I did it in A&P class a few years ago. 3 minutes 26 seconds. I could have gone a little longer but people commenting started making me lose my focus and I eventually just said screw it there is no benefit to this.
One thing I can tell you is you can train yourself to hold your breath, 3 minutes is good and I haven't practiced in a long time but Back when I swam alot I could do 4 or 5 minutes. There are free divers who can go MUCH MUCH longer. Like 10+ minutes. And thats while swimming around.
One benefit for the average person is if someone drops a really nasty fart, you can hold your breath for a long enough time to either wait it out or to move away from the carnage.