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Is The Keto Diet Harming Your Athletic Performance?

Athletes’ bodies endure high levels of stress. With intense training constantly pushing the body to its limits, most professional or competing sportspeople follow specialist dietary plans which ensure that their bodies can recover from high-stress levels and reach peak performance when it matters the most.

Developed as a nutrition plan for sufferers of drug-resistant epilepsy, the high protein and fat, low-carb ketogenic diet has become incredibly popular in recent years, appealing to a huge range of people, from those wanting to lose weight or control type-2 diabetes, to gym-goers looking to promote muscle growth and fat loss.

Suzannah Robin, Operations Director for dietary technology experts Ketoscan has noticed a rise in uptake of the keto diet among athletes:

“Many athletes are trying the ketogenic diet in the hope of achieving results through maintaining a stable level of ketosis.

However, while the keto diet has proved successful for millions of people, evidence suggests that the diet could harm performance for certain types of athletes.

It’s important that this information is shared, to ensure that everyone who decides to follow the ketogenic diet is making a fully informed choice.”

A recent study by St Louis University found that the keto diet worsened performance for athletes taking part in high intensity, low duration sports – such as sprinting and weightlifting, who traditionally use carbohydrates to access the quick energy they need for their event.

Researchers tested a group of 16 men and women, following either a low-carbohydrate ketogenic diet or a high carbohydrate diet and found that, on average, those on a low-carb diet performed 4 – 15% lower than those on a higher carb diet.

Further studies have also found that athletes on ketogenic diets can suffer from early onset fatigue when taking part in short-duration activities.

However, the effect of a ketogenic diet actually works in the favour of endurance athletes, and there is lots of evidence to suggest that following a ketogenic diet can be beneficial for long-duration events.

After an adaptation period, the keto diet helped to prevent burnout – when the body runs out of glucose during an event.

On a ketogenic diet, the body becomes adapted to burning ketones (released from the body’s fat stores) for energy, rather than glucose from carbohydrates.

The body’s fat stores contain over 80,000 calories, which means that if you begin an endurance event in a state of ketosis, you have access to far greater stores of energy than you could gain from a high-carbohydrate diet.

This can help athletes sustain energy levels for long periods of time and decrease the amount of refuels needed during an event.

To prevent energy fluctuations and disruptions to training, it is essential for anyone following a ketogenic diet plan to track their ketone levels, either using blood tests, urine tests, or a portable ketone breath analysis device like the Ketoscan Mini or the Ketoscan Lite

Suzannah added:

“For athletes competing in high-intensity, short-duration sports, it can be useful to check your ketone levels to make sure you are not in ketosis – particularly if your nutrition plan is already relatively low in carbohydrates because eating this way long-term can cause your body to go into early-stage ketosis without you realising.”

When performance is so linked to nutrition, it’s vital for athletes to carefully monitor any nutritional changes. Anyone wanting to make changes to their diet should consult a doctor before beginning any new dietary plan.

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