Used my FR235 for the last 8 years and the hr zones are set. I tried to set my HR zones on my new FR 165 with max Heart Rate of 168. Watch continues to revert to max 150 heart Rate. I am using an armband HR monitor and all my runs on treadmill show that I am in zone high 3 and 4. I am running at 125 bpm per minutes. My resting heart rate is 43 bpm. So the HR zones for FR 165 do not make sense. How to modify them