In-home climbing walls are the latest rage in over-the-top home gyms. If your gym has the space, dedicate an entire custom wall to climbing. Or for a climbing experience that can last as long as you can, add a Treadwall M4. It's a treadmill version of a climbing wall that can fit into virtually any space. To keep that adventurous spirit alive in every workout, decorate your gym with the outdoors in mind. Paint the space with forest greens and earth tones, and add photos of mountains you've summited or want to climb.