Sit on a flat bench holding a dumbbell with both hands. Lift the dumbbell overhead until your arms are fully extended. Keep your elbows close to your head and slowly bend them to lower the dumbbell behind your head in a controlled motion. Pause briefly at the bottom, then extend your arms back up by contracting your triceps. Keep your core tight and avoid arching your lower back or flaring your elbows.
Log your dumbbell seated bench extension sets in 1RM.fit and watch your estimated 1RM update automatically as you get stronger.