I am believer in intermittent fasting for sure and I use my own version of it when it's time to get lean and mean... and I also believe there is A LOT of benefit from fasted workouts. that's one reason I get up so early to train.
I don't do 16:8 though.... I can't handle that when training a lot. I'm more like 12:12 or 14:10. I would like to experiment with 16:8. maybe in the winter.
I always kind of did it: coffee only before workouts, water only for the first 90 minutes of long rides. It's calorie restriction, just in a version that's "easier" for me to manage right now. I hit 40 and my metabolism just STOPPED.