HIIT and Mental Health, Quality of Life, Enjoyment and Adherence
HIIT improves quality of life and, in trials, stress, anxiety, depression and affect; enjoyment during sessions is genuinely mixed, and dropout is comparable to or better than traditional exercise where reported.
- Chest pain, pressure, or unusual shortness of breath during exertion
- Fainting, dizziness, or palpitations with exercise
- Known or suspected cardiovascular, metabolic, or renal disease without medical clearance
What the evidence says
The sources on this entry studied HIIT's effects beyond fitness: quality of life, mental health, cognition, enjoyment and affect during sessions, and adherence and dropout. Griffiths 2024 (meta-analysis, 22 studies, 1322 participants) reports that engaging in HIIT produces statistically significant improvements in physical, mental and overall quality of life in clinical and non-clinical populations at a small to moderate effect size (SMD 0.405 physical, 0.473 mental, 0.554 overall). Oliveira 2024 (meta-analysis, 29 studies, 1,227 participants) reports significant effects on VO2max, fat mass, waist circumference, testosterone and cognitive function in older adults, and concludes that HIIT might be suitable for improving fitness and health in older adults. Borrega-Mouquinho 2021 (randomised trial) reports that HIIT and MIT decreased anxiety, stress and depression and increased resilience during COVID-19 confinement, with HIIT seeming more beneficial for depression; Ram 2021 (randomised trial) reports that HIIT can improve positive affect in sedentary males with overweight or obesity (d = 0.70), although it may not significantly enhance enjoyment. On enjoyment and affect the trials differ: Heisz 2016 (randomised trial) reports that HIT can increase enjoyment and potentially adherence in sedentary young adults; Saanijoki 2015 (randomised trial) reports that a HIT session led to a significant increase in negative emotions during and after exercise in sedentary subjects compared with MIT, even though both modes led to a similar increase in aerobic fitness; Dierkes 2023 (randomised trial) reports that starting with moderate continuous training and then switching to HIIT may improve affective experience during exercise. On adherence, Reljic 2019 (meta-analysis, 55 studies, 1318 participants) reports a dropout rate of 17.6% and concludes that HIIT-based interventions are tolerable and acceptable for previously sedentary individuals, with generally lower dropout rates than commonly reported for traditional exercise programs, and Martland 2019 (umbrella review of 33 systematic reviews) reports HIIT associated with multiple benefits, with high adherence and no reported acute injuries.
- 'Pick whichever protocol is most time-efficient' (the trials on this entry differ on enjoyment and affect during sessions: Heisz 2016 reports that HIT can increase enjoyment in sedentary young adults, while Saanijoki 2015 reports a significant increase in negative emotions during and after HIT compared with MIT)
- No cure claims for any disease
- No guaranteed outcomes or fixed numeric results for any individual
- Does not replace prescribed medical treatment
- Agreement
- Not computed: the review summary this entry was written from says “mixed”, and all 6 sources that state a direction at this claim report improvement. Direction recorded for 6 of 9 sources; not yet recorded for the rest. A review summary is the written synthesis this entry was first built from; it is not one of the sources counted here.
- The claim's outcome
- Outcome not yet recorded
- Certainty
- No source states a certainty rating.
What each source measured and concluded (9)
- What it measured
- Physical, mental, and overall quality of life (QoL)
- How it measured it
- Validated questionnaires (e.g., SF-36, SF-12, HRQOL, WHOQOL, WEMBES, MLHFQ, MSqOL-54, KCCQ, EQ-5D, EQ-5D-5L, IBDQ)
- How it was read
- read in full text
- What the review says it includes
- meta-analysis, systematic review
- Studies and participants, as stated
- N = 1322 participants across 22 studies
- Heterogeneity, as stated
- LIMITATIONS: Limited activity monitoring in control groups, no blinding of assessors and participants, lack of intention to treat analysis, significant statistical heterogeneity, publication bias for physical QoL domain.
- What it measured
- Cardiorespiratory fitness (VO2max), body composition (% fat, fat mass, waist circumference), vascular variables (systolic and diastolic blood pressure), metabolic variables (glycemia), hormonal variables (testosterone), cognitive function (complex Stroop test), and quality of life.
- How it measured it
- Statistical analysis using Hedge's effect sizes (g)
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What the review says it includes
- meta-analysis
- Studies and participants, as stated
- N = 1,227 participants across 29 studies
- What it measured
- Symptoms of depression.
- How it measured it
- Validated questionnaire: 13-item Beck Depression Inventory (BDI-13).
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What it measured
- Affective state changes (positive and negative affect), enjoyment.
- How it measured it
- Affective state changes were assessed after 6 weeks of training; enjoyment was measured using a 7-point scale.
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What it measured
- Enjoyment of exercise via the 18-item Physical Activity Enjoyment Scale (PACES).
- How it measured it
- Validated questionnaire (PACES).
- Direction it states for the claim's outcome
- Improved
- Its conclusion, in its own words
- “The results point to HIT as a promising protocol for promoting exercise enjoyment and adherence in sedentary young adults.”
- How it was read
- read in full text
- What it measured
- Perceived exertion, stress, affective state, peak oxygen consumption (V ˙O2peak), peak workload (Load peak).
- How it measured it
- Borg RPE 6-20 scale, Self-Assessment Manikin rating scale, Perceived Stress Questionnaire (PSQ), Positive and Negative Affect Schedule (PANAS), visual analog scale (VAS), ramp exercise test to exhaustion.
- How it was read
- read in full text
- What it measured
- Affective attitude, intrinsic motivation, in-task affective valence, post-exercise enjoyment.
- How it measured it
- Validated questionnaires (affective attitude, intrinsic motivation), in-situ measurements during a standardized VICE session (in-task affective valence, post-exercise enjoyment).
- How it was read
- read in full text
- What it measured
- Dropout rate
- How it measured it
- Quantitative calculation from study data
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What the review says it includes
- meta-analysis
- Studies and participants, as stated
- N = 1318 participants across 55 studies
- What it measured
- Cardiorespiratory fitness, anthropometric measures, blood glucose and glycaemic control, arterial compliance and vascular function, cardiac function, heart rate, inflammatory markers, exercise capacity, muscle mass, anxiety, depression.
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
Each source below is shown with its study design and a link to the original study, or, where it is not a completed research paper, with what kind of record it is; those are not counted. This is the audit trail.
Why do some records show a record type instead of a study design?
A study design is shown for a completed, peer-reviewed paper. A registered protocol, a preprint, a conference abstract, a referee report or a book chapter has not been through peer review as a finished paper, so it is labelled for what it is, and it is counted in no source count. Where a record could not be confirmed as a completed paper at all, it says so rather than guessing. They all stay in the list, and their DOI still resolves, because the count of what was screened is part of the audit trail.
- Protocol / registration A registered plan for a review or trial, not its results.
- Preprint Posted by its authors before peer review.
- Conference abstract A conference summary rather than a peer-reviewed paper.
- Peer-review report A referee's report on a paper, not the paper itself.
- Guideline / position stand A recommendation derived from evidence, which is a step further from the data than the evidence itself.
- Book chapter A chapter in a scholarly book rather than a journal paper.
- Type not recorded Our record does not say what kind of publication this is, so it is counted in no source count. That is a gap in our data, not a judgement about the research.