Anaerobic threshold and maximal oxygen consumption during arm cranking exercise in paraplegia

The major purpose of this investigation was to compare the anaerobic threshold (AT) and maximal cardiopulmonary responses to arm exercise between persons with paraplegia and the able-bodied. The locomotive stress on the heart in paraplegic subjects was also examined. Thirty-nine paraplegic subjects (T1-L4 lesions) and 32 able-bodied subjects completed a continuous, progressive, resisted arm cranking exercise test. The AT was determined from the ventilatory parameters. At the AT, the mean values of Vo2/body weight (BW) for class II (T1-T5, N = 9), III (T6-T10, N = 11), and IV (T11-L4, n = 19) paraplegic subjects were 10.9, 13.2, and 13.5mL/kg/min, respectively, and only class II had significantly lower value than the able-bodied (14.4mL/kg/min). During maximal exercise, the mean values of maximal oxygen consumption per body weight (Vo2max/BW) for class II and III paraplegics were 17.4 and 17.7mL/kg/min, respectively, which were significantly lower (p < 0.05) than that of class IV (21.3mL/kg/min) and the able-bodied (28.2mL/kg/min). The heart rate (HR) during wheelchair-propelling (119bpm, n = 37) was significantly less than that at the AT (134bpm), but the HR during crutch-walking (151bpm, n = 17) was significantly higher. The results indicate that both submaximal and maximal cardiopulmonary functions in high-lesion paraplegics were less than that of the able bodied. Furthermore, the intensity of wheelchair-propelling at comfortable speed is not enough for improving the cardiopulmonary functions.