The straight-arm plank is the most demanding of positions, but thankfully, the exercise works way more than just your abs.

Planks are a go-to exercise for delivering full-body benefits with zero equipment. “If done correctly, they activate our major abdominal muscles, which are essentially the major muscles of the core, ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Planks are a go-to exercise for delivering full-body benefits with zero equipment. "If done correctly, ...