[silly]

Wear a heart rate monitor that tracks calories and eat enough to sustain the activity. Cycling a ten or twenty miles a day will not hurt you. Sure, we tend to slim down as we ride more, but most of the skinny roadies and mtbers you see put in massive hours a week while closely monitoring diet: up to 20ish a week, so they're definitely not the norm. We cyclists have the same recovery principles in place as lifters: recovery food 30 min - a couple of hours. To make you feel better, I'm in a deficit (500-1000 cals/day) and training 15-20 hours a week. I've lost ten pounds in about 6 weeks, but it isn't muscle. How do I know? I'm also increasing the amount of power I can produce on the bike, and my legs and stomach are looking pretty good right now. So, if you ride and smell "ammonia" you need to eat more because you're breaking down protein, but its the same as any other activity. Ammonia smell = bad = more calories.