Background: I am just coming from collegiate running. I am strong aerobically and have handled 92 mpw indicating that my body can handle a decent amount of stress. I used to race all the way till the age of 14 then had to quit however at that time I was putting in 350 hrs per year.
Currently: I am in college, looking for a team (college doesn't have a team). I am beginning to transition back into racing and I am curious what I should limit my yearly mileage to, any help or personal stories will be greatly appreciated. BTW I am not limited on time.
I also switched to cycling from running. My first ride was all of 6 miles, less than most of my runs, and it hurt! It wasn't long before I was doing 50 mile rides.
Even if you're a top runner you can't just jump into cycling full throttle. It'll take some time to build up the cycling specific muscles and conditioning. If you tried to start off doing the cycling equivalent of your running program you'd be in a lot of pain and perhaps hurt something.
If you are looking for a number to plan your season on and you're currently doing 350 running try writing a plan for 400. Then see how you're doing in 4-6 months and adjust it accordingly. As a beginner racer your races will be short and won't require super long rides for training so you don't need lots of hours. Unless you cat up to 1/2 and do the longer races, or aim for the comparatively few long road races that are available to 3/4s, you may never need 650 hours. More is not always better.