Reference Data for a Treadmill-Based Peak Oxygen Uptake (VO) in Older Adults.

Although the level of cardiorespiratory fitness (CRF) in older adults has been well documented, little evidence has been provided regarding sex- and age-specific reference standards. Therefore, the main purpose of the study was to examine objectively measured CRF in older adults based on sex and age. This observational study included 450 men (N = 170) and women (N = 280) aged ≥60 years with mean ± standard deviation (SD) for age (67.4 ± 5.4), height (165.7 ± 8.6 cm), weight (75.1 ± 13.3 kg) and body mass index (BMI, 27.1 ± 3.9 kg/m). Participants performed an incremental exercise ramp test until exhaustion on a treadmill, and the outcome of CRF was presented as peak oxygen uptake (VO) in milliliters per kilogram of body mass per minute (ml/kg/min). Relative VO values were 37.3 ± 7.1, 30.3 ± 6.6, 24.8 ± 5.4 and 21.7 ± 5.8 mL/kg/min for men aged 60-64 years, 65-69 years, 70-74 years and ≥75 years. For the same age groups in women, values were 30.5 ± 4.8, 27.1 ± 5.4, 22.4 ± 3.4 and 18.9 ± 4.7 mL/kg/min. Age-related declines were observed in both men and women ( < 0.001). In a sex-age interaction term, significant main effects occurred, where men in every age group exhibited higher VO values, compared to women in the same age groups. This study shows that CRF needs to be assessed by considering sex and age as significant predictors. Thus, sex- and age-specific reference findings may serve as an avenue to monitor, track and compare between older adults of different nationalities.