OK, I've had my Polar M21 for about a month now and have been logging HR results as I train. Training has been outside riding, indoor riding on a trainer and a few times jogging.
Age is 44, current weight is 252. My Max HR is 182 (measured riding), pretty close to the calculated rate checked a over several different calculations. Goal is to drop weight, and improve my overall riding (distance, avg speed, etc.).
I have been trying to keep my HR in the 70-85% Max HR when I ride. I have my HRM set to 127/155. When I ride outside I just can't keep my HR in that range. Over a 1 hr ride I will end up with a average HR of 160-163. When I ride on the trainer I can easily keep it in the range, or really whatever HR I desire.
I realize the difference between riding outside compared to the contolled environment of riding on a trainer is the reason for the variations.
Question is...am I doing the right things here? Having the HRM has really been interesting for me. Last year I just got on the bike and rode as far and as hard as I could. I lost weight and had fun, just trying to improve things a bit this year.