The Effect of High Intensity Interval Training Versus Steady State Aerobic Training on Skin Microvascular Reactivity in Moderately Active Young Adults: A Pilot Study

A sedentary lifestyle is associated with endothelial dysfunction, leading to vascular pathology and impaired microvascular reactivity (MVR). Enhanced endothelial functioning has been seen in aerobically trained individuals. The purpose of this study was to determine if there was a differential training response of skin MVR in response to high intensity aerobic interval training (HIAIT) as compared to steady state aerobic training (SSAT). The study involved 16 moderately active male students (age: 20.93 ± 5.05 yrs). They were randomly assigned to one of three groups; HIAIT, SSAT, and control group (CG). Baseline testing was performed to determine the VO2max, lactate threshold, blood pressure, body composition and a post-occlusive reactive hyperemia response (PORH) test was used to assess microvascular reactivity on the right palmer forearm using a moorVMS-Laser Doppler Flowmetry (LDF) These parameters were reassessed after three weeks (mid-point) and six-weeks (post intervention) weeks. Statistical significance was set at p≤0.05. There were no significant interactions between the variables measured in the three groups over time. There was a positive linear relationship in the SSAT group for PORHmax/time to peak (Tp) at baseline (r = 0.998, p = 0.039), midpoint (r = 0.992, p = 0.083), and the post intervention (r = 0.987, p = 0.103). Training in the SSAT group had improved PORHpeak at midpoint and post intervention time points (r = 0.999, p = 0.22; r = 1, p = 0.006; r = 1, p = 0.011). Training in either the HIAIT or the SSAT group had no significant effect on skin MVR in moderately active young adults. SSAT did display a positive linear relationship with PORHmax/Tp, and PORHpeak, which are variables influencing skin MVR.