Long-Term Effects of Real-Time Remotely Supervised High-Intensity Interval Training in Adolescents With Obesity

High-intensity Interval Training (HIIT) has emerged as an effective strategy in the management of adolescents with obesity, including delivery through real-time remote models. What remains unclear is whether these clinical benefits are sustained once direct professional supervision is discontinued. This study aimed to analyze the effects of a 6-month, real-time, remotely supervised HIIT program, integrated into a multi-component clinical obesity treatment on post-intervention and 12-month follow-up outcomes after sessions were discontinued. Furthermore, the association between motivation dimensions and program engagement was explored.

A quasi-experimental study involving 96 adolescents with obesity (BMI z-score ≥ 2) was assigned to an Experimental Group (EG; n = 50) and a Control Group (CG; n = 46). The EG completed a remote-supervised HIIT program (∼20 min, 4 × /week) alongside standard care, whereas the CG received only standard care. Engagement was categorized into three levels based on the duration of participation. EG participants were included in analyses if they attended at least 80% of the training sessions during the intervention period. Assessments were conducted at baseline, 6 months, and 12 months.

Group-by-time interaction showed reductions in the EG for BMI (β = 2.1 kg/m², p < 0.001), BMI z-score (β = 0.2, p = 0.002), and WC (β = 3.3 cm, p = 0.004) post-intervention. A significant interaction was observed for water intake (β = 0.3 L/day, p = 0.042). Within EG, improvements were found in flexibility (β = 4.1 cm, p < 0.001) and muscular endurance (β = 3.2reps, p = 0.016). No significant changes occurred during the follow-up period. Appearance motivation was negatively associated with engagement (r _p = -0.29, p = 0.049).

The real-time, remotely supervised HIIT program integrated into a multi-component clinical obesity treatment was an effective approach to promote weight loss and improve physical fitness, with effects sustained for at least 12 months of follow-up. Appearance-driven goals may be associated with lower program engagement.

Brazilian Clinical Trials Registry (ReBEC): RBR-35hyxxv.