Why can Sunny and Chaem swim and not breathe?

[undone spear]

I have swam so many times and each time Sunny has gotten 10 seconds, while Chaem 90% of the time gets the same score as Sunny. If I have to stop and breathe/get energy, how can they not? If by chance this is possible to beat them, it's very slim and has to be for those who are insanely skilled.
Also I've noticed on a YouTube video posted 2 weeks ago, a player on Xbox has a completely different mechanism for swimming and an options of "How To Play" that explains how the minigame works. I'm a PC user with the game through Steam and it's not even an option for me.

[strange perch]

yeah it seems like it go reworked slightly, but it still uses the same Idea, of using your stamina, I remember being able to clear it with 800 stamina (I think, gone up since then) without stopping, so if your max stamina is lower than that, that will likely be why, I also found from testing in the practice it started at my current stamina total. so I ate food before the next practice and it was at my max. so try leveling up more skills (+3 per) and finding more stamina fruits before next year I guess