Physiological and Perceptual Responses to Weight Lifting and Treadmill Exercise at Matched Rates of Oxygen Uptake

The purpose of this study was to compare the physiological and perceptual responses to weight lifting and treadmill exercise performed at matched rates of oxygen uptake. Fifteen males (mean (+SD) age= 22.7 + 1.6 yrs: height= 175.0 + 6.2 an: weight= 82.0 + 14-:J kg) performed a 27-minute bout of weight-lifting consisting of two circuits of eight exercises performed at 60% of one repetition maximum with a work/rest ratio of 45 seconds/60 seconds. Approximately five days following weight lifting each subject walked or jogged on the treadmill at a pace which elicited an oxygen uptake matched with his mean value during weight lifting. Oxygen uptake, respiratory exchange ratio, and ventilation were measured during both exercise sessions using ~en circuit spirometry. Blood sarrples were drawn immediately post-exercise and analyzed for lactate using an enzymatic procedure. Heart rate was determined from electrocardiograph recordings. Rating of perceived exertion was determined using the Borg scale. Oxygen uptake during weight lifting (1.58 1/min) and treadmill exercise (1.55 1/min) were not significantly different (p>.05), thus the two activities were matched for rate of oxygen uptake. weight lifting elicited a significantly (p<.05) higher respiratory exchange ratio (0.97 versus 0.77), ventilation (54.7 versus 37.2 1/min), lactate (9.5 versus 0.8 mmol/1), heart rate (140 versus 110 bts/min), and rating of perceived exertion (12.8 versus 9.6) compared to treadmill exercise. In conclusion, weight lifting elicits greater physiological and perceptual stresses compared to treadmill exercise when the two activities are performed at matched rates of oxygen uptake and equal durations.