Abstract:
Objective: To evaluate the effects of high-intensity interval training (HIIT) and resistance training (RT) on reducing the fat-to-muscle mass ratio (FMR), explore individual variability, identify genetic markers by genome-wide association study (GWAS), and construct predictive models combining phenotypic and genetic factors for precision exercise. Methods: Adults with insufficient physical activity were subjected to 12 weeks of HIIT (
n=260) or RT (
n=177) exercise intervention, and the difference in FMR improvement before and after 12 weeks of intervention was analyzed. GWAS identified molecular markers associated with FMR improvement (
P<1.0×10
−5). The polygenic scores (PGS) were calculated based on the GWAS results, and the relationship between PGS and the effect of exercise-induced FMR reduction was analyzed. The prediction model of exercise-induced FMR reduction was constructed by four methods: random forest, support vector machine, eXtreme gradient boosting and logistic regression. Results: 1) Both HIIT and RT significantly reduced FMR (
P<0.05), with HIIT showing superior efficacy (
P<0.05). Individual variability was noted, with 34.0% (HIIT) and 40.1% (RT) showing no response. 2) Fourteen and 12 single nucleotide polymorphisms (SNPs) were significantly associated with FMR improvement after HIIT and RT, respectively (
P<1×10
−5). Among these, rs2277512 reached genome-wide significance (
P<5×10
−8) and explained 14.1% of the variance. PGS explained 53.9% and 52.6% of the variability in FMR decrease for HIIT and RT, respectively. 3) The random forest model based on gender, age, PGS, initial BMI, initial muscle mass, initial fat mass and exercise program can effectively predict the effect of exercise on FMR improvement (AUC=0.935, cut-off=0.339). Among the model features, PGS is the most important. Conclusions: There were individual differences in the improvement effect of FMR after HIIT and RT exercise intervention, and the PGS explained over 52% of the variability in FMR under two exercise modes. The random forest prediction model constructed by combining phenotypic and genetic factors can predict the effect of exercise on improving FMR before exercise, and provide a basis for scheme selection for precise fitness.