Anaerobic Work Capacity From Linear And Nonlinear Mathematical Models

Abstract

The critical torque (CT) test for isometric muscle actions provides estimates of two parameters; CT and anaerobic work capacity (AWC). Theoretically, CT is the maximal isometric torque that can be maintained without fatigue and AWC is the total "isometric work" associated with stored energy sources within the muscle. PURPOSE: The purpose of this study was to determine if there were differences between the estimates of AWC from two linear and two nonlinear mathematical models. METHODS: Nine adults (4 men, 5 women; age ±SD = 21.6 ± 1.2 yr) volunteered for this study. The first of five visits served as an orientation. Maximum voluntary isometric contraction (MVIC) of the dominant leg extensors was determined during the second visit. During visits 2-5, each subject performed one continuous, fatiguing, isometric muscle action to voluntary exhaustion to determine the time to exhaustion (limit time; Tlim) and total isometric work performed (limit work; Wlim) at a randomly ordered percentage of MVIC (30%, 45%, 60%, or 75%). The Tlim, Wlim, and torque values were used in two linear and two nonlinear mathematical models to calculate four separate estimates of AWC. RESULTS: A one-way repeated measures ANOVA indicated no significant differences between the estimates of AWC from the four mathematical models. In addition, the AWC estimates were highly intercorrelated at r = 0.986 to 0.999. CONCLUSION: The results of the current study indicated that linear and nonlinear mathematical modeling of the Tlim, Wlim, and torque data had no effect on estimates of AWC during isometric muscle actions of the leg extensors. Thus, the four mathematical models examined in the present study can be used to estimate the total isometric work that can be performed from stored energy sources within the muscle.