The impact of high intensity interval training on physical and psycho-social outcomes in low active adolescents

The 8-week pilot study compared the effects of HIIT to a non-training control group (N=65 students from 3 classes) in one secondary school. The HIIT sessions were delivered 3 times/week during Health/PE lessons and lunch-time by our research team. The 8-week program involved minimal equipment and combined cardio-respiratory and muscle strengthening exercises. The program achieved high recruitment (86%), good adherence (mean attendance was 2.2 sessions/week) and retention (90.8%). Intervention participants reported the program was enjoyable (4.2/5). Similarly, teachers involved in the study completed a post-intervention questionnaire and agreed: (i) their students had enjoyed participating in the intervention (4.3/5) and, (ii) they intended to include HIIT in their PE lessons in the future (4.5/5). We found improvements in cardio-respiratory fitness, waist circumference, BMI and well-being.