Factors that show aggressiveness towards the endothelium are associated with the development of arteriosclerosis. Exercise can attenuate or prevent this process, but little is known about how high intensity interval training (HIIT) can influence this process in adolescents.
The results of a study have recently been published (da Siiva et al, 2019; Physiol Behav 29: 112728; doi: 10.1016 /j.physbeh.2019.112728) with the aim to assess the effects of HIIT on endothelial function, lipid profile, body composition and physical capacity in adolescents with normal weight, overweight and obesity. 38 physically inactive adolescents between 14 and 17 years of age participated who were assigned to one of the following two groups: normal weight (NW) and overweight-obesity (OW). Body composition, lipid profile, functional capacity, and endothelial function (flow-mediated dilation, FMD) were assessed before and after applying HIIT for 12 weeks (approx. 15 min) + sports activities (30 min, 3 days / week), without diet.
The results did not show changes in body mass, BMI and body fat after the training period, but the OW group showed a reduction in waist circumference and abdominal circumference. Improvement of functional capacity (cardiorespiratory, explosive strength, abdominal resistance, and flexibility) was observed in both groups. FMD increased in both groups (NW Δ4.1%; OW Δ4.5%; p <0.001) with no differences between groups.
The authors concluded that a HIIT routine even without dietary changes improves physical capacity and endothelial function in adolescents.
JL. Chicharro (PhD) Opinion:
These findings are clinically relevant because they support the influence of exercise (in this case HIIT) in reducing endothelial damage that precedes the development of arteriosclerosis.