The effect of simultaneous submaximal physical exercise and mental exertion on fatigue indices in active men

Abstract

Purpose: The purpose of this study was to investigate the effects of performing cognitive task during submaximal exercise on fatigue indices. The scientists believe that both mental and body determine endurance performance. Since there are common neural pathways between physical and mental fatigue. Methods: 10 athlete’s men (mean ± SD, age: 20 ± 2 years, weight: 71 ± 10 kg, height: 176 ± 9 cm) participated in this study. The participants were present in lab for three separate sessions. In the first session after familiarization, maximal oxygen consumption (VO2max) was determined using incremental protocol on treadmill. In two subsequent sessions, participates ran on treadmill with 70 percent of VO2max intensity for 45 minutes with (intervention) and without (control) cognitive task. Heart rate (HR) and rate of perceived exertion (RPE) were recorded every 10 minutes during both exercise sessions. Maximal voluntary contraction (MVC), cortisol and prolactin concentration were measured pre-and post- sessions. All data was analyzed with dependent t-test and two-way ANOVA.Results: The results showed that there is no significant difference between two sessions for, prolactin (P = 0.668), cortisol (P = 0.25), MVC (P = 0.664), RPE (P = 0.9), and HR (P = 0.34) but cortisol, prolactin, RPE and HR increased from pre-to post-sessions.Conclusion: Present study results show that, performing a cognitive task during submaximal exercise couldn’t induce more fatigue indices compare submaximal exercise. However, cannot be totally discarded thr effects of performing cognitive task during submaximal exercise on fatigue indices. Factors like duration and kind of cognitive and physical tasks should be consider.

Keywords

• prolactin
• cognitive task
• rate of perceived exertion