Aging is associated with diffuse impairments in vascular endothelial function and traditional aerobic exercise is known to ameliorate these changes. High intensity interval training (HIIT) is effective at improving vascular function in aging men with existing disease, but its effectiveness remains to be demon-strated in otherwise healthy sedentary aging. However, the frequency of com-monly used HIIT protocols may be poorly tolerated in older cohorts. Therefore, the present study investigated the effectiveness of lower frequency HIIT (L f HIIT) on vascular function in a cohort of lifelong sedentary (SED; n = 22, age 62.7 AE 5.2 years) men compared with a positive control group of lifelong exercisers (LEX; n = 17, age 61.1 AE 5.4 years). The study consisted of three assessment phases; enrolment to the study (Phase A), following 6 weeks of conditioning exercise in SED (Phase B) and following 6 weeks of low fre-quency HIIT in both SED and LEX (L f HIIT; Phase C). Conditioning exercise improved FMD in SED (3.4 AE 1.5% to 4.9 AE 1.1%; P < 0.01) such that the difference between groups on enrolment (3.4 AE 1.5% vs. 5.3 AE 1.4%; P < 0.01) was abrogated. This was maintained but not further improved fol-lowing L f HIIT in SED whilst FMD remained unaffected by L f HIIT in LEX. In conclusion, L f HIIT is effective at maintaining improvements in vascular func-tion achieved during conditioning exercise in SED. L f HIIT is a well-tolerated and effective exercise mode for reducing cardiovascular risk and maintaining but does not improve vascular function beyond that achieved by conditioning exercise in aging men, irrespective of fitness level.
Grace, F. M., Herbert, P., Ratcliffe, J. W., New, K. J., Baker, J. S., & Sculthorpe, N. F. (2015). Age related vascular endothelial function following lifelong sedentariness: Positive impact of cardiovascular conditioning without further improvement following low frequency high intensity interval training. Physiological Reports, 3(1). https://doi.org/10.14814/phy2.12234