Feasibility of a field-based submaximal stair ascent test for estimating aerobic capacity and lower-limb strength in middle-aged and older adults

Abstract

Background: Assessing functional capacity is a key aspect of exercise testing and offers important insights into health in adult populations. However, accurate assessment often requires laboratory-based maximal tests. This pilot study investigated whether a field-based self-paced submaximal stair ascent test could feasibly assess aerobic capacity and lower-limb strength in middle-aged and older adults.

Methods: Twenty-eight participants (20 women, 8 men) aged 40 to 70 years completed maximal treadmill and isometric leg press tests to assess maximal oxygen consumption (VO₂max) and lower-limb strength, respectively. Participants also performed two separate self-paced stair ascents of four and six flights. Ascent time, mean vertical power, as well as rate of perceived exertion, absolute heart rate, and relative heart rate following the test were recorded.

Results: Ascent time and mean vertical power were associated with VO₂max and lower-limb strength, with standardized regression coefficients ranging from -0.61 to -0.27 and from 0.41 to 0.73, respectively. However, these associations were attenuated and no longer statistically significant after controlling for age and sex. Predictive models based on the two best-performing stair ascent predictors selected by LASSO regression showed weak-to-moderate ability to predict VO₂max (R² = 0.21-0.52) with cross-validated model performance significantly different from zero. In contrast, the models did not significantly predict lower-limb strength.

Conclusions: These preliminary findings suggest that a brief self-paced stair ascent test may offer a feasible field-based approach for estimating aerobic capacity in middle-aged and older adults. However, its predictive accuracy appears limited and should be further examined in larger samples.

Keywords: cardiorespiratory fitness; field testing; physical performance; stair climbing; submaximal exercise test.