Verdict: Great for strength, sprints and surges, but it will not raise VO2max and the extra weight can cost runners
Safety: Well tolerated in healthy people in long-term studies; loading often adds about 0.5–1 kg of water weight at first
Key takeaways
Creatine does not raise VO2max, and one meta-analysis found VO2max rose slightly less with creatine than with placebo
In trained endurance athletes, a 2023 meta-analysis found no overall change in endurance performance
Creatine helps strength training, repeated sprints and finishing surges, which can matter in cycling, rowing, team sports and Hyrox
Creatine is the most researched sports supplement there is, and for strength and power it works. But if you mainly care about cardio, the picture is different. The short answer: creatine does not raise VO2max, and the best available meta-analysis suggests it may slightly blunt VO2max gains. It can still be useful for endurance athletes in specific situations.
What it is
Creatine is a compound made from amino acids. Your body produces some, and you get more from meat and fish. In muscle it is stored largely as phosphocreatine, which rapidly regenerates ATP during the first seconds of all-out effort. Supplementing raises muscle creatine stores, which is why it helps with short, repeated, intense efforts.
The International Society of Sports Nutrition (ISSN) position stand (Kreider et al., 2017) concludes that creatine consistently increases muscle creatine and improves high-intensity exercise performance, leading to greater training adaptations. It also notes possible benefits for recovery and tolerating heavy training loads.
Does it raise VO2max?
No. VO2max depends mostly on how much oxygen your heart and blood can deliver, and creatine does not change those.
The most direct evidence is a 2023 systematic review and meta-analysis by Gras and colleagues. It pooled 19 randomised controlled trials with 424 people, most of whom were also training. VO2max increased in both groups, but it increased less with creatine than with placebo (effect size −0.32). The authors concluded creatine has a negative effect on VO2max regardless of training, dosing or population.
How worried should you be? The effect is small, and part of it may simply be body mass. Loading typically adds roughly 0.5–1 kg of water, and VO2max in ml/kg/min is divided by your weight. Gain weight and your relative VO2max drops a little even if your heart and lungs are unchanged. For more on that link, see VO2max and body weight.
Does it improve endurance performance?
Mostly not for steady efforts. A 2023 meta-analysis in trained endurance athletes (Fernández-Landa et al.) included 13 placebo-controlled studies and found no significant change in endurance performance, with a trivial negative effect.
A 2023 ISSN narrative review (Forbes et al.) adds nuance. Creatine tends to increase time to exhaustion in high-intensity endurance tasks, probably by boosting anaerobic work capacity, and it may help with surges and end spurts that often decide races. Time trial results are mixed. The authors also stress that the added body mass can cancel out benefits in weight-bearing sports like running.
So creatine is more interesting for sports with repeated changes of pace, such as cycling, cross-country skiing, rowing, team sports or Hyrox, than for steady road running.
How it is used in studies
- Maintenance dose: about 3–5 g of creatine monohydrate a day. Muscle stores rise over roughly 3–4 weeks.
- Loading (optional): 5 g four times a day for 5–7 days, then a maintenance dose. Loading fills stores faster but makes early weight gain more noticeable.
- Form: creatine monohydrate is by far the best studied. Pricier forms have not been shown to work better.
- Timing: matters little. Taking it daily is what counts, often with a meal.
Side effects, safety and anti-doping
The ISSN position stand reports that short and long-term use, up to 30 g a day for five years, has been safe and well tolerated in healthy people. The most common effect is weight gain from water stored in muscle. Some people get stomach upset with large single doses, which splitting the dose usually solves.
Creatine is not banned in sport. However, supplements can be contaminated with prohibited substances, and the IOC consensus statement (Maughan et al., 2018) warns about this. If you compete, choose third-party tested products such as those certified by Informed Sport or NSF Certified for Sport.
This is not medical advice. If you have kidney disease, another medical condition, or take regular medication, talk to your doctor before taking creatine.
Who might benefit
- People doing strength training alongside cardio, including older adults trying to keep muscle.
- Athletes in sports with sprints, surges and intervals: team sports, track cycling, rowing, Hyrox.
- Vegetarians and vegans, who tend to have lower muscle creatine stores.
It is less useful, and possibly a slight handicap, for runners and climbers who care most about power-to-weight. If you want a supplement for steady endurance, caffeine and beetroot nitrate have better support.
Bottom line
Creatine is excellent for strength, power and repeated sprints, but it does not improve VO2max, and the best evidence suggests it may slightly blunt VO2max gains, partly through weight gain. For cardio fitness, training does the heavy lifting: see how to improve VO2max and track your progress with the VO2max calculator. Browse other options on the supplements page.
Frequently asked questions
Does creatine reduce VO2max?
Possibly a little. A 2023 meta-analysis of 19 trials found VO2max improved in both groups during training but slightly less with creatine than with placebo. The effect was small, and creatine does not damage your heart or lungs.
Is creatine good for cardio?
Not for steady cardio. It does not improve VO2max or long steady efforts, but it can help high-intensity intervals, sprints and surges within longer races.
Does creatine affect cardio performance in runners?
The main issue is body mass. Creatine often adds water weight, and in weight-bearing sports like running that extra mass can offset any benefit.
What is the effect of creatine on VO2max tests?
Do not expect a higher score. If you gain weight on creatine, relative VO2max in ml per kg per minute can even dip slightly because the same oxygen uptake is divided by a higher body mass.
Sources
- Kreider RB, et al. International Society of Sports Nutrition position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr, 2017.
- Gras D, et al. Creatine supplementation and VO2max: a systematic review and meta-analysis. Crit Rev Food Sci Nutr, 2023.
- Fernández-Landa J, et al. Effects of creatine monohydrate on endurance performance in a trained population: a systematic review and meta-analysis. Sports Med, 2023.
- Forbes SC, et al. Creatine supplementation and endurance performance: surges and sprints to win the race. J Int Soc Sports Nutr, 2023.
- Maughan RJ, et al. IOC consensus statement: dietary supplements and the high-performance athlete. Br J Sports Med, 2018.