Feasibility and Provisional Efficacy of Embedding High-Intensity Interval Training Into Physical Education Lessons: A Pilot Cluster-Randomized Controlled Trial.

Purpose: The aim of this study was to determine the feasibility of generalist school teachers delivering curriculum connected high-intensity interval training in a school's physical education class time. Method: Two schools volunteered to participate. A total of 84 students (11.9 [0.51 y, M = 64 and F= 19) volunteered to participate. Four classes from 2 schools were randomized to either intervention (n = 53) or control (n = 31) for one school term (8 wk). Intervention class teachers participated in a 1-day workshop instructing them how to deliver twice weekly, high-intensity interval training sessions. The control classes continued with their usual physical education curriculum. Recruitment, intervention fidelity, and program satisfaction were assessed. Preliminary efficacy (primary outcome cardiorespiratory fitness) was quantified using generalized linear mixed models, expressed as effect size. A range of secondary outcomes was also assessed. Results: The recruitment rate was 88%. About 84% of the sessions were delivered. The heart rate peak over all sessions was 89.6% (13%) of the predicted maximum. The intervention teachers reported high levels of satisfaction. Almost all student participants were positive about participating. No adverse events occurred. The adjusted between-group difference for cardiorespiratory fitness was trivial (effect size 0.02). Conclusions: This teacher-delivered high-intensity interval training program was feasible and acceptable to both teachers and student participants. It is therefore potentially scalable. [ABSTRACT FROM AUTHOR]