I've had this problem too in a challenge where Sims had full autonomy. I resolved the issue for myself by just not building any pools on lots with uncontrolled Sims anymore. The autonomous action to back float is set way to strong. Sims will ignore all their other needs while doing it. In my opinion, it needs to be tweaked so if their energy is too low, they won't do it at all or stop doing it when their energy reaches a certain lower level.
Of course though, there's some Simmers that might look at this as an easy way to kill their Sims and not want it changed at all. In that case I can see why they'd like it. Here's another example of where toggles would be a good idea. Unfortunately though, the Devs have said that toggles are not an option or doable in this iteration. *shrugs*
