"In the real world, we don't get to work symmetrically. We're kind of off balance a little bit. This puts you in an off-balance position," Ebenezer Samuel, Men's Health fitness editor, says.
This is because the exercise stabilizes your body against the weight you choose on the cable stack. How?Only one arm is handling the weight of from the cable machine. Since the other arm handles no weight, your entire body will get pulled off-center by the weighted side unless your abs, obliques, hips, and glutes work together to keep you in a strong and stable position.
Only once your core is stabilized can you adequately perform the pressing motion to work your chest and triceps. This imbalance is what makes the exercise challenging, and it's great if you're looking to not only sculpt those chest and arm muscles, but a six-pack as well. (Here's how this man dropped 60 pounds and carved out his abs.)
Watch the video above as Samuel breaks down the half-kneeling chest press, one of his favorite moves from the Beginner's Guide. You can add this exercise into your pushing workouts as a core-focused pecs finisher to build a more stable midsection and increase your pushing power, too.