Skipping rope can work for boxers, and it can work for you too. Actually, it can work even better now, thanks to this smart rope ($60 on Kickstarter). Basically, it has a bunch of sensors and whatnot that connect with an app, which allows you to catalogue your workout. Or, the app will give you a program. The most handy thing, though, is a jump rope is extremely versatile. No gym membership? Jump rope. Snowing outside? Jump rope. Live in a shoebox condo? Jump rope.