Lie on your back, plant hands by your sides. Place a stability ball at mat's end, heels resting on it. Engage glutes to lift butt and low back off mat, legs extended.
For proper squat form, try this stability ball exercise. Hug the ball, face a wall with a towel between legs, rounding back. Activate glutes, tuck pelvis, and squat while keeping heels planted for stability.
Avoid rushing the Russian twist and engage obliques properly. Use this variation for stability challenge. Rest shoulders, upper back on ball, knees bent, feet planted.
Kneel on mat, squeeze towel between legs, hands on ball. Tuck pelvis, round upper back. Lower torso towards ball, bending elbows. Keep back rounded, avoid shoulder blades coming together
Kneel on mat, towel between legs, hands on ball. Keep arms straight, tuck pelvis. Engage core, push upper body away from ball with slight rounding, no arching lower back.
Lie on back, hands at sides. Squeeze towel between knees. Place ball at mat end, feet on ball. Engage glutes, lift butt and low back off mat. Squeeze towel, hold 30 sec. Lower butt to mat.
Place ball against wall, lie sideways in straight line. Draw ribs inward like crunch. Keep hips square, lift bottom leg toward midline while extending other leg. Do ten reps, repeat other side.
Kneel on right leg, left foot flat. Pull front leg toward midline, engage inner-thigh. Plant front heel for pelvic stability. Hold ball with straight arms, round over it. Rotate torso left, keeping hips square.