I've been using ~400 hours/year training plans, which includes all exercise - riding, skiing, hiking, weights, etc. I keep track of everything because it all matters in terms of training stress. This year, I'm at about a 480 hour pace for the year. I could probably handle a little more, but to very little point. I'm having fun. My wife and I are doing more backpacking and weights than riding in August/September this year. Legs should be good when we start bike training for next summer, in mid-October.