SETUP: Use a 90* bench to support your back. Keep your shoulders pinned back and chest puffed out.
LIFT: The rep starts with your dumbbells slightly below a 90* angle. Press the weights up and overhead, bringing them together (not clanging them), then control the weights as you return to the start position.
TIP: Performing a Marathon Set up to 10 would mean hitting one rep then pausing at the start point for a couple of seconds, then performing 2 reps and pausing again, then 3 reps and pausing for another couple of seconds. The pauses are always short, but the reps quickly mount up and holding the start position will absolutely zap your front delts, so go lighter than you would for a normal set!