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 b e enhanced by considering the simultaneous rates of change of certain key v ariables, 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)),Del ta 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, ther e are no published age- and sex-dependent reference values for these relati onships that were appropriately obtained in randomly selected subjects. We therefore prospectively evaluated 120 sedentary individuals (60 male, 60 fe male, age 20 to 80 yr) who were randomly selected from more than 8,000 subj ects, 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 attribu tes (p < 0.05). A comprehensive set of linear prediction equations is provi ded; the limits of normality (at the 95% confidence level) differed substan tially 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 se dentary males and females up to 80 yr of age.