The Effect Of Exercise Intensity On Appetite Hormones And Energy Compensation In Female Students With High/Low Exercise Motivation

Objective:This study investigated the effect of exercise at different intensities on appetite and energy intake(EI)in female students with high or low exercise motivation.Method:In a randomized crossover study,14 participants(18-23years,19.15-23.56kg/m²)were divided into high motivation group(HM)and low motivation group(LM)and randomly performed three main trials:(I)HIIT(50min,6×3 min at 90%VO_2maxwith 3min 50%VO_2max,7min warm-up and 7min recovery);(II)MICT(50 min,70%VO_2max)and(III)REST(50min,control group,no exercise).Cortisol,AG,PYY and GLP-1 were assessed at:(I)PRE:pre-exercise;(II)POST:immediately post-exercise;(III)POST-1h:1h post-exercise.EI was assessed after ad libitum meals offered 1h post-exercise and in 24 hours.Results:For subjective appetite sensation,there was no interaction between exercise motivation and intensity and time(P>0.05).At POST-1h,there was no significant difference among the three main trials(P>0.05).For cortisol,there was an interaction of motivation*intensity*time(P<0.05)and an interaction of intensity*time(P<0.01).The concentration of cortisol was significantly higher in HIIT than that of REST at POST(P<0.05).There is no significant difference between MICT and REST.At POST-1h,there was no significant difference among the three trials.In LM group,the cortisol concentration of HIIT and MICT were significantly higher than that of REST at POST and POST-1h(P<0.05).For appetite hormones,there was no interaction among exercise motivation,intensity and time(P>0.05).The AG concentration of HIIT at POST was significantly lower than that of REST(P<0.05).The AG concentration of LM group was significantly lower than that of REST at POST-1h in HIIT trial(P<0.05).For PYY concentration,in HM group,HIIT was higher than REST at POST-1h(P<0.05).There was no significant difference in PYY concentration after exercise in LM group(P>0.05).GLP-1 in HM and LM groups increased significantly at POST(P<0.05).There was no significant difference between HIIT and MICT(P>0.05).The energy intake of HIIT and MICT was significantly higher in LM group at POST-1h than that of REST(P<0.05).There was no significant difference among three trials in HM group.Both HIIT and MICT were significantly higher than REST(P<0.05).Conclusion:Compared with HM group,the stress response in LM group can increase the post-exercise energy compensation.There is no difference between HIIT and MICT in affecting post-exercise energy compensation.