Effects of exercise at the anaerobic threshold on respiratory quotient in young male subjects

Aim: Exercise has great influence on increasing metabolic system functions. The work load corresponded to anaerobic threshold provide optimal aerobic strain for metabolic activity in exercising muscle. In the present study we intended to evaluate body substrate oxidation ratio during constant load exercise test at the intensity of anaerobic threshold in healthy young male subjects. Material and Method: Total of 15 male performed an incremental ramp exercise test to estimate anaerobic threshold. Standard V-slope method used to estimate anaerobic threshold. Then each subject performed a constant load exercise test for a 30 min period with a work load corresponded to their anaerobic threshold. Respiratory quotient (RQ) used to evaluate substrate oxidations during exercise. Anova test used to evaluate significance of data obtained every 5 minutes of constant load exercise. Results: The subjects’ anaerobic threshold occurred at approximately 63% of their maximal exercise capacity. RQ varied markedly among the subjects but as a mean value, but it systematically decreased with increasing exercise time. Body mass index and exercise time has great importance on fat and carbohydrate oxidation ratio. Conclusion: Exercise intensity at the anaerobic threshold provides meaningfully fat oxidation and could be acceptable in subjects with high body fat mass.