I wonder if the difference isn't that your aerobics shoes probably don't have high heels. Generally it's only running shoes that do that, where "cross-trainers" and court shoes are much more neutral.
I'm just not ready for minimalist shoes, and the only "regular" shoes I've been able to find that fit have high heels. Having briefly worn the zero-drop shoes, I'm desperately missing not having to smack my heels every step I take. Why do they make shoes like that?????
I'm feeling a bit better and that means I'm going to run long today ... accountability post ...
ETA - done. 15.4, a really nice day for a run.