Transfer effects of endurance training with the arms and legs

The purpose of this study was to examine whether endurance training in the form of arm or leg cycling resulted in significant transfer effects when exercise was performed with the untrained muscle group. Sixteen middle-aged male volunteers completed 24 training sessions over 8 wk on either an arm cycle ergometer (AG, N = 8, mean age = 35.2 +/- 6.6 yr) or a leg cycle ergometer (LG, N = 8, mean age = 41.0 +/- 4.7 yr). The two groups were initially equated for their pre-training peak oxygen uptake (pVO2) determined during leg cycling (44.5 +/- 5.0 and 43.8 +/- 7.7 ml.kg-1.min-1 for the AG and LG, respectively). Training was performed at an intensity that was mid-way between the pre-training ventilatory threshold (VT) and the pVO2 for both cycling methods. Significant increases (P less than .05) were observed in the relative values of the oxygen uptake at the VT and the pVO2 as a result of both these methods of training, but these elevations were specific to the muscle groups that were trained. This specificity of training was also evident in the cardiorespiratory and metabolic measurements obtained during submaximal steady state exercise performed at the power output corresponding to the pre-training VT during arm and leg exercise. Hence, it was concluded that improvements in exercise performance resulting from short-term aerobic training with the arms or legs in middle-aged males with relatively high aerobic powers are due primarily to peripheral adaptations in the trained muscles.