Creatine and Trail Running: Useful or Useless for Endurance?
Creatine and Trail Running: What the Science Really Says
Creatine frequently comes up in discussions among trail runners. This supplement, an undisputed star in bodybuilding, raises many questions in the endurance world. Its usefulness in trail running warrants a nuanced analysis, far from marketing promises.
Creatine and Pure Endurance: Generally No Effect
Creatine is among the most scientifically studied supplements, particularly for its effects on strength and power. Its recognized benefits include:
- Improved maximal strength
- Increased power output
- Enhanced ability to repeat very intense efforts
However, concerning continuous endurance (time trials, time to exhaustion, average speed over long distances), recent data show no significant overall improvement in trained athletes. In other words, for long, steady efforts typical of ultra-trail, the benefit remains limited.
Body Weight: A Decisive Factor in Trail Running
Creatine supplementation frequently leads to an increase in body mass, primarily through intracellular water retention. This weight gain has direct consequences in trail running:
- Possible decrease in relative VO₂max (per kilogram of body weight)
- Penalizing mechanical effect in weight-bearing sports like running
- Increased negative impact in mountainous terrain where every extra kilo counts
Important clarification: This is not a negative effect on the cardiovascular system or mitochondria, but rather a mechanical effect related to the weight being carried. In trail running, particularly on courses with significant elevation gain, this variable becomes crucial.
Where Creatine Becomes Interesting: Intermittent Efforts
The nuance lies in the type of effort exerted. In endurance disciplines that include specific phases, creatine can provide an advantage:
Favorable contexts:
- Frequent surges on varied terrain
- Repeated changes of pace
- Explosive finishes in competition
- Phases above the lactate threshold
Mechanisms of action:
- Increased phosphocreatine reserves
- Improved ability to repeat very intense efforts
- Optimization of final sprints
The benefit, therefore, is not on average speed, but potentially on decisive moments: a final sprint, a demanding technical section, or repeated surges on broken terrain.
What Scientific Research Says
A meta-analysis published in 2023 on trained endurance athletes concluded that there was no significant improvement in overall endurance performance with creatine monohydrate supplementation.
However, another review from the same year suggests that creatine can:
- Improve the repetition of intense efforts
- Support end-of-race sprints
- Aid in anaerobic phases integrated into endurance
- Potentially enhance glycogen stores when taken with carbohydrates
Scientific references:
Practical Recommendations for Trail Runners
For continuous, steady, and long endurance (classic ultra-trail), creatine offers no proven benefit. However, for endurance disciplines with explosive phases (mountain biking, cross-country skiing, rowing, sprint triathlon, short trail races), it can present a strategic interest.
Recommended testing protocol:
- Always test during training, never during competition
- Accurately assess the impact on body weight
- Adapt to the athlete's individual profile
- Never consider creatine as a substitute for fundamentals: sleep, training load management, balanced nutrition
Conclusion: Prioritize the Fundamentals
Performance in ultra-trail is not built on a dietary supplement, however well-studied it may be. It is built on consistent training, quality recovery, and optimized nutritional fundamentals.
Creatine can have its place in specific contexts, but it will never replace solid and coherent long-term preparation.
— Antoine, Baptiste, and Etienne from TRL