Progressing Toward a One Arm Push-up
Obviously you should first have the strength to perform many regular push-ups at least 30 consecutively before even thinking about trying a one arm push-up. It's also helpful to practice other push-up variations, like the close-grip (diamond) push-up. A man who can perform 30 straight diamonds can usually progress to a one arm push-up quickly.
What's Your Angle?
The best way to start is to practice an angled one arm push-up against a wall. The resistance will be easy, so just focus on keeping your body tight and stable. This will help you get a feel for the movement pattern.
Soon you'll be ready to lower yourself down onto a bench or rail. Find something around waist height; the lower it is, the harder it's going to be, so start fairly high and work your way down.
The next step is to practice a self-assisted one arm push-up on the ground with your free arm outstretched and resting on a nearby object. Keep the reps low at first, as you're just looking to get the skill down before you do higher reps I recommend 5 sets of 5 reps as a reference point.
Practicing the negative phase of the one arm push-up (OAP) should be added once you can perform the self-assisted OAP for 5 sets of 5 reps.
The Progression looks something like this:
Weeks 1-2: Wall OAP 5x5
Weeks 3-4: Bench/Rail OAP 5x5
Weeks 5-6: Self-assisted ground OAP 5x5
Weeks 7-8: Negatives + Self-assisted OAP 5x5 each
Two weeks per phase is just a guideline stay on any given level as long as needed until you can complete all sets with good form.
You can also create half-steps between phases two and three by using benches of different heights. When practicing towards this move, remember that a strong midsection helps to get the whole body to work together. Make sure you keep your abs tight throughout the range of motion.
You also need to think about your opposite leg if you're doing a one arm push-up on your right arm, your left leg needs to be braced and vice versa. In short, keep your whole body tight!
