Exercise Strategy for Reducing Visceral Adipose Tissue in Community Residents With Obesity: A Sequential Multiple Assignment Randomized Trial.

Background: Exercise is the most effective method of reducing visceral adipose tissue (VAT). However, the optimal exercise modality and strategy for reducing VAT have yet to be determined.

Purpose: This study was designed to identify the optimal sequence exercise strategy for reducing VAT in community residents with obesity.

Methods: A sequential multiple assignment randomized trial design was used to conduct a two-stage (8 weeks each) adaptive exercise for 40- to 64-year-old residents with obesity. In the first stage, the participants were randomly allocated into two groups, one of which did 30 minutes of moderate-intensity continuous training (MICT; n = 58) and the other which did 20 minutes of high-intensity interval training (HIIT; n = 58) three times per week. In the second stage, the nonresponders (with VAT decreases < 3%) were randomly reallocated into a group that performed MICT combined with an additional 10 minutes of resistance exercise or one that performed the opposite of the first-stage treatment (HIIT or MICT). Those who responded to the first-stage intervention (with VAT decreases of ≥ 3%) continued the same exercise treatment until 16 weeks.

Results: The MICT intervention was found to be more efficacious than the HIIT intervention in reducing VAT during the first 8 weeks (β = -4.10, p = .029). Among the nonresponders to MICT, the HIIT outperformed MICT combined with resistance exercise as the alternative choice in the second stage (β = -7.36, p = .006). On the contrary, there were no significant differences between MICT and MICT combined with resistance exercise for the nonresponders to HIIT (β = 1.34, p = .626). Those participants who repeated the same exercise modality (either MICT or HIIT) in both stages exhibited superior VAT reduction to those who changed exercise modalities after the first stage.

Conclusions/implications for practice: The optimal sequence exercise strategy for reducing VAT is captured by a two-stage sequential multiple assignment randomized trial design. Community residents with obesity are advised to reduce VAT efficiently through participation in an 8-week MICT program. For those preferring HIIT rather than MICT, a 16-week program without changing the modality midway is recommended.