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An allergy might be another cause, hard to track down exactly wha,t but it's easy to try some antihistamine and see if it makes any difference.
I seem to remember reading someone's account of the tour divide remembering he had an allergy to pine resin, was struggling on a climb, about to call it a day, then took some anti allergy medication and popped right back up.
I had similar symptoms this winter. Took me 4 months of very little exercise to recover. Very little sleep due to baby and trying to carry on training led to overtraining I think and I just kept getting viruses and colds. Currently worrying that it has started again. Have tight chest etc you describe. Work is very stressful at the moment.
I've started taking vit d
Maybe you are allergic to the gel stuff they use to bulk up tablets ?
Maybe you aren't getting enough milk?
Very good for fighting off cat AIDS that.
@Tom_w1987 I've had that effect when hooked up to an ECG - alarm bells going off, medic returns and says "Oh, it thinks you're dead!", makes an adjustment "Just lie down and relax"
"Relax! The ruddy thing thinks I'm dead!"
Basically they'd set the minimum heart rate at something stupid like 60 and anything below that flagged the alarm.
