Reference values for dynamic responses to incremental cycle ergometry in males and females aged 20 to 80

Interpretation of incremental cardiopulmonary;exercise tests (CPET) might be enhanced by considering the simultaneous rates of change of certain key variables, e.g.,Delta oxygen uptake/Delta work rate (Delta (V) over dot o(2)/Delta WR), A heart rate/DeltaV o(2) (Delta HR/Delta (V) over dot o(2)),Delta ventilation/Delta carbon dioxide production (Delta (V) over dot E/Delta (V) over dot co(2)), and the linearized A tidal volume/Delta (V) over dot E (Delta (V) over dot T/Delta In(V) over dot E) relationships. However, there are no published age- and sex-dependent reference values for these relationships that were appropriately obtained in randomly selected subjects. We therefore prospectively evaluated 120 sedentary individuals (60 male, 60 female, age 20 to 80 yr) who were randomly selected from more than 8,000 subjects, and submitted to standard ramp-incremental CPET on an electronically braked cycle ergometer. We found that sex and age significantly influenced several of the dynamic relationships, in addition to anthropometric attributes (p < 0.05). A comprehensive set of linear prediction equations is provided; the limits of normality (at the 95% confidence level) differed substantially from previous recommendations based on single discrete values. These data therefore provide a frame of reference for assessing the normalcy of the response profiles of four standard indices of metabolic, cardiovascular, and ventilatory function during rapidly incremental cycle ergometry in sedentary males and females up to 80 yr of age.