What Muscles Work In A Bird Dog, And How To Work It Out For Any Exercise

What muscles work in a bird dog

The deep core and erector spinae, bracing the spine so it doesn't sag or twist while only two points, one hand and the opposite knee, stay on the ground. The glute maximus of the extending leg, lengthening as the leg reaches back and then contracting to drive the hip straight, with the hamstrings assisting. The posterior deltoid and lats of the reaching arm, lifting it level with the spine. And the obliques on the opposite side, doing the real work of the exercise, resisting the rotation the reaching arm and extending leg are both trying to create.

That's the answer, and like the squat, the lunge, the deadlift, the press-up, the row, the shoulder press, the loaded carry, the suspended plank, the sprint, the medicine ball throw, the vertical jump, the kettlebell swing and the band wood chop before it, it came from a method rather than a memorised list.

Nobody's taken a client yet, and that's fine

Somebody weighing up a career change into personal training can watch a bird dog on a phone and file it under "balance exercise," which tells them nothing about the obliques doing the actual job of stopping the trunk twisting. One of the things you learn on our CIMSPA-recognised personal training course is a method that turns that vague word into a specific list of muscles, each doing exactly the job it's built for, on every rep.

Fourteen exercises in, and the method still hasn't changed

A squat, a lunge, a deadlift, a press-up, a row, a shoulder press, a loaded carry, a suspended plank, a sprint, a medicine ball throw, a vertical jump, a kettlebell swing and a band wood chop have all run through the same four steps:

1. Decide where the force is acting on the body
2. Identify which muscles work directly against that force (muscles that lengthen are easiest to see)
3. Identify which secondary muscles assist that movement
4. Identify which muscles would support that joint / movement

Run it on a bird dog.

One, where is the force acting? Trying to rotate and sag the trunk, because reaching one arm forward and the opposite leg back leaves only two points of contact holding the whole body up.

Two, what works directly against it? The deep core and erector spinae, bracing the spine so it stays level rather than sagging toward the floor or twisting toward the side that's moving.

Three, what assists? The glute maximus and hamstrings of the extending leg, driving the hip straight once it's reached back, and the posterior deltoid and lats of the reaching arm, lifting it level with the spine rather than letting it drop.

Four, what supports? The obliques on the opposite side, resisting the rotation the reaching limbs create, and the shoulder and hip on the supporting side, holding that two-point base steady for the whole rep.

Why that fourth answer changes how it's coached

A trainer who only knows "bird dogs are for balance" has nothing useful to say when a client's hips rock toward the reaching arm on every rep. A trainer who has run the four steps knows that's the opposite-side obliques losing the job of holding the trunk level, and can fix the rep by cueing the resistance rather than the balance.

Point it at anything

A dead bug, the same anti-rotation job done lying on the back instead of on all fours. A single-arm suspended row, where the same opposite-side obliques resist the pull instead of a reach. A Pallof press, where a band or cable tries to rotate the trunk directly and the core's only job is to refuse it. Any exercise that asks the trunk to resist a rotational force can be answered the same way, without a new list to learn.

PT Manager opens the moment you sign up with any FASTER course, and adding real clients unlocks the day you pass one. Read more about the Level 3 Personal Trainer Certificate this method comes from.

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