From beetroot shots to baking powder: the science behind the most popular sports supplements

IIn August, Keely Hodgkinson won Britain’s only Olympic gold medal on the track. The basis for the 800m star’s world-famous achievements came from a regime that includes intensity over miles, cross training, sand dune workouts and a £15 supplement that has been around for years but had a breakthrough year in 2024. Hodgkinson uses sodium bicarbonate – also known as baking soda – to power her training and racing, particularly Maurten’s “bicarb system” which was used by 80% of endurance athletes in Paris, according to a leading coach. “I couldn’t recommend it highly enough,” said Hodgkinson’s coach, Trevor Painter. But why? What about sodium bicarbonate and the Maurten system that has been labeled “gold dust” by another leading coach? And what other legal supplements are used besides bicarb? The industry is currently valued at $17.61 billion (£13.15 billion) – that’s a hell of a lot of pills, powders and drinks claiming to improve sports performance. Here we look at the evidence for four of them.

Beetroot shots

The root vegetable is packed with nitrates, which can improve athletic performance. To be effective, however, they must be highly concentrated; a 75 ml shot requires approximately six beets.

“When you eat nitrate-containing food, some of it ends up in your enterosalvage system,” says Andy Jones, professor of applied physiology at the University of Exeter. “Salivary glands secrete nitrate-rich saliva, which the bacteria in your mouth break down into nitrite. You swallow this nitrite, which is converted into nitric oxide by your intestines.” In turn, your blood vessels relax and dilate and blood flow increases, making exercise “easier” and allowing you to work harder.

The proof
Jones’s Study from 2009 saw cyclists enjoy a 16% increase in time to exhaustion during a time trial. There have been since then multiple studies supporting claims of the winnings from the shots. It was originally thought that endurance athletes were the only beneficiaries, but recent research suggests they also optimize performance in high-intensity sports such as sprinting and football. Additionally, “recreational athletes benefit more than elites,” says Jones, because elite athletes’ cardiovascular systems are already functioning near maximum capacity.

Dosage and side effects
Ideally, the injections should be taken two to three hours before training, as this is when nitrite concentrations peak. Fifteen Beet It shots cost £25 (about £1.66 each).

Apart from pink urine, there are no side effects. Remember to avoid mouthwash as this kills the bacteria in your mouth that starts the nitric oxide process.

What was it like for me?
I used beetroot shots when I completed l’Étape du Tour (where amateurs complete a stage of the Tour de France) a few years ago. I felt fresher and fitter, although this could have been down to making better food choices.

Probiotics and prebiotics

Probiotics are live microbial nutritional supplements, while prebiotics are a source of fiber that fertilizes the good bacteria in your gut. You can get probiotics from fermented foods like sauerkraut and kombucha, while prebiotic foods include asparagus and garlic. Both are also available in supplementary form. And both have the potential to improve your athletic skills, especially if you’re a recreational runner or cyclist.

“Probiotics and prebiotics are associated with better general health, but there is increasing research to suggest they can also improve performance,” says Adam Collins, who is doing a PhD in prebiotics and exercise at Bath University.

The proof
“A 2020 study showed that cyclists burned more carbohydrates per hour when supplemented with probiotics due to changes in the intestinal lining,” says Collins. The more carbohydrates you can break down and use during exercise without suffering from cramps and gastrointestinal problems, the theory goes, the more energetic you are, and the longer and stronger you can run, cycle or swim.

“Research also shows that probiotics can reduce the duration and incidence of disease in athletes, but not their severity,” Collins adds. And there are even more benefits to be had when it comes to reducing the effects of diabetes respiratory diseasewhich is common for people who exercise outdoors in dry, winter conditions.

Dosage and side effects
Many commercial probiotic drinks or pills contain 25-50 billion bacteria per dose, of which you take one per day. “You’re looking at a daily dose of 2.5 grams to 10 grams of prebiotics,” says Collins. You can buy a joint probiotic and prebiotic supplement for around £20 for 60 capsules (about 33p per day).

When it comes to side effects, Collins says some people experience gas and bloating. “In the most serious cases you should stop exercising and go to the toilet. Some also have to poop every time they urinate. But generally this passes quickly.”

What was it like for me?
I am currently a guinea pig in Collins’ prebiotic study. I may be given a placebo, so it’s too early to say what the benefits are. Collins hopes to publish his research next year.

Creatine

Creatine is stored in the muscles as phosphocreatine and plays a key role in generating energy for maximum, maximal effort. “The problem is that stores are limited,” says Dr Marc Fell, team nutritionist at cycling team Ineos Grenadiers. “So by consuming more creatine, you will resynthesize phosphocreatine faster during exercise, which means you can work harder.”

Creatine is usually found in red meat and shellfish, but in relatively small amounts. That is why supplementation is popular. It’s also why supplementation could benefit vegetarians more than carnivores.

The proof
A 2003 review of more than 500 studies found that approximately 70% of these studies reported statistically significant positive results. A 2017 study found that the creatine group increased muscle mass by 7.2% compared to the placebo group, while study from 2000 found that football players maintained their sprinting and jumping performance on creatine. There is also mounting evidence that creatine improves brain health, cognition and memory, especially in older people.

Dosage and side effects
Creatine comes in many forms, but choose the monohydrate version. It is proven to be quickly absorbed and there is evidence to support this, unlike supplements such as creatine ethyl ester.

When it comes to dosage, “It depends on how quickly you want to increase your creatine stores,” says Fell. “One option is a loading dose of 20 grams of creatine per day (taken in four 5-gram doses) for five days, followed by a daily dose of 3-5 grams. Or simply consume 5 grams per day. You may benefit more from taking creatine immediately after exercise and with carbohydrates such as rice or pasta.” A 250 gram container of creatine powder starts from around €10. At 5 grams per portion, that is 20 cents per day.

“The most common side effect is weight gain, which occurs because creatine causes water retention in the muscles. This can amount to up to 2 kg.” That’s not great for weight-based sports like cycling.

What was it like for me?
It provided moderate strength gains, but unfortunately for this 47-year-old, the water retention was more noticeable, making me look bloated. Fortunately, the claims that creatine causes hair loss turned out to be unfounded.

Baking powder

Research on the performance-enhancing effects of baking strength dates back to the 1930s, but the common and undesirable effects it has on the gastrointestinal tract have prevented widespread use by athletes.

Recently, however, sports nutrition companies have discovered ways to offer the powder in a gel, which largely solves these problems.

When you train hard, you feel the ‘burn’. This is due to a buildup of hydrogen ions that make your blood more acidic, resulting in a decrease in muscle strength and performance. That’s where the “savior” sodium bicarbonate comes into the picture. It is an alkaline buffer. Consume this before exercise and, the theory goes, because you’ve started on a more alkaline basis, you have the ability to work harder and, in Hodgkinson’s case, run faster before the blood turns acidic and slows you down.

The proof
In 2021, the International Society of Sports Nutrition concluded that sodium bicarbonate supplementation improves performance in “muscular endurance activities… including boxing, judo, karate, taekwondo and wrestling, and in high-intensity cycling, running, swimming and rowing.”

Dr. Andy Sparks, honorary visiting scholar at Liverpool John Moores University, has conducted research in this area that led to him being hired by sports nutrition company Maurten. Their hydrogel formulations have enjoyed widespread acceptance. “The carbohydrate hydrogel protects it in the stomach and optimizes bicarbonate release,” he says. “This new ingestion method has expanded its reach to endurance athletes and reduced potential side effects.”

Dosage and side effects
At this time there are no independent studies on Maurten’s bicarb system. “But I wouldn’t put my name on an article that I wasn’t confident was done properly, analyzed and interpreted properly,” Sparks says. “There is no way I would have made the transition from full-time academia if I wasn’t convinced of the efficacy of the products. The athletes are also happy with it.”

As for cost, baking soda is nominal and can work. Maurten’s product starts from around £60 for four portions, so £15 each time. So not cheap. Also try it first during training and not while racing, because you don’t want any gastro surprises.

What was it like for me?
I briefly played with sodium bicarbonate in both pill and Maurten form, but couldn’t draw any conclusions. I tried Maurten’s mix for a parkrun. There was no bloating or wind, although again the gusts whipping off the Severn Canal meant no conclusions could be drawn.