Intensity and enjoyment of play-based HIIT in children and adolescents with obesity.

High-intensity interval training (HIIT) has been suggested as an effective treatment approach of childhood obesity. The objective of the present study was to examine intensity, enjoyment, and perceived exertion of a 4x4-minute play-based HIIT program for children and adolescents with obesity. 83 participants (42.2% girls, 12.3±1.5 years, 57.8% boys, 12.0±1.6 years) completed a 12-week intervention comprising three weekly sessions. After nine sessions (weeks 2, 6, and 11), participants rated perceived exertion (RPE) with a Borg scale and enjoyment of activities using the Physical Activity Enjoyment Scale (PACES). Heart rate (HR) was recorded to assess time spent in high- and moderate-intensity. Participants spent more time in high-intensity during strength-based (P=0.004) and running-based (P=0.007) activities compared to ball games, and more time was spent in moderate-intensity during ball games compared to strength-based (P=0.033) and running-based (P=0.028) activities. Overall, boys spent more time in moderate-intensity than girls (P=0.007). Participants rated RPE lower for ball games than for strength-based (P<0.001) and running-based (P<0.001) activities. Boys rated running-based activities more enjoyable than girls (P=0.021). Exercise intensity and RPE vary by activity in HIIT for children and adolescents with obesity. Ball games led to less high-intensity time and were seen as less exhausting. No differences in RPE or enjoyment were found over time.