What is the clinical evidence from this study?

Study design: RCT. Population: Metabolic syndrome (MetS). Intervention: High-intensity interval training (HIIT) vs. Medical treatment alone. Primary outcome: Myocardial function (p=0.002).

What question did this study set out to answer?

To determine whether repeated high-intensity interval training can improve myocardial function in patients with metabolic syndrome over 16 months.

May 8, 2026Open Access

Effects of repeated periods of high-intensity interval training on myocardial function in patients with metabolic syndrome: A 16-month follow-up

Key Result

Two periods of high-intensity interval training, spaced one year apart, significantly improved myocardial function in middle-aged adults with metabolic syndrome compared to medical treatment alone (p=0.002).

Key Points

To determine whether repeated high-intensity interval training can improve myocardial function in patients with metabolic syndrome over 16 months.
Participants with metabolic syndrome underwent two periods of HIIT, each lasting 4 months, spaced one year apart.
Myocardial function and metabolic syndrome components were assessed at baseline, post-first HIIT, and post-second HIIT.
An intention-to-treat analysis using linear mixed model was conducted.
Significant improvement in myocardial function was observed in the HIIT group (Group*Time p = 0.002).
No significant differences in ejection fraction (Group*Time p = 0.964) and MetS z-score changes (Group*Time p = 0.419) between groups.

Study Design

Type

RCT

Structured PICO

Do repeated periods of high-intensity interval training improve myocardial function in middle-aged adults with metabolic syndrome?

Population

Middle-aged adults receiving medical treatment for metabolic syndrome (MetS)

Intervention

Two periods of high-intensity interval training (HIIT), spaced one year apart, added to medical treatment

Comparator

Medical treatment alone

Outcome

Myocardial functionsurrogate

Two periods of high-intensity interval training spaced a year apart significantly improved myocardial function in middle-aged adults with metabolic syndrome compared to medical therapy alone.

Main Result

p-value: p=0.002

Abstract

BACKGROUND: One program of exercise training is useful to improve myocardial function in patients with cardiovascular disease (CVD) but not in patients with CVD risk factors. However, it is unknown whether repeated periods of high-intensity interval training (HIIT) can reverse the progressive myocardial dysfunction observed in patients with metabolic syndrome (MetS). We aimed to follow MetS patients for 16 months and determine the effect of two periods of HIIT, separated by a year, on their myocardial function. METHODS: ), and MetS components were assessed at baseline, after the first HIIT period (4 months), and one year later, after the second HIIT period. Variables were analyzed following the intention-to-treat analysis principle using linear mixed model. RESULTS: improved only in the HIIT group (group*time p = 0.002), while ejection fraction and MetS z-score changes were not different between groups (group*time p = 0.964 and p = 0.419, respectively). CONCLUSIONS: Among middle-aged adults receiving medical treatment for MetS, the addition of two HIIT periods, spaced one year apart, led to significant improvements in myocardial function, that were not observed in the control group receiving medical treatment alone. CLINICAL TRIALS NUMBER: NCT06262256.