Utility of a high-intensity interval training app as a remote exercise support strategy in children with obesity: An exploratory study of adherence, effect, and perceptions of its use.

Objective: This study aimed to explore the utility of a high-intensity interval training (HIIT) app as a remote exercise support strategy in children with obesity through assessing adherence, possible effects on obesity-related outcomes, and perceptions of its use to support counseling and improve the treatment of children with obesity. Methods: Thirty-seven children (94.6% with obesity; 45.9% girls), with a mean age of 10.4 (±1.8) years and a mean body mass index (BMI) z-score of 3.31 (±1.09) were recruited to use the app during 6 weeks. Assessments were performed at baseline, 6 (end of intervention), and 12 weeks (follow up). Results: Thirty-two (86.3%) participants completed both intervention and follow-up assessments and were analyzed. On average, children used the HIIT app 2.5 times per week (95% confidence interval (CI): 1.9 to 3.0), with the highest perceived exertion of 4.1 (95% CI: 3.6 to 4.5). No over-time differences were found in body composition, physical activity, screen time, sleep duration, or water intake after the intervention; however, an over-time decrease in sugary beverages intake (Δ-0.9, 95% CI: -1.6 to -0.1, Conclusion: Although feasible, the 6-week effect of HIIT app use is modest or absent regarding body composition, movement, and nutritional behavior change, probably due to its low volume. More studies are needed to explore the utility of HIIT apps as a remote exercise support strategy for children with obesity further.