Reet, this might be a bit of a rambling one, but while I am trying to get through to my local docs, I figured I would canvas some opinions.
History: Usually bike 100m a week and run 20-30m a week with no bother. Sometimes will do more of one than the other, depending on the weather.
Last Saturday, 7th, I had to abandon a run after a couple of miles as I just felt really bad. Bit generalised, but just felt I had nothing to give, was a bit short of breath and just felt cack. Walked back to the car grumbling and felt pretty wiped out for several hours after...also felt cold.
Sunday I went for a 7.5m run with my sis, at a relaxed pace, and despite feeling a bit weak, all seemed ok.
Monday went for a walk, but after 2-3 miles felt a bit lightheaded and didn't feel great for the 3 mile back.
Rested for the rest of the week, figuring I may have over done things, as I did make the most of the mini-heatwave we had a week or so back. Also in the 24 hrs previous I had played badminton for an hour, run for an hour straight after and then do a half century on the road bike at 6am the following morning.
Roll on to today, I figured I would see how I got on. As it turned out, badly. After a mile at quick-ish pace I felt pretty run down already. Same symptoms as the previous Sat and elected to turn back. Feelings that followed were the same weak, lightheadedness, pins/ aching in chest area and being a bit short of breath.
What has worried me, is that looking back on my Garmin info from the 7th and 13th runs, they both have me spiking upto 220/230 in the first mile. Something I have never done in the last year of having a HRM. Usual max is around 190, which tallies with the 220 - your age approximation.
So in summary....how long have I got left?