How A Keto Diet Can Help Endurance Athletes Improve

We are very lucky today to have a guest post by Louise Hendon, co-host of The Keto Summit and author of The Essential Keto Cookbook

Is the keto diet an effective tool to improve your exercise performance?

There are plenty of sites recommending athletes “go keto”.

But what does the science say?

In this article we’ll run through the evidence available from current scientific studies.

As well as quickly recapping what the keto diet is and what you eat – plus a few tips for getting started.

What is the Keto Diet?

The primary goal of a ketogenic diet is to force your metabolism to burn fat for energy, rather than just carbs.

When your body is burning primarily fat as a result of a keto diet, this is a state called “nutritional ketosis”.

When your body breaks down fat into fuel, one of the byproducts is called a “ketone”. Ketones are also used as fuel (to create energy) by various cells in your body.

And as I’ll explain further down this post, you can get into nutritional ketosis just by changing what you eat.

Can A Keto Help Endurance Athletes?

Ketosis might not be ideal for all sports, but endurance athletes tend to do very well on a ketogenic diet.

There are 2 big reasons for this.

First, fat and ketones are more efficient energy sources than carbs, which means that your body doesn’t need to work as hard to produce the same amount of energy.

Secondly, because endurance sports generally require the ability to produce and burn energy for an extended period of time, it’s impossible to rely solely on stored glycogen and preferable to be very good at burning fat for fuel to begin with.

Want to see some of the scientific studies on this? Here we go…

1 – Elite athletes who are low-carb are adapted to burn more fat when they exercise

Researchers looked at twenty elite endurance athletes: ultra-marathoners and ironman triathletes.

Half of them usually consumed a high-carb diet, while the other half usually stuck to a low-carb diet.

The results?

When they exercised, the elite low-carb athletes relied significantly more on fat as a source of fuel. Their bodies had become keto-adapted.

This is good news if you’re interested in trying a keto diet for its various health benefits – like weight loss, greater mental clarity and reduced risk of heart disease.

It means you can get the health benefits of keto and still perform athletically at a high level.

Check out the full study here.

2 – A keto diet can help you burn more fat while you exercise WITHOUT negatively impacting your performance

In one study, researchers assigned 60 participants to a calorie restricted diet – either a calorie-restricted high-carb diet or a calorie-restricted low-carb diet (similar to keto).

What did they find?

Compared to folks on the high-carb diet, the low-carb dieters did not show decreased aerobic exercise performance or muscle strength.

So although the keto diet didn’t actively improve their exercise performance, it didn’t harm it either.

But folks on the low-carb diet did burn more fat as fuel when they exercised…

Meaning their bodies had adapted to be less reliant on carbs as a source of fuel – and some folks think this adaptation may help you preserve your glycogen stores so you avoid “hitting the wall.”

You can see the full study here.

3 – Even endurance athletes who’ve only been following a keto diet for three weeks DON’T show decreased performance

This study looked at endurance cyclists who followed a ketogenic diet for three weeks.

They consumed less than 20g of carbohydrates per day and the rest of their caloric intake came from protein and fats.

The findings?

The cyclists did not show a drop in exercise performance because their bodies quickly and successfully adapted to burn fat instead of glucose.

Have a look at the study here.

What can you eat on the Keto diet?

If you want to try Keto to improve your athletic performance, then just note that there are healthy and unhealthy ways to follow a keto diet –

The unhealthy way: eating lots of processed, low-carb junk foods with the sole aim of reaching your macros…

The healthy way: sticking to nutrient-dense whole foods so you nourish your body while meeting your macros…

Here’s what you’ll eat if you’re following a healthy keto diet:

Enjoy these foods:
● Proteins: meats, organ meats, seafood
● Low-carb veggies: Leafy greens like kale and spinach, cauliflower, broccoli, zucchini
● Healthy fats: olive oil, coconut oil, lard, ghee

Eliminate these foods:
● Legumes: lentils, beans, soy, and others
● Grains: rice, wheat, corn
● Sugars: honey, agave, fructose, white or brown sugar, artificial sweeteners
● Starchy vegetables: sweet potatoes, white potatoes, squash, and others
● High-sugar fruits: bananas, oranges, apples
● Processed foods: cookies, crackers, candy and others

Eat these foods in moderation:
● Dairy: it’s tricky to digest and can cause inflammation even if you aren’t lactose intolerant – we recommend avoiding all dairy, except for ghee.
● Nuts and seeds: they’re easy to overeat and higher in carbs than you think.

Tips for getting started on a Keto Diet

Here are a few practical tips to help you get your keto diet started:

1 – Clear the non-keto food out of your house then restock your cupboards with keto-approved options.

It’ll be a lot easier to stick to your diet if you don’t have non-keto treats in the house to tempt you! Also a lot easier if you do it with a group. Accountability and a place to ask questions as they come up is essential to enhance success.

2 – Prepare for keto flu (which is caused by your body trying to adapt to the keto diet) by drinking plenty of fluids, taking in lots of electrolytes and keeping your schedule light when you first go keto.

After a week, the tiredness and flu-like symptoms should be gone.

3 – Eat unlimited protein/fat when you first begin and just focus on keeping your daily carb intake under 25g.

It’s best to keep things simple when you first start out – you can tweak your protein/fat ratios later.

4 – Think about getting some health tests before starting to make sure you don’t have underlying issues like an autoimmune disease, gut infection or vitamin/mineral deficiency.

It’ll help you get the full benefits of the keto diet if you’re completely healthy first!