Ketones provide twice as much ATP (energy) as glucose. Keto means you’re using oxygen more efficiently, leading to improved performance on Keto for athletes.
Any athlete would tell you the importance of refuelling during an endurance type exercise. A quick GU or Glucose-type sachet and you can instantly feel your energy levels spike. The problem with using glucose as your only fuel source is that you have to replenish your fuel often as the body can only store limited amounts of sugar. The Keto Diet, being in ketosis, can radically improve physical performance.
Athletes also run the risk of becoming insulin resistant. Using glucose or these sugar-rich drinks results in a sudden spike in blood sugar, which in turn triggers insulin. Over months and years, as your pancreas work so hard to make insulin to shuttle the sugar out of your bloodstream, your pancreas gets worn out and can no longer keep pace with the demand for more and more insulin. This eventually can lead to insulin resistance and Type II Diabetes.
Ketones are virtually limitless and can provide a consistent and alternative fuel source. Keto can also prevent crashing when doing prolonged, endurance exercise. In fact, studies show a considerable improvement in cognitive function and perceived fatigue when athletes are utilising ketones for energy during endurance events.
When it comes to the benefits of being in ketosis for athletes; keto-adaptation is vital. Once you have made the transition from using glucose to utilising ketones, you can then train harder and with better endurance while recovering faster due to the anti-inflammatory properties of being on keto.
Once the body is adapted to burning fat as its primary fuel source, muscle glycogen is preserved which improves endurance capacity. Ketosis will help your body burn fat for energy more quickly when your body has used up its glycogen stores.
It is well documented that ketones provide twice as much ATP (energy) as glucose. Being in ketosis means using oxygen more efficiently, ultimately leading to better performance for endurance athletes that is on keto.

The athletes following a Ketogenic Diet managed to lose more weight, body fat percentage, fat mass and BMI compared to the athletes in the control group who did CrossFit without dietary changes.
The study showed the following results:
- Body weight: The keto athletes lost an average of 3,5 kilograms whereas the control group lost no body weight and actually gained weight.
- Body fat percentage: The athletes in the keto group lost an average of 2.6% body fat compared to the control group lost no body fat.
- Fat mass: The keto athletes lost an average of 2,8 kilograms of fat mass whereas the control group lost none.
Health Benefit to Exercise in Keto
It might seem like ketosis is a hindrance to long-term exercise, but it actually has shown to provide significant benefits:
- In one recent study, during a three-hour-long run, 2-3 times more fat burn was seen in ultra-endurance athletes who ate low-carb for an average of 20 months versus those following a high-carb diet.
- In the same study, the low-carb group used and replenished the same amount of muscle glycogen as the high-carb group.
- Being in ketosis might also help prevent fatigue during longer periods of aerobic exercise.
- Plus, ketosis has been shown to help with blood glucose maintenance during exercise in obese individuals.
- As mentioned above, the power of keto-adaptation helps low-carb dieters perform better in all forms of exercise with less carbs over time.
Historical Evidence For Improved Performance on Keto
Besides what we know today, we also have records showing the power of ketosis for movement and peak physical performance.
- For example, demographic verification of European cultures from the past has shown us people were living as mostly hunters, meaning they had very little dietary intake of carbs and were still functioning without any physical hindrances.
- Before the diets of the Inuit people were altered more, their traditional diet was virtually devoid of carbs with a heavy emphasis on animal foods and no known problems. They also were hunters, meaning prolonged steady movement was required for survival.
Although ketosis might get a bad rep in terms of exercise due to popular carb-heavy philosophies, the truth is the diet has a healthy place within a regular low or moderate exercise routine and can easily be adapted to fit the lifestyles of those who are more active. It just takes a little tweaking to find what works best for you.