Standardized submaximal exercise testing in never smokers: a normative study

In a population survey on the south-western coast of Norway, 373 never smokers aged 18-73 years (230 women) without respiratory symptoms performed a standardized, progressive, incremental submaximal bicycle exercise test. All individuals were able to do an exercise involving oxygen uptake of 1.0 l min(-1), 80% of the subjects reached 1.5 l min(-1) and 50% of the subjects reached 2.0 l min(-1). The respiratory frequency (RF), ventilation (VE) and heart rate (HR) for a given oxygen uptake were all higher in women than in men. Significant predictors of failure to reach oxygen uptake of 1.5 and 2.0 l min(-1) were sex, age, body height and weight. Prediction equations are given for respiratory frequency, heart rate and ventilation for an oxygen uptake of 1.0 l min(-1) in women and 1.5 l min(-1) in men; and body height is a strong predictor for all dependent variables. A multiple linear regression analysis in women showed that age was a significant predictor of respiratory frequency (P <0.05), ventilation (P <0.001) and heart rate (P <0.001), while in men age was a significant predictor only of ventilation (P <0.001) during the bicycle exercise protocol.