Wow, that was quite possibly one of the best non-lifting workouts I've ever completed. It's a workout just elevating your ribcage to fill your lungs with air.
I live in Nashville so I took my 40lb X-Vest down to the state capitol building. There's this huge hill with sairs going all the way up to the capitol's front door. It's like a 100 yards of stairs. I sprinted 4 rounds up. I also performed vertical jumps and skips.
I might have rather been hit by a freight truck. Whew!!