High-intensity Interval Training And Ambulatory Blood Pressure In Women With Hypertension And Type 2 Diabetes.

Previous results from our group and others reported that low-volume HIIT (6-10 x 1 min) was insufficient to improve ambulatory blood pressure (ABP) in older women with type 2 diabetes (T2D). Nevertheless, a reduction of systolic 24-hour ABP was noticed after higher volume HIIT (4 x 4 min) in middle-aged adults with hypertension. It is therefore possible that the interval duration or volume are important HIIT parameters that should be considered for hypertension management. PURPOSE: To evaluate the acute effect of interval protocol/duration on 24-hour ABP monitoring in older women with hypertension and T2D. METHODS: Preliminary data from 10 women (65-85 years) with hypertension and T2D who completed three experimental conditions were analyzed: 1) REST (seated control); 2) HIIT10 (10 x 1 min at 90% maximum heart rate [HRmax]) and 3) HIIT4 (4 x 4 min at 90% HRmax). Workload-matched HIIT4 and HIIT10 sessions were randomly performed. After each experimental condition, 24-hour ABP was monitored in controlled conditions (4 h) at the lab and for 20 h while participants continued their habitual daily activities. RESULTS: Preliminary results showed that throughout the 4-hour controlled period, only the 5-min systolic BP measured after HIIT10 (117 ± 17 mmHg) and HIIT4 (109 ± 10 mmHg) was lower compared to REST (123 ± 14 mmHg) (p = 0.043 and p = 0.003, respectively). A reduction of the 24-hour systolic ABP was observed after HIIT10 compared to REST (mean difference [95%CI]: -3.7 [-7.7 - 0.3], p = 0.024), while the difference between HIIT4 and REST was not statistically significant (-1.2 [-6.0 - 3.5]; p = 0.47). Diastolic ABP (HIIT10 vs. REST: -1.8 [-3.9 - 0.4] mmHg, p = 0.097; HIIT4 vs. REST: -0.1 [-2.7 - 2.5] mmHg; p = 0.921) and nocturnal dipping (HIIT10 vs. REST: 0.9 [-3.7 - 5.4] %, p = 0.626; HIIT4 vs. REST: 2.4 [-1.1 - 5.8] %; p = 0.160) were not significantly modified by either HIIT protocol. CONCLUSION: Contrary to our hypothesis, preliminary results only reveal a minor reduction in 24-hour systolic ABP after HIIT10 in older women with hypertension and T2D. Neither HIIT4 nor HIIT10 was sufficient to impact 24-hour diastolic ABP or nocturnal dipping. Supported by Diabète Québec and CEUS DOCC.