Predicting endurance limits in arm cranking exercise with a subjectively based method

Abstract

The purpose of this study was to compare a method for predicting endurance capacity at different workloads based on subjective perception of effort with the technique for determining ‘critical power’ (CP) proposed by Moritani et al. (1981). Three trained paraplegic subjects performed two protocols during separate sessions. The ‘subjective’ protocol consisted of graded and continuous tests on an arm crank ergometer, during which cardiorespiratory (heart rate, oxygen consumption, ventilation and respiratory exchange ratio) and subjective (Borg's 10-point scale) parameters were monitored continuously. A statistical regression analysis for power functions was performed to obtain the individual ‘iso-percep-tion’ curves in a power/duration reference system. The other protocol consisted of the determination of the CP of the muscle groups involved in arm cranking exercises according to the protocol proposed by Moritani et al. (1981). Subjects performed three tests in which the power output remained constant (50, 37.5 and 25 W) and led to the onset of muscular fatigue. The results of the two protocols were compared. The validity of the subjective perception of effort as a predictor of individual endurance capacity was confirmed by the relationship between time to exhaustion and work performed during constant-power tests as proposed by Moritani et al. (1981).

Keywords:

• Subjective perception
• Endurance
• Ergometry
• Workload