When I was in the army 23 years ago (ouch!), when there were some kind of speeches or other events where we were supposed to stand to attention for a long time

When I was in the army 23 years ago (ouch!), when there were some kind of speeches or other events where we were supposed to stand to attention for a long time there always was 1 or 2 guys that would pass out. It was considered normal by the hierarchy. I never understood why, and the guys weren't able to explain why neither. Maybe we should have given them plenty of water (but then they would have run the risk of pissing themselves, choices choices :)