I use a polar f11 its great... i am not sure if i would wear one on tour or not but i could see using it to see how many calories you need to replace. and to make sure you are not over extending yourself... the chest straps could be a bit of a pain to wear 8-10 hours a day everyday for the tour tho.. you can usually check to see if you are getting sick or in need of a rest day by checking your resting pulse ... if it increases dramatically take a break you need it... dramatically is like 5-10 bpm above your average resting pulse....