Influence of Exercise Modalities on Relative Aerobic Energy Contribution in 4 min Running and Cycling Time Trial

Aim The relative aerobic energy contribution is a fundamental characteristic of maximal exercises.Previous investigations have reported some values of relative aerobic energy contribution,or some correlation equation,for different duration of maximal exercises,without verifying the influence of exercise modalities.The aim of this study is to investigate the influence of exercise modalities on relative aerobic energy contribution in 4 min running and cycling time trial.MethodsThis study recruited 16 amateur athletes from triathlon,cycling,and long-distance running(33.5±10.6yrs,180±9cm,75.8±8.4kg,training experience 14±10yrs)to participate in two 4 min time trails,with the exercise modalities of field-running,and ergometer-cycling.The energy contributions and oxygen uptake kinetics were compared for these two exercise modalities.We utilized a portable gas analyzer and a blood lactate analyzer to measure and assess the relative parameters.The energy contributions were calculated with the method based on the accumulated oxygen uptake,and blood lactate during the maximal exercise,as well as the fast component of the oxygen debt during the recovery.ResultsThe results demonstrated similar aerobic energy contributions(77.0±3.8% vs.75.9±2.6%,P>0.05),similar phosphate energy contributions(11.4±2.6% vs.10.0±2.0%,P>0.05),but significantly different glycolysis energy contributions(11.6±3.4% vs.14.1±3.3%,P<0.05)between running and cycling.The oxygen uptake kinetics were similar in the fast component(16.2±3.69 s vs.14.5±4.84 s,P>0.05),but significant different in the slow component(0.26±0.09L/min vs.0.54±0.32L/min,P<0.05).ConclusionThe results from the 4 min time trials of running and cycling indicate seemly that the exercise modalities don't influence the relative aerobic energy contribution in maximal exercises.This conclusion warrants future investigations which emphasize on more exercise modalities,and more duration.