Gyms are clearing out weight machines to make way for equipment that puts the focus on function.
Bosus are used to create an unstable platform for everything from squats to push-ups, forcing you to recruit the core along with the big muscles of the arms and legs. But, as Boyle points out, using Bosus for lower-body work adds unnecessary risk of injury (except for skiers or surfers); in life, we rarely engage our legs on an unstable surface. When we push with our upper bodies, however, it's rarely against a stable surface. That makes Bosus perfect for engaging the small muscles that stabilize the shoulder.
Try: Bosu Mountain Climbers
Credit: Courtesy Bosu
With the rounded side down, hands on the outer edges of the platform, start in a push-up position and jump your feet up toward your hips, alternating sides.