Today i experienced it in a pretty dangerous situation. I was riding my over unders outside (5 x 12 mins) and on the fourth interval while i was riding ~50 km/h i suddenly noticed lightheadedness, it was a pretty busy town road, managed to slow down at least but couldn’t remove the pedals and fell over the bushes on the side of the road.
This was happening pretty frequently ~5 years ago and i went to a general practitioner, she said i have no issues and my heart is healthy.
I am really worried today, if i was going to the left side of the road could easily die. Is this really because my aerobic system improving or I was over-challenging myself today.
PS: UNFORTUNATELY, I couldn’t record the HR of today’s activity. simply HRM didn’t couple with Garmin time was limited and i didn’t care 