# Effects of High-Intensity Interval Training vs Moderate-Intensity Continuous Training on Body Composition and Blood Biomarkers in Coronary Artery Disease Patients: A Randomized Controlled Trial

PMID: 39076951
Journal: Reviews in cardiovascular medicine
Published: 2024 Mar
Authors: Gonçalves C, Raimundo A, Abreu A, Pais J, Bravo J

## Question

In low-risk coronary artery disease patients after coronary events and angioplasty, how do supervised HIIT and MICT compare with control advice for blood pressure, body composition, and blood biomarkers over six weeks?

## Summary

This randomized trial tested 6 weeks of supervised treadmill HIIT, moderate continuous treadmill training, or control advice in coronary artery disease patients about two months after angioplasty. Both exercise programs improved blood pressure, body composition, and several biomarkers versus control. HIIT showed larger improvements than MICT for body fat mass, waist circumference, HbA1c, and TSH. Adherence was 96% in both exercise groups and no adverse events were reported during the exercise interventions.

## Population

- Low-risk coronary artery disease patients referred to community exercise after coronary event/angioplasty.
- Sample size: 69
- Age: Group means 50-57 years; inclusion 18-80 years.
- Sex: Mostly male, about 14% women.
- Fitness level: Clinical cardiac rehabilitation population with baseline VO2peak about 23-25 mL/kg/min.
- Health status: CAD, mostly post-PCI, NYHA I-II, LVEF at least 45%, many with diabetes, hypertension, dyslipidemia, and cardioprotective medications.

## Methodology

- Randomized controlled trial with HIIT, MICT, and control groups.
- 6 weeks
- Community-based supervised cardiac rehabilitation exercise program in Portugal.
- Randomized and controlled study design.

## Protocol

- HIIT cardiac rehabilitation.
- Modality: Treadmill.
- Work intervals: 4 minutes.
- Recovery: 1 minute at 40% HRpeak.
- Sets or repetitions: 4 intervals.
- Intensity: 85-95% HRpeak, Borg CR10 6-9.
- Session duration: About 38-43 minutes including warm-up and cool-down.
- Frequency: 3 sessions/week.
- Program length: 6 weeks.
- Progression: Gradually increased intensity toward hard to very hard RPE.
- MICT and control.
- Modality: Treadmill or lifestyle advice.
- Work intervals: 28 minutes continuous MICT.
- Sets or repetitions: One continuous bout.
- Intensity: 70-75% HRpeak, Borg CR10 3-5.
- Session duration: About 38-43 minutes including warm-up/cool-down.
- Frequency: 3 sessions/week for MICT.
- Program length: 6 weeks.
- Progression: Intensity adjusted under supervision; control received exercise/diet advice only.

## Outcomes

### Blood pressure
Status: improved
Both HIIT and MICT lowered systolic and diastolic BP compared with control.

HIIT SBP -9 mm Hg and DBP -6 mm Hg, p<0.001; MICT SBP -8 mm Hg and DBP -6 mm Hg, p<0.001.

### Body composition
Status: improved
HIIT and MICT improved body composition, with larger reported body-fat-mass and waist-circumference improvements for HIIT.

Abstract reports body fat mass delta HIIT 4.5% vs MICT 3.2%, and waist circumference delta HIIT 4.1% vs MICT 2.5%.

### Blood biomarkers
Status: improved
Exercise improved several biomarkers versus control; HIIT showed larger HbA1c and TSH changes than MICT.

Abstract reports HbA1c delta HIIT 10.4% vs MICT 32.3% and TSH delta HIIT 16.5%, p=0.007 vs MICT 3.1%, p=0.201; direction wording in source should be reviewed before consumer display.

### Adherence and safety
Status: improved
Both exercise protocols had high adherence and no adverse events.

96% adherence in HIIT and MICT; no adverse events during exercise interventions.

## Practical Insights

- HIIT evidence in CAD should be used as clinical-rehab content, not generic workout advice.
- For cardiac contexts, RPE plus HR is useful because beta-blocker therapy can alter HR response.
- Long-interval HIIT can be safe in selected low-risk CAD when tightly screened and supervised.

## Limitations

- Small sample size.
- Short intervention.
- Selected low-risk CAD patients only.
- Some achieved intensity details were in supplementary material not extracted here.

## Safety And Adherence

- No adverse events occurred during HIIT or MICT exercise interventions.
- Participants were selected low-risk CAD patients and were monitored by a physiologist.
- The protocol excluded uncontrolled angina, arrhythmia, ischemic signs/symptoms, and severe comorbid limitations.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/39076951/) (pubmed)
- [DOI](https://doi.org/10.31083/j.rcm2503102) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11263861/) (full text)

## Agent Guidance

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