On the rare occasion I max out. Especially for squats for some reason, yes I have a mouth guard.
I ordered a expensive one off Ebay for like $30 bucks and I hated it! It was way too bulky and just... wrong!
So I ended up buying a $2 one from Walmart as a last ditch effort because I refused to spend any more money on a freaking mouthpiece!
Turns out its perfect! I had to cut a tiny bit off the back, but that took 2 seconds with a pair of scissors. Getting it hot and formed is everything!
I've had it a while now and it's still perfect.
You're not doing combat sports, so the breathing and being secure isn't nearly as important.
Just need something to bite down on. Go cheap, you won't regret it! And if you work out at a gym, I promise you're gonna lose it! So buy 2