IOC Endurance Supplement
Decision Matrix

The IOC 2018 consensus statement rates dietary nitrate, caffeine, and creatine as having strong evidence for exercise performance. Beta-alanine and sodium bicarbonate have moderate evidence. Nitrate is the only one of the five that specifically improves oxygen efficiency and is most relevant for endurance events lasting 30 minutes to 4 hours.

Yes. Nitrate and caffeine work through independent pathways (nitric oxide vasodilation versus adenosine receptor antagonism). They are commonly stacked by elite endurance athletes. Take beetroot nitrate 60 to 90 minutes before the start and caffeine 45 to 60 minutes before. No negative interactions have been documented.

For a marathon, the evidence-based stack is: beetroot nitrate (300-600 mg, 60-90 minutes pre-race) for oxygen efficiency, caffeine (3-6 mg/kg, 45-60 minutes pre-race) for CNS drive, and beta-alanine (loaded over 4-10 weeks pre-race) for lactic acid buffering. Creatine loading is less impactful for pure endurance events but can support training quality in the build phase.

Creatines primary benefit is for high-intensity efforts lasting less than 30 seconds. For endurance athletes, creatine supports interval training quality, glycogen synthesis, and recovery between hard sessions. It does not directly improve VO2 max or submaximal endurance but can enhance the training stimulus that drives those adaptations.

Beta-alanine requires loading. Muscle carnosine levels increase measurably after 2 weeks of supplementation (4-6 g/day), with full saturation at 10-12 weeks. The ergogenic effect is proportional to the increase in muscle carnosine, which means the benefit builds over time and is not immediate. Maintenance dosing (1-2 g/day) preserves saturation.

Sodium bicarbonate causes significant GI distress in 30-50 percent of athletes, including bloating, cramping, nausea, and diarrhea. This is the primary limitation of its use. Strategies to reduce GI issues include splitting the dose (e.g., 0.2 g/kg as two doses 60 and 120 minutes pre-exercise), using enteric-coated capsules, and testing the protocol multiple times in training before race day.

Dietary nitrate (beetroot) has the most favorable risk-to-reward ratio for endurance athletes. It has strong IOC evidence, minimal side effects (beeturia, mild GI at high doses), no banned substance concerns, and a well-understood mechanism relevant to endurance performance. Caffeine is similarly low-risk but carries sleep and anxiety considerations. Sodium bicarbonate has the highest side-effect burden.

Nitrate, creatine, and beta-alanine do not require cycling and are safe for year-round use. Caffeine tolerance does develop, and many athletes cycle caffeine (2-4 weeks on, 1 week off) to maintain sensitivity. Sodium bicarbonate is typically used only for specific competitions or training blocks due to the GI side-effect burden.

None of the five supplements listed in this matrix (nitrate, caffeine, creatine, beta-alanine, sodium bicarbonate) are on the WADA prohibited list. Caffeine was on the monitoring program from 2000 to 2023 but was removed. However, any supplement carries contamination risk. Choose brands that use third-party testing (ISO 17025 or similar) and cGMP certified manufacturing.

Nitrate: endurance and ultra events. Caffeine: all event types including sprint. Creatine: sprint and middle-distance efforts, plus recovery. Beta-alanine: middle-distance efforts (1-4 minutes) and repeated sprints. Sodium bicarbonate: middle-distance efforts where acidosis limits performance. No single supplement covers all event types, which is why stacking strategies are common.