ABSTRACT
Studies have been conducted on 13 young healthy adults of average fitness on endurance work of varying durations lasting for 2-31 minutes using bicycle ergometer. Aerobic-anaerobic fractions of oxygen supply during each effort was determined. The data from Astrand and Rodahl on aerobic O2--supply and duration in maximal efforts from 1-120 minutes on a highly trained subject have also been considered. The plot of log endurance time against log (aerobic/anaerobic ratio) exhibits a slight departure from linearity, indicating independent contributions from aerobic and anaerobic fractions of oxygen supply. An equation was derived of the form: T - Au1k1u2--k2 where u1 end u2 are the aerobic and anaerobic fractions respectively which has been found to yield highly significant correlation coefficient between log-estimated and log-observed endurance time (0.9996 for Astrand and Rodahl's data on a single subject and 0.9640 for the present data on 13 subjects). This index is, therefore, quite suitable for the assessment of endurance capacity in terms of a single physiological parameter, and is likely to be superior to indices in current use.