Physiological and Performance Effects of a High-Intensity Interval Training in University Students

High-Intensity Interval Training (HIIT) is an efficient exercise modality involving alternating short bouts of intense activity with recovery periods. It is increasingly popular among recreationally active individuals due to its time efficiency and broad health benefits. Literature supports its efficacy in enhancing cardiovascular capacity, promoting fat oxidation, and improving anaerobic performance. Given rising sedentary trends among young adults, HIIT emerges as a practical alternative to traditional endurance training, especially for those with limited training time.Building on this context, the present study investigates the physiological impacts of a structured 6-week HIIT intervention on key fitness markers in recreationally active university students aged 20 to 25. The focus is on changes in maximal oxygen uptake (VO₂ Max), body fat percentage, and lower body muscular power, as reflected by vertical jump performance. By comparing pre- and post-intervention values, the aim is to evaluate HIIT’s benefits across aerobic capacity, body composition, and explosive strength.Thirty recreationally active students (mean age: 22.1 ± 1.6 years) completed a 6-week HIIT program comprising three sessions per week. Each session included 20–25 minutes of high-intensity work intervals at 85–95% HRmax interspersed with active recovery. Assessments of VO₂ Max, vertical jump height, and body fat percentage were conducted before and after the program. Paired sample t-tests evaluated differences, repeated-measures ANOVA tested time effects, and Cohen’s d determined the magnitude of changes.The results demonstrated statistically significant improvements across all measured domains following the intervention. Participants showed enhanced aerobic capacity, increased lower-body muscular power, and reduced body fat percentage. These changes were supported by large effect sizes, confirming the practical relevance of the observed adaptations and reinforcing the efficacy of HIIT as a multidimensional training strategy for recreationally active young adults.In conclusion, this study confirms that HIIT is a potent training modality for enhancing cardiovascular endurance, muscular power, and body composition in recreationally active young adults. Its time efficiency and multi-domain benefits support its integration into youth fitness and health programs.