Creatine for Runners: Good or Bad? What the Research Says About Endurance, Speed and the Scale

Why runners argue about creatine

Search creatine for runners and you will find two camps. One says it is a gym supplement that only adds weight you have to carry for 26.2 miles. The other says every athlete should take it. Both are partly right, and the useful answer depends on what kind of running you do and what else is in your week.

Creatine fills your muscles' store of phosphocreatine, a quick backup that rebuilds ATP in the first seconds of a hard effort. That is the energy behind a heavy squat, a 200 m repeat or a sprint to the finish line. Easy and steady running relies mostly on aerobic metabolism instead, which is why the results for distance runners look so different from the results for lifters.

What the research says about creatine and endurance

The most direct answer comes from a 2023 meta-analysis in Sports Medicine. Researchers pooled 13 placebo-controlled studies of creatine monohydrate in trained athletes and found no meaningful change in endurance performance. The pooled effect was trivial and not statistically significant.

A 2023 narrative review in the Journal of the International Society of Sports Nutrition adds nuance. Its authors note that creatine raises phosphocreatine stores, helps buffer acid during hard efforts and, taken with carbohydrate, supports glycogen storage. Across studies, creatine increased time to exhaustion during high-intensity endurance work, while time trial results were mixed. They conclude it is most likely to help events with repeated surges or a sprint finish. The same review points out that the added body mass may cancel out benefits in weight-bearing sports like running. Several authors disclose industry ties, so read it as a well-argued case, not a final verdict.

On glycogen, a 2016 study had 14 men cycle to exhaustion, then eat a very high-carb diet with either 20 g of creatine a day or a placebo. Muscle glycogen was clearly higher in the creatine group after just one day of recovery, and it stayed higher. That was cycling, with a large dose, so it is a promising signal for marathoners rather than proof of faster race times.

Where creatine can help a runner

• Strength training. The ISSN position stand calls creatine monohydrate the most effective nutritional supplement available for increasing high-intensity exercise capacity and lean mass during training. If you lift twice a week to run stronger, creatine supports that work.*
• Intervals and hills. Repeated short, hard efforts are where creatine research is strongest.
• The finishing kick. 5K and 10K races often come down to the last 400 m.
• Glycogen. Paired with carbs, it may help you store more muscle fuel, based on early research.
• Female runners. A 2021 review in women found benefits for strength and exercise performance, especially with resistance training.
• Vegetarian and vegan runners. Meat and fish are the main food sources of creatine, so plant-based runners tend to start with lower stores and often see a bigger rise when they supplement.

The scale question for distance runners

Creatine pulls water into muscle. Most people gain about 2 to 4 lb (1 to 2 kg) in the first weeks, mostly after a loading phase. For a 150 lb runner, 2 lb is about 1.3% of body weight. Whether that matters depends on your event and how you feel carrying it. Running data helps here: in one study of trained endurance runners, about 2 lb (0.9 kg) of extra body water from a creatine and glycerol mix did not change the oxygen cost of running. The good news: a 2009 systematic review found that creatine does not hurt heat tolerance or hydration status at recommended doses, and the 2021 ISSN review of common creatine questions does not support the claim that it causes cramping.

Side effects runners ask about

The most common effects are a little water weight and, for some people, an upset stomach or bloating, mostly during loading. Skip loading, take it with a meal and split the dose into two smaller servings if your stomach complains. The 2021 ISSN review of common questions found that creatine does not harm healthy kidneys at recommended doses, and the hair-loss claim rests on one small study that has not been repeated. If you have a kidney condition or take medication, talk to your doctor first.

How runners should take creatine

The ISSN position stand describes two routes. The fast route is a loading phase of about 0.3 g per kg of body weight a day (0.14 g per lb), usually split into four doses for 5 to 7 days, then 3 to 5 g a day. The slow route is 3 to 5 g a day from the start, which fills your stores in about three to four weeks. For runners, we recommend the slow route with plain creatine monohydrate. It keeps the early water gain smaller and is gentler on your stomach before runs.

Take it at a time you will remember every day, ideally with a meal. If you are in a marathon build, start at least 6 weeks before race day so you know how you feel at full stores, or wait until after the race. Do not start creatine for the first time during taper.

How to pick a creatine

• Creatine monohydrate. It is the form used in almost all of the research.
• A clear dose. Look for 3 to 5 g of creatine per serving, listed in grams, with no proprietary blend.
• Few extras. One ingredient is easiest to dose and to fit around race-day fuel.

On hot days, our Creatine Hydration Powder (Lemon) gives you the same 5 g of creatine plus 1,000 mg of sodium, 200 mg of potassium and 60 mg of magnesium. Use it instead of your plain scoop, not on top of it, and only one scoop a day. Want the full comparison? Read creatine monohydrate vs. creatine with electrolytes.

For the bigger picture, see our complete guide to supplements for runners, and for race day, how to fuel for a marathon. Building mileage? Start the Build Endurance mission. If speed work is your focus, the Peak Performance mission pairs well with a daily creatine habit. Lifting and running in the same week? The Daily Performance and Electrolyte Stack pairs Creatine Monohydrate with Hydration Powder; find it on the shop page. Making weight for a fight instead? See creatine for combat athletes.

This article is for general education and is not medical advice. Talk to your doctor before starting a supplement, especially if you have a health condition, take medication, are pregnant or are under 18. Results vary from person to person.