High-intensity interval training irrespective of its intensity improves markers of blood fluidity in hypertensive patients

ABSTRACT

Aim: The present study examined and compared the effects of two different HIIT (High-intensity interval training) protocols on markers of blood fluidity in hypertensive patients.

Methods: Thirty hypertensive (stage 1, systolic BP >140 and diastolic BP>90 mmHg) patients (age, 47.96 ± 3.20 yrs), were randomly allocated to short-duration HIIT (SDHIIT, n = 10), long-duration HIIT (LDHIIT, n = 10), and control (n = 10) groups. After 2 weeks of continuous mild training, patients in SDHIIT group performed 8 weeks of HIIT included 27 min HIIT that encompassed 27 repetitions of 30 s activity at 80%-100% of VO₂peak interspersed by 30 s passive/active (10%-20% of VO₂peak) recovery, while, patients in LDHIIT group performed 8 weeks of HIIT (32 min per session) included 4 repetitions of 4 min activity at 75%-90% of VO₂peak interspersed by 4 min passive/active (15%-30% of VO₂peak) recovery. Two blood samples were taken before and after training and were analyzed for hemorheological variables.

Results: Significant (P < .05) reductions in systolic blood pressure (SBP), blood and plasma viscosity, fibrinogen concentration and red blood cell (RBC) aggregation (8–12%) were found following two training protocols (P < .05), though, the differences between adaptations were not statistically significant (P > .05). In addition, HIIT protocols increased RBC deformability significantly (P < .05), with no significant differences being observed between two protocols.

Conclusion: It is concluded that HIIT training reduces SBP and markers of blood fluidity in patients with stage 1 hypertension irrespective of the HIIT intensity and duration. Therefore, this type of exercise training could be prescribed for improving the blood fluidity markers in hypertensive patients.

KEYWORDS:

• Interval training
• exercise intensity
• hypertension
• red blood cell
• blood viscosity

Acknowledgments

The authors would like to thank the patients for their participation and to the head of Rajaie’s Cardiovascular Medical and Research Center, Iran University of Medical Sciences for providing assistance with subjects and training facilities. The authors declare that no fund has been received for this study.

Author contribution

SA, MS, and NAB contributed to the conception or design of the work. MS, and NAB contributed to the acquisition, analysis, or interpretation of data. SA and MS drafted the manuscript. All critically revised the manuscript. All gave final approval and agree to be accountable for all aspects of work ensuring integrity and accuracy.

Conflict of interest statement

The authors declare that there are no conflicts of interest with respect to the research, authorship, and publication of this article.