"Hearst Magazines and Yahoo may earn commission or revenue on some items through the links below." Today's ab routines are more versatile than ever. Sure, you can slog through sets of situps and ...

This month in the Lifehacker Fitness Challenge we are taking on the ab wheel, aka ab roller, aka “crap, I fell on my face again.” Last week we did a plank on the wheel, but today we’re going to use it ...