Creatine for runners: Does it help endurance?

Creatine is one of the most researched performance supplements in existence. Its benefits for sprint and strength performance are well-documented. Its effects for endurance runners are significantly less clear, and understanding why requires a brief trip into the energy systems that power your training.

What creatine actually does in your body

Creatine is stored in muscle as phosphocreatine (PCr). When you perform a short, maximal effort, your muscles break down PCr almost instantly to regenerate ATP, the energy currency your cells spend with every contraction. This is the ATP-PC energy system, and it operates for roughly 5 to 10 seconds at maximum intensity before it's exhausted and your aerobic system takes over.

Creatine supplementation increases your phosphocreatine stores by roughly 20 to 40%. For sprint athletes, weightlifters, and team-sport athletes performing repeated short maximal efforts, this is meaningful: more PCr means faster ATP regeneration, which means more power output in the early seconds of each effort.

For a runner covering 42 kilometres at 75% VO2 max, the ATP-PC system is essentially irrelevant. You're operating on oxidative phosphorylation, the aerobic energy pathway, which is fuelled by glycolysis and mitochondrial respiration. Phosphocreatine is not the rate-limiting factor here. Mitochondrial capacity is.

What the research actually shows for endurance runners

A 2023 review by Forbes et al. examined the evidence on creatine supplementation and endurance performance. The conclusion was measured: creatine shows mixed results for pure aerobic endurance performance, with some evidence of benefit for repeated surges and sprint finishes, but limited consistent benefit for sustained steady-state output in trained endurance athletes.

A separate 2023 meta-analysis in Sports Medicine on creatine monohydrate and endurance performance found that while creatine did not consistently improve VO2 max or time-trial performance in trained endurance athletes, there were signals of benefit for running economy and performance in high-intensity intervals late in a long effort.

In plain terms: if your race requires a kick at the end, repeated surges over rolling terrain, or maximal efforts in the final kilometre, creatine may help. If your goal is to maintain 4:30/km pace for four hours without a sprint finish, the evidence for creatine is thin.

The weight question: does creatine slow you down

This is the practical concern that stops most endurance runners from trying creatine. Creatine causes water retention in muscle tissue as part of its mechanism. The loading phase (if you use one) can add 0.5 to 1.5kg of body mass within the first week, mostly as intramuscular water.

For a road runner where every kilogram costs time on the clock, this is a legitimate trade-off to consider. The research on this is mixed: some studies find that the performance benefits of creatine outweigh the weight cost in endurance athletes; others find the opposite. The individual response varies, and the context matters. A trail runner covering hilly terrain cares more about power-to-weight ratio than a flat-road marathoner focused on pace-consistency.

Where creatine might actually help a runner

Three specific contexts where the creatine evidence is more compelling for runners. First, training adaptation: creatine may support higher-intensity interval sessions during training blocks, allowing you to perform more quality work per session. The aerobic adaptations from higher-volume quality training outlast the supplementation period. Second, late-race surges: if your events include significant surges or a fast closing kilometre, creatine's effect on short-burst power output may be relevant. Third, altitude or heat: some research suggests creatine supports adaptation in physiologically stressful training environments, though this evidence is preliminary.

What endurance runners actually need that creatine doesn't provide

The energy system that matters most for distance running is oxidative phosphorylation, the aerobic pathway driven by your mitochondria. Your mitochondria produce over 90% of the ATP your muscles spend during sustained endurance effort. The health, density, and efficiency of your mitochondria are the actual limiting factors in your performance at hour two, three, and four of a long run or race.

This is the gap that creatine doesn't address, and it's where mitochondrial support compounds become relevant. Research from Gherardi et al. (2024) showed that oleuropein directly activates mitochondrial calcium uptake, a key mechanism in cellular energy production. Lanfranchi et al. (2026) demonstrated that oleuropein-based olive leaf extract enhances muscle mitochondrial bioenergetics during sustained human exercise. For an endurance athlete, this is the cellular intervention that maps to the energy system you're actually using across your training and racing.

The OLEUS Daily Shot is built around this principle. It's not an acute performance stimulant. It supports the mitochondrial foundation that determines how well your aerobic energy system operates day after day, training week after training week. For a comparison of how natural plant-based compounds differ from synthetic supplements in their mechanisms and evidence base, see the OLEUS guide on natural vs. synthetic pre-workouts.

Should you take creatine as a runner

Creatine is safe, well-studied, and cheap. If your training includes a significant amount of high-intensity interval work, plyometrics, or you compete in events with repeated surges or sprint finishes, it may be worth a trial period. Use a maintenance dose of 3 to 5g daily (no loading phase) to minimise the initial water retention, and assess your response over four to six weeks.

If your goal is sustained aerobic performance over distance, the cellular intervention that has the strongest mechanistic alignment with endurance physiology is mitochondrial support. The evidence for oleuropein and its effect on the aerobic energy pathway is more directly relevant to the energy system you rely on from kilometre one to the finish line.

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Sources

1. Forbes, S.C., et al. (2023). Creatine supplementation and endurance performance: surges and sprints to win the race. Journal of the International Society of Sports Nutrition. 

2. Gherardi, G., et al. (2024). Mitochondrial calcium uptake declines during aging and is directly activated by oleuropein to boost energy metabolism and skeletal muscle performance. Cell Metabolism.

3. Lanfranchi, C., et al. (2026). Oleuropein-based olive leaf extract enhances muscle mitochondrial bioenergetics response to moderate but not maximal intensity exercise in humans. Journal of Physiology. 

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.