Pre-workout beetroot juice found to improve fitness gains in late postmenopausal women

Drinking beetroot juice before a workout could enhance the benefits of exercise training in postmenopausal women, according to new research. The findings from the study are published in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology . As we age, declining mobility can lead to a dangerous cycle that raises the risk of falls, physical inactivity and dependence on others.

In some cases, it can even lead to premature death. While exercise training is the most effective way to counter the age-related decline in physical function, late postmenopausal women —those at least six years past their final menstrual period—often find it harder to build strength and improve fitness compared to premenopausal women and men of the same age. Reduced nitric oxide availability may diminish the responsiveness of skeletal muscles and blood vessels during exercise, potentially explaining why late postmenopausal women respond differently to exercise training.



To address these challenges, the researchers investigated whether beetroot juice, rich in dietary nitrate, could enhance the health benefits of exercise for late postmenopausal women. Nitrate is stored in limited amounts in skeletal muscle and converted to nitric oxide during physical exertion. For the study, 24 postmenopausal volunteers completed supervised, circuit-based exercise training three times per week for eight weeks.

Half of the participants drank 140 milliliters (about half a glass) of beetroot juice two to three hours before each workout. Before and after the training period, all participants underwent physical fitness assessments, including a six-minute walk test and maximal knee extensor strength test. Participants who drank the beetroot juice prior to exercise showed greater improvements in several aspects of physical function such as aerobic capacity and recovery compared to those who did not consume beetroot juice.

Specifically, those who drank beetroot juice increased their distance in the six-minute walk test by 40 meters, while the exercise-only group improved by just eight meters. These gains were reflected in an increase in aerobic capacity of 1.5 milliliters per kilogram per minute among beetroot juice consumers compared to just 0.

3 milliliters per kilogram per minute in the exercise-only group. Heart rate recovery also improved, with a 10 beats-per-minute decrease after the six-minute walk test for the beetroot juice group compared to a one beat-per-minute decrease for the exercise-only group. According to the researchers, the study results provide compelling preliminary evidence that consuming beetroot juice before exercise could be uniquely beneficial for late postmenopausal women.

These findings could inform new, targeted, non-pharmacologic interventions to help sustain mobility independence and quality of life in this population. More information: Stephen J. Carter et al, Preworkout dietary nitrate magnifies training-induced benefits to physical function in late postmenopausal women: a randomized pilot study, American Journal of Physiology-Regulatory, Integrative and Comparative Physiology (2024).

DOI: 10.1152/ajpregu.00150.

2024.