Creatine for Endurance Athletes: Benefits, Risks and What the Research Really Says

Picture the final climb of a hilly sportive. You’ve ridden steadily for four hours, fuelled well and paced it perfectly. Then someone attacks. Whether you can go with them depends far less on your aerobic engine and far more on how quickly your legs can produce a burst of power.

Endurance races are rarely decided at a steady pace. They’re decided by the surge on the climb, the kick for the line at parkrun, or the move out of a corner on the bike in a draft-legal triathlon. These are exactly the moments where creatine, a supplement most endurance athletes associate with bodybuilders, has a credible job to do.

In this article, we look at how creatine works, what the research says about creatine for endurance athletes, the trade-offs you should know about, and the myths around kidneys, hair loss and cramp. We finish with practical advice on dosing.

What is creatine and how does it work?

Creatine is a compound made from amino acids. It is stored mainly in skeletal muscle as phosphocreatine (PCr), which rapidly regenerates ATP, the molecule that powers every muscle contraction. Topping up creatine stores helps you sustain maximal efforts for longer and recover more quickly between those bursts.

ATP is the energy currency of the body, but in practice muscles only hold enough of it for a couple of seconds of all-out work. To keep contracting, ATP has to be regenerated constantly.

Phosphocreatine is the fastest way to do that: it donates a phosphate group to ADP (the “spent” form of ATP), rebuilding ATP almost instantly and without needing oxygen.

Think of phosphocreatine as the small battery pack in a hybrid car. Your aerobic system is the engine, efficient and capable of running all day. When you floor it to overtake, the battery delivers an immediate boost. It only lasts around 10 seconds at maximal effort before it needs recharging, which happens during the easier riding or running that follows.

Around 95% of the body’s creatine is stored in skeletal muscle (Kreider et al, 2017). We make some ourselves in the liver and kidneys, and we get roughly 1–2 g a day from an omnivorous diet, mostly from meat and fish. Vegetarians and vegans therefore tend to start with lower muscle creatine stores, which becomes relevant later on.

Supplementing with creatine can raise muscle creatine and phosphocreatine stores by around 20–40% (Kreider et al, 2017). More stored PCr means more fuel for high-intensity efforts, and faster recharging between them. This is why creatine is one of the most researched ergogenic (performance-enhancing) aids in sports nutrition.

Does creatine improve endurance performance?

For steady-state endurance performance, the short answer is no. Creatine does not meaningfully improve time trials or long runs at a constant pace. However, where it can help is with the repeated sprints, surges and hill efforts that happen within endurance events.

The best evidence against creatine for endurance comes from Fernández-Landa et al (2023), a systematic review and meta-analysis of 13 placebo-controlled trials in trained athletes. They found no significant change in endurance performance after creatine supplementation, with a pooled effect that was trivially negative.

Their conclusion was clear: creatine monohydrate on its own does not improve endurance performance in trained populations.

An early study by Balsom et al (1993) helps explain why. Well-trained men who loaded with creatine gained body mass, and their times over a 6 km run got slightly slower, while time to exhaustion on a treadmill didn’t improve. If your event is purely aerobic, carrying extra mass offers no benefit and can cost you time, more so during running than cycling.

That isn’t the full story though and more we should give more consideration regarding creatine for endurance – these races usually aren’t run at a perfectly even effort. Forbes et al (2023) reviewed the evidence and argued that creatine’s value for endurance athletes lies in “surges and sprints”: the moments where you briefly switch from aerobic to anaerobic energy, and where races are frequently won and lost.

Engelhardt et al (1998) tested this directly with triathletes. After five days of creatine supplementation, power output in repeated 15-second high-intensity bouts within an endurance session improved by around 18%, while the steady endurance part of the test was unchanged. In practical terms, that’s the kind of advantage needed to respond to an attack on the bike or hold your position at a turnaround, not boost average speed over 40 km.

It’s worth flagging: many creatine studies are small, short duration and lab-based, and a sprint test in a laboratory is not the same as the final kilometre of a half Ironman. When it comes to creatine for endurance events, the overall picture is consistent, though: creatine won’t raise your aerobic ceiling, but it may sharpen the high-intensity moments within an endurance event.

Creatine for runners vs cyclists vs triathletes: does the extra weight matter?

Yes, for some athletes. The 1–2 kg weight gain that often comes with creatine matters most in weight-bearing sports and hilly events, such as fell running, trail ultras and road running. It matters least in sports where body mass is supported, such as flat cycling, rowing and swimming.

In cycling on flat or rolling terrain, your bike carries your weight and power output is king (combined with aerodynamics). A small gain in muscle water is unlikely to cost you much, and greater sprint power for attacks, crits and lead-outs could be a net gain. This makes creatine for cyclists a more straightforward decision than for runners.

For runners, every kilogram has to be lifted and moved with every stride, and for climbers the cost rises further on steep ground. A fell runner or hilly trail runner has to consider a small gain in surge power against carrying extra mass for several hours. For many flat 10K and marathon runners, the benefit is limited because their races contain few maximal efforts.

Triathletes sit in the middle. The swim and a flat bike favour creatine, while the run carries the weight penalty, so it comes down to your course profile and where you gain or lose time.

A sensible middle ground for many athletes is to use creatine during the off-season or a strength block. This is when gym work and hard interval sessions benefit most from the extra training quality, and when race weight matters least. You can then choose whether to continue into the race season based on how your body responds.

Creatine, glycogen and carb loading

Creatine appears to help muscles store more glycogen when it is taken alongside carbohydrate. This could make your post-race recovery or race-week carb load more effective. This is perhaps the most interesting finding for endurance athletes.

Glycogen, the stored form of carbohydrate in muscle, is the main fuel for hard endurance efforts, and glycogen depletion is a leading cause of fading late in a race. Roberts et al (2016) had participants complete prolonged, exhaustive cycling, then recover on a high-carbohydrate diet with or without creatine. Adding creatine increased muscle glycogen storage during the first 24 hours of recovery compared with carbohydrate alone.

The mechanism isn’t fully understood, but one leading theory is that creatine draws water into muscle cells, and the increase in cell volume encourages glycogen storage. It’s a promising finding, but it comes from a small number of studies, so should be considered a potential bonus of creatine, rather than a reason to take it.

Creatine doesn’t replace good fuelling. If you want to understand how much carbohydrate you need before and during racing, our guide to the importance of carbohydrates for sport performance is the place to start.

Can creatine help recovery after long races and hard sessions?

There’s some evidence that creatine reduces markers of muscle damage and inflammation after long races, but the research is limited, and we don’t know yet whether it leads to faster real-world recovery.

Santos et al (2004) gave experienced runners creatine for five days before a 30 km race. Compared with the placebo group, the creatine group showed smaller increases in blood markers of muscle cell damage (creatine kinase and lactate dehydrogenase) and inflammation (including TNF-α and PGE2) after the race.

That’s encouraging for marathon runners and ultra runners, who know how much a long race can take out of the legs. However, blood markers aren’t the same as feeling ready to train again, and this is a single, relatively small study. Forbes et al (2023) also listed recovery as a possible benefit, so it’s an area to watch rather than a guarantee.

Recovery still comes down to the basics: carbohydrate to replenish glycogen, protein to repair muscle, and enough sleep. VOOM’s Rapid Recovery shake combines carbohydrate and protein with 2 g of creatine per serve, which can be a convenient way to bring creatine into your post-session routine alongside the fuel you need anyway.

Is creatine safe? Myths and side effects explained

Creatine monohydrate is one of the most extensively studied supplements in sport, and controlled research shows it is safe for healthy adults at recommended doses. Most of the common fears about creatine side effects aren’t supported by the evidence (Antonio et al, 2021).

Will creatine make me gain weight?

Often, yes, but probably not in the way you think. Creatine water retention is mostly intracellular, meaning the water is drawn into your muscle cells along with the creatine, rather than sitting under the skin as bloating. A gain of around 1–2 kg in the first week of loading is typical (Kreider et al, 2017). Not everyone responds the same way, and a lower daily dose without loading tends to produce a smaller, more gradual change.

Is creatine bad for your kidneys?

In healthy people, the research says no. A systematic review and meta-analysis by de Souza e Silva et al (2019) found no significant effect of creatine supplementation on markers of kidney function.

There’s one important practical point. Creatine is broken down into creatinine, which is the marker doctors use to check kidney function on a routine blood test. Supplementing can raise blood creatinine slightly without any harm to the kidneys, but it can make test results look concerning.

If you’re having blood tests, tell your GP you take creatine. Athletes with existing kidney conditions, those on medication, and anyone under 18 should speak to their GP before taking creatine.

Does creatine cause hair loss?

The creatine hair loss myth comes from a 2009 study of rugby players that found an increase in dihydrotestosterone (DHT), a hormone linked to male pattern baldness, after creatine loading. That study never measured hair.

Lak et al (2025) finally tested the claim directly. Resistance-trained men took 5 g of creatine or a placebo daily for 12 weeks. There were no differences in DHT, the DHT-to-testosterone ratio, hair density, follicle count or hair thickness between the groups. This trial only included men, but it’s the strongest evidence to date that creatine does not cause hair loss.

Does creatine cause cramp or dehydration?

No. This myth persists in endurance circles, particularly for racing in the heat. A systematic review with meta-analyses by Lopez et al (2009) found that creatine did not impair heat tolerance or hydration status, and did not increase cramping. Cramp is complex, and the usual suspects are fatigue, pacing, fluid and sodium balance. Our article on preventing muscle cramp with electrolytes covers the science.

Is creatine a steroid or banned in sport?

Creatine is not a steroid or a hormone, and it isn’t on the WADA Prohibited List. If you compete under anti-doping rules, it is prudent to choose a batch-tested product with Informed Sport certification, to avoid any doubt.

Can creatine upset your stomach?

Occasionally, particularly with large single doses during loading, athletes report stomach upset after consuming creatine. Splitting the dose across the day and taking it with food usually solves the problem.

How much creatine should endurance athletes take?

The best-supported approach is 3–5 g of creatine monohydrate per day. Alternatively, you can saturate muscle stores faster with a loading phase of around 20 g per day, split into four doses, for 5–7 days, followed by 3–5 g daily as a maintenance creatine dose (Kreider et al, 2017).

Loading vs no loading. Loading fills your muscle stores in about a week, but tends to cause a more noticeable jump in body weight. Taking 3–5 g per day reaches the same level of saturation in around 3–4 weeks, with a gentler change in weight. For runners and anyone mindful of race weight, the slower route is often the smarter one.

Timing. Consistency matters more than timing. Creatine works by gradually building up stores, not by giving you an immediate boost before a session, so the most important thing is to take it every day, including rest days. Taking it with a meal or a carbohydrate and protein drink may slightly improve uptake.

Which type? Creatine monohydrate is the most researched form, the best value, and the one used in almost all the studies in this article. There’s no good evidence that newer “advanced” forms work better.

Stacking. Creatine works through a different mechanism from other well-known performance boosters, so it can sit alongside them in your plan. If your races involve sustained hard efforts of one to ten minutes, it’s worth reading about beta-alanine and sodium bicarbonate, which help buffer acid during those efforts. Beta-alanine is also found in VOOM’s Pocket Rocket Beta Blast.

Who might benefit most from creatine?

Creatine for endurance athletes is most likely to help those who start with lower creatine stores, or who regularly rely on short, maximal efforts in training and racing.

Vegetarians and vegans. With little or no creatine in their diet, plant-based athletes tend to have lower muscle stores and may see a greater response to supplementation.

Female athletes. Research in women is growing, and creatine appears to be equally safe and effective for women, with a growing interest in its role across the menstrual cycle and menopause (Antonio et al, 2021). Women may also experience less weight gain from water retention.

Veterans or masters athletes. Muscle mass and power typically decline with age. Combined with strength training, creatine can help older athletes maintain muscle and power, which supports their running economy and climbing.

Athletes whose races are decided by surges. Crit racers, cyclo-cross riders, draft-legal triathletes, and anyone who races for position rather than time.

Anyone in a strength block. Gym work is where creatine for endurance performance has the strongest evidence, as better strength work transfers to better endurance outcomes.

Creatine  for endurance athletes: the verdict

Creatine for endurance athletes isn’t about going longer. It’s about having more power for the surges, climbs and sprints that decide where you finish. The research is clear that it won’t improve your steady-state performance. It’s also reassuring on safety: the fears about kidneys, hair loss and cramp don’t stand up to controlled trials in healthy people.

If your races involve plenty of changes of pace, you follow a plant-based diet, or you’re starting a strength block, 3–5 g of creatine monohydrate a day is a low-cost, well-researched option to try. Start it in training, track your weight and how you feel, and decide for yourself whether the trade-off is worth it for your event.