Pressor Responses To High And Low-intensity Continuous Or Interval Cycling With/without Blood Flow Restriction.

Abstract

A single bout of continuous or high-intensity interval cycling has been able to induce post-exercise hypotension (PEH). However, it is not clear if low-intensity continuous cycling with blood flow restriction (CLI-BFR) induces PEH. PURPOSE: To compare post-exercise pressure responses between high-intensity interval cycling (HII), continuous low-intensity cycling (CLI), and continuous low-intensity cycling with blood flow restriction (CLI-BFR). METHODS: Eleven young obese adults (age=24.63 ± 5.7 yrs, body mass index=33.42 ± 2.04 kg/m2, body fat percentage=27.7 ± 3.0 %, and peak oxygen consumption [VO2peak]=26.26 ± 3.54 mL·kg-1·min-1) participated in a crossover randomized counterbalanced study design. Subjects completed four separate visits, each separate by 4-9 days. Following the first visit, assessing VO2peak, subjects completed three different cycling sessions which included: CLI – continuous cycling at 45% VO2peak for 15 min; HII – high-intensity interval cycling at 90% of VO2peak consisting of 5 sets of 90 second exercise intervals with 90 second active rest periods at 45% VO2peak; and CLI-BFR – continuous low-intensity cycling with BFR at 45% of VO2peak for 15 min. BFR was applied at the proximal portion of the thigh using a 76 mm wide elastic knee wraps based upon the thigh circumference. Systolic (SBP) and diastolic blood pressures (DBP) were assessed at rest, immediately post-exercise, 10 min, 20 min, 30 min, 40 min, 50 min, and 60 min post-exercise. To compare SBP, DBP, and mean arterial pressure (MAP) measurements, a two-way ANOVA with Newman-Keuls post hoc was used. RESULTS: The main effect of condition was not significant for any of the pressor responses (p>0.05), however there was a significant main effect for time. When compared to rest there were significant increases immediately post-exercise for SBP, DBP, and MAP (p<0.05), and a significant increase in DBP at 60 min post-exercise (p<0.05). CONCLUSION: CLI-BFR, HII, CLI were not capable of inducing PEH in young obese adults up to 60 min post-exercise.