Can a healthy adult runner safely use beta‑alanine (3.2–6.4 g per day split into two doses with meals, loading ≥4 weeks) to improve high‑intensity effort or repeated‑sprint ability, and what are the expected benefits, side‑effects such as paresthesia, and considerations regarding renal function?

Beta-Alanine Supplementation for Running Performance

Beta-alanine supplementation (4–6.4 g daily for ≥4 weeks) can safely improve high-intensity running efforts lasting 1–4 minutes and attenuate neuromuscular fatigue during repeated sprints, though the evidence is less robust than for creatine or caffeine. 1, 2

Mechanism of Action

Beta-alanine increases intramuscular carnosine concentrations, which acts as an intracellular pH buffer against acid buildup during high-intensity exercise. 1, 2 Four weeks of supplementation at 4–6 g daily significantly augments muscle carnosine levels, with the rate-limiting factor being beta-alanine availability rather than histidine. 2, 3

Dosing Protocol

Recommended dosage: 65 mg/kg body weight daily (up to 6.4 g/day total) using a split-dose regimen. 1, 2

• Divide the daily dose into smaller amounts (≤1.6 g per dose) taken with meals to minimize paresthesia. 1, 2
• Continue supplementation for 4–12 weeks minimum before expecting performance benefits. 1, 4, 2
• Alternatively, use sustained-release formulations to reduce tingling sensations. 2, 3

Expected Performance Benefits

High-intensity efforts (1–4 minutes duration): Beta-alanine shows the most pronounced effects on open-ended tasks and time trials in this duration range. 2, 3

Repeated sprint ability: A 2019 study demonstrated that 6.4 g/day beta-alanine during high-intensity interval training improved total sprint time by 3.0% and best sprint time by 3.3%, while also increasing muscle carnosine by 34.4 mmol/kg compared to 20.7 mmol/kg in placebo. 5

Neuromuscular fatigue attenuation: Beta-alanine supplementation preserved voluntary activation at 87.2% versus 78.9% in placebo after repeated sprints, indicating reduced central fatigue. 5

Limited benefit for: Single maximal sprints, VO₂max, maximal strength, or endurance efforts beyond 25 minutes show minimal to no improvement. 2, 3, 6

Side Effects and Safety

Paresthesia (tingling sensation): The only consistently reported side effect occurs when single doses exceed 800 mg. 2, 3

• This is transient, harmless, and directly related to plasma concentration spikes. 2, 3
• Completely preventable by splitting doses to ≤1.6 g or using sustained-release formulations. 1, 2

General safety: Beta-alanine appears safe in healthy populations at recommended doses with no serious adverse effects reported in current literature. 2, 3

Renal Function Considerations

No evidence suggests beta-alanine negatively impacts kidney function in healthy adults at recommended doses. 2, 3 Unlike creatine, which raises serum creatinine as a marker of increased turnover (not impaired function), beta-alanine does not produce similar biomarker changes. 7

Critical Limitations and Caveats

Evidence quality: The evidence for beta-alanine is contradictory and less robust than for caffeine or creatine, with some studies showing no benefit for repeated sprint performance. 1, 4, 6

Supplement contamination risk: Studies show 15–25% of sports supplements contain undeclared prohibited substances. 1, 7, 4 Choose only third-party tested products from reputable manufacturers to minimize this risk. 1, 7, 4

Individual variability: Response to beta-alanine varies widely between individuals. 7, 4 Trial the supplement during training for at least 4 weeks before using in competition to assess personal response. 4

Cost-benefit consideration: Given the modest and inconsistent performance effects, weigh the financial investment against the limited magnitude of improvement (typically 3% or less). 1, 4

Practical Algorithm for Runners

For high-intensity training or racing (800m–1 mile events):

• Start with 4–6 g daily split into 3–4 doses with meals. 1, 2
• Continue for minimum 4 weeks, ideally 8–12 weeks. 1, 2
• Monitor for performance improvements in interval training. 1

For longer distance running (>25 minutes):

• Prioritize carbohydrate intake (30–60 g/hour during events >1 hour) and proper hydration strategies instead. 8, 1
• Beta-alanine offers minimal benefit for sustained aerobic efforts. 2, 3

For runners returning after hiatus:

• Focus first on carbohydrate loading (days before events >1.5 hours), proper hydration (6 mL/kg every 2–3 hours pre-exercise), and maintaining <2–3% body weight loss during exercise. 8, 1
• Consider beta-alanine only after establishing solid nutritional foundation. 1