Beetroot Juice: a Natural Aid for Boosting the Health Benefits of Exercise in Post-menopausal Women?

Beetroot Juice: a Natural Aid for Boosting the Health Benefits of Exercise in Post-menopausal Women?

Menopause and ageing bring several changes to women's health, partly due to a decline in the hormone estrogen. This reduction affects multiple systems in the body, including muscles and bones, and also influences the production of nitric oxide, a molecule that plays a key role in regulating blood flow and blood pressure. An reduced ability to produce nitric oxide is associated with higher blood pressure and an increased risk of cardiovascular and metabolic diseases.

Many women also experience lower levels of physical activity and changes in body composition during midlife, such as increased body fat and reduced muscle mass and strength, which may further decrease exercise capacity.

This PhD project investigates whether a simple, natural strategy, combining exercise with beetroot juice, can help postmenopausal women achieve greater benefits from exercise. Beetroot juice is naturally rich in nitrates, which the body can convert into nitric oxide, thereby enhancing blood flow. Exercise itself also stimulates nitric oxide production, and together these approaches may have additive or even synergistic effects.

The study examines whether consuming beetroot juice before exercise can enhance training adaptations and health outcomes in postmenopausal women. Key outcomes include cardiovascular function, body composition, musculoskeletal function, and aerobic capacity.

Some evidence suggests that beetroot juice may amplify the body's response to exercise, which could be particularly beneficial for postmenopausal women, who often face greater barriers to physical activity. By exploring this combined approach, the project aims to evaluate a safe, non-pharmacological strategy to improve physical function and overall health in women after menopause.

Menopause and ageing are associated with significant changes in women's health, partly due to the decline in estrogen production. Estrogen contributes to the regulation of cardiovascular function and metabolism, as well as the maintenance of musculoskeletal health, in part by stimulating nitric oxide (NO) production, a key signalling molecule involved in vascular function. Ageing per se is also linked to reduced NO bioavailability, meaning that postmenopausal women may experience a combined decline driven by both lower estrogen levels and age-related physiological changes. Together, these factors are associated with an increased risk of cardiometabolic dysfunction, reduced exercise tolerance, and potential declines in quality of life.

This PhD project examines a non-pharmacological approach: the combination of beetroot juice (BRJ) supplementation and exercise (BRJ+EX). Both BRJ and exercise can enhance NO production through different pathways, which may result in additive effects. This approach may be relevant for postmenopausal women, in whom both estrogen-related and age-related NO production are reduced.

The study will investigate whether BRJ+EX can influence exercise-induced adaptations, including changes in cardiometabolic health, body composition, musculoskeletal function, and exercise tolerance, compared with placebo beetroot juice combined with exercise (BRJplacebo+EX). Some recent evidence suggests that BRJ ingestion prior to combined exercise training may enhance certain training responses, which could be particularly relevant for postmenopausal women who may experience barriers to exercise. Thus, building on this evidence, this study aim to test the hypothesis that pre-workout ingestion of BRJ enhances exercise adaptions in post-menopausal women comprehensively.

Furthermore, given the lack of information on the impact of hormone replacement therapy (HRT), this study also aim to explore whether HRT modulates exercise adaptions by also including women taking HRT.

Overall, this project aims to contribute to the evidence base on non-pharmacological approaches to supporting health and physical function in postmenopausal women.

Inclusion Criteria:

• Self-reported biological female and postmenopausal (≥12 months of amenorrhea)
• Aged 50-70 years
• Body mass index (BMI) 25-39.9 kg/m²
• No contraindications to exercise
• Physically inactive (<150 minutes/week of moderate-intensity activity)
• Able to walk on a treadmill and ambulate without limitations
• Adequate proficiency in Norwegian to complete questionnaires
• Willingness and ability to comply with the study schedule and visits

Exclusion Criteria:

• Known allergy to nitrates or beetroot juice
• Current smoker or use of nicotine/tobacco products
• Resting blood pressure <90/60 mmHg
• Hypertension greater than stage II (≥160/100 mmHg, ESH criteria)
• Use of prescription medications affecting heart rate (e.g., systemic β-adrenergic blockers) or nitrate availability (e.g., nitrates, proton pump inhibitors)
• History of cardiovascular disease (e.g., myocardial infarction, stroke, ischemic heart disease, peripheral artery disease, valvular disease, or aortic aneurysm)
• Symptoms suggestive of heart disease (e.g., chest pain or dyspnea)
• Major metabolic disease (e.g., type 1 or type 2 diabetes) or thyroid disorders
• Recent cancer diagnosis or treatment (within the past 5 years)
• Significant orthopedic limitations or other contraindications to exercise
• Diagnosed cognitive impairment
• Planned travel or elective surgery that would interfere with adherence to the intervention
• Psychological or social factors that may interfere with study participation
• Residing beyond a reasonable distance from the study site (logistical constraints)