Well, I have to eat some of my words about heart rate monitors. I've used a Polar "FT7" for several years. This HRM has a digital "code" which prevents interference from other heart rate monitors and, as I've said, from microwave towers. Or so I thought. Today I went out for a nice, relatively relaxed 20-mile ride (only 600 feet of climbing). Average speed about 11 MPH. Average heart rate about 140, normal for me. But... Maximum was 198! I wasn't watching the screen, but I know I was never running that heart rate. My faith in the FT7 is shaken!