Acute beetroot juice supplementation improves selected physical performance parameters, but not cardiovascular...

Aging is associated with declines in muscle strength and functional capacity, driven by both neuromuscular and cardiovascular changes. In parallel, ageing is accompanied by reduced nitric oxide (NO) bioavailability and potentially a reduced efficacy of the nitrate (NO₃-)-nitrite (NO₂-)-NO pathway, a route for NO generation that supports vascular and skeletal-muscle function. Thus, the aim of the present study was to examine the effects of acute ingestion of 70 mL of nitrate-rich beetroot juice (6.4 mmol NO₃-) versus 70 mL placebo (0.04 mmol NO₃-) on strength and functional performance in healthy older women aged between 70-80 years. Nine healthy women (75.4±4.0 years) participated in this randomized, double-blind, placebo-controlled crossover experiment. Participants completed a physical performance test consisting of 6-m walk test, isometric handgrip strength (i.e., dominant and non-dominant hand), Timed Up-and-Go Test (TUG), and sit-to-stand (STS) muscle power test along with cardiovascular assessments (systolic/diastolic blood pressure, heart rate response and 6-minutes' walk performance) after ingesting either 70 mL of beetroot juice (6.4 mmol NO₃-) or 70 mL of placebo (0.04 mmol NO₃-) in a randomized order. Beetroot juice ingestion resulted in significant improvement vs. placebo in isometric dominant handgrip strength (9.6%, p=0.046, ES=0.78), with no changes observed in the non-dominant hand (1.2%, p=0.553, ES=0.11). No differences were found in beetroot juice vs placebo for 6-m walk performance (-3.3%, p=0.306, ES=-0.19), TUG (-5.0%, p=0.225, ES=-0.17), STS leg extensor muscle power (5.0%, p=0.121, ES=-0.25), or 6-minute walk performance (-7.7%, p=0.110, ES=-0.48). Acute ingestion of nitrate-rich beetroot juice led to increased isometric handgrip strength in healthy older women, with no significant effects observed in functional performance (TUG), lower limb STS power, cardiovascular responses, or short-term (6-m) as well as long-term (6-min) walking performance compared with placebo conditions.