Mielke, M, Housh, TJ, Hendrix, RC, Camic, CL, Zuniga, JM, Schmidt, PJ, and Johnson, GO. Oxygen uptake, heart rate, and ratings of perceived exertion at the PWCV̇O2,. J Strength Cond Res 23(4): 1292-1299, 2009-The purpose of the present study was to examine the oxygen uptake (V̇O2), heart rate (HR), and ratings of perceived exertion (RPE [OMNI-Leg 0-10]) responses during continuous 1 -hour cycle ergometer rides at the PWC V̇O2, (physical working capacity at the oxygen consumption threshold). Eight subjects (mean age ± SD = 23 ± 3.2 years) performed a maximal test to exhaustion for the determination of V̇o 2peak and ventilatory threshold (VT). The subjects also performed 4 randomly ordered 8-minute workbouts at different power outputs (ranging from 84 to 245 W) to determine the PWCVO2, and a continuous 1 -hour cycle ergometer ride at the PWCV̇O2, during which V̇O2, HR, and RPE data were collected every 2 minutes. The PWCVO2, (114 ± 39 W) and VT (133 ± 44 W) were not significantly different and occurred at 56 and 63% V̇O2peak, respectively. Linear regression showed that the slope coefficients for the V̇O2, HR, and RPE vs. time relationships for the continuous 1 -hour workbouts were significantly greater than zero. Furthermore, a Mest about a single mean indicated that the mean slope coefficient for the HR vs. time relationship was significantly greater than 0.1 bpnvmin-1 (the rate of increase in HR that can be maintained for an 8-hour day). The results of this study indicated that PWC V̇O2, could be maintained for an extended period. However, the maximal power output associated with steady state VO2, HR, and RPE responses was overestimated. The mean increase in V̇O2 during the continuous 1 -hour ride was 270 mL, which suggested that the PWC V̇O2, may demarcate the moderate from heavy exercise domains. The mean HR slope coefficient of 0.3 bpnvmin-1 indicated that the power output at the PWCV̇O2, could likely be maintained for greater than 2 hours.
- Endurance exercise
- Fatigue threshold
- Physical work capacity
- Ventilatory threshold
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation