For fitness, there is no need to be a winner of the last Olympic Games. A basic level of fitness is good enough. There is certainly no problem if you feel tired after the daily voyage. Problems might occur, also on the best cardio fitness level, when you not used doing cycling. There might be some problems not expected, such as knee ache, backache, some problems with tendons, etc. Such annoyance could seriously spoil your tour. Even worse if you get these problems on early stages on the trip. The best preparation to avoid these troubles is to carry out daily trips in advance.