Acute Effect of High-Intensity Interval Exercise on Blood Pressure in Females Living with Type 2 Diabetes and Hypertension

BACKGROUND: The acute effects of high-intensity interval training (HIIT) on blood pressure (BP) may depend on the exercise protocol performed. PURPOSE: To compare the acute effect of high- and low-volume HIIT on post-exercise and ambulatory BP in untrained older females diagnosed with both type 2 diabetes and hypertension. METHODS: Fifteen females (69 (65-74) yr) completed a crossover study with three experimental conditions: 1) REST (35 min in sitting position); 2) HIIT10 (10 × 1 min at 90% heart rate max (HRmax)), and 3) HIIT4 (4 × 4 min at 90% HRmax). After each experimental condition, BP was measured under controlled (4 h) and in subsequent free-living conditions (20 h). RESULTS: In the controlled post-condition 4-h period, no significant interaction (time-condition) was observed for all BP parameters ( P ≥ 0.082). Similarly, during the subsequent 20-h free-living ambulatory monitoring (diurnal and nocturnal), no differences between conditions were detected ( P ≥ 0.094). A significant reduction in nighttime pulse pressure was observed in both HIIT4 and HIIT10 compared with REST (46 (44-50), 45 (42-53) vs 50 (45-57) mm Hg, respectively; P ≤ 0.018) with no differences between HIIT conditions ( P = 0.316). Changes in nocturnal systolic BP approached but did not reach statistical significance ( P = 0.068). CONCLUSIONS: This study suggests that in untrained older females living with type 2 diabetes and hypertension, the HIIT10 and HIIT4 protocols have very limited to no acute effect on post-exercise and ambulatory BP. The fact that the vast majority of participants had well-controlled office and ambulatory BP values as well as low cardiorespiratory fitness could explain these findings.