High-intensity-interval exercise to reduce cardio-metabolic risk in youth
Although typically associated with adulthood, the origin of cardio-metabolic diseases, such as cardiovascular disease and type II diabetes, starts in childhood. This means preventative strategies should start early in life. Physical activity is known to reduce a child’s cardio-metabolic risk, but very few children meet the current guidelines of performing 60 minutes per day of at least moderate intensity physical activity. This means, alternative exercise strategies, such as performing low volume high-intensity-interval exercise (HIIE) may be an attractive alternative to reduce cardio-metabolic risk in youth.
We have conducted a series of studies to examine the effect of performing HIIE compared to a work-matched bout of moderate intensity exercise (MIE) on a range of health outcomes in adolescents. We have shown that performing just 8 minutes of HIIE provides either comparable or superior changes in blood glucose, insulin and triglyceride, blood pressure and lipid oxidation when compared to ~ 30 minutes of MIE.
In addition, using measures of macro- (flow mediated dilation, FMD) and micro- (laser Doppler imaging) function we have shown that HIIE provides superior changes in vessel function when compared to MIE in the fasted state or following the ingestion of a high-fat meal. Finally, we have recently shown that just 6 sessions of HIIE performed over 2 weeks noes not alter traditional risk factors in adolescents (e.g. blood glucose, insulin, cholesterol) but blood vessel function and the control of heart rate is augmented.
Collectively, these studies provide evidence that the intensity of a single exercise bout is important for promoting health in adolescents, and that HIIE is a superior and feasible alternative to MIE.