Riding my bike for an hour or two almost every day out in the hilly country several days per week didn't do it for me. Visiting a gym for an hour or two (weights and cardio) almost every day didn't do it for me, either.

The times in my life when I've done lots of exercise and the times when I have not have been the same as far as how I feel. I've tried a number of special diets of different kinds in the past, and none of them made me feel any better.

My diet is full of fruits, vegetables, brown rice, beans, lentils, homemade sourdough, etc.

A fully vegan diet doesn't supply B12, and I don't think a diet that doesn't supply all vital nutrients is sustainable. If you've found something that does work well for you, that's great. But there's no reason to think it is right for everyone.