A BOSU is a fun exercise tool that resembles a stability ball cut in half and attached to a flat base. The word BOSU actually stands for “both sides up.” True to its name, it can be used with the ball section facing up or down. Because you recruit numerous core muscles to balance on its unstable surface, a BOSU ball is a good tool for training the oblique muscles — the fan-like muscles that wrap around the sides of your waist down to your lower back. These muscles are responsible for rotating, flexing and side bending your torso. They also provide stability for your torso during balance exercises.

Stabilize Your Spine With Abdominal Bracing

Whenever you are in an awkward or unstable position, such as balancing on a BOSU, you should practice abdominal bracing to stabilize your spine. When done correctly, abdominal bracing activates the internal and external obliques. To brace your abdominals, roll your shoulders backward and down and then forward. Tilt your pelvis into a neutral position by pulling your bellybutton in toward your spine. Then exhale with an open throat, as if you are breathing fog onto a mirror.

Balance Exercises

Start your BOSU training with balance exercises. Hold each position for up to one minute. You can kneel or stand on a BOSU with the flat base on the floor. Once you are comfortable standing, progress to balancing on one leg. For a greater challenge, turn the BOSU over so the rounded side is down and balance on the flat surface. It’s a good idea to practice this by a wall for support. Front planks on a BOSU force you to stabilize your core, thus engaging your obliques. For a more advanced front plank, flip the BOSU over so the rounded side is down. Hold onto the side handles of the base and push up into a plank position. Side planks will target your oblique muscles even more. Start in a side plank with your knees bent and your forearm resting on the BOSU. Lift your hip up so you are balanced over your lower knee. To do a more advanced version of the side plank, extend the arm and leg that are not resting on the BOSU and floor and lift up to balance over your palm and the outside of your lower foot.

Complex Exercises

BOSU exercises can be complex functional exercises that challenge your balance and your muscles and joints. Some BOSU exercises that will target your oblique muscles include side crunches, side planks with leg lifts, side planks with torso twists, bicycles, medicine ball torso rotations and push-ups. It is advisable to work with a personal trainer to learn the correct technique for these exercises.

Frequency and Duration

You should train your abdominal muscles 3 to 5 days per week. A daily workout is optimal. This will help counteract the tightening of your lower back and hip flexor muscles that can develop from a sedentary lifestyle. Do 10 to 20 repetitions of each complex exercise and do 3 to 5 repetitions of each balance exercise, holding the pose for up to a minute. There is no ideal order for performing core exercises. Your goal is to challenge your body to respond and adapt to new stimuli — variety is the key.