exercisibitionist 

One who chooses the most public of places to conduct their lunges, push-ups or other exercises, and often glances around as if waiting for someone to ask them if they work out.

I spotted an exercisibitionist today, doing push-ups off a park bench next to the patio of the busy restaurant on the corner.

exercisibitionist by E.B. Wite-Out June 8, 2009

Facebook exercibitionist 

A person, usually overweight & out-of-shape, that always posts on facebook when they're working out (& often exaggerates their accomplishments).

John: "Just finished 5 hours at the gym."
Brian: "You Facebook exercibitionist! You've never even looked at a gym for that long."

Matt: "Just ran a marathon in 2 hours."
Brian: "That'd be a record for someone your size, you Facebook exercibitionist."

Jen: "Off to do yoga, then on to insanity cardio & P90X."
Brian: "I know you're trying to attract a man, but don't be a Facebook exercibitionist."

Facebook exercibitionist by Johnny Drama Johnson August 21, 2011