Training With Shawn Rhoden - Overhead Dumbbell Tricep Extension: Isolate the triceps and keep constant tension on the muscle using this fantastic single arm exercise. To start, grab a dumbbell, raise it above your head and slowly lower the dumbbell towards your other side by bending at the elbow. Pause at the bottom of the movement before raising the dumbbell back up to the original position, making sure you do not lock the elbows. Aim for 3-4 sets of 10-12 reps with 60-90 seconds rest in between sets. Shawn Rhoden - IFBB Pro & Nick Jones - World Bodybuilding Champion.