After doing a leg press session where I increased the weight and reps, I stood up and nearly blacked out. I sat down at the next machine and all was OK after a minute or so.

I didn't want to tell the gym people because they said dizziness is not normal. But my guess is that it's to do with a lot of oxygen being used by my leg muscles, then reduced blood pressure to my brain when I change from a fairly horizontal position to a vertical position.

Next time I propose to just rest a bit longer after the final set of reps. Am I on the right track here?