"You look like you've worked hard" from a woman at a running club.This means "You are bright red, very sweaty and your nose is running. I am much fitter than you."
"Looking good!" from a much faster than me bloke on Parkrun.This does not mean he wants to take me out for dinner. It means I am bright red and very sweaty, but at least my nose probably isn't running. Also that I look like I need a LOT of encouragement to get to the finish line.
"That's quite a good time" from a bloke on a dating site.This means "My ex was much faster than you. I think I'll get back with her, but continue to email and text you all the fricking time, in case it doesn't work out".
Erm, that's obviously a hypothetical one.
"Why have you got a water bottle? You're only doing 5K!" from a spectator to my son on Parkrun.This means this bloke is a tosser.