Two tiered warmup, depending on how far I am going. If it's only 25 miles or so, the first 4 is easy warmup and the next 4 intermediate. If I'm going for a century or better, the first 4-5 is easy and the next ten is intermediate. And I don't really cut it loose on the century rides, just probably 80% +/-. When I get to start riding the first of the year, it is hard to keep myself from pushing it too early. I blame it on the spinning classes, as we push it from the git-go there. Bottom line when I'm touring and doing 50-150 miles a day, it's best to ease into it so I'm still strong down the road.