Effect of training on total and regional blood flow and metabolism in paddlers

R. BECKLAKE. Efect of training on total and regional blood Jlow and metabolism in paddlers. J. Appl. Physiol. 28(4) : 397-406. 1970.-Physical training of canoe paddlers resulted in a decrease in exercise cardiac output for a given submaximal work load. Resting forearm blood flow was reduced but the exercising limbs blood flow was unchanged after training. It was concluded that the reduced cardiac output was achieved by a reduced blood flow to nonexercising areas. After training there was no change in the forearm energy metabolism as measured by RQ, glucose utiliza-tion, or fatty acid uptake. Lactate production during sustained exercise of the forearm was reduced after training, Potassium and calcium loss from forearm tissues was observed at the onset of exercise which reversed to uptake while the exercise continued. These results are consistent with a closer regulation of blood flow following the training program and with adaptation in muscle. cardiac output; acid me tabolism forearm; glucose; blood flow; respiratory quotient; fatty lactate * potassium; calcium; magnesium> PREVIOUS WORK from this laboratory (3) has shown that athletic training results in a fall of cardiac output and in heart rate for a given submaximal work load. This posed the question as to whether the fall in exercise cardiac output resulted from a decrease in blood flow to both exercising and nonexercising limbs, or from a more advantageous distribution of cardiac output, with the de-crease in flow being mainly in the nonexercising areas. This study was designed to answer the question by examining the effects of training on exercise cardiac output, as well as local blood flow at rest and during exercise and recovery. In addition it provided an opportunity to measure the local metabolic effects of training. The total-body metabolic effects of training have been reported (43) ; however, there are few data on the local effects, particularly the metabolic effects of training on voluntary muscle.