I have a Garmin Heart Rate Monitor the Dual. Generally it has worked fine but lately it will not pick up the heart rate for the first 10-15 minutes of a bike ride. Sometimes it drops out. I check battery and put a new one in just to be sure. The device will pair with no problems but seems not to keep HR all the time. I know it needs to be wet and I wet the strap even run it under water. So the last few bike rides both on the trainer in the basement it will not pick up the HR until I am well into the ride 20-25 minutes and dripping sweat. Then it works but all the wetting at first nothing. Then I notice that riding outside is even worse. Now it is winter here and dry but I dont remember having this much problems. Would getting a heart rate gel they use for medical things help. In some ways my old first black plastic strap seemed to be the one that worked the best and consistent. If finally went bad but I wish this was better. I use on my Garmin 935 and 645 The645 has wrist HR but that is override mode with chest strap. Does a Polar HR strap do better? I take any thoughts.