Reliability and validity of the YMCA submaximal cycle ergometer protocol

Submaximal exercise tests are being used with increasing frequency in medical and fitness fields to predict maximal oxygen uptake. As the reliability of these types of tests are not well documented, the purpose of this study was to test the reliability of the YMCA Submaximal Cycle Ergometer (YMCA) test. Sixteen male subjects, ages 17 - 26 (22.6±2.7yrs) performed a maximal GXT on an electrically-braked cycle ergometer and three YMCA tests on a Monark ergometer each spaced two days apart. During the YMCA test, HR was measured by telemetry; VO2max was predicted by both the extrapolation method (YMCAext) and use of the ACSM energy equations (YMCAACSM) . Both prediction methods were compared to measured VO2max using repeated measures ANOVA. Correlational analysis was also performed to determine the reliability between submaximal tests. Measured VO2max was 3.88 ±.52 L/min (range: 2.8-5.0 L/min). In 17 of 48 trials, VO2max was unable to be predicted from the YMCAext using age-predicted HRmax. The YMCAACSM mean VO2max (4.35±1.4 L/min) was significantly different from measured VO2max. Within the three YMCAACSM tests, the VO2max were not significantly different (4.42±1.2, 4.32+1.8, and 4.35±1.4 L/min, respectively). The test-retest reliability ranged between .71-.75 for the three YMCAACSM tests trials. The overall CV of the YMCAACSM tests was 13.72 ±8.9% (range: 4.12-40.81). Due to the relatively modest r between measured and predicted VO2max and the relatively high CV for the measure, it is concluded that the VO2max cannot be reliably estimated from the YMCA protocol. When using this protocol to predict VO2max caution should be used.School of Physical EducationThesis (M.A.