Nitrate and Power Output After Two Beetroot Juice Drinks

• The main aim of this study is to determine and compare the optimal time to achieve peak concentration of blood plasma nitrite after ingestion of beetroot juice (BR) and isotonic beetroot juice (ISO-CB), respectively. Optimal timing of drink consumption in relation to exercise can then be prescribed in relation to nitrite appearance in the blood.
• A secondary aim of this study is to evaluate the association between blood plasma nitrite concentration and saliva nitrite concentration after ingestion of the two drinks to determine whether blood plasma analysis can be fully or partially substituted with a salivary nitrite test.
• A final aim of this study is to investigate the ergogenic effects of ISO-CB compared with BR during a single 30 second cycling sprint bout (Wingate test) and two jumping tests.

A randomised controlled trial recruiting 24 healthy male and female participants. Each participant will complete two conditions: (i) BR and (ii) ISO-CB. On each condition participants will consume During each trial, participants will ingest 2 x 285ml of beverage 3 hours prior to performing two jump tests follow by a Wingate test. In the next trial, participants will undergo the same procedures, but ingest the beverage that they did not take the previous round. The study will be double-blinded study. Blood samples will be taken before supplementation, 2 hours and 3 hours after consuming the beverage. Salivary NO content will be measured at the start of the morning, 1 hour, 2 hours, 3 hours after consumption of beverage and at the end of the exercise. For each trial, participants will also fill out a sensory evaluation form in relation to the drink consumed. It is hypothesized that blood plasma nitrite and saliva nitrite appearance will be earlier with ISO-CB and that participants will have improved peak and mean power when ISO-CB is consumed compared with BR.

Inclusion criteria

• Age: 21-35 years.
• Healthy and injury-free: defined as no positive (Yes) answers to the Physical Activity Readiness Questionnaire (PAR-Q+) and not reporting any other health issues that may be affected by exercise.
• Blood pressure: <130/90 mmHg.
• Physically active: Engaging in a minimum of 150 minutes of moderate-intensity exercise or 75 minutes of vigorous-intensity physical activity each week determined via self-report Global Physical Activity Questionnaire (GPAQ).
• Body mass index (BMI): 18.5-25.0 kg/m2.
• Non-smoker.

Exclusion criteria

• Any allergies to beetroot or isotonic drink.
• Asthma.
• Any report of personal health issues that may compromise the individual's ability to undertake exercise safely.