Way I see it...even if you remain still above the pool/beach water... you’re still exercising your legs holding yourself up. But it then goes into what I call "gaining much fitness" vs "minor fitness"- Lazy sims shouldn’t have an issue with minor fitness- and allow it so when you raise up fitness levels or do minor activities, you can still "keep yourself from getting fat". The “fitness way" of swimming, or other activities, should be "stronger"-and those would be the ones that the sim would hate. Your way can work too if EA doesn’t wanna expand swimming and other activities to "many different levels". It’s ultimately up to them, but either way, I’d like Lazy sims to be able to enjoy water too, without just using hot tubs, hot springs, or that kiddie pool. And hell...adding it in as a Like/dislike- can factor it in too: so if you hate fitness, but like swimming, would level off each other so the sim doesn't get the "Having a bad time" debuff.