Why the hell does happen when you lift weights!? [Watch]

Woah! I'm no body builder yet alone go to the gym but I never knew that weigh lifting can paralyze you for a second after a lift. Ok, I'm not sure why this happens and I've googled it everywhere and can't seem to find a answer. Is it because they are holding their breathe for a long time? Can you help me? Hit me up on twitter @Louiegeezy