Effects of Single Sodium Bicarbonate Supplementation on National-Level Finswimming Performance

NCT07135934 | Recruiting

• 1 other identifier: FTK_2024_002
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized, double-blind, placebo-controlled crossover trial will investigate the acute effects of sodium bicarbonate supplementation on performance, stroke biomechanics, and selected physiological and perceptual responses during a simulated 200-meter Bi-Fins race in elite finswimmers.

Conditions

Sport Performance; Acid Base Imbalance; Ergogenic Support; Sodium Bicarbonate; Water Sports; Biomechanics

Keywords

Sodium Bicarbonate; Stroke Rate; Finswimming; Stroke Length; Athletes; Biomechanics; Gastrointestinal Discomfort; Rate of Perceived Exertion

Outcome Measures

Primary Outcomes (3)

• Stroke rate (SR; cycles/min)

  Calculated from video analysis to determine the number of stroke cycles per minute.

  Measured from video analysis of the 200-m Bi-Fins trial; final values reported at race completion on Day 1, Day 3, and Day 5.

• Total race time (seconds)

  Total time to complete the 200-meter Bi-Fins time trial, measured using an electronic timing system. Lower values indicate better performance.

  Measured from video analysis of the 200-m Bi-Fins trial; final values reported at race completion on Day 1, Day 3, and Day 5.

• Stroke length (SL; meters/cycle)

  Calculated from video analysis to determine the average distance traveled per stroke cycle.

  Measured from video analysis of the 200-m Bi-Fins trial; final values reported at race completion on Day 1, Day 3, and Day 5.

Secondary Outcomes (10)

• Underwater distance (meters)

  Measured from video analysis of the 200-m Bi-Fins trial; final values reported at race completion on Day 1, Day 3, and Day 5.

• Blood lactate concentration (mmol/L)

  Baseline (10 minutes before warm-up) and 3 minutes post-exercise on each testing day

• Actual base excess (ABE; mmol/L)

  Baseline (10 minutes before warm-up), 10 minutes after warm-up, 5 minutes before race start, and 3 minutes post-exercise on each testing day

• Blood bicarbonate concentration (HCO₃-; mmol/L)

  Baseline (10 minutes before warm-up), 10 minutes after warm-up, 5 minutes before race start, and 3 minutes post-exercise on each testing day

• Rate of Perceived Exertion (RPE; score on Borg Category Ratio 1-10 scale)

  Immediately post-exercise on each testing day

Study Arms (2)

Placebo Comparator

PLACEBO COMPARATOR

Placebo: Food-grade starch Participants will ingest 300 mg·kg-¹ body mass of food-grade starch encapsulated in gelatin capsules 60-90 minutes prior to the simulated 200 m Bi-Fins race. Dietary Supplement: Placebo Gelatin capsules filled with food-grade starch, indistinguishable in appearance from sodium bicarbonate capsules. Water is consumed ad libitum during ingestion. Other Names: Placebo Capsules

Dietary Supplement: Placebo

Sodium Bicarbonate (NaHCO₃)

EXPERIMENTAL

Sodium Bicarbonate: NaHCO₃ Participants will ingest 300 mg·kg-¹ body mass of sodium bicarbonate encapsulated in gelatin capsules 60-90 minutes prior to the simulated 200 m Bi-Fins race. Dietary Supplement: Sodium Bicarbonate Gelatin capsules containing sodium bicarbonate (NaHCO₃), matched in appearance, weight, and texture to placebo. Water is consumed ad libitum during ingestion. Other Names: NaHCO₃ Capsules

Dietary Supplement: Sodium Bicarbonate (NaHCO3)

Interventions

Sodium Bicarbonate (NaHCO3) DIETARY_SUPPLEMENT

Gelatin capsules each containing 1g sodium bicarbonate (NaHCO₃)

Sodium Bicarbonate (NaHCO₃)

Placebo DIETARY_SUPPLEMENT

Gelatin capsules each containing 1g food-grade starch

Placebo Comparator

Eligibility Criteria

• Age: 15 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

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

You may not qualify if:

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

Sponsors & Collaborators

• Palacky University: lead

Study Sites (1)

Palacký University, Faculty of Physical Culture

Olomouc, Olomoucký kraj, 77900, Czechia

RECRUITING

MeSH Terms

Conditions

Acid-Base Imbalance

Interventions

Sodium Bicarbonate

Condition Hierarchy (Ancestors)

Metabolic Diseases; Nutritional and Metabolic Diseases

Intervention Hierarchy (Ancestors)

Bicarbonates; Carbonates; Carbonic Acid; Carbon Compounds, Inorganic; Inorganic Chemicals; Sodium Compounds

Study Officials

• Tomáš Michalica, Mgr.

  Palacký University, Faculty of Physical Culture

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Tomáš Michalica, Mgr.

CONTACT

+420605320688; tomas.michalica01@upol.cz

Zbyněk Svozil, Assoc. Prof.

CONTACT

+420 585 636 111; zbynek.svozil@upol.cz

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator, Doctoral Researcher and Assistant Lecturer, Faculty of Physical Culture, Palacký University Olomouc

Study Record Dates

• First Submitted: August 1, 2025
• First Posted: August 22, 2025
• Study Start: July 1, 2025
• Primary Completion: August 17, 2025
• Study Completion (Estimated): December 20, 2026
• Last Updated: August 22, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Time Frame: Beginning 1 year after the publication of results with no end date.

Locations

CZ (1)