The Nature of the Perception of Effort at Sea Level and High Altitude,
ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MASS
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This study compared the Rating of Perceived Exertion RPE and selected physiological measures, during both short term and prolonged work of equal relative intensities i.e., VO2 max, at 4300 m to those at sea level. Ss N 20 performed bicycle work at supramaximal intensities, for six minutes each at 60, 80 and 95 VO2 max and to exhaustion at 85 VO2 max. At 4300 m, VO2 max was reduced 19, while V sub E max and R max increased 17 and 8, respectively HR max and RPE max was unchanged. For any given relative work intensity, VO2 and absolute work intensity were of course reduced, while V sub E was about 12 and R about 7 greater at 4300m again HR was unchanged. At 4300 m, RPE at the lower intensities and early during prolonged work were significantly less than at sea level. These differences were reduced and finally eliminated as work intensity increased toward maximal or as prolonged work continued to exhaustion. Endurance time to exhaustion at 4300 m was not different from that at sea level. To account for the perceptual differences between work at 4300 m and sea level we proposed that RPE was a positively acclerating power function of central influences tachycardia, tachypnea, dyspnea, and either a linear or positively decelerating power function of local influences muscular strain.
- Stress Physiology