Low Heart Rate and Dizziness while working out in Gym

[badbud]

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. It doesn't even really raise when lifting weights. My resting heart rate is around 50.

I thought the dizziness could be due to creatine, that I started supplementing around a month ago, because somehow I noticed increased dizziness in that time (yes I know that it's essential to drink plenty of water when taking creatine - did that). I stopped taking the creatine three days ago and the didn't feel dizzy in todays workout, although I had the low heart rate mentioned above.

Should I be worried about the low heart rate and see a doctor? It really confuses me that it doesn't considerably raise when lifting weights.