32, Male, 175cm, 75kg, no existing medical issues.
Four days ago, I got dizzy while working out in the gym. I can almost rule out that it was due to dehydration or low sugar levels, as I always drink a lot and eat a little snack before workout. I also felt dizzy and powerless the day after that. Today I wore a Fitbit while working out and I noticed that my heart rate during workout is pretty low. During exercises and in the breaks as well, it always seems to be around 90-100.