How many hours can you ride per-week?

My 2 or 3 75 minute rides during the week are very hard efforts that include 2 or 3 15-minute long intervals at max effort (~100% FTP). Sometimes it's referred to as 2x20's. I'm pretty torn up from those efforts and the intervals are quite unpleasant. I try to have a rest day between the workouts. On the weekend I try to do a 3-4 hour ride at 70-80% FTP and try to include climbing...might be a hard effort here or there up a climb, fartlek style.

If you can ride more than 6-7 hours a week, then you probably won't want to be doing such hard efforts every workout. For me, I found that doing what I just described gave me power gains faster than what I was using from "the time crunched cyclist" book.

I make sure to get enough sleep, and rest days to me are ultra important. I'm at peak form after about 5-7 days of little to no riding, so I just do a couple easy 20 milers the week of a big event or race.