Oxygen Uptake, Heart Rate, and Ratings of Perceived Exertion at the PWC JOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-png o2

Mielke, M, Housh, TJ, Hendrix, RC, Camic, CL, Zuniga, JM, Schmidt, RJ, and Johnson, GO. Oxygen uptake, heart rate, and ratings of perceived exertion at the PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2. J Strength Cond Res 23(4): 1292-1299, 2009-The purpose of the present study was to examine the oxygen uptake (o2), heart rate (HR), and ratings of perceived exertion (RPE [OMNI-Leg 0-10]) responses during continuous 1-hour cycle ergometer rides at the PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 (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 o2peak 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 PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 and a continuous 1-hour cycle ergometer ride at the PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 during which o2, HR, and RPE data were collected every 2 minutes. The PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 (114 ± 39 W) and VT (133 ± 44 W) were not significantly different and occurred at 56 and 63% JOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2peak, respectively. Linear regression showed that the slope coefficients for the o2, HR, and RPE vs. time relationships for the continuous 1-hour workbouts were significantly greater than zero. Furthermore, a t-test about a single mean indicated that the mean slope coefficient for the HR vs. time relationship was significantly greater than 0.1 bpm·min−1 (the rate of increase in HR that can be maintained for an 8-hour day). The results of this study indicated that PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 could be maintained for an extended period. However, the maximal power output associated with steady state o2, HR, and RPE responses was overestimated. The mean increase in o2 during the continuous 1-hour ride was 270 mL, which suggested that the PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 may demarcate the moderate from heavy exercise domains. The mean HR slope coefficient of 0.3 bpm·min−1 indicated that the power output at the PWCJOURNAL/jscr/04.03/00124278-200907000-00035/OV0312_11/v/2021-02-09T093622Z/r/image-pngo2 could likely be maintained for greater than 2 hours.