# Effect of HIIT Training Modality in People with Pre-Diabetes

PMID: 41718176
Journal: Journal of Functional Morphology and Kinesiology
Published: 2026-01-22
Authors: Tene T, Zambrano-Villacres R, Puruncajas-Rodríguez CI, Tettamanti Miranda D, Tello-Moreno MC, Campos-Moposita AP, Caiza Lema SJ, Montalvan M, Tene-Fernandez R

## Question

In adults with prediabetes, how do HIIT plus hypocaloric diet, HIIT alone, and hypocaloric diet alone compare for metabolic risk and fitness outcomes?

## Summary

In adults with prediabetes, a 13-week program combining HIIT with a hypocaloric diet produced the largest improvements in fasting glucose, VO2max, systolic blood pressure, BMI, and diabetes-risk score compared with HIIT-only or diet-only groups. The HIIT protocol details were less precise than ideal, the sample was clinical and convenience-based, and the diet co-intervention makes it hard to isolate the independent HIIT effect.

## Population

- Adults with prediabetes.
- Sample size: 68
- Age: Group means 42.22-46.60 years.
- Sex: 73.5% women.
- Fitness level: Clinical lifestyle-intervention sample; baseline activity documented but not tightly controlled.
- Health status: Prediabetes.

## Methodology

- Controlled longitudinal single-blind three-arm parallel intervention.
- 13 weeks including adaptation and 12-week structured intervention.
- Type C Latacunga Health Center, Ecuador.
- Randomized and controlled study design.

## Protocol

- HIIT with or without hypocaloric diet.
- Modality: Mixed running, cycling, and bodyweight exercise.
- Work intervals: 30-120 s high-intensity bouts; practical section also describes 1-4 min work intervals.
- Recovery: Recovery near 50% HRmax; practical section describes 1-2 min at 50-60% HRmax.
- Sets or repetitions: 4-8 sets.
- Intensity: 80-95% HRmax work using Karvonen equation and chest-strap HR.
- Session duration: About 30 min.
- Frequency: 2-3 sessions/week in practical guidance.
- Program length: 12 structured weeks after adaptation week.
- Progression: Individual feedback/intensity adjustment if target missed in more than 20% of intervals.
- HIIT only or hypocaloric diet only.
- Modality: HIIT alone or 1800 kcal hypocaloric diet alone.
- Intensity: Diet arm: 1800 kcal plan; HIIT arm same exercise without diet.
- Frequency: Diet monitored weekly; HIIT frequency as intervention.
- Program length: 13 weeks.

## Outcomes

### Fasting glucose
Status: improved
Combined HIIT plus diet had the largest glucose reduction.

Group A 111.94 to 91.28 mg/dL; post-test group difference p < .001.

### VO2max
Status: improved
VO2max improved most in combined HIIT plus diet.

Group A 21.27 to 24.02; post-test group difference p < .001.

### Blood pressure and diabetes risk
Status: improved
Systolic blood pressure and diabetes-risk score improved, favoring the combined intervention.

Systolic BP p < .001; diabetes risk p = .038.

### Body weight and waist
Status: no clear change
Between-group differences were not significant for body weight or waist circumference.

Body weight p = .271; waist p = .174.

## Practical Insights

- Combined diet and supervised HIIT may be effective for prediabetes risk improvement.
- Do not isolate the combined-program effect as a pure HIIT effect.
- Use HR/RPE targets and professional oversight for clinical users.

## Limitations

- Clinical prediabetes population.
- Convenience single-center sample.
- Short duration with no maintenance follow-up.
- Diet co-intervention confounds exercise-specific effects.
- Protocol details are imprecise and mixed-modality.
- No detailed adverse-event reporting.

## Safety And Adherence

- No concrete adverse-event details were reported.
- Professional supervision, HR monitoring, and RPE monitoring were used.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41718176/) (pubmed)
- [DOI](https://doi.org/10.3390/jfmk11010048) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12921740/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.