Single sodium bicarbonate dose to improve 200 m Bi‑Fins performance in national finswimmers

Evaluation of the Effects of Single Sodium Bicarbonate Supplementation on Finswimming Performance of National Level Finswimmers: A Randomized, Double-Blind, Placebo-Controlled Crossover Study

This will test whether a single dose of sodium bicarbonate helps national‑level finswimmers swim faster and affect stroke mechanics and fatigue during a simulated 200‑meter Bi‑Fins race.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 20 (estimated)
• Ages: 15 Years to 30 Years
• Sex: All
• Sponsor: Palacky University (other)
• Locations: 1 site (Olomouc, Olomouc Region)
• Trial ID: NCT07135934 on ClinicalTrials.gov

What this trial studies

This randomized, double‑blind, placebo‑controlled crossover trial enrolls 20 members of the Czech junior or senior national finswimming teams to compare a single dose of sodium bicarbonate (300 mg·kg⁻¹) versus placebo and a no‑intervention control. Each participant completes three test sessions (control, bicarbonate, placebo) separated by 48 hours without training, with sessions conducted under standardized conditions in a 25‑meter indoor pool. Primary measures include 200‑meter time, stroke biomechanics (stroke rate and stroke length), and selected physiological and perceptual responses including repeated blood sampling for acid‑base balance. Capsules are indistinguishable and allocation is concealed so participants and investigators are blinded to supplement condition.

Who should consider this trial

Good fit: Ideal candidates are junior or senior national‑level finswimmers aged 15–30 who train at least four sessions per week, have no chronic illness or recent injury, are not taking medications or supplements, and can comply with pretest restrictions.

Not a fit: People with a history of gastrointestinal intolerance to bicarbonate, cardiovascular/metabolic/musculoskeletal disorders, current illness, regular use of interfering substances, or recreational swimmers who do not meet the national‑level training requirements are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, this approach could provide a simple, short‑term supplement strategy to help elite finswimmers improve 200‑meter Bi‑Fins performance.

How similar studies have performed: Previous research has repeatedly shown that sodium bicarbonate can improve high‑intensity efforts of similar duration in athletes, but its specific effects in elite finswimming are less well established.

Eligibility criteria

Inclusion Criteria:

1. Member of a wider national selection in finswimming (junior or senior level)
2. Regular participation in competitive finswimming training (≥4 sessions per week)
3. Age between 15 and 30 years
4. Absence of chronic illness or injury
5. No use of medications or dietary supplements during the study period
6. Signed informed consent (for minors, also signed by a legal guardian)

Exclusion Criteria:

1. History of gastrointestinal disorders affecting supplement tolerance
2. Presence of cardiovascular, metabolic, or musculoskeletal disorders
3. Current illness or acute infection
4. Regular use of substances that may interfere with acid-base balance
5. Refusal to comply with pre-test restrictions (e.g., 48 hours without training)

Where this trial is running

Olomouc, Olomouc Region

• Palacký University, Faculty of Physical Culture — Olomouc, Olomouc Region, Czechia (RECRUITING)

Study contacts

• Principal investigator: Tomáš Michalica, Mgr. — Palacký University, Faculty of Physical Culture
• Study coordinator: Tomáš Michalica, Mgr.

Conditions: Sport Performance, Acid Base Imbalance, Ergogenic Support, Sodium Bicarbonate, Water Sports, Biomechanics, Stroke Rate, Finswimming