I'm curious how in shape you need to be / should be before attempting a tour. I'm wondering for training and conditioning what I should be able to do before venturing out on a tour. When I read what people are able to do on this forum, I think I'm not in good enough shape yet !

For example, in another thread people talk about doing 60 miles or 100km a day on average, but that it's all relative to what you're able to do. What I'm wondering is what kind of pace is typical, or reasonable in a day, for example if people are riding to be at a campsite 100 km away before sundown.

For doing 60 miles / 100 km each day, (lets say without significant wind or incline) what kind of breaks are people taking during the day? Do people ride continuous for an hour at 20 kph and then stop to rest for a half hour and then do another 20? Or is it necessary to be able to do 40 km straight for 2 hours without resting?

Thoughts?