How many reps of the duck-under should you do when you are new to the exercise?

Start with 2 sets of 4 to 5 full side-to-side passes, keeping the pace slow enough that both heels stay planted the whole time. Add reps once you can go all the way across without either heel lifting.

How do I make the duck-under easier or harder?

If staying low the whole way across is too demanding, narrow your stance slightly or shorten the distance you travel to each side. To make it harder, widen the stance further or add a two-second pause over each leg before shifting back.

What is the duck-under good for and when is it a poor choice?

It trains end-range hip strength and lateral mobility in a fully loaded, low position, building resilience that carries over to squats, lunges, and getting low in daily life. It is a poor choice for anyone with acutely irritated knees, since the whole drill keeps them in deep, sustained flexion.

Intermediate

Duck-Under

The duck-under keeps you loaded in a deep squat while you travel sideways, ducking your head and hips under a low obstacle. It trains end-range hip strength and lateral mobility in the adductors and glutes without ever standing up, so it builds the resilience needed for deep positions in squats, lunges, and daily life. Use it as mobility work or light conditioning.

Equipment: Body Weight
Body part: Quads, Thighs
Type: Functional, Stretching
Browse by muscle: Adductor Magnus, Gluteus Maximus, Rectus Femoris
Browse by movement: Squat

How to do it

1
Drop into a deep squat with feet wider than shoulder width and heels down.
2
Shift your weight over one leg while the other stays long and open.
3
Dip your head and lead with the hips as if passing under a low bar to the loaded side.
4
Arrive in a deep squat over the far leg without letting your hips rise.
5
Reverse to duck back under toward the other side, staying low the whole time.
6
Keep moving smoothly from side to side for the set.

Tips

Stay low; the whole point is to not stand up between reps.
Keep both heels rooted so the hips, not the ankles, take the range.
Lead the transition with your hips and let the head follow.

Variations

Common mistakes

The trailing leg locks out straight and stiff instead of staying long but soft, jamming the hip instead of letting it open.
Partway across, the near heel lifts off the floor as the weight shifts, letting the ankle take range that belongs to the hip.
The upper back rounds hard to duck the head under, instead of the hips doing the work of dropping the whole body.
Speeding up through the middle of the shift and slowing only at the ends skips the control needed exactly where balance is hardest.
The hands drop to the floor for support partway through, instead of staying free so the hips alone manage the transition.

Frequently asked

How many reps of the duck-under should you do when you are new to the exercise?: Start with 2 sets of 4 to 5 full side-to-side passes, keeping the pace slow enough that both heels stay planted the whole time. Add reps once you can go all the way across without either heel lifting.
How do I make the duck-under easier or harder?: If staying low the whole way across is too demanding, narrow your stance slightly or shorten the distance you travel to each side. To make it harder, widen the stance further or add a two-second pause over each leg before shifting back.
What is the duck-under good for and when is it a poor choice?: It trains end-range hip strength and lateral mobility in a fully loaded, low position, building resilience that carries over to squats, lunges, and getting low in daily life. It is a poor choice for anyone with acutely irritated knees, since the whole drill keeps them in deep, sustained flexion.

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