[Note] There may be problems when partaking in high intensity exercise but you can get around this by targeting carbohydrates around these times. Some research here: Research on exercise and heart rate.
Low-carbohydrate diets for athletes: what evidence?
"What of the long-term health consequences of habitually eating a high-carbohydrate diet especially for that increasing number of recreational athletes who may be unaware that they are insulin resistant (IR)4–⇓6 and for whom carbohydrates pose a major health hazard including the risk of developing type 2 diabetes mellitus? "
Ketogenic diet does not affect strength performance in elite artistic gymnasts.
"Our data suggest that athletes who underwent a VLCKD with adequate protein intake lost weight and improved body composition without any negative changes in strength and power performance. Taken together these results suggest that a properly monitored and programmed ketogenic diet could be a useful, and safe, method to allow the athletes to reach their desired weight categories without the unnecessary and harmful procedures currently in use."
Ketogenic diets and physical performance
"Impaired physical performance is a common but not obligate result of a low carbohydrate diet. Lessons from traditional Inuit culture indicate that time for adaptation, optimized sodium and potassium nutriture, and constraint of protein to 15-25 % of daily energy expenditure allow unimpaired endurance performance despite nutritional ketosis."