Betta Fish: what does his swimming mean?

this is a 25L established tank, no tank mates & my betta swims like this a lot.

not all the time but definitely more than i feel is normal?

i’m not too sure if this is either he’s happy, energetic, & wants to be fed, or if this is a stressed, too small of a tank, swim pattern.

it’s super fast & he does obviously take breaks for air but he’ll usually go straight back to sprinting from wall to wall of the tank lol