effect of a high intensity interval training (hiit) on serotonin and cortisol levels in obese women with sleep disorders

Background: physical and physiological changes in obese middle-aged women cause hormonal changes, which are threatening factor for quality of life and health of elderly. objectives: the purpose of this study was to investigate the effect of a one-week hiit on serotonin and cortisol levels in obese women with sleep disorders. methods: the research method was semi-experimental with pre-test post-test design, in which 34 middle-aged obese women with mean age of 47.11 ± 2.3, body mass index of 33.4 ± 2.7, and body fat percentage of 35.8 ± 2.3 were selected based on convenience sampling. subjects were randomly divided to experimental groups (hiit exercises) and control group. the experimental group performed a training program for one week, including three sets of rast protocol (six bouts of 35 meters with 10 seconds of rest between each) with a four-minute rest between each set. pittsburgh sleep test was used to diagnose sleep disorders (score 11 and above). actiwatch 8 was used to evaluate quality of sleep in the post-test. in order to to measure the serotonin and cortisol levels, a serotonin kit from the german company lbl and ssgn kit was used, respectively. independent and dependent t-test were used for data analysis at p ≤ 0.05. results: the results suggested that cortisol level of hiit training group was decreased significantly after the exercise intervention (p = 0.01; t = 0.93). on the other hand, the serotonin levels of the hiit training group was significantly lower (p = 0.001; t = 11.02), while in the control group, the change was not significant (p = 0.15; t = 1.53) and the quality of sleep in the training group was improved significantly (p = 0.001; t = 6.52). conclusions: in conclusion, hiit exercises can improve the quality of sleep through hormonal changes and as a result, improve the physiological functions of middle-aged women.