Reliability Of A Newly Developed Cycle Ergometer For Estimating Cardiorespiratory Fitness

In fitness facilities, it is important to evaluate the cardiorespiratory fitness (CRF: maximal oxygen uptake) of program participants to develop appropriate aerobic exercise programs and evaluate their effectiveness. This is especially important in older adults. However, direct measurement of CRF is risky and expensive, making its implementation in fitness facilities impractical. For this reason, submaximal exercise testing methods have been developed to estimate CRF. However, a cycle ergometer that can safely and accurately measure CRF in older adults has not been developed. PURPOSE: This study aimed to verify the reliability of a newly developed cycle ergometer for estimating CRF in a short time safely. METHODS: Reliability was assessed in 28 women (median 69 age years) and 13 men (median age 66 years) who regularly use sports facilities. Reliability was assessed by performing the measurements twice and visually evaluating whether there were systematic errors in the two estimates by Bland-Altman analysis, as well as by calculating Pearson's correlation coefficient (r) and 95% confidence interval (95% CI). In addition, measurements were performed on 446 middle-aged and older subjects (median 50 age years) to see how the estimated CRFs were distributed. RESULTS: The estimated CRF (mean ± SD) in the first measurement was 34.1 ± 8.8 mL/kg/min and 34.8 ± 10.7 mL/kg/min in the second. The correlation coefficient (95% CI) between the two measurements was r = 0.94 (0.88 − 0.97). Bland-Altman analysis showed that only two data (5%) exceeded the limits of agreement (-8.53 ~ 7.23 mL/kg/min). The results of the independent-samples t-test and linear regression analysis of errors confirmed systematic errors (β = -0.21: p < 0.001), although no fixed errors were present (p = 0.306). Furthermore, the distribution was confirmed to be approximately normal. CONCLUSIONS: Although there was a negative systematic error, the reliability of the newly developed cycle ergometer was generally good. It was considered possible to evaluate the effectiveness of exercise programs in fitness facilities among older adults. Supported by Senoh Corporation and MHLW Program Grant Number JPMH22FB1002.