Sport Insight
Which supplements do athletes take and why?
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Which supplements do athletes take and why?
Image source, Getty Images Image source, Getty Images Image source, Getty ImagesBySarah Dawkins and Sonia Oxley
BBC Sport senior journalists
It was at the 1992 Olympics in Barcelona when the mutterings about a new “secret weapon” started.
Dozens of Great Britain athletes had been taking a new product that increased muscle mass and improved athletic performance – a “wonder pill” that didn’t fall foul of any doping rules.
They were talking about creatine.
Now found in tubs and bags on many supermarket shelves and tagged in your social feeds, it is the supplement of choice for millions of people and one of the most scientifically researched.
But back then, when it came on the scene at the very top of British elite sport, there were suspicions and stigma around the use of any substance described as ‘performance enhancing’ – even if it was legal.
From the minute an athlete wakes, to the moment they go to bed, they are thinking about how they can optimise their performance and recovery.
Today, creatine is just one of a long list of supplements taken by elite athletes in this pursuit of marginal gains. Some help with muscle size and strength, while others correct deficiencies in the diet.
“There are various reports in the literature of some studies that say maybe up to 90% of athletes take supplements. I often jokingly say that means 10% are lying,” says Prof Graeme Close, professor of human physiology at Liverpool John Moores University.
“The sports teams that I’ve worked in, I think that’s probably closer to 100% of athletes will be taking some form of supplementation.”
So, what do supplements actually do and why do athletes take them? And in the world of strict liability, where elite athletes are solely responsible for what they put in their bodies, how do they make sure they stay clean?
What’s inside an elite athlete’s vitamin box?
While experts like Close advocate for seeking to meet nutritional needs through food in the first instance, it may not always be possible or practical to do this – and that is where supplements come in.
Take, for example, creatine, which is found naturally in meat and fish.
“You would need the best part of a kilogram of raw chicken a day to get the amount of creatine you need,” says Close. But it is unsafe to eat raw poultry because of the food poisoning risk from harmful bacteria.
Creatine is a natural compound in the body produced in the kidneys, liver and pancreas. It is a quick source of energy for muscles, which is especially important for short-duration, high intensity activities such as sprinting.
Its big break as a supplement came in the 1990s when two scientists who had been researching it for two decades shared their findings with Steve Jennings, whose Maxim sports nutrition company supplied products to the British Olympic team.
During the 1992 Barcelona Games, investigative reporter Doug Gillon had learned of a ‘secret trial’ involving British athletes and seen a box of their Ergomax C150 – effervescent creatine tablets. He wrote that if the scientists’ claims – that creatine could improve explosive athletic performance by 1-3% – were true, then “sport may never be the same again”.
In terms of sport supplements and nutrition, he was right. By the time of the next Olympics in 1996, an estimated 80% of athletes were taking creatine, and since then it has become mainstream, with research suggesting there may be cognitive benefits as well as physical.
According to the Journal of the International Society of Sports Nutrition, the creatine breakthrough of the 1990s had “launched a new era in sports nutrition” and “sparked exploration into other supplements”.
The global dietary supplements market size was valued at $209.5bn (£154bn) in 2025 and is projected to grow to $431.7bn (£317.4bn) by 2033, according to Grand View Research., external
Close, who oversaw nutrition for last year’s British and Irish Lions rugby union tour, sees supplements as the “final piece of the jigsaw” rather than a starting point.
“What we’re talking about is small margins of benefit, where actually these athletes who focus on the food, I think what you often find is that they’ve got the big-ticket items right,” he says.
“So they’re seeing great performance benefits because their overall diet is immaculate.
“They might be missing out on the one per-centers, but they’ve really nailed the 99 per-centers. And they often do better than those who chase the one per-centers but have not given enough attention to the 99 per-centers.”
Australian cyclist Nicole Frain agrees, adding: “I’m a pretty big believer that they are called sport supplements. They are there to supplement the things you already do right.
“I don’t think supplements are the answer to fix my problems.
“You need to be eating a balanced diet, training well, sleeping right, recovering well, hydrating – all of those things – before we add in all of the extras.”
The most scientifically researched supplement
Close puts protein powders top of the list of supplements taken by athletes he works with, followed by creatine and vitamin D.
Protein powders maximise muscle repair and contribute to muscle growth, while creatine is a quick source of energy for muscles and important in short-duration, high-intensity activities like sprinting. Vitamin D, meanwhile, is essential for bone health and supports muscle function.
Other popular supplements include carbohydrate gels, which Close says were key in the first sub-two hour marathon run earlier this year by Kenyan long-distance runner Sabastian Sawe.
“As sport nutritionists we were all fascinated at what the fuelling programme was, and it was the sports drinks and gels that played a huge part of that fuelling,” Close says.
“There was a calculation done of what it would take to break the two-hour marathon, and that did involve making sure that over 100 grams of supplemental carbohydrate were ingested per hour.
“And the reports coming out of the recent sub-two-hour marathon was that it was 110 grams of carbohydrate per hour that was achieved.”
Supplements can improve performance, but there is an uneasy ring to describing them as ‘performance enhancing’ because of the association with banned substances and anti-doping rule violations.
So what determines whether something is on the World Anti-Doping Agency’s (Wada) banned list?
“For Wada to put anything on the list, it’s got to hit two out of three criteria: dangerous to health, performance enhancing, and against the spirit of sport,” Close explains.
“So just because something enhances performance, if it’s not dangerous to health and not against the spirit of sport, Wada will not touch it.
“So creatine is a good example.
“Though something like an anabolic steroid, where it’s against the spirit of sport to be injecting yourself for a performance benefit, it’s dangerous to health and it’s performance enhancing – that hits all three.”
But taking a supplement still carries anti-doping risks.
“No guarantee can be given that any particular supplement is free from prohibited substances,” UK Anti-Doping advice states, urging athletes to “be vigilant” in using them.
And if you test positive for a prohibited substance, consuming it unintentionally can result in the same four-year ban as if you deliberately took it.
There are supplement-testing programmes which batch test products before they are sold to make sure they do not contain any Wada-prohibited substances.
One of those is Informed Sport, which says as many as one in 10 supplements is contaminated with ingredients and compounds prohibited in sport and points to a study carried out by the Anti-Doping Knowledge Centre that showed product contamination was responsible for 8% of all anti-doping violations between 2005 and 2022.
While Informed Sport is a very well used system among athletes, Wada makes it clear that quality assurance schemes can reduce but do not eliminate the risk of an anti-doping infringement.
If you do accept the risk, you need to be organised to keep track.
In the case of Great Britain rower Heidi Long, it takes a spreadsheet.
“I’ve recorded the batch number of every product that I’ve taken and its expiry date because if you take it after the expiry date the Informed Sport [certification] is no longer viable,” she says.
Close says he has also done site visits to factories to see where the supplements are made to check the manufacturing processes because “the risk of failing a drugs test is huge”.
There are risks to the general population too, he adds, saying: “You can be buying supplements off the internet that are made in somebody’s garage and you’ve got no idea of the manufacturing processes.”
He points to studies on creatine products which have found there is no creatine in them and so “you’re completely wasting your money” and that in the worst case scenario it may contain substances that are dangerous to your health.
“So it is really important that the message is that while they can play a small role, the safety considerations are the key factor,” he says.
There is, however, more than one way for an elite athlete to chase a competitive edge – and some are going back to basics.
For every trending supplement, there is an unprocessed, wholefood alternative – from the anti-inflammatory benefits of turmeric, staving off cramp with pickle juice or consumption of high-nitrate foods like beetroot before competition.
It is what Close calls a “food-first” or “food-only” approach and something he says every athlete should use as a starting point.
The newest to have its moment in the spotlight is an ancient Ethiopian grain called teff.
Used for thousands of years in traditional east African diets, teff is now making its mark globally in performance nutrition.
In comparison to other popular grains like wheat, rice and quinoa, teff has a high mineral content and is rich in calcium, iron and vitamin C. Naturally gluten-free and good for the gut, it is also unique for being a ‘complete’ protein, meaning it provides all nine essential amino acids required for human nutrition.
These superfood credentials have caught the attention of some of the world’s best athletes over the years, from Olympic champion marathon runner Haile Gebrselassie to seven-time Grand Slam singles champion Venus Williams, and it is now becoming a more common sight on UK supermarket shelves.
British boxer Fran Hennessy was introduced to teff by her nutritionist and it is now part of her daily routine.
“I’ve never looked back,” she says. “What I’m putting in my body is good fuel and energy and teff has so much. It energises you so much before a workout and it gives you the fibre you need.”
As well as boosting her performances, Hennessy credits teff with being key to recovery.
She says: “Each meal I’m having there’s a reason behind and everything that’s in it there’s a reason behind… I know what I’m putting in my body is fuelling me, recovering me, energising me.”
Image source, Getty ImagesHeidi Long (left) has won World and European gold medals and an Olympic bronze
Cost is another consideration when athletes are deciding on supplements.
“The supplement industry is really expensive,” says Long. “And we’re definitely not made of money. So I think it’s really picking and choosing when you want to put that investment in.”
She says it makes sense to have more supplements around racing time “when the performance is super critical and very time dependent”.
“[But] on a daily basis if I can get the protein intake from my dinner and a glass of milk or yoghurt and breakfast then actually I was going to be eating that food anyway so it’s not as expensive.”
And then there is taste.
“I would much rather enjoy a coffee in the morning with friends or while I’m working rather than have one of the gels,” she says. “Some of the gels … you’ll end up holding your nose when you take it.
“I guess it’s just like the enjoyment of what you’re taking, you know, it’s nicer to eat food than it is to take supplements.”
Related topics
- Cycling
- Rugby Union
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