It is a ton of miles for the period of time, because it's an average including all stops. If something breaks, you lose time. If you get sick, you lose time.

It is a ton of miles for the period of time, because it's an average including all stops. If something breaks, you lose time. If you get sick, you lose time. If you get saddle sores, you lose time. Doing that many miles without a serious injury that sidelines you for weeks is a skill in itself. Many people, with at most a month of practice, could survive riding 40-100 miles in a day, but many of them would be so worn out or would injure some sort of muscle such that they couldn't do 2 in a row - much less 200. Citation: I've done a variety of 200-400 mile community group rides and seen people in all sorts of shape, but have done it enough times with enough different people to see a diverse number of outcomes.