Relation Between Muscular Strength and Cardiorespiratory Fitness in People With Thoracic-Level Paraplegia

Abstract

Zoeller RF, Riechman SE, Dabayebeh IM, Goss FL, Robertson RJ, Jacobs PL. Relation between muscular strength and cardiorespiratory fitness in people with thoracic-level paraplegia. Objectives To determine the relation between muscular strength, aerobic power (V o 2peak), submaximal blood lactate accumulation, and endurance performance in people with thoracic-level paraplegia. Design 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. Setting Research laboratory in a university setting. Participants Ten adult male volunteers with thoracic-level paraplegia. Interventions Not applicable. Main Outcome Measures The relations between strength, V o 2peak, submaximal blood lactate accumulation, and endurance were determined by correlation analysis. Results Shoulder flexion strength correlated with V o 2peak and power output at V o 2peak. Shoulder strength accounted for 68.4% of the variation in performance time. Greater isokinetic elbow flexion and extension strength was associated with higher V̇ o 2 and power output at a blood lactate concentration of 4mmol/L (flexion) and with a greater power output at V o 2peak (extension). Conclusions 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.