YOU usually couldn't tell. I guarantee that everyone else can tell.
Excerise doesn't make you instantly stink, you'll just smell like sweat. The stink happens over time as bacteria eat that sweat, regardless of how much you sweat. Since you're not regularly washing away those bacteria and their byproducts, you will stink.
Pineapple pizza really is kinda meh by itself. But, pineapple + jalapeno + a salty/savory topping like pepperoni can be amazing.
Semi-tangential non-sequitor: The news algorithms offered up the recipe for an "Italian treat" recently that had me appalled and curious in the same way I expect pineapple pizza haters are. It was very ripe cantaloupe slices wrapped in prosciutto. I don't even really know what to say. I just don't want to be alone in knowing about that monstrosity.