I'm having this same problem. I triple-checked, and although I made sure I had Fitness checked off on all
62 of my characters who currently have it, on My Account Overview, it says I only have it on
9.
I'm guessing this bug also carries through on the overall Statistics page... can't be sure, but if all 62 of mine were counting, I'd be about half of the 134 of all characters tracked with Fitness.