MUSCLES ENGAGED Abdominals The abdominal muscles (abs) provide movement and support to your core area. The deeper and closer to the spine the particular abdominal muscle is, the more effect over body posture it will have, and this often contributes significantly to a healthy back. Equipment Used Bosu The BOSU balance trainer stands for "Both Sides Utilized" and is most often used for balance training, various athletic drills and aerobic activities. Exercise Instructions Step 1 Start in a bridge on top of the Bosu. Be sure to have your hips lowered and tucked as well as you abs contracted and you belly button sucked up. Step 2 Keeping your core tight, push your body up into a push up position, hold and then lower your body back down. Step 3 Perform as many as you can on your right/left side while still maintaining good form and then repeat the same amount of reps on the other side.