HIIT Improves Cardiometabolic and Vascular Risk Factors
Meta-analyses report that HIIT lowered blood pressure (Edwards 2023; Carpes 2021), improved flow-mediated dilation against continuous training and controls in people with metabolic disorders and cardiovascular diseases but not in those free of cardiometabolic diseases (Khalafi 2022) and against continuous training in groups including people with heart failure, hypertension, metabolic syndrome, coronary artery disease or type 2 diabetes (Ramos 2015), improved HDL cholesterol but not other lipids relative to continuous training (Wood 2019), improved hemostatic and arterial-stiffness markers (Jiao 2025) and can enhance mitochondrial indices in overweight and obese adults (Hadjispyrou 2023).
Coordinate with clinicians if on glucose- or blood-pressure-lowering medication
- 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
- Poorly controlled diabetes or hypertension
What the evidence says
The sources on this entry are nine meta-analyses of HIIT and cardiometabolic and vascular risk factors: blood pressure, flow-mediated dilation, blood lipids, hemostatic and arterial-stiffness markers, and mitochondrial indices, compared with moderate continuous training and with controls. For blood pressure, Edwards 2023 (97 studies, 3399 participants) reports a systolic reduction of 4.08 mmHg and support for HIIT in the clinical management of cardiometabolic risk factors, particularly for reducing blood pressure in hypertensive individuals; Carpes 2021 (10 studies, 266 participants) reports that HIIT reduced blood pressure in older adults (systolic MD -7.36, diastolic MD -5.48 mmHg), with HIIT and MICT providing comparable reductions; Way 2019 (7 studies, 346 participants) reports a larger reduction in night-time diastolic blood pressure with HIIT than with MICT (ES -0.456). For vascular function, Khalafi 2022 (36 studies, 1,437 participants) reports HIIT effective for improving vascular function in individuals with metabolic disorders and cardiovascular diseases, with FMD 1.59% higher than MICT and 3.80% higher than control; Ramos 2015 (7 studies, 182 participants) reports HIIT more effective than MICT at improving brachial artery vascular function (mean difference 2.26% in FMD), especially with a protocol like 4 × 4 HIIT three times a week for at least 12 weeks; Sabouri 2022 (8 studies, 208 participants) reports that exercise training, particularly HIIT, could improve endothelial function in overweight and obese adults. Wood 2019 (26 studies, 823 participants) reports that HIIT appeared to significantly improve HDL cholesterol compared with MICT, and that “Neither HIIT nor MICT is superior for altering TC, TRG, or LDL-C, or TC-HDL-C ratio”. Jiao 2025 (68 studies, 2,679 participants) reports that HIIT notably improved fibrinogen, carotid-femoral pulse wave velocity, augmentation index and flow-mediated dilation compared with MICT or usual care. Hadjispyrou 2023 (28 studies, 530 participants) reports that HIIT can be used to enhance mitochondrial-associated indices in overweight and obese individuals, and that this improvement may be health-status dependent.
- 'HIIT does nothing for metabolic conditions' (meta-analyses report blood-pressure reductions in hypertensive individuals (Edwards 2023) and improved endothelial function in overweight and obese adults (Sabouri 2022); clearance and clinician coordination are this entry's own cautions)
- No cure claims for any disease
- No guaranteed outcomes or fixed numeric results for any individual
- Does not replace prescribed medical treatment
- Does not cure metabolic disease; supports risk-factor management
- Agreement
- The review summary this entry was written from does not say whether its sources agree at this claim. Direction recorded for 7 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
- A source states a certainty rating for 1 outcome.
What each source measured and concluded (9)
- What it measured
- Systolic blood pressure (sBP) and diastolic blood pressure (dBP)
- How it measured it
- Data from randomized controlled trials (RCTs) reporting changes in sBP and dBP
- 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 = 3399 participants across 97 studies
- Heterogeneity, as stated
- Significant heterogeneity and publication bias
- What it measured
- Blood pressure (systolic and diastolic)
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What the review says it includes
- systematic review and meta-analysis
- Studies and participants, as stated
- N = 266 participants across 10 studies
- What it measured
- Central arterial stiffness (via pulse wave velocity and augmentation index), 24-hour blood pressure responses (night-time diastolic and daytime systolic and diastolic BP).
- How it measured it
- Validated methods: pulse wave velocity and augmentation index for arterial stiffness; sphygmomanometers for BP.
- 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, systematic review
- Studies and participants, as stated
- N = 346 participants across 7 studies
- What it measured
- Vascular function via brachial artery flow-mediated dilation (FMD).
- How it measured it
- Laboratory test; FMD is a validated measurement tool.
- How it was read
- read in full text
- What the review says it includes
- systematic review and meta-analysis
- Studies and participants, as stated
- N = 1,437 participants across 36 studies
- Heterogeneity, as stated
- LIMITATIONS: Significant heterogeneity in results; lack of studies using Sprint Interval Training (SIT).
- What it measured
- Vascular function via brachial artery flow-mediated dilation (FMD).
- How it measured it
- Brachial artery FMD, a validated method.
- 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, systematic review
- Studies and participants, as stated
- N = 182 participants across 7 studies
- What it measured
- Vascular endothelial function via flow-mediated dilation (FMD)
- How it measured it
- Laboratory test (flow-mediated dilation)
- 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 = 208 participants across 8 studies
- What it measured
- Changes in blood lipid profiles: total cholesterol (TC), triglycerides (TRG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and the TC/HDL-C ratio.
- How it measured it
- Pre-post intervention lipid measurements reported in mmol/L or mg/dL, likely through laboratory tests.
- How it was read
- read in full text
- What the review says it includes
- systematic review and meta-analysis
- Studies and participants, as stated
- N = 823 participants across 26 studies
- What it measured
- Platelet count (PLT), fibrinogen (FIB), D-dimer (D-D), carotid-femoral pulse wave velocity (cfPWV), augmentation index (AIx), AIx normalized to a heart rate of 75 beats·min−1 (AIx@75HR), flow-mediated dilation (FMD), and brachial flow-mediated dilation normalized (nFMD).
- How it measured it
- Standardized mean differences (SMD) of changes from baseline to post-intervention.
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What the review says it includes
- systematic review and meta-analysis
- Studies and participants, as stated
- N = 2,679 participants across 68 studies
- What it measured
- Citrate synthase (CS), cytochrome C (COX-IV), beta-hydroxyacyl CoA-dehydrogenase (β-HAD), PGC-1α, SIRT1, mitochondrial respiratory chain complexes (Complex I-V), VO2max.
- How it measured it
- Data from multiple studies expressing these indices in terms of protein content, activity, gene expression, and mitochondrial respiratory capacity.
- Direction it states for the claim's outcome
- Improved
- How it was read
- read in full text
- What the review says it includes
- systematic review and meta-analysis
- Studies and participants, as stated
- N = 530 participants across 28 studies
Certainty ratings the sources state (1)
- Rating, as the source states it
- low
- Framework
- not named by the source
- Applies to
- Some primary outcomes were assessed with low-quality evidence
- Stated by
- Hadjispyrou et al. (2023)
Every source below is shown with its study design and links to the original study. This is the audit trail.