The effect of high Intensity interval training (HIIT) upon resting and ambulatory blood pressure in physically inactive males and females

Purpose: Physical inactivity is associated with and increased risk of hypertension and cardiovascular disease. High intensity interval training (HIIT) has been shown to reduce resting blood pressure. However, the response of HIIT upon ambulatory blood pressure has been limited, despite evidence highlighting that the use of ambulatory blood pressure monitoring can be of clinical significance. Therefore, the aim of the present study was to investigate the effects of HIIT upon resting and ambulatory blood pressure.

Methods: In a randomised controlled trial 41 physically inactive males and females (aged 23 ± 2.7 years) completed 4 weeks of HIIT. The HIIT protocol consisted of 3 x 30s maximal cycle ergometer sprints with a resistance of 7.5% body weight, with 2 minutes active recovery in between intervals. In total, 12 sessions were performed. Ambulatory blood pressure was measured using a Welch Allyn 6100 ambulatory blood pressure monitor.

Results: Following the 4-week HIIT intervention, it was reported that there were statistically significant reductions in resting systolic blood pressure (-6.86 ± 8.76 mmHg, P < 0.041) when compared against the control group. It was also reported that there was a statistically significant reduction in 24-hour systolic blood pressure (-4.06 ± 8.08 mmHg, P < 0.008), 24-hour diastolic blood pressure (-3.43 ± 8.18 mmHg, P < 0.012) and 24-hour mean blood pressure (-2.17 ± 4.04 mmHg, P < 0.002) when compared against the control group.

Conclusion: A 4-week HIIT programme was associated with a significant decrease in resting systolic blood pressure in addition to significant reductions in 24 hour systolic, diastolic and mean ambulatory blood pressure.