Relation between muscular strength and cardiorespiratory fitness in people with thoracic-level paraplegia.

Abstract

To determine the relation between muscular strength, aerobic power (V O2 peak), submaximal blood lactate accumulation, and endurance performance in people with thoracic-level paraplegia. Participants performed tests of isokinetic strength, a graded exercise test, and 2 endurance performance tests. A Latin square counterbalanced design was used to determine the order of testing. Research laboratory in a university setting. Ten adult male volunteers with thoracic-level paraplegia. Not applicable. The relations between strength, V O2 peak, submaximal blood lactate accumulation, and endurance were determined by correlation analysis. Shoulder flexion strength correlated with V O2 peak and power output at V O2 peak. Shoulder strength accounted for 68.4% of the variation in performance time. Greater isokinetic elbow flexion and extension strength was associated with higher V O2 and power output at a blood lactate concentration of 4 mmol/L (flexion) and with a greater power output at V O2 peak (extension). These findings suggest that in this population, greater muscular strength is associated with greater aerobic power and endurance. Greater muscular strength could exert a positive influence on exercise performance by enabling higher levels of cardiorespiratory stress as the result of reduced or delayed local muscle fatigue.