I've just got a Polar HRM and I'm assuming I've used the right formula to set it up - Max is 220 less age. I'm 38 and have never really done much in the way of exercise at all. I did an hour on the turbo trainer this morning, nothing heavy I don't think, probably legs going around for the most part at 65-100 rpm, I averaged 159 and maxed at 187. The 187 was when I cranked the turbo remote up to number 9 and had a minute out of the saddle, my legs wouldn't let me carry on anymore than that.