"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." THE BACK extension, that time-tested move for building back strength, has been around the block. But here ...

You lean back against the pad, using the strength of your lower back to move the weights. Trainers don't like this machine because it places unnecessary stress on your spine without building the type ...

Forget the crowded squat rack—trainers say the back extension machine might be the stealth weapon for building stronger glutes, the powerhouse muscles that drive athletic performance and protect your ...

"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." And when it comes to choosing one, quality matters. We rolled up our sleeves and got to testing and ...