Lose Your Breath Watching Olympian Petter Northug's Shirtless Altitude Training

9/2/2015 12:01 AM PDT

Cross country skier Petter Northug took to the hills of Italy with some funny looking rollerblades to do some big time training at high elevations ... but the most breathtaking thing about the adventure is what he's been hiding under all those winter layers.

He's gold medal winning.