Beetroot juice intake with different amounts of nitrate does not change aerobic exercise-mediated responses in heart rate variability in hypertensive postmenopausal women: A randomized, crossover and double-blind study

Victor Hugo V Carrijo; Ana Luiza Amaral; Igor M Mariano; Tállita Cristina F de Souza; Jaqueline P Batista; Erick P de Oliveira; Guilherme M Puga

doi:10.1016/j.jesf.2020.12.001

Beetroot juice intake with different amounts of nitrate does not change aerobic exercise-mediated responses in heart rate variability in hypertensive postmenopausal women: A randomized, crossover and double-blind study

J Exerc Sci Fit. 2021 Apr;19(2):104-110. doi: 10.1016/j.jesf.2020.12.001. Epub 2020 Dec 18.

Authors

Victor Hugo V Carrijo¹, Ana Luiza Amaral¹, Igor M Mariano¹, Tállita Cristina F de Souza¹, Jaqueline P Batista¹, Erick P de Oliveira², Guilherme M Puga¹

Affiliations

¹ Laboratory of Cardiorespiratory and Metabolic Physiology, Physical Education and Physical Therapy Department, Federal University of Uberlândia, Uberlândia, MG, 38400-678, Brazil.
² Laboratory of Nutrition, Exercise and Health (LaNES), School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais, Brazil.

Abstract

Objectives: To compare the acute effects of a single dose of beetroot juice (BJ) with different concentrations of nitrate (NO₃ ^-) on heart rate variability (HRV) in postmenopausal hypertensive women.

Methods: Thirteen hypertensive postmenopausal women (58.1 ± 4.6 years of age and 27 ± 4 kg/m² of BMI) completed the protocol that consisted of three visits with different beverage intakes in a randomized and crossover design. The three beverages were BJ with a high content of nitrate (high-NO₃ ^-), BJ with a low content of nitrate (low-NO₃ ^-), and an orange flavored non-caloric drink (OFD). Heart rate (HR) were evaluated during 20 min after sitting rest at 7:20 a.m. (baseline), after they drank one of the drinks, and remained at sitting rest for 120 min and then performed 40 min of aerobic exercise at 65-70% of the HR reserve on a treadmill. HR was recorded for 90 min after exercise for time, frequency, and non-linear domains of HRV index analysis.

Results: Two-way ANOVA showed that there were no interaction effects (time∗sessions) in any of the HRV indexes after exercise in all three sessions. HRV indexes increased after exercise (p = <0.05) similarly in all three sessions when compared with the baseline time point.

Conclusion: Therefore, a single dose of BJ, independent of NO₃ ^- content, does not change aerobic exercise-mediated responses in HRV indexes in hypertensive postmenopausal women.

Keywords: Autonomic nervous system; Exercise; Hypertension; Inorganic nitrate; Menopause.