Predicting Cardiorespiratory Fitness with a Cycle Ergometry Equation in Middle-Aged and Older Adults at Low and High Risk of Cardiovascular Disease.

Abstract

PURPOSE Low cardiorespiratory fitness (CRF) has consistently been associated with an increased risk of premature mortality and has been shown to be comparable to traditional cardiovascular disease (CVD) risk factors in terms of health outcomes. Thus, the purpose of this study was twofold: 1) to determine the accuracy of commonly proposed cycling ergometry equations to predict maximum oxygen uptake (pV̇O2max) in middle-aged and older adults and, 2) to assess if the accuracy is impacted by the presence of CVD risk factors. METHODS A total of 1255 participants (62.4 ± 6.9 years; 62.9% male) were included. V̇O2max was measured during an incremental maximal exercise test (IMET) on a cycle ergometer. In addition, three non-gender and gender-specific cycle ergometry equations (Storer et al. 1990, de Souza et al. 2015 and (FRIEND) Kokkinos et al. 2018) were used to pV̇O2max. RESULTS Both FRIEND and Storer equations pV̇O2max with a low relative bias for both non-gender-specific (-0.81 ± 12.9%; -0.31 ± 13.1%, respectively) and gender-specific (Women: -0.03 ± 13.6%; -3.31 ± 13.3%, Men: -045 ± 11.5%; 0.61 ± 11.5%, respectively) equations. Bland-Altman results also showed no difference between measured and pV̇O2max with excellent accuracy based on the Cb (0.99 and 1.0) and Lin's CCC (0.91 and 0.92) scores for both the FRIEND and Storer equations, respectively. The coefficient of determination (R2) was high (0.84-0.88) displaying good accuracy with low RMSE values. CONCLUSIONS Both the Storer and FRIEND-cycle ergometry equations predicted CRF with good accuracy in adults at low and high risk of CVD. Using the gender-specific equations slightly improved the accuracy, however the FRIEND equation performed better overall. Therefore, the FRIEND equation provides an attractive and simple alternative to assess CRF in adults when the direct measurement of V̇O2max is not feasible.