After spending weeks in ketosis, I have found that I can eat up to 200 carbs at night if I’m training hard. Though I will exit ketosis at that time, after fasting overnight, when I measure in the morning, I am already back in ketosis. As long as I keep the carbs at night and am training hard, it works. I learned this technique from reading Ben Greenfield, a biohacker who is much smarter than I am.
Is my whole diet ketogenic? No, but I am in ketosis for most of my day until my dinner meal.
I do this style of eating to so I can restore my glycogen stores for hard exercise. Many people strength training on full ketogenic diets though and feel fine, and even many adherents of Carnivore don’t have issues with exercise.
I think the body is highly adaptable. I just think the night meal, with fibrous carbs like sweet potato, combined with hard exercise and doing keto the rest of the time, is a powerful diet for performance.