TRX stands for total body resistance exercise, but that doesn't mean a thing unless you've tried it for yourself. The instability and suspension aspect of this type of exercise makes it different from anything you've ever tried. And once you try these moves, you'll never want to strength train without it. You can pick one up ($170) for your home workouts or try one at your gym. This piece of equipment is life-changing and will open up a whole new world of workouts.