the prime determinant in the trained subject. At maximum exercise the capacity of the muscle capillary network is never reached.
KeywordsMaximal Oxygen Uptake Arterial Oxygen Saturation Inspiratory Muscle Muscle Blood Flow Untrained Individual
Unable to display preview. Download preview PDF.
- Dempsey JA, Hanson P, Henderson K. Exercise-induced arterial hypoxemia in healthy humans at sea-level. Journal of Physiology (London) 355: 161–175, 1984Google Scholar
- Dempsey JA, Johnson BD. Demand vs capacity in the healthy pulmonary system. In Sutton JR & Balnave R. (Eds) Cardiovascular and respiratory responses to exercise in health and disease, Cumberland College of Health Sciences, Sydney, 1991Google Scholar
- Dempsey JA, Powers SK, Gledhill N. Discussion: cardiovascular and pulmonary adaptation to physical activity. In Bouchard C et al. (Eds) Exercise, fitness and health pp. 205–213, Human Kinetics Books, Champaign, 1990Google Scholar
- Ekblom B. Effect of physical training on oxygen transport system in man. Acta Physiologica Scandinavica (Suppl. 328): 5–45, 1969Google Scholar
- Rahn H. Maximal oxygen uptake: central or peripheral limitation? In Sutton JR et al. (Eds) Hypoxia: the tolerable limits, pp. 35–37, Surron JR, et al. Benchmark Press, Indianapolis 1988Google Scholar
- Rowell LB. Human circulation regulation during physical stress, Oxford University Press, New York, 1986Google Scholar
- Saltin B. Limitations to performance at altitude. In Sutton JR, et al. (Eds) Hypoxia: the tolerable limits pp. 9–31, Benchmark Press, Indianapolis, 1988Google Scholar
- Sutton JR. Exercise-fitness. In Nash & Lazarus L (Eds) Contribution to medicine and surgery, pp. 84–86, EJ Dwyer, Sydney, 1968Google Scholar
- Sutton JR, Houston CS, Cymerman C. Hypoxia: the tolerable limits. In Sutton JR, et al. (Eds) Operation Everest II. pp. 3–6, Benchmark Press, Indianapolis, 1988aGoogle Scholar
- Wagner PD, Reeves JT, Sutton JR, Groves BM, Cymerman, et al. Operation Everest II: Evidence for peripheral tissue diffusion limitation of maximal oxygen uptake. Journal of Applied Physiology, in press, 1992Google Scholar