Normally my resting heart rate is about 45-46, but last night before I went to bed I measured it and it was about 50. I was a little surprised because it was an easy day with 2 moderate 5 milers.
Then today I woke up late (slept like 12 hours) and felt like crap-light headed and had a sore throat/chest. Also I took my heart rate and it was 80 beats/minute. Took it again a few minutes later and got 76 beats/ minute.
That is a bit scary as I run about 8-9 miles a day but only managed 3 today. Is this something to worry about or is a 75% increase in reasting heart rate serious?