Author(s): NG, T., JOSHUA, B., YU, A., LEUNG, C., TAM, B., FONG, D., LEE, C., SETO, W., CHAN, D., WONG, S., KEATING, S., SIU, P., Institution: UNIVERSITY OG HONG KONG, Country: HONG KONG, Abstract-ID: 1072

INTRODUCTION:
Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common metabolic disorder. Adults with MASLD are advised to engage in 150 minutes of moderate or 75 minutes of vigorous exercise weekly, but the optimal distribution of this activity is not well established. It is unclear whether a "weekend warrior" approach yields benefits comparable to a thrice-weekly exercise routine.

Cardiorespiratory fitness (CRF), assessed by maximal oxygen uptake (VO₂ max), is essential for metabolic health. Individuals with obesity and MASLD often display lower CRF levels, which raises risks for various health issues, including insulin resistance, unfavourable cardiometabolic profiles, and increased liver-related and cardiovascular complications.

This study examines the effects of 4-month, duration-matched once-weekly and thrice-weekly exercise on VO₂ max in adults with central obesity and MASLD, aiming to determine if different exercise frequencies yield similar CRF improvements to optimize fitness recommendations for this clinical population.

METHODS:
This single-center, assessor-blinded, three-arm parallel-group RCT conducted in Hong Kong enrolled 300 adults with MASLD (aged 18–69 years; BMI ≥23 kg/m²; waist circumference ≥90 cm [males], ≥80 cm [females]; intrahepatic triglycerides >5%). Participants were randomized to control, once-weekly exercise, or thrice-weekly exercise arms. Exercise groups completed supervised treadmill training delivering 75 minutes/week of vigorous-intensity exercise (6–7 METs) per WHO guidelines, distributed as either one 75-minute session (once-weekly) or three 25-minute sessions (thrice-weekly). Controls attended biweekly 150-minute health education sessions. VO₂ max was measured via cardiopulmonary exercise testing at baseline and 4 months. Group by time interactions were analysed using GEE models adjusted for baseline VO₂ max, with results reported as adjusted means (SE), between-group differences, and 95% Cis.

RESULTS:
GEE analysis revealed a significant group by time interaction for VO₂ max (p=0.012). At 4 months, thrice-weekly exercise exceeded control by 1.81 ml/kg/min (95% CI -2.73 to -0.89, p=0.001) and once-weekly exercise exceeded control by 1.34 ml/kg/min (95% CI -2.29 to -0.40, p=0.005). Thrice-weekly and once-weekly groups did not differ significantly (0.27 ml/kg/min difference, 95% CI -1.46 to 0.53 to 1.23, p=0.360).

CONCLUSION:
Both exercise patterns significantly improved VO₂ max versus control, with thrice-weekly showing a modest advantage over once-weekly. These findings provide evidence that exercise frequency influences improvements in cardiorespiratory fitness, supporting refined physical activity prescriptions to optimize metabolic health outcomes in MASLD management.