Participants in this arm consumed 140 mL of nitrate-rich beetroot juice (~12.8 mmol nitrate) as a single acute dose, approximately 2.5 hours before the performance assessments. The supplementation was administered in the morning under supervision, and participants were instructed to maintain their usual diet but avoid additional nitrate-rich foods 24 hours prior to testing.

Participants in this arm consumed 140 mL of blackcurrant juice containing negligible nitrate (<0.1 mmol) as a single acute dose, approximately 2.5 hours before the performance assessments. The supplementation was administered in the morning under supervision, and participants followed the same dietary instructions as the experimental group, avoiding nitrate-rich foods 24 hours prior to testing.

This intervention involves a single 140 mL dose of a commercially available concentrated beetroot juice supplement (Beet-It Pro Elite Shot, James White Drinks Ltd., UK), containing approximately 12.8 mmol (800 mg) of dietary nitrate. Participants consume the juice 2.5 hours prior to performing a 30-second Wingate anaerobic test. The purpose of this intervention is to examine its acute effects on anaerobic performance, muscle oxygenation, and metabolic responses.

Average power (in watts) generated during the 30-second Wingate cycling test will be compared between beetroot juice and placebo conditions to assess anaerobic performance.

SmO₂ will be assessed using Near-Infrared Spectroscopy (NIRS) on the vastus lateralis muscle. Measurements will be taken continuously before, during, and after the 30-second Wingate anaerobic test to evaluate changes in muscle oxygenation in response to the intervention.