Index for Volume 33 [1962]

Abstract

In order to develop a more effective method for measuring individual differences in heavy work endurance, quantitatively corrected for the inflation of apparent reliability caused by differences in body size, data were secured on 78 college males. All started at an initial work rate of 1650 kpm/min on a bicycle ergometer, and endeavored to maintain this rate as best they could during the entire 12 min of work. One group of 26 performed at an initial rate of 60, another at 70, and the third at 84 pedal rpm. All were retested one week later. Body weight correlated r = .54 with endurance, so its effect was removed by the W-score technique. Net individual differences rose progressively from the first few minutes to a plateau at about min 7; they were greatest for the 84 and least for the 60 rpm condition, and were greater for min-by-min cumulated work scores, while drop-offs and time to designated drop-off gave irregular results. Individual differences could have been measured nearly as well with an 8- or 9-min test, but a full 12 min was required to establish an endurance criterion. The 84 rpm schedule gave the highest reliability, although it yielded the lowest work output and exhibited a faster decline in work rate and a lower fatigue level.