Creatine has found itself trending in recent months, yet it was discovered almost 200 years ago and its function as a supplement has been known for almost a century. The new kid on the block, it is not.
For decades, it has been used by fitness enthusiasts and athletes of all stripes, and continues to be well-researched and safe to use for most people.
It’s also cheap, in supplement terms: a £40 tub from UK health store Holland & Barrett, in the most popular and studied form, creatine monohydrate, would last you five months of daily servings.
What is creatine?
So, what is it, how does supplementation work and how can it benefit fitness enthusiasts? A compound formed in the human body from three amino acids, it’s produced in the liver, pancreas and kidneys (around 1g per day).
It’s also found in meat and fish, though in much lower levels than in supplements (the dose of which is typically 5g a day, as recommended in a lot of the literature, either before or after workouts).
The muscles use it as an ingredient for the fastest source of energy.
There are three energy systems in the human body. Endurance athletes such as runners and cyclists tend to rely on the oxidative, or aerobic system, where the body uses oxygen to break down carbohydrate, fat and protein for its energy – this is how you keep going for the bulk of a long run or ride.
Then there’s the glycolytic, or anaerobic system. During really tough intervals, carbs are broken down in the absence of oxygen. Where creatine comes in handy is in the third – and fastest-working – energy system, ATP-PC.
It provides instant energy for very quick bursts (up to 10 seconds) of the highest-intensity activities, such as lifting a heavy weight, jumping or sprinting.
In these instances, muscles convert creatine into phosphocreatine (the ‘PC’ in the system), which then makes ATP (adenosine triphosphate) – the energy source that muscles use in order to contract.
What does it do?
“Creatine can improve repeated high-intensity exercise [such as cycling],” says Javier Gonzalez, a professor of nutrition and metabolism at the University of Bath and a former team nutritionist at pro cycling team Ineos Grenadiers.
“One of the potential limitations of creatine is a small increase in bodyweight (due to water) from creatine supplementation.
"However, this may be offset by even greater increases in power for some cyclists and scenarios.
"Despite some claims, there isn’t any good evidence for health risks of taking creatine, so the only practical risk is the increase in bodyweight.”
Let’s take each of these points in turn, using cycling as an example. The question you may have is, does a ‘certain type of cyclist’ include me? How could creatine benefit me on the bike, when so little of my time in the saddle would be spent relying on the ATP-PC system?
Not all of us need to finish a five-hour ride with a sprint at 50mph, but what a lot of us do make a habit of is all-out efforts to town signs on club runs, or repeated 10-second hard efforts on the turbo trainer.
Some of us might also race, and these scenarios are when creatine serves its purpose.
First of all, it’s important to make clear that creatine’s muscle-builder reputation is a fair one, but it’s not as if taking the supplement is going to make you ripped.
Think of it as an enabler of harder workouts – longer, more intense maximal intervals on the turbo, or more reps of a heavier weight in your weekly strength and conditioning session.
Doing no exercise while taking creatine will get you nowhere.
Research into creatine supplementation as an on-bike, in-race performance enhancer favours those events where brief, high-intensity efforts are required on their own (such as a track sprint) or repeatedly (a criterium or sprints out of a peloton in a road race).
It doesn’t appear to be as useful for those participating in longer, albeit intense efforts, such as time trials, as a 2003 study found.
These findings were highlighted in a 2018 paper that looked at the previous 25 years of creatine monohydrate supplementation.
Elsewhere in this study, it found that ‘loading’ the body with 20g of creatine for five consecutive days maxed out the body’s levels of creatine, with subsequent 5g a day enough to keep it at this level.
Others think that the loading phase isn’t necessary and only serves to increase the risk of creatine side-effects, such as intestinal bloating and water retention.
The Rawson study also found that performance during longer-duration exercise, and sprints included during or at the end of endurance exercise, may also be enhanced by creatine supplementation, possibly because it increases glycogen synthesis (glycogen is the storage form of glucose in the muscles and liver).
Increased bodyweight, through water retention, has been shown in creatine studies, but is it enough to deter some cyclists who are sensitive to bodyweight changes?
A 2021 study in the Journal of the International Society of Sports Nutrition, a literature review that looked at the common misconceptions of creatine supplementation, found that while some studies show water retention in the short-term, over the long-term, body water weight didn’t alter.
The intensive loading phase of creatine in some studies may be the cause of this.
The latest research
Creatine’s extensive research continues into 2025, and a recent study out of the University of New South Wales Sydney cast doubt on the effectiveness of supplementation to build muscle, at least in the short term.
They led a clinical trial involving 54 people in a 12-week resistance-training programme (three sessions a week). One group took the supplement at 5g a day, while the other didn’t take any, and at the end of it, both groups put on an average of 2kg of muscle.
The authors suggest a longer study would be needed to give more context to the results, while also calling into question the effectiveness of the 5g daily dose and whether it needs to increase.
Putting on muscle isn’t the goal for most cyclists, however. Strength and conditioning training off the bike usually focuses more on the latter, with the aim of stabilising the body, particularly putting under-used parts from the pedal action under stress, and to address imbalances.
Remember, creatine’s action doesn’t lead directly to muscle growth – it merely provides the conditions for them to do more work.
Do pro cyclists use it?
Will Girling, a nutritionist who’s worked in elite men’s cycling with WorldTour team EF Education, says creatine is probably used across the board and certainly in the teams that he’s worked with.
He argues that for the cheap cost of creatine monohydrate, tallied with the wide-ranging benefits, it’s a “no-brainer” to take.
“While the [Desai] study shows no real difference in terms of muscle gain, there are a lot of proven effects that we know about,” he says. “Peak power output, recovery between efforts of 10 seconds or fewer, improved cognitive focus and even faster recovery from concussion – creatine has been shown to improve a multitude of different areas.
"Muscle gain is certainly not the be-all and end-all in endurance sport. Creatine is incredibly beneficial – it can even help prevent muscle loss when incapacitated.”
Girling also says he’s seen an increase in popularity in different types and forms of creatine – gummies, for example – but warns not to fall for the marketing.
“I’d advise everyone that powdered creatine monohydrate is the only type that you should be buying. It also happens to be the cheapest.”
