Rest-pause training is a method used by bodybuilders to push individual muscle groups to the point of failure and beyond, resulting in massive fatigue and equally-massive growth.

The technique is deceptively simple, you hit a set of a movement, take an extremely brief rest and jump straight back in. By not giving the muscle anywhere near enough time to fully recover, you force your body to tap into progressively more motor units, stimulating more of the muscle than simple straight sets would allow. Rinse and repeat until you hit a wall.

Rest-pause isolation takes the technique a step further by using unilateral or single-sided movements. You’ll work back and forth between sides, one side resting while the other works. This will result in you getting the same rest-pause effect for the muscle you’re working, as well as a continuous, whole-body effect throughout your set – pushing your heart and lungs in the process.

Requiring only one dumbbell, this workout uses RPI to blow up your shoulders. Roll this protocol out once a week at the end of a session, or use it as standalone home workout if you’re looking to supersize those deltoids.

Begin by performing five single arm presses with your weaker side, and, as soon as you’re finished, repeat on the other side. Move back and forth between arms, five times, for twenty-five reps on each side. That's one set. Rest for 2 minutes and repeat for five total sets, for a shoulder burn you won’t forget.

Single-arm Dumbbell Press 5 Left/ 5 Right x 5

Clean a dumbbell onto your shoulder, palm facing in. Take a breath and brace, filling out your trunk and bracing your core. (A). Press your dumbbell overhead explosively (B), before lowering under control, with a slow tempo, and repeating. Squeeze the opposite hand to create tension through your whole body.