Comparison of predicted aerobic capacity to measured aerobic capacity in menopausal women: an analysis of three methods.

Maintaining fitness throughout menopause is crucial for sustaining functional capacity and supporting healthy aging. Declines in physical activity and changes in physiology threaten cardiovascular health in menopause. Aerobic capacity is an indicator of current health status that can be measured directly, by maximal rate of oxygen uptake (V̇O_{2 max}), or using submaximal predictive methods that require fewer resources. This study aimed to establish the validity of these predictive methods for midlife women. Forty-four women (age 52 ± 4 years) completed three predictive cycle ergometer protocols (YMCA, Astrand-rhyming and Ekblom-Bak) and an incremental cycle ergometer V̇O_{2 max} test. Predicted V̇O_{2 max} scores were compared for agreement with directly measured V̇O_{2 max}. All methods evidenced moderate correlations with V̇O_{2 max}. The mean V̇O_{2 max} value derived from the YMCA (35.6 ± 9.7 ml·kg-¹·min-¹) and Astrand-Rhyming (35.5 ± 8.8 ml·kg-¹·min-¹) tests was no different to measured V̇O_{2 max} (34.5 ± 7.2 ml·kg-¹·min-¹), but the Ekblom-Bak test (37.5 ± 7.2 ml·kg-¹·min-¹, p < 0.01) overpredicted V̇O_{2 max}. All methods showed wide limits of agreement, suggesting variability in the accuracy of predictions. When measuring aerobic capacity or prescribing exercise using these predictive methods, the results should be interpreted with caution. Where possible, direct measurement of aerobic capacity should be utilized for prescription of exercise intensity in menopausal women.