Beetroot juice is a rich source of nitrate (NO3-), which serves as a precursor to nitric oxide (NO) via the NO3- to nitrite (NO2-) to NO conversion pathway. This pathway is believed to enhance vasodilation and improve neuromuscular function, such as by increasing sarcoplasmic reticulum calcium release and re-uptake, leading to enhanced force production in type II muscle fibers and improved muscle contractile recruitment. Therefore, the aim of this study was to investigate the effects of beetroot juice supplementation on muscle contractile properties, as assessed by tensiomyography, and neuromuscular performance in sprint-trained athletes.

Sports nutrition is a rapidly expanding scientific field that has experienced a significant increase in interest from the academic community over the past decade. Despite the extensive marketing of numerous nutritional products that claim to optimize athlete health, function, and performance, only a limited number of sports foods or dietary supplements have been supported by robust evidence for enhancing performance. Among these, caffeine, creatine, beetroot juice, β-alanine, and bicarbonate are notable for their validated efficacy, though the effectiveness of these supplements can vary based on the specific event, context of use, and the individual athlete's goals and responsiveness.

Beetroot juice, in particular, is a rich source of nitrate (NO3-), which serves as a precursor to nitric oxide (NO) through the NO3- to nitrite (NO2-) to NO conversion pathway. This pathway is believed to promote vasodilation and improve neuromuscular function, such as by increasing sarcoplasmic reticulum calcium release and re-uptake, leading to enhanced force output in type II muscle fibers and improved muscle contractile recruitment. Therefore, the aim of this study was to investigate the effects of beetroot juice supplementation on muscle contractile properties, as assessed by tensiomyography, and neuromuscular performance in sprint-trained athletes. The goal was to gain a deeper understanding of the physiological effects induced by beetroot juice intake in short-distance track and field disciplines.

Inclusion Criteria:

• Between 18 to 40 years old.
• With a regular training practise in track and field disciplines > 5 years.

Exclusion Criteria:

• Intolerance to beetroot juice or NO3- derivatives
• Presence of any chronic pathology or injury within three months prior to the study-
• Use of medications or supplements (e.g., caffeine) during the study.
• Failure to attend all experimental sessions.
• Failure to adhere to the dietary guidelines established in the study