I wondered if anyone else had got some strange HR readings from their Garmin 305. I treated myself to one last week and on my third time out today, it says I have had a maximum HR of 219bpm which seems rather high for a middle aged woman. The graph I got showed the HR increasing to this figure by about 1.5km out of 5 then dropping off to something I would call more normal at about 150-155 bpm by 2.5km. The gradients on the run didn't tie in with this either. Has anyone else had strange readings or should I be worried about my heart?