As a Keto Coach, I am often asked if a keto or low carb lifestyle is a good idea for runners. My answer - ABSOLUTELY! What better fuel than fat? Why is fat a better fuel you ask? Carbohydrates cannot be stored in large amounts in the body. Fat on the other hand, will typically be more than 20 times the maximum level of carbohydrate stored in the body! Vigorous exercise can deplete glycogen reserves in just a few hours, once a person is keto/fat adapted they have enough fat to fuel several days of exercise. Crazy, huh?!
Becoming keto/fat adapted usually takes weeks so I recommend going a little easy during your workouts and/or runs to allow your body to adjust. During adaptation your body makes the switch from burning primarily carbs/glucose to burning fat for fuel. Since a keto or low carb lifestyle significantly reduces the amount of glucose/carbs you are consuming your body seeks out an alternate fuel source which is fat. Once fully adapted, you will notice you have more energy and you may start performing at a higher level.
Fat adapted keto/low carb athletes notice an improvement in endurance, strength/power, and cognitive performance as well as a faster recovery period. Contrary to what you may have heard, a keto/low carb lifestyle will NOT cause muscle loss and weakness. If you are following the lifestyle properly by staying on top of electrolytes and consuming a good amount of protein, lots of low carb veggies and healthy fat you may just start performing at a level you never imagined possible!