The ketogenic diet has widely been praised for its health benefits, such as weight loss and improved energy. However, its impact on exercise remains a subject of debate. The ketogenic diet places the body in a state of ketosis, a state in which the body burns fat instead of carbohydrates for energy, which can influence how your body performs during physical activity.

High-intensity exercises which require short, intense bursts of energy are typically powered by carbohydrates. On a ketogenic diet, since the body is burning fat for energy, performance during high-intensity workouts may be limited. On the flip side, steady state aerobic exercises such as distance running may see a boost in fat burning while on the ketogenic diet.

However, evidence suggests that individuals on the ketogenic diet may feel less energetic during workouts, especially in the initial stages when the body is adjusting to using fat for energy. Over time, though, athletes who have become “keto-adapted” have reported increased energy levels during exercise.

Whilst a ketogenic diet may help in maintaining muscle mass, adding muscle could be more challenging due to the lower intake of calories and proteins. It's also worth noting that burning fat does not equate to losing fat. Fat reduction requires burning more calories than consumed, and even on a ketogenic diet, a calorie deficit must be achieved to lose weight. Thus, while the ketogenic diet changes the fuel source for your body, its impact on fat and weight loss depends on many variables, including exercise intensity and overall caloric intake.