It's really irrelevant whether it can definitely be spread through sweat or not, although the current thought is it can't be. The problem is, one rarely sweats (unless you're sick) without also breathing heavy and that is one of the most effective ways to spread the virus.
A good rule of thumb is, avoid people who are actively sweating. Gyms are one the worst risk places you can go, which makes DeSantis's comments ridiculous. It doesn't matter how fit the person at the gym is. It's not how sick they might get that matters, it's that it can contribute to the spread. I'm not sure what anyone can do at this point to make people understand it's the spread we should be concerned with, not if 1 person is going to die getting it.