Core Training Exercise – Alternating Diagonal Arm Reach

Stephen Holt, Timonium personal trainer

Millions of readers of national fitness magazines including Shape, Women's Health, Fitness. Woman's Day, Family Circle, Runner's World, (and many others) have made their exercise programs both more effective AND more efficient with fitness and nutrition advice from "America's Baby Boomer Expert," Stephen Holt.

The Alternating Diagonal Arm Reach is one of our “classics” here at 29 Again Custom Fitness in Timonium, MD because it fits well as both a Core – Anterior exercise AND a Core – Frontal/Transverse exercise.

Any exercise that challenges all three planes and can be done at home and by virtually anyone is a definitely a keeper.

Anyone who does The Plank for more than about 60 seconds isn’t very imaginative or thoughtful (in the true sense of the word).

Sure, you need a challenge, but the marginal return on holding a plank for more than a minute diminishes quickly.

Just make it harder …

Here’s How You Do It

Start on the mat or floor in the standard plank position. Slowly and deliberately reach out diagonally with one arm at about 45 degrees – ideally with your thumb turned up (shoulder external rotation).

This helps strengthen your lower trapezius – important for your posture and for your shoulder stability – in a way that doesn’t bore the heck out of you. [Few people enjoy lower trap-focused exercises.] 

We typically ask clients to reach out in a “2-count,” as in “one thousand one, one thousand two.”

The tendency, unfortunately, is to throw out your arm and quickly yank it back.

But that’s not challenging – or useful – at all. Right? 

The trick in this exercise is to use all your core muscles – mainly your obliques – to keep your pelvis level. As you see in the demo, our model “has a little issue” keeping her hips level when she lifts her left arm. 

If something like this happens to you, take your time at the bottom position, focus on how “level” is supposed to feel, then maintain that feeling as you lift your arm.

 You can also regress [fancy trainer-talk meaning “make it easier’] this exercise by doing it on a bench.

(Our model’s form is much better here.) 

Elevating your upper body makes the exercise easier. The closer your body is to horizontal, the harder this exercise becomes.

“Simple trigonometry,” I like to say.

Therefore, we could make this Bench version a little more difficult by placing our model’s feet on a Step or small box (since benches tend to come in one and only one sexist* height). 

[*Weight benches are made to fit men – okay, some taller women can use them comfortably, too.]

The key is to find a level that’s “appropriately challenging” (as I’m so fond of saying) – not so hard you can’t maintain decent form, yet not so easy you’re basically wasting your time.


You May Also Like…

Put the “no” in Granola

Put the “no” in Granola

What we now call granola (originally, “granula”) was invented in 1863 and started as unsweetened bran nuggets soaked...