1) Acquire treadmill or elliptical. Check Craigslist.
2) Place in front of TV. Turn on Battlestar Galactica.
3) Put on your 75# ALICE pack bug out bag and other tacticool gear. Carry rifle. Replace Mountain Dew with water bottle.
> But anon, it's too hot!
Then put on a fan. Your gear won't be easier when you need it.
> But anon, it's too heavy!
Then maybe a steel entrenchment tool and 500 rounds isn't realistic kit. Figure out what you don't need.
> But anon, the straps hurt and flap everywhere
Then buy a better bag and cut/tape excess straps for a better fit.
> But anon, my drop-leg holster is slapping me
Then ditch the drop leg garbage, buy a proper holster and adjust it.
> But anon, I'm fat!
Keep it up, you won't be.
What are your other workout suggestions?