Stand up straight with a dumbbell in one hand with your feet about shoulder width apart. Position the dumbbell above your head with the arm fully extended to be in starting position.
Lower the dumbbell in a semicircular motion behind your head until your forearm is ideally touching your bicep. Remember to keep your upper arm close to your head and your elbow in.
Bring the dumbbell back up to starting position via tricep muscle.
Repeat for desired reps and switch to other arm.
One Arm Dumbbell Tricep Extension Tips
Start with your non-dominant arm (for most people, left).
Inhale as you lower the weight and exhale as your extend.
