Sodium Bicarbonate Intake on Endurance Performance

NCT06826222 | Recruiting

• 1 other identifier: KA-24026
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

Brief Summary

Sodium bicarbonate (SB) is one of the ergogenic aids that enhance short-duration, high-intensity sports performance by improving the buffering system. However, studies suggest that SB may also be beneficial for prolonged high-intensity endurance exercises, where anaerobic glycolysis plays a role. The commonly used SB dose in these studies (0.3 g/kg) often leads to gastrointestinal (GI) discomfort, necessitating alternative approaches. Among various protocols, consuming SB with a carbohydrate-rich meal has been identified as an effective strategy to mitigate GI distress. Although some studies indicate a positive effect of SB on performance, research involving female athletes remains limited, comprising only 7.4% of the total studies. Given that women generally have lower muscle mass and fewer type II muscle fibers, their glycolytic capacity might be lower, and SB could have distinct physiological effects on them. While SB has been shown to enhance anaerobic performance in female athletes, its impact on high-intensity endurance exercise performance has not yet been investigated. This study aims to examine the effects of acute sodium bicarbonate ingestion, consumed with a carbohydrate-rich meal, on prolonged high-intensity running performance, acid-base balance, and GI response in female runners. In this double-blind, crossover-designed study, 19 recreational female runners will be randomly assigned to either a bicarbonate or a placebo group. The bicarbonate group will ingest 0.3 g/kg SB, while the placebo group will consume 0.03 g/kg salt, both 90 minutes before exercise, alongside a carbohydrate-rich meal. Participants will then complete a 10 km time-trial run, aiming for their best performance. Throughout the study, GI symptoms, exercise completion time, blood lactate, pH, bicarbonate levels, heart rate, and perceived exertion during exercise will be assessed. Performance tests will be conducted twice during the follicular phase of the menstrual cycle, with a 3-7 days washout period between trials. A two-way repeated measures ANOVA will be used to compare the effects of the interventions.

Conditions

The Effects of Sodium Bicarbonate Supplementation on Endurance Performance in Recreational Female Runners

Keywords

Sodium Bicarbonate; Female Athletes; Endurance Performance; Running; Buffering Capasity

Outcome Measures

Primary Outcomes (1)

• 10 km time-trial run

  To assess the impact of SB on prolonged high-intensity exercise, participants will perform a 10 km time trial following a warm-up routine of 5 minutes jogging at 8 km/h and 5 minutes stretching.Participants will be informed that they are expected to deliver their best performance. During their first visit, participants will be asked to verify their previous fastest 10 km performance using an application. For each performance trial, the percentage relative to their previous personal best 10 km performance will be calculated to assess their actual performance. The performance time obtained at the end of the test will serve as the primary performance outcome for the study. In addition to the 10 km completion time and speed, the time and speed for every 400 m, the first 1 km, 1-5 km, 5-9 km, last 1 km, and final 400 m will also be evaluated.

  1 year

Secondary Outcomes (1)

• blood gas parameters

  1 year

Other Outcomes (1)

• gastrointestinal (GIS) symptoms

  1 year

Study Arms (2)

Sodium Bicarbonate (NaHCO3)

ACTIVE COMPARATOR

In this double-blind, crossover-designed study, 19 recreational female runners will be randomly assigned to either a bicarbonate or a placebo group.

Dietary Supplement: Sodium Bicarbonate (NaHCO3)

Sodium Chloride

PLACEBO COMPARATOR

Each participant will complete two trials: acute SB and placebo. A dose of 0.3 g/kg/day SB will be administered in 7 ml/kg water with a carbohydrate-rich meal to minimize gastrointestinal (GIS) symptoms.

Dietary Supplement: Sodium Chloride

Interventions

Sodium Bicarbonate (NaHCO3) DIETARY_SUPPLEMENT

Participants will complete two interventions: sodium bicarbonate (SB) and placebo (PL). In the SB condition, participants will receive 0.3 g/kg SB, while in the PL condition, they will receive 0.03 g/kg table salt, administered double-blind.

Sodium Bicarbonate (NaHCO3)

Sodium Chloride DIETARY_SUPPLEMENT

Participants will complete two interventions: sodium bicarbonate (SB) and placebo (PL). In the SB condition, participants will receive 0.3 g/kg SB, while in the PL condition, they will receive 0.03 g/kg table salt, administered double-blind.

Sodium Chloride

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: female
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Female, aged 18-40.
• Recreational runner with a minimum one-year history of regular training (at least three days per week).
• Experience in races of 10 km or more (verified by an official race result).
• Ability to complete a 10 km distance at an average pace below 6.00 min/km (confirmed through best-record evidence via applications like Strava).

You may not qualify if:

• Usage of any medications or supplements that could impact metabolism.
• Presence of any acute or chronic condition limiting physical activity (musculoskeletal, cardiovascular, or respiratory issues).
• Alcohol and/or smoking habits.
• Adherence to a specific diet influencing metabolism during the study period (intermittent fasting, ketogenic, vegan diets, etc.).
• Pregnancy or breastfeeding during the study period.
• Severe menstrual irregularities or amenorrhea.
• Body Mass Index (BMI) outside the range of 18.5-30.
• History of gastrointestinal disorders (e.g., IBS, Crohn's disease).
• Allergy or intolerance to sodium bicarbonate or related compounds.
• History of disordered eating.

Sponsors & Collaborators

• Hacettepe University: lead

Study Sites (1)

Hacettepe University

Ankara, Ankara, 06800, Turkey (Türkiye)

RECRUITING

Related Publications (2)

• Carr AJ, McKay AKA, Burke LM, Smith ES, Urwin CS, Convit L, Jardine WT, Kelly MK, Saunders B. Use of Buffers in Specific Contexts: Highly Trained Female Athletes, Extreme Environments and Combined Buffering Agents-A Narrative Review. Sports Med. 2023 Dec;53(Suppl 1):25-48. doi: 10.1007/s40279-023-01872-7. Epub 2023 Oct 25.

  PMID: 37878211 BACKGROUND

• Aktitiz S, Kosar SN, Turnagol HH. Effects of acute and multi-day low-dose sodium bicarbonate intake on high-intensity endurance exercise performance in male recreational cyclists. Eur J Appl Physiol. 2024 Jul;124(7):2111-2122. doi: 10.1007/s00421-024-05434-1. Epub 2024 Feb 29.

  PMID: 38421429 BACKGROUND

MeSH Terms

Interventions

Sodium Bicarbonate; Sodium Chloride

Intervention Hierarchy (Ancestors)

Bicarbonates; Carbonates; Carbonic Acid; Carbon Compounds, Inorganic; Inorganic Chemicals; Sodium Compounds; Chlorides; Hydrochloric Acid; Chlorine Compounds

Central Study Contacts

Selin Aktitiz, pHD Candidate

CONTACT

+905345543408; selinaktitiz@hacettepe.edu.tr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Double Blind Study
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant

Study Record Dates

• First Submitted: February 10, 2025
• First Posted: February 13, 2025
• Study Start: November 3, 2024
• Primary Completion: November 1, 2025
• Study Completion (Estimated): December 31, 2026
• Last Updated: February 13, 2025

Record last verified: 2025-02

Locations

TU (1)