Sodium Bicarbonate (Bi-Carb) For Endurance Sport: Evidence-Based Guide

Ever feel your legs screaming and fatigue building halfway through a race? Could sodium bicarbonate help you delay fatigue and push harder for longer? This humble, science-backed compound may help soak up lactic acid and boost your training and racing performance. Discover how athletes use it to gain that extra edge.

Table of Contents

• What Is Sodium Bicarbonate & How It Works

• Why Endurance Athletes Use Bi-Carb

• Performance Benefits: What the Research Shows

• Who Benefits Most & When It’s Useful

• Dosing, Timing & Practical Use

• Side Effects, Safety & Key Takeaways

What Is Sodium Bicarbonate & How It Works

Sodium bicarbonate, commonly known as bi-carb, is a well-researched extracellular buffering agent¹² that plays a key role in high-intensity exercise performance. During hard efforts, hydrogen ions accumulate in the muscles and blood, leading to a drop in pH³⁴. This acidic environment can interfere with muscle contraction and energy production, contributing to the onset of fatigue. By increasing blood bicarbonate concentration, sodium bicarbonate enhances the movement of hydrogen ions out of the muscle and into the bloodstream, helping to stabilise pH levels⁵. This buffering effect can delay fatigue and support sustained performance during high-intensity efforts⁶⁷.

Why Endurance Athletes Use Bi-Carb

• To improve tolerance of high-intensity work within endurance events¹,².

• Helps 'soak up' lactic acid build-up during prolonged high-intensity exercise, reducing fatigue and improving performance³,⁷.

• Supports repeated surges, climbs, breakaways, and sprint finishes⁴,⁵.

• For long endurance events, supplementation is best used in training to enhance high-intensity workouts and adaptations⁸.

Performance Benefits: What the Research Shows

• Strong evidence for performance improvements in high-intensity efforts lasting around 1-10 minutes²,³,⁸.

• Meta-analyses report average performance gains of around 2-3%, meaningful in competitive sport¹,³,⁸.

• Benefits observed across cycling, rowing, running, swimming and team-based endurance sports⁶,⁷.

• Effects are most consistent in trained athletes and competitive settings⁴,⁵.

Who Benefits Most & When It’s Useful

Endurance Athletes Competing in Events With:

• Repeated high-intensity efforts

• Tactical surges or variable pacing

• A fast or hard finish¹,³

Examples Include:

• Road and track/crit cycling

• Middle-distance running

• Draft-legal triathlon

• Rowing

Less useful for steady-state, low-intensity endurance events⁷.

Dosing, Timing & Practical Use

• Evidence-based dose → 200-400mg/kg of body mass with a small, carbohydrate dense meal (~1.5 g/kg BM CHO), 120 to 150 mins prior to exercise²,⁵,⁶,⁸.

• Lower doses (0.1-0.15 g/kg) may still be beneficial with fewer GI side effects³.

• Peak blood bicarbonate generally occurs between 60 and 180 minutes after ingestion, though timing varies widely between individuals¹,⁴.

• Current evidence suggests that combining beta-alanine with sodium bicarbonate may enhance performance⁸,⁹,¹⁰.

• Chronic loading over several days is emerging but less established⁵.

Pro Tip → Keep dosage simple by taking your weight based FLYCARB BICARB bicarb and energy mix 120-150 minutes before exercise with a small, carbohydrate-rich meal (~1.5 g/kg body mass CHO) for optimal performance.

Side Effects, Safety & Key Takeaways

• The primary limitation is gastrointestinal distress (bloating, nausea, diarrhoea)³,⁴.

• Risk increases with higher doses and liquid forms.

• Capsules, food co-ingestion and split dosing can improve tolerance⁵.

• High sodium load requires caution in athletes with hypertension or renal conditions⁶.

• Trial dosing in training.

Key Takeaways:

• Sodium bicarbonate is one of the most evidence-backed ergogenic aids in sports nutrition¹,⁶.

• Best suited to athletes competing in high-intensity efforts lasting 30 seconds to 10 minutes or endurance athletes undertaking high-intensity training³,⁷.

• Performance benefits are small but meaningful⁴,⁵.

• Individual tolerance determines real-world usefulness⁶,⁸.

Ash Miller
Dietitian and Nutritionist (Masters)
Bachelor of Physical and Health Education
Instagram: @ashthomo_nutrition

References

1. Carr, A. J., Hopkins, W. G., & Gore, C. J. (2011). Effects of acute alkalosis and acidosis on performance: A meta-analysis. Sports Medicine, 41(10), 801–814.

2. International Society of Sports Nutrition. (2021). Position stand on sodium bicarbonate supplementation: doses, timing, and effects. J Int Soc Sports Nutr, 18, 61.

3. Grgic, J., Rodriguez, R. F., et al. (2020). Effects of sodium bicarbonate supplementation on muscular strength and endurance: systematic review and meta-analysis. Sports Medicine, 50, 1361–1375.

4. Marshall, P. W., Bishop, D. J., Shaw, G., & Green, S. (2016). Mechanistic insights into sodium bicarbonate’s efficacy as an ergogenic aid. Sports Med Open, 2, 41.

5. McNaughton, L. R., Gough, L., Deb, S., Bentley, D., & Sparks, S. A. (2016). Recent developments in the use of sodium bicarbonate as an ergogenic aid. Current Sports Medicine Reports, 15(4), 233–244.

6. Burke, L. M., Peeling, P., & Gifford, J. A. (2023). Contemporary supplements for endurance athletes. International Journal of Sport Nutrition and Exercise Metabolism, 33(1), 1–15.

7. Lane, A. (2025, April 25). Sodium bicarbonate as a lactic acid buffer in endurance racing with repeated lactate peaks. FLYCARB Insights.

8. AIS. (2025). Sodium Bicarbonate Infographic. Australian Institute of Sport. Retrieved from
   https://www.ausport.gov.au/ais/nutrition/supplements/group_a/performance-supplements2/bicarbonate

9. Carr, A., A. McKay, L. Burke, E. Smith, C. Urwin, L. Convit, W. Jardine, M. Kelly, & B. Saunders, B. (2023). Use of buffers in specific contexts: highly trained female athletes, extreme environments and combined buffering agents-a narrative review. Sports Med, 53 (Suppl 1), 25-48.

10. Curran-Bowen, T., A. da Silva, G. Barreto, J. Buckley, & S. Saunders. (2024). Sodium bicarbonate and beta-alanine supplementation: Is combining both better than either alone? A systematic review and meta-analysis. Biol Sport, 41(3), 79-87

Disclaimer:

The content in this blog is for general information only and is not a substitute for professional medical advice, diagnosis, or treatment. Always speak with your doctor or allied health team before changing your diet, exercise, or taking supplements, especially if you have a health condition or take medication. Please use this information as a guide only. Aid Station doesn't take responsibility for individual outcomes.