HIIT
Interval training lowers insulin resistance and, when fasting glucose is raised, glucose. HDL rises a little more than with steady endurance work. Triglycerides and LDL get no row of their own.
Order of magnitude
Two to three HIIT sessions per week for at least two weeks. The dose comes from the HIIT studies, not from the endurance entry.
Jelleyman 2015: insulin resistance versus control SMD −0.49; fasting glucose −0.92 mmol/L only in the diabetes-risk subgroup. Batacan 2017: short-term HIIT lowered glucose in overweight, with no insulin or lipid-profile effect. Wood 2019: HIIT is not superior to MICT for TC, TG or LDL; it raises HDL 0.07 mmol/L more. Ferritin and uric acid stay without a row.
Effects in detail
Each row is a directed edge from our database, with range, latency, evidence grade and the condition under which it applies at all.
| Marker | Effect | Latency | Mode of action | Outcome | Evidence | Condition | Sources |
|---|---|---|---|---|---|---|---|
| HOMA-IR | helps. Lowers 10–30 % Derived from Jelleyman 2015 SMD −0.49 versus control, roughly 0.5 HOMA units if SD ≈ 1 at a baseline of 3.0. Batacan 2017 found no insulin effect. No separate insulin row. | 2–12 weeks | chronic | no | Evidence grade B | applies regardless of the starting value | |
| Fasting glucose | helps. Lowers 10–18 % Jelleyman 2015 −0.92 mmol/L only in diabetes risk or type 2 diabetes, at about 110 mg/dL. No overall effect in mixed samples. The row therefore only applies from 100 mg/dL. | 2–12 weeks | chronic | unclear | Evidence grade B | Glucose at or above 100 mg/dL |
What this measure costs
Counteracting effects of the same measure.
No counteracting effect is on file for this measure. That does not mean there is none, only that we found no defensible edge.
Moves without implying progress
Informational or no established effect: the marker moves or was checked, and that is not progress.
| Marker | Effect | Latency | Mode of action | Outcome | Evidence | Condition | Sources |
|---|---|---|---|---|---|---|---|
| HDL cholesterol | moves, and does not count. Raises 5–12 % Wood 2019: +0.07 mmol/L HDL versus steady endurance training, counted on top of the aerobic HDL rise of about 2.1 mg/dL. Raising HDL is not a treatment goal. | 4–12 weeks | chronic | no | Evidence grade B | applies regardless of the starting value |
Sources
Full details of every study the rows above rely on.
Effects of exercise training on blood lipids: a systematic review and meta-analysis of randomised controlled trials
Smart et al. · Sports Medicine · 2025 · Meta-analysis
The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis
Jelleyman et al. · Obesity Reviews · 2015 · Meta-analysis
HIIT is not superior to MICT in altering blood lipids: a systematic review and meta-analysis
Wood et al. · BMJ Open Sport & Exercise Medicine · 2019 · Meta-analysis
Effects of high-intensity interval training on cardiometabolic health: a systematic review and meta-analysis of intervention studies
Batacan et al. · British Journal of Sports Medicine · 2017 · Meta-analysis