Today I was doing an extremely rigorous legs session at the gym and 3/4 of the way through the session during an exercise i felt like i was about to black out... i became very disoriented, dizzy and out of breath so i stopped. My disorientation continued for about an hour after the session. And now 9 hours after my heart gets a short wave of mild tingles that lasts about 2 seconds every minute or so. My energy levels were adequate having had 2 meals in the prior 5 hours my water intake was low for that time of day only about 1L. I did consume a preworkout supplement high in caffeine prior to the workout however this is common for me and has never resulted in the current feelings.