Self-Directed High-Intensity Interval Versus Moderate Continuous Training on Cardiometabolic Health in Metabolic Dysfunction-Associated Steatotic Liver Disease: A Randomized Controlled Trial.

Both HIIT and MCT significantly reduced hepatic steatosis compared to the observation group, with no between-group difference.

• Both exercise groups showed significant hepatic steatosis reduction versus OBS (both p < 0.05)
• No statistically significant difference was found between HIIT (n=46) and MCT (n=49) groups for liver fat reduction
• Hepatic steatosis was confirmed by ultrasonography at baseline
• The trial duration was 24 weeks with assessments at baseline and week 24

HIIT achieved greater improvements in peak oxygen consumption (V̇O2peak) than both MCT and the observation group.

• HIIT produced superior V̇O2peak improvements compared to MCT and OBS (p < 0.05)
• HIIT protocol consisted of 5 cycles of 4-minute intervals at 80%–90% V̇O2peak with 3-minute recovery at 50% V̇O2peak
• MCT protocol consisted of 30–40 minutes at 60% V̇O2peak
• Both exercise groups performed self-directed treadmill training three times weekly in free-living settings

Both HIIT and MCT increased minute ventilation and carbohydrate utilization at moderate-to-high intensities compared to the observation group.

• Both exercise groups showed significant increases in minute ventilation versus OBS (p < 0.05)
• Both exercise groups showed significant increases in carbohydrate utilization at moderate-to-high intensities versus OBS (p < 0.05)
• No between-group differences between HIIT and MCT were reported for these outcomes
• Outcomes were assessed at baseline and week 24

The trial compared self-directed HIIT versus MCT over 24 weeks in patients with ultrasonography-confirmed NAFLD/MASLD in free-living settings.

• HIIT group: n=46; MCT group: n=49; non-randomized observation group (OBS): n=20
• Exercise was self-directed and performed at home, residential gyms, or community fitness facilities
• Training frequency was three sessions per week for 24 weeks
• The study was registered at ClinicalTrials.gov (NCT04463667)

Exercise participation, rather than exercise intensity, was identified as the more important factor for liver fat reduction in MASLD.

• Both HIIT and MCT produced equivalent hepatic steatosis reductions despite differing intensities
• The observation group did not show significant hepatic steatosis reduction
• Authors concluded 'exercise participation matters more than intensity for liver fat reduction'
• Exercise is recommended for MASLD but the optimal exercise mode was previously unclear