How many reps of the bird-dog reach-under should a beginner do?

Do 2 sets of 6 to 8 slow reaches per side, pausing briefly at both the crunched and extended ends of each rep. Progress by adding a one- or two-second hold at full extension before you add more reps, since holding the end position is what carries over to loaded pulling later.

How do you make the bird-dog reach-under easier or harder?

Make it easier by keeping the reach shorter, tapping the knee and elbow together without extending all the way out, or by working just the arm or just the leg reach on its own first. Make it harder by slowing the tempo further, holding the full extension for a few seconds, or adding light ankle and wrist weights once the pattern is smooth.

What is the bird-dog reach-under good for, and who does not need it?

It teaches beginners to move the spine through a small, controlled range from a stable quadruped base, which builds the coordination and core control that loaded rowing and carrying patterns later depend on. If you can already hold a strict bird-dog and do loaded anti-rotation work like the banded version cleanly, this drill will feel too easy to be useful.

Beginner

Bird-Dog Reach-Under

Where the classic bird-dog is a hold, the reach-under adds a dynamic crunch through the midline before returning to full extension. That teaches the rectus and obliques to move the spine through a small, controlled range while the erectors and glute manage the return. It is a great coordination and stability drill for beginners learning to own the quadruped position.

Equipment: Body Weight
Body part: Abs
Type: Functional, Strength
Browse by muscle: Abdominal External Oblique, Lower Rectus Abdominals
Browse by movement: Core Brace

How to do it

1
Set up on hands and knees with wrists under shoulders and knees under hips, spine neutral.
2
Reach one arm forward and the opposite leg back until both are level with the torso.
3
Round slightly and draw the elbow and knee together under your body, exhaling fully.
4
Reverse smoothly, re-extending the arm and leg to full length without arching the low back.
5
Finish all reps on one side, then switch to the other arm and leg.
6
Keep the movement slow so balance comes from control, not momentum.

Tips

Only round as far as you can control; the return to neutral matters more than crunch depth.
Keep the standing knee and hand firmly planted so the base does not wobble.
Do not let the low back sag when the limbs extend; brace before you reach.

Variations

Common mistakes

The support hand and knee shift or scoot during the reach, so the base of the position moves instead of staying planted while the limbs travel.
The reaching arm and leg swing up together instead of extending under control, turning the reach into a small kick rather than a held extension.
Coming back from the crunch position too fast lets the low back snap into an arch instead of settling back to neutral.
The hips rotate to let the reaching leg lift higher, tilting the pelvis instead of keeping it level as the leg extends straight back.
The exhale gets skipped or rushed during the crunch phase, so the trunk stays braced against itself instead of actually rounding through the midline.

Frequently asked

How many reps of the bird-dog reach-under should a beginner do?: Do 2 sets of 6 to 8 slow reaches per side, pausing briefly at both the crunched and extended ends of each rep. Progress by adding a one- or two-second hold at full extension before you add more reps, since holding the end position is what carries over to loaded pulling later.
How do you make the bird-dog reach-under easier or harder?: Make it easier by keeping the reach shorter, tapping the knee and elbow together without extending all the way out, or by working just the arm or just the leg reach on its own first. Make it harder by slowing the tempo further, holding the full extension for a few seconds, or adding light ankle and wrist weights once the pattern is smooth.
What is the bird-dog reach-under good for, and who does not need it?: It teaches beginners to move the spine through a small, controlled range from a stable quadruped base, which builds the coordination and core control that loaded rowing and carrying patterns later depend on. If you can already hold a strict bird-dog and do loaded anti-rotation work like the banded version cleanly, this drill will feel too easy to be useful.

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