Should I worry about my DH’s strange breathing pattern?

My DH has, in the past few months, picked up a new method of breathing! Sounds daft, I know, but instead of just breathing in and out he takes one breath in and three small breaths out. Sounds a bit like like a steam train chuffing along (but quieter, obviously!). There has been quite a lot in the media recently about the importance of ‘breathing’ correctly and I wondered if anyone else has any advice. I have mentioned to him but he doesn’t realise he’s doing it and thinks I’m just being silly, which is fair enough, but am I? Advice/information welcomed!