Heterogeneous responses of personalised high intensity interval training on type 2 diabetes mellitus and cardiovascular disease risk in young healthy adults

Hypertension, decreased glucose tolerance, adverse lipid profiles and low physical activity levels are associated with increased type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) risk. High intensity interval training (HIIT), a low volume, reduced time, high intensity programme, may be a useful alternative to current government guidelines which specify a minimum of 150 minutes of physical activity per week. We describe a personalised programme of high intensity exercise which provides significant improvements in CVD risk markers. Healthy volunteers undertook 6 weeks of HIIT. T2DM and CVD risk predictors including glucose tolerance, VO2max, blood pressure (BP), and lipids were measured before and after HIIT. HIIT training was associated with beneficial changes in a range of predictors of blood flow and cardiovascular risk. There was a heterogeneous response to HIIT, with some subjects responding with favourable changes and others being non-responders to HIIT. In responders, HIIT was associated with a statistically significant (p = 0.023) increase in VO2max, from 45.4 (38.4,52.5) to 56.9 (51.2,65.7) (median (interquartile range)(ml/min/kg)). In responders HIIT resulted in a decrease in systolic BP from 127 (126,129) to 116 (106,122) (mmHg) with p = 0.026 and a decrease is diastolic blood pressure from 72 (69,74) to 57 (56,66) with p = 0.026. There was also some evidence of a beneficial change in blood lipid and glucose concentrations with HIIT. In conclusion, personalised HIIT has potential as an intervention to improve blood flow and cardiovascular health.