Paul Ryan -- First Order of Business ... Crunches!

Paul Ryan has gone back to work on Capitol Hill ... as a mere congressman ... and the question on everybody's mind since the election ... DOES HE STILL FIND TIME TO WORK OUT???

Mitt Romney's former #2 was taking a stroll through Washington D.C. today ... when our camera guy asked the Wisconsin rep if he's been able to hit the gym since he's been back.

Of course, Ryan is a gym-aholic -- who's rumored to have a killer set of abs ... like the kind of abs that would give Rep. Aaron Schock a run for his money.