Oxygen uptake during arm cranking with and without leg electrical stimulation in able bodied individuals

Abstract

Ten able bodied subjects (AB) volunteered to be tested with a Respond II neuromuscular stimulator applied to the lower extremities during submaximal arm crank exercise (ACE) to determine its effect on heart rate (min−1) and VO2 in ml·min−1 ·kg−1. One to two hours after a maximal ACE test, subjects performed four 9‐minute submaximal bouts of ACE; two at 25% and two at 70% of VO2peak. Each work rate was performed with and without, a randomly ordered, electrical stimulation (ES) of the quadriceps and hamstring muscle groups respectively. Electrical stimulation intensity was determined by a subject's maximal tolerance. Data, from four submaximum tests were analyzed with a two 2×2 repeated measures analysis of variance. The main effects were work rate (25% VO2peak and 70% VO2peak) and electrical stimulation (STIM) no stimulation (NOSTIM). No statistical differences was found between the STIM and NOSTIM in VO2 or heart rate at either 25% VO2peak (11.0 ml·min−1·kg−1 vs. 11.2 ml·min−1·kg−1; and 89 min−1 vs. 88 min−1 respectively) or 70% VO2peak (22.8 ml·min−1·kg−1 vs. 22.8 ml·min−1·kg−1; 128 min−1 vs. 127 min−1 respectively). There was a difference in VO2 and heart rate for the main effect of work rate 25%VO2peak or 70%VO2peak (11.1 ml·min−1 ·kg−1 vs. 22.8 ml‐min−1 ·kg−1; 88 min−1 vs. 127 min−1). The results of this study may have been affected by the low level of ES intensity used, due to human subjects' ES guidelines, and use of the lower limbs for stability with increasing intensity of work rate.