I'm 74 and recently decided to get fit again having been out of bike training and racing for some 20 years. All seemed to be going fine with me making fast progress as I used to, but on Sunday I was feeling a bit unwell and had a sore throat but still went out for a training ride. I use a Garmin Edge 1000 with the heart rate function and I noticed that my heart was running at 175 bpm which seemed too high for the speed and cadence I was maintaining. I still carried on not taking too much notice of my heart monitor and the only thing I did notice was that I kept getting rear wheel spin like I was putting out a lot of power then after a while I became very weak and had trouble climbing.
When I got back home I felt really dizzy and had to sit down and my daughter said I looked really pale. When I checked the Garmin it showed for some 5 to 10 minutes my heart had been running at 185 bpm rising to a max of 254 bpm before I lost strength with my heart rate dropping back to about 134 bpm. I went out again today but stayed off the worst of the hills and recorded a steady 140 bpm with a high power output according to the speed I set. Comparison with recent previous rides showed that my highest heart rate was 172 bpm with an average of 155 bpm while climbing the worst of the hills on my regular training run.
I'm not sure what to make of all this. Should I be worried enough to see my doctor?
All the best.