A systematic review and meta-analysis of the effectiveness of high-intensity interval training for physical fitness in university students | BMC Public Health

To our knowledge, this study is the first systematic review and meta-analysis to evaluate the effectiveness of HIIT specifically among university students. Fifteen studies reaching the criteria were identified, with data extracted and synthesized for meta-analysis. The results indicate that, compared to aerobic training, moderate-intensity training, or no training controls, HIIT significantly reduces BMI, BF%, WHR, and HR, and significantly improves VO₂max and muscle strength. Furthermore, Intervention duration played a significant role in enhancing muscle strength, with durations longer than eight weeks showing greater benefits compared to interventions lasting eight weeks or less.

However, the methodological quality of the included studies varied. Of the 15 studies, only 4 were rated as high quality. Many studies did not report whether blinding was implemented during outcome assessments, failed to describe participants’ adherence to the intervention protocols, or lacked information on follow-up data. Additionally, the sample sizes in these studies were generally small, limiting the generalizability of the findings.

The studies we reviewed employed a range of modalities, including running, sprint, bodyweight exercises, battle ropes with kettlebell combinations, and Tabata. Each of these protocols emphasizes different aspects of fitness. For example, running and sprint-based protocols predominantly target cardiovascular capacity and improve VO₂max, whereas bodyweight training and combined modalities engage both muscular endurance and strength alongside aerobic benefits. Tabata protocols, characterized by very brief, high-intensity bursts with short recovery periods, offer a balanced approach that can simultaneously stimulate metabolic and neuromuscular adaptations. Additionally, small-sided games (SSGs), a novel HIIT strategy, integrate multiple fitness components—enhancing agility, coordination, and tactical skills along with cardiovascular function—by simulating sport-specific activities in a competitive, team-based setting. Recognizing these distinctions can inform the design of HIIT programs that are specifically tailored to target the diverse health and fitness needs of university students, ensuring that the chosen modality aligns with desired outcomes while considering factors such as exercise intensity, duration, and baseline fitness levels.

Body composition

The findings demonstrate that HIIT significantly improves body composition metrics among university students, including reductions in body mass index (BMI), body fat percentage (BF%), and waist-to-hip ratio (WHR), findings that are consistent with previous studies [26, 49, 50]. From a physiological perspective, HIIT promotes energy expenditure both during and after exercise (EPOC effect) through repeated high-intensity efforts in a short period, enhancing fat oxidation rates and basal metabolic levels [51]. Furthermore, compared to MICT, HIIT offers a more appealing and practical option for time-constrained university students who are particularly sensitive to the effectiveness of exercise, supporting its broader application in health management [52].

A notable finding of this study is that subgroup analysis approached significance(P = 0.06), suggesting that short-interval HIIT may be more effective in reducing BF% compared to long-interval HIIT, which is consistent with findings from previous studies [53]. This outcome may be attributed to the short rest intervals reducing the reliance on glycolysis for energy production, thereby increasing the proportion of energy derived from aerobic metabolism [54]. This shift may enhance overall metabolic efficiency, promoting greater fat oxidation and improved endurance capacity. The increased aerobic contribution during shorter rest intervals allows participants to sustain exercise intensity for longer periods, potentially amplifying the physiological benefits of HIIT. Therefore, for college students whose main goal is to lose fat, if their physical foundation and health status allow, they can moderately adopt the short-interval HIIT mode within a safe range to obtain higher fat oxidation efficiency per unit time. Moreover, given the academic pressures and time constraints commonly faced by university students, short-interval HIIT offers greater flexibility in terms of duration and intensity, making it easier to integrate into campus health education or physical education programs. However, when intervening, it is necessary to consider personal physical ability, sports experience, and tolerance to high-intensity training; excessively shortening rest time or blindly extending working hours may lead to excessive fatigue or sports injuries. Finally, given the relatively small sample size in this study, this result should be interpreted with caution.

Cardiorespiratory fitness

HIIT interventions significantly improve VO₂max and reduce resting or exercise-related heart rate (HR), further supporting the notion that HIIT is effective in enhancing cardiorespiratory fitness [25]. VO₂max is a core indicator of an individual’s aerobic capacity and cardiorespiratory function, while HR serves as a critical parameter for monitoring exercise intensity and cardiovascular load. During each high-intensity interval of HIIT, HR rapidly elevates to higher zones, requiring the heart to efficiently supply oxygen-rich blood within a short time. This process not only strengthens myocardial contraction but also improves the compliance of peripheral blood vessels [55]. During overextended intervention periods, these physiological adaptations become more pronounced, leading to significant improvements in both VO₂max and HR.

For university students, enhanced cardiorespiratory fitness contributes to better athletic performance and offers potential protective effects against chronic conditions such as cardiovascular diseases and metabolic syndrome [56]. Incorporating HIIT-based cardiorespiratory training into university physical education programs or exercise guidance can provide students with an efficient and diverse workout experience within limited time constraints, while also promoting overall health in the young adult population [57]. Additionally, individual differences in fitness levels must be considered. For students with weaker baseline cardiorespiratory function or underlying cardiovascular risks, HIIT protocols should be carefully tailored, including adjustments to work duration, rest intervals, and exercise intensity, to prevent excessive fatigue or exercise-related injuries. Tailoring such interventions ensures both the safety and effectiveness of HIIT for diverse student populations.

Physical fitness

The meta-analysis in this study highlights the significant effects of HIIT on improving the muscle strength of university students, Additionally, two studies reported enhancements in agility, while one study demonstrated speed improvements. HIIT exerts substantial stimuli on the neuromuscular and energy metabolism systems by achieving high-intensity loads repeatedly in a short period, facilitating rapid and efficient improvements in physical performance and fitness metrics [58].

Notably, the study found that HIIT protocols lasting longer than eight weeks demonstrated more pronounced improvements in muscle strength among university students. Extended intervention durations provide sufficient time for physiological adaptations such as mitochondrial biogenesis, muscle fiber type transformation, and enhanced neuromuscular conduction efficiency [59]. Over these longer training cycles, the students’ physical capacities adapt more effectively to high-intensity loads, resulting in greater gains in metrics such as maximal strength, speed, and aerobic-anaerobic metabolic efficiency. However, in the subgroup analysis of rest intervals, no significant differences were found in the effects of HIIT on muscle strength. This suggests that variations in rest interval duration alone may not be a decisive factor in determining strength adaptations within HIIT protocols. One possible explanation is that muscle strength improvements depend more on overall training volume, intensity, and resistance load [60]. While shorter rest intervals are often associated with greater metabolic stress and endurance adaptations, longer rest intervals may allow for higher force production and better neuromuscular recovery, potentially benefiting strength development. However, since the overall effect of rest intervals on muscle strength was not significant, it is possible that other training variables—such as exercise selection, resistance level, and total workload—play a more dominant role in strength gains. Moreover, the nature of HIIT exercises used in the included studies may have influenced these findings. Many HIIT protocols prioritize aerobic-based or bodyweight exercises (e.g., jumping jacks, burpees, and sprints) rather than high-resistance strength exercises, which are traditionally more effective for increasing maximal muscle strength. Consequently, the rest interval duration within these HIIT sessions may not have been a limiting factor for strength development.

Unique characteristics and novel insights in university students

An important consideration in interpreting our findings is the distinct nature of university students compared to other adult groups. University students experience more flexible schedules, unique academic pressures, and rapid developmental changes that can influence their physiological and psychological responses to exercise. Unlike many working adults with established routines, students face fluctuating stress levels, variable social engagements, and intermittent periods of intense study—all of which may enhance their neuroplasticity and metabolic responsiveness to time-efficient, high-intensity training protocols [61]. Additionally, the communal university environment, with its strong social support and group dynamics, tends to boost adherence and motivation, potentially amplifying the positive outcomes of HIIT. Recognizing these unique lifestyle attributes underscores the need for tailored HIIT interventions that optimize both short-term performance gains and long-term health outcomes in university students, distinguishing their responses from those of the broader adult population.

This study diverges from previous research in several key ways. While numerous recent studies have established the benefits of HIIT for reducing body fat and enhancing cardiorespiratory fitness [17, 62], our meta-analysis specifically examines university students—a group with distinct lifestyle patterns and adherence challenges. In doing so, we uncovered a novel, duration-dependent effect on muscle strength, with interventions lasting more than eight weeks eliciting significantly greater neuromuscular adaptations, an outcome that has not been prominently reported in prior literature [17, 63, 64]. Additionally, our analysis distinguishes between different HIIT modalities—ranging from traditional running and sprint-based protocols to Tabata and small-sided games, thereby offering fresh insights into how specific exercise formats can be strategically tailored to optimize both physical and functional outcomes in a university setting. These nuanced findings suggest that, beyond the established benefits, HIIT programs for young adults may need to be customized not only in terms of intensity and duration but also by selecting the modality that best aligns with the unique demands and preferences of the academic environment.

This study also uncovered an intriguing finding regarding work-rest ratios. In our subgroup analysis, no significant differences emerged across any physical indicators—such as BF%, VO₂max, or muscle strength—when comparing various work-rest ratios. This contrasts with earlier studies that have reported variable physiological adaptations with different work-rest configurations in HIIT protocols [28]. One possible explanation is that, within the university student population, factors like overall adherence, baseline fitness, and external stressors (e.g., academic pressures) may overshadow the effects of work-rest ratio modifications. Alternatively, the range of work-rest ratios employed in the studies we reviewed might have been too narrow to reveal distinct differences. Further investigation is warranted to elucidate how work-rest configurations interact with the unique lifestyle and physiological characteristics of university students.

Incorporating HIIT into student health initiatives

The practical applications of our findings for university settings are multifaceted and warrant a tailored approach that leverages the unique characteristics of the campus environment. First, universities inherently foster a communal and group-oriented atmosphere. This social structure can be harnessed by implementing group-based HIIT programs, which not only promote adherence through peer support and accountability but also enhance the overall enjoyment and motivation of exercise sessions. Organized group HIIT classes or intramural competitions can capitalize on the inherent group dynamics of student life, transforming physical activity into a social event that reinforces campus community.

Second, the high receptivity of university students to novel and technology-driven initiatives presents another opportunity. Integrating HIIT programs with advanced wearable technologies, mobile applications, or even gamification elements can increase engagement and provide real-time feedback. For instance, using wearable devices to monitor heart rate and track progress, coupled with app-based challenges and rewards, can appeal to tech-savvy students and create a more interactive and personalized exercise experience.

Given the flexible nature of university schedules, HIIT can be woven throughout campus life to promote consistent physical activity. For example, brief HIIT sessions—or “exercise snacks“ [65]—can be integrated into physical education classes, orientation events, or even during short breaks between lectures to interrupt sedentary periods. Rather than presenting these short bouts as a complete intervention on their own, it is more effective to position them within a comprehensive movement strategy that considers variations in intensity, frequency, and individual fitness levels. By tailoring these flexible exercise opportunities to meet the diverse needs of students, universities can cultivate a proactive health management culture that supports sustained engagement and overall well-being.

Finally, collaboration between university athletic departments, student health centers, and academic units can facilitate the development of comprehensive health initiatives that include HIIT as a core component. Such partnerships could support research-based adjustments to HIIT protocols tailored specifically for student populations, continuously optimizing program design based on feedback and emerging evidence. In doing so, universities not only promote physical health but also contribute to improved mental well-being and academic performance, thereby enhancing the overall student experience.

Future direction

Although this study demonstrated that intervention duration effectively improved muscle strength in university students—further research is needed to identify the optimal configurations of intervention frequency and training duration. Moreover, when investigating these parameters, it is crucial to control confounding factors such as participants’ baseline health status. Tailoring protocols to specific subgroups (e.g., beginners versus experienced individuals or across different genders and age ranges) may maximize training efficacy while ensuring safety. Such refined protocols would provide actionable guidelines for designing effective and inclusive HIIT interventions for university populations.

In addition, future studies should focus on observing the long-term maintenance of health outcomes following the completion of HIIT interventions. Particular attention should be given to changes in lifestyle, exercise habits, and physical function during the post-intervention period. Longitudinal studies with follow-up periods of six months, one year, or longer would provide valuable insights into the sustained effects of HIIT on health management in university students. Moreover, these studies could identify intervention strategies that help participants retain the health benefits initially gained through HIIT.

Lastly, With the increasing prevalence of wearable devices and digital exercise platforms, future research could explore the integration of technologies such as heart rate monitoring, motion tracking, virtual reality (VR), and gamification into HIIT interventions. These advancements could provide real-time monitoring and instant feedback, potentially enhancing university students’ interest and adherence to exercise programs.

Strengths and limitations

This is the first study that provides a systematic and comprehensive meta-analysis of HIIT interventions targeting university students (specific population, such as academic stress and limited time), synthesizing findings across diverse studies to identify overall trends and effects. Furthermore, the study’s subgroup analyses, examining factors such as intervention duration and rest interval, provide nuanced insights into how specific HIIT configurations influence outcomes, aiding in the development of optimized protocols. Findings emphasize the potential of HIIT as a time-efficient and versatile exercise strategy, particularly suited to university settings, with applications in physical education and health promotion programs.

However, there are some limitations in this study. Significant heterogeneity was observed among included studies, likely due to variations in protocols, participant characteristics, and measurement methods, which may affect the reliability of pooled results. In addition, many studies had methodological limitations, such as inadequate blinding, small sample sizes, and a lack of adherence or follow-up data, which may introduce bias into the results. These strengths and limitations underline the importance of further research to address gaps and build upon the foundational insights provided by this study.