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Health

Legal ketone sports supplement pushes athletes further, faster

By Alice Klein

27 July 2016

Cyclists on road bikes

Go faster with ketones?

Claudio Arnese/Getty

Here’s a way to pick up some speed. An energy supplement drink pushes endurance athletes over the line faster, and it is legal.

The drink, known as ∆G, was originally developed for the US army, and works by releasing a ketone chemical that muscles can burn to produce energy.

Now Kieran Clarke at the University of Oxford and her colleagues have shown that their supplement really does seem to improve performance. When they gave the drink to elite cyclists, they found they were able to cycle an average of 411 metres further during a 30-minute time trial, compared with cyclists drinking a glucose drink.

The finding bolsters the results of a study in 22 elite rowers reported in 2011, in which those drinking the supplement obtained one world record, six personal bests and 10 season’s best performances.

“The results are really dramatic,” says Clarke.

Energy boost

Ketones are naturally produced by the body when it breaks down fat. This normally occurs when energy reserves are running low, for example, in people who are starving or sticking to a low-carb, high-fat diet.

But providing ketones as a supplement – in the form of beta-hydroxybutyrate – means athletes can draw energy from three energy sources at once. As well as drawing on their glucose and fat reserves, the athletes can get a boost from ketones which would normally only be produced when a person’s reserves are heavily depleted.

“This means that muscles can generate energy from ketones, fat and glucose at the same time,” says Clarke. As a result, more of an athlete’s glucose reserves can be preserved, lowering the chances of hitting the wall, she says.

This theory is supported by the fact that cyclists who consumed the ketone drink produced significantly less lactic acid – a product of burning glucose and breaking down glycogen, the chemical that is used to store glucose.

Perplexing metabolism

However, John Hawley at the Mary MacKillop Institute for Health Research, Australia, says he is perplexed by the suggestion that muscles can use both ketones and glucose for energy at the same time.

The vast body of research shows that muscles only tap into ketones after very prolonged exercise, when glycogen stores are spent, he says. “The logic of this ketone supplement is that it spares your muscle glycogen. But you have more than enough glycogen for 30 minutes of cycling, so I can’t see why sparing it would do you any good.”

Hawley says that independent studies are needed, but says he has heard anecdotal reports from endurance athletes who believe the ketone drink improves their performance under certain conditions. “At the end of the day, some athletes have said they feel a little bit better on this, and that carries some weight,” he says.

Going the distance

The drink will not be commercially available until the end of the year, but Clarke’s research group has provided ∆G to more than 300 top athletes. Specific teams cannot be named due to sponsorship agreements with other supplement providers, but they have reported positive results and no adverse side effects, Clarke says.

Despite the extra boost that ∆G appears to give endurance performers, the World Anti-Doping Agency ruled in 2011 that it would not add it to its banned list. Since ketones can be increased through diet, it wouldn’t make sense to ban them, Clarke says. “If ketones were banned, the diets of all athletes would have to be monitored for several weeks before competing.”

But this kind of supplement is likely to be only of interest to endurance athletes. Sprinters get most of their energy without using oxygen, but the body cannot burn ketones in this way.

Journal reference: Cell Metabolism, DOI: 10.1016/j.cmet.2016.07.010

 

 

 

 

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