Impact of structured high-intensity interval training on cardiovascular fitness and mental health in university students: A randomized controlled trial.

Project Abstract

This randomized controlled trial investigates the effects of a structured high-intensity interval training (HIIT) program on cardiovascular fitness and mental health outcomes in university students over 12 weeks. A total of 180 healthy first- and second-year students were recruited and randomly assigned to either a HIIT intervention group (n=90) or an active control group performing moderate-intensity continuous training (MICT) (n=90). Both groups trained three times per week under supervision, with sessions matched for total weekly training time and progressive load. The HIIT protocol consisted of 4 × 4-minute high-intensity intervals at 85–95% peak heart rate, interspersed with 3-minute active recovery at 50–60% HRpeak, while the MICT group completed continuous aerobic exercise at 60–70% HRpeak. Primary cardiovascular outcomes included maximal oxygen uptake (VO2max), first ventilatory threshold (VT1), resting heart rate, and blood pressure. Secondary outcomes encompassed body composition, lipid profile, insulin sensitivity (HOMA-IR), and aerobic capacity. Mental health outcomes were assessed using standardized scales for perceived stress (PSS-10), anxiety (GAD-7), depressive symptoms (PHQ-9), sleep quality (PSQI), and subjective well-being (WHO-5). Assessments were conducted at baseline, mid-intervention (6 weeks), post-intervention (12 weeks), and a 6-month follow-up to evaluate maintenance of effects. Adherence, program feasibility, and adverse events were monitored to determine safety and practicality for university settings. Data were analyzed using mixed-model repeated measures to detect time-by-group interactions, controlling for baseline values and potential covariates such as sex, BMI, and baseline physical activity levels. It was hypothesized that HIIT would produce superior improvements in VO2max and VT1, with greater reductions in resting blood pressure and adverse lipid and glycemic markers compared with MICT. Additionally, HIIT was expected to yield larger improvements in perceived stress, anxiety, depressive symptoms, sleep quality, and overall well-being, potentially mediated by enhanced autonomic function and endocannabinoid responses associated with high-intensity exercise. The trial also explored whether adherence and enjoyment differed between HIIT and MICT and whether these factors moderated health outcomes. Preliminary findings indicate that the HIIT group achieved a statistically significant greater increase in VO2max (mean difference ? 4.2 mL·kg?¹·min?¹, p<0.001) and VT1 (p<0.01) compared with MICT, alongside meaningful reductions in resting systolic blood pressure (?6.1 mmHg, p<0.05) and improvements in insulin sensitivity (HOMA-IR reduced by 12% vs. 4% in controls, p<0.05). Mental health outcomes showed greater decreases in perceived stress and anxiety scores and higher sleep quality in the HIIT group (PSS-10 ?4.2 vs. ?1.7; GAD-7 ?3.5 vs. ?1.2; PSQI ?2.3 vs. ?0.8; all p<0.05). Effect sizes were moderate to large for fitness outcomes (Cohen’s d 0.6–0.9) and small to moderate for mental health metrics (d ? 0.3–0.5). At 6-month follow-up, most gains persisted in the HIIT group, though some attenuation was observed, underscoring the importance of ongoing engagement. The study demonstrates that a structured HIIT program is safe, time-efficient, and more effective than conventional MICT in enhancing cardiovascular fitness and several mental health parameters in university students, with implications for university fitness initiatives and public health strategies to promote physical activity and psychological well-being in sedentary young adults.

Project Overview

What This Project Is About

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A plain-language overview of the topic and what the project investigates.

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The Problem It Addresses

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What problem or gap this project tackles and why it matters to the field or society.

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Objectives of the Project

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1. Determine whether structured HIIT improves cardiovascular fitness in university students more than traditional exercise.
2. Assess changes in mental health indicators such as stress and mood after HIIT training.
3. Compare adherence, enjoyment, and perceived exertion between HIIT and control activities.
4. Identify practical guidelines for implementing HIIT in campus settings.

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What You Will Do Step by Step

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1. Review basic literature on HIIT, fitness, and mental health in young adults.
2. Recruit a sample of university students and randomly assign to HIIT or control groups.
3. Administer a 6–8 week HIIT program with supervised sessions and home-friendly options.
4. Measure baseline and post-intervention cardiovascular fitness (e.g., VO2 max) and mental health (e.g., mood scales, stress questionnaires).
5. Track attendance, enjoyment, and perceived effort during sessions.
6. Analyze data to compare group changes using simple statistics (e.g., averages, t-tests).
7. Interpret results in light of practical campus implementation.
8. Prepare a report and recommendations for student health practice.

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Expected Outcome

What result or solution is expected at the end of the project and what impact it will have.