# Comparative effects of high-intensity interval training and moderate-intensity continuous training on weight and metabolic health in college students with obesity PMID: 39019997 Journal: Scientific Reports Published: 2024-07-17 Authors: Song X, Cui X, Su W, Shang X, Tao M, Wang J, Liu C, Sun Y, Yun H ## Question How do energy-matched HIIT and moderate-intensity continuous training compare for body composition and metabolic health in male and female college students with obesity? ## Summary In college students with obesity, 8 weeks of supervised treadmill HIIT and energy-matched moderate continuous training both improved weight, body composition, and several metabolic markers. HIIT produced larger reductions in body fat percentage and triglycerides, with some sex-specific differences in LDL-C and ALT. The trial was small, had no non-exercise control group, and diet was not rigorously measured. ## Population - Forty full-time college students with obesity completed the study: male HIIT n=10, female HIIT n=10, male MICT n=10, female MICT n=10. Participants were 18-25 years old with BMI at least 25, stable recent weight, and no major metabolic, cardiovascular, orthopedic, infectious, or hormonal disease. - Sample size: 40 - Age: 18-25 years; group means about 21-22 years - Sex: 20 male and 20 female - Fitness level: College students with obesity; no extra exercise - Health status: BMI at least 25; screened free of major metabolic/cardiovascular/orthopedic disease ## Methodology - Randomized 8-week exercise intervention - 8 weeks - Supervised evening treadmill sessions - Randomized and controlled study design. ## Protocol - Treadmill HIIT; details: HIIT treadmill sessions 3 times/week for 8 weeks: 3 min warm-up at 35% HRmax, 4 x 4 min at 85-90% HRmax interspersed with 3 min at 50-60% HRmax, then cooldown/stretching. Energy expenditure was matched to MICT using measured oxygen consumption. - Modality: Treadmill running/walking. - Work intervals: 4 min. - Recovery: 3 min. - Sets or repetitions: 4 intervals per HIIT session. - Intensity: HIIT 85-90% HRmax; recovery 50-60% HRmax; MICT 60-70% HRmax. - Session duration: HIIT training duration 28 min plus warm-up/cooldown; MICT 35 min plus warm-up/cooldown. - Frequency: 3. - Program length: 8 weeks. - Progression: No formal progression reported; intensity targets held constant. - Energy-matched treadmill MICT; details: MICT treadmill sessions 3 times/week for 8 weeks: 3 min warm-up at 35% HRmax, 35 min at 60-70% HRmax, then cooldown/stretching. Diet was intended to remain usual with general advice and daily steps recorded. - Modality: Treadmill running/walking. - Work intervals: 4 min. - Recovery: 3 min. - Sets or repetitions: 4 intervals per HIIT session. - Intensity: HIIT 85-90% HRmax; recovery 50-60% HRmax; MICT 60-70% HRmax. - Session duration: HIIT training duration 28 min plus warm-up/cooldown; MICT 35 min plus warm-up/cooldown. - Frequency: 3. - Program length: 8 weeks. - Progression: No formal progression reported; intensity targets held constant. ## Outcomes ### Body weight Status: improved Weight decreased significantly in all groups: female MICT -4.89 +/- 1.82 kg, male MICT -5.45 +/- 2.18 kg, female HIIT -5.75 +/- 2.01 kg, male HIIT -6.92 +/- 1.08 kg; all p<.001 within group. p<.001 ### Body fat percentage Status: improved Body fat percentage decreased more in HIIT: male HIIT -23.71%, female HIIT -26.76%, male MICT -9.81%, female MICT -7.16%; post-training between-protocol differences were significant. ### Triglycerides Status: improved Triglycerides were lower after HIIT than MICT: female HIIT 18.91% lower and male HIIT 16.39% lower than corresponding MICT groups. ### LDL cholesterol Status: improved LDL-C post-training differed between training protocols in males only, with male HIIT 22.13% lower than male MICT. ### HDL cholesterol Status: improved HDL-C improved in both training protocols without a clear between-group difference. ## Practical Insights - Heart-rate monitored 4 x 4 HIIT can be a time-efficient alternative to longer moderate treadmill training for young adults with obesity. - Metabolic claims should stay specific: strongest comparative signals were body fat percentage and triglycerides. - Because diet was not measured rigorously, weight-loss claims should avoid attributing all change solely to exercise intensity. ## Limitations - Small subgroups of 10 participants each. - No non-exercise control group. - Diet was not formally tracked with food records or recalls. - HRmax may have changed over training. - Some internal inconsistency in reporting of uric acid and selected p-value thresholds. ## Safety And Adherence - No adverse events were reported. - Six recruited participants did not complete the intervention and four had missing data; reasons were not described. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/39019997/) (pubmed) - [DOI](https://doi.org/10.1038/s41598-024-67331-z) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11255215/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.