Inorganic nitrate supplementation and blood flow restricted exercise tolerance in post-menopausal women

The effects of dietary nitrate ingestion on physical performance tests in 50-65 years old postmenopausal women: A pilot randomized, double-blind, placebo-controlled, and crossover study

BACKGROUND & AIMS

The post-menopausal period represents a noteworthy stage in a woman's life characterized by hormonal shifts that can influence diverse biological processes encompassing energy metabolism and physical performance. NO3- effects on physical performance in 50-65 years old postmenopausal women after short-term supplementation remain unknown.

METHODS

This is a randomized, double-blind, placebo-controlled, crossover study. After two sessions in non-consecutive days of familiarization tests, fifteen post-menopausal women aged between 50 and 65 were enrolled in this study. The trial consisted of two eight-day arms: a) NO3- -70 mL of beetroot juice (BRJ) with ˜400 mg of NO3-, and b) placebo (PLA) -70 mL of BRJ NO3- depleted. Both interventions were obtained from the same manufacturer's product, presenting the same organoleptic properties. After this period, five physical performance tests (handgrip strength, arm curl, sit-to-stand, agility and dynamic balance and 6-min walk test (6MWT)) were applied.

RESULTS

Fourteen participants completed all experimental protocols, including a minimum seven-day washout period between protocols. NO2- plasma concentrations were consistently elevated in the NO3- condition at 0.41 (0.40) μM compared to the PLA at 0.18 (0.18) μM (p < 0.001). The 6MWT showed higher values in BRJ with NO3- condition (19.6 m [95%CI: 1.33 to 37.88]; p = 0.038), while the other physical performance tests did not show significant difference between conditions (p > 0.05).

CONCLUSIONS

Our findings suggest benefits in the physical performance of activities with longer durations, indicating that the adaptation caused by ingestion of NO3- may be related to the cardiorespiratory capacity.

Acute and short-term beetroot juice nitrate-rich ingestion enhances cardiovascular responses following aerobic exercise in postmenopausal women with arterial hypertension: A triple-blinded randomized controlled trial

BACKGROUND

The increase in blood pressure (BP) levels in the postmenopausal period can be partly explained by the decrease in nitric oxide synthases (NOS).

OBJECTIVE

To investigate the acute and one-week effects of beetroot juice nitrate-rich (BRJ-NO3-rich) ingestion on cardiovascular and autonomic performance in response to submaximal aerobic exercise in postmenopausal women with systemic arterial hypertension (SAH) who are physically inactive.

METHODS

Fourteen postmenopausal women with SAH [mean (SD) age: 59(4) y; BMI (kg/m2): 29.2(3.1)] completed submaximal aerobic exercise bouts after an acute and a one-week intervention with BRJ in a placebo-controlled, randomized, triple-blind, crossover design. Participants ingested either BRJ (800 mg of NO3-) or placebo acutely and drank either BRJ (400 mg of NO3-) or placebo every day for the next six days. After two and ½ hours, they performed a session of aerobic submaximal aerobic exercise, and their systolic BP (SBP) and diastolic BP (DBP), flow-mediated dilation (FMD), heart rate (HR) recovery, and HR variability were measured.

RESULTS

In the post-exercise recovery period, SBP dropped significantly in the BRJ-NO3-rich group (-9.28 mmHg [95%CI: -1.68 to -16.88] ES: -0.65, p = 0.019) compared to placebo after acute ingestion. The FMD values increased after acute BRJ-NO3-rich on post-exercise (3.18 % [0.36 to 5.99] ES: 0.87, p = 0.031). After the one-week intervention, FMD values were higher in the BRJ-NO3-rich group before (4.5 % [1.62 to 7.37] ES: 1.21, p = 0.005) and post-exercise measurements (4.2 % [1.52 to 6.87] ES: 1.22, p = 0.004) vs. placebo. HRV indices with remarkable parasympathetic modulation to heart recovered faster on the BRJ-NO3-rich group than placebo group. No between-group differences were identified in values of HR post-exercise recovery in the 30s, 60s, 120s, 180s, and 300s.

CONCLUSIONS

Acute and short-term BRJ-NO3-rich ingestion may enhance cardiovascular and autonomic behavior in response to aerobic exercise in postmenopausal women diagnosed with SAH.

CLINICAL TRIAL REGISTRY NUMBER

https://clinicaltrials.gov/ct2/show/NCT05384340.