Sodium Bicarbonate for Endurance Athletes: Does It Actually Work?

If you've been around endurance sports long enough, you've probably heard the rumor: chugging baking soda (sodium bicarbonate) before a hard workout or race can help you go faster or longer. It sounds like a cheap kitchen hack — and in many ways, it is. But is it worth the hassle (and potential stomach upset)? Let's break down the science, benefits, risks, and practical protocols so you can decide if it's right for your training or racing.

How Sodium Bicarbonate Works

During high-intensity exercise, your muscles produce lactic acid (lactate + H⁺ ions), which contributes to the burning sensation and fatigue. Sodium bicarbonate acts as an extracellular buffer: it increases blood bicarbonate levels, helping shuttle those H⁺ ions out of the muscle cells and delay the drop in pH that limits performance.

In short: it buys you time before acidosis forces you to slow down or stop.

The Evidence: What the Science Says

Multiple meta-analyses and position stands (including from the International Society of Sports Nutrition) show sodium bicarbonate is one of the most evidence-backed ergogenic aids:

• Strongest effects in high-intensity efforts lasting 45 seconds to ~8–12 minutes (e.g., 4K–10K running, criterium cycling sprints, rowing 2K, time trials, or repeated intervals). Typical improvements: 1–3% in time to exhaustion or power output.

• Moderate benefits in longer endurance events (e.g., half-marathon to marathon pace efforts or cycling races with hard surges) when there's a late-race kick or repeated high-intensity bouts.

• Little to no benefit in steady-state low-intensity Zone 2 work or very long ultra-endurance events without surges.

A 2021 umbrella review and recent 2023–2025 analyses confirm these effects, with average gains of 2–3% in relevant protocols.

Potential Benefits for Endurance Athletes

• Delays fatigue in the final push of a race or key interval session.

• Improves repeated sprint performance (e.g., in cyclocross, mountain bike XC, or triathlon run legs).

• May enhance training quality — harder intervals or longer threshold efforts.

• Cheap and legal — just baking soda from the grocery store.

Risks and Side Effects

The biggest downside is gastrointestinal (GI) distress — bloating, nausea, stomach cramps, vomiting, or diarrhea — reported in up to 50% of users at standard doses.

Other minor risks:

• Temporary blood pressure changes (usually negligible).

• Increased urine output (mild diuretic effect).

• Not recommended for those with kidney issues, high blood pressure, or GI conditions.

Dosage & Protocol (How to Do It Right)

The evidence-based sweet spot is 0.2–0.3 g/kg body weight (often 0.3 g/kg for max effect).

• Example: 70 kg athlete → 14–21 g total

                  Baking Soda: about 3–5 teaspoons of baking soda

                  Maurten BiCarb: 19 g system

• Timing: Take 60–150 minutes before exercise (peak blood bicarbonate levels occur around 60–90 min).

• Mitigation strategies (to reduce GI issues):

  • Split the dose: e.g., take half 120 min before, half 60 min before.

  • Ingest with a carbohydrate-rich meal (e.g., 1.5 g/kg carbs) — this buffers the stomach and reduces upset significantly.

  • Use enteric-coated capsules or tablets (less direct stomach contact).

  • Pair with plenty of water (500–1000 ml).

  • Start with a lower dose (0.2 g/kg) in training to test tolerance.

  • Avoid on race day first — always trial in training.

Chronic use (daily low doses) shows mixed results and isn't generally recommended over acute loading.

Bottom Line: Should You Try It?

Sodium bicarbonate is one of the few supplements with solid evidence for improving high-intensity endurance performance — especially if your events or workouts involve efforts of 1–15 minutes or repeated hard surges. It's cheap, accessible, and can be a game-changer for threshold sessions or late-race kicks.

But the GI side effects are real, so test it in training first — many athletes find the benefits aren't worth the stomach risk. If you tolerate it well, it can be a valuable tool in your arsenal.

Have you tried bicarb loading before? Drop your experience in the comments — I'd love to hear how it went for you.

(As always, this is not medical advice — consult a doctor or sports RD before trying new supplements, especially if you have health conditions.)