Comparison between continuous and intermittent submaximal exercise at the intensity of maximal fat oxidation

Abstract

The aim of the study was to determine the rate of fat oxidation during continuous and intermittent acute endurance exercise. Eleven healthy untrained men participated in this study. Subjects performed Bruce protocol test on cycle ergometer to determine maximal oxygen consumption (VO2max). The exercise intensity in which the highest fat oxidation rate occurs was determined in this exercise test for each subject. Oxygen uptake (VO2) and carbon dioxide (VCO2) production during the exercises were followed by respiratory gas analyzer and whole-body fat oxidation was calculated by indirect calorimeter equations. Subjects performed 45min intermittent (IE) and continuous (CE) exercises in respiratory exchange ratio (RER) at intensity correspondent at the highest fat oxidation rate (Fat max). The peak fat oxidation rate was equal to 40.6% of maximum oxygen consumption of subjects. The changes occurring with time in fat (F=20.67) and carbohydrate (F=19.44) oxidation rates were statistically significant (P<0.01). However, the changes of fat and carbohydrate (CHO) oxidation with time did not show any statistically significant differences between the continuous and intermittent exercises (P>0.05). The results of the study indicate that the continuous and intermittent exercises performed at the exercise intensity ensuring maximum fat oxidation rate provide similar fat oxidation. Especially, for the individuals starting regular exercise applications newly, it can be said that similar positive results regarding fat oxidation can also be obtained by avoiding the insipidity of long lasting exercises and giving breaks.