Sit on a stability ball and walk your feet forward until your upper back, shoulders, and head are supported on the ball. Hold a dumbbell with both hands above your chest, arms extended. Keeping your elbows tucked in and stable, slowly bend your elbows to lower the weight toward your forehead or slightly behind your head. Pause briefly, then extend your arms back up by contracting your triceps until your arms are fully extended again. Keep your core tight and hips level throughout the movement.
Log your exercise ball supine triceps extension sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.