What is a good starting dose for the TRX oblique crunch, and what should I master first?

Two sets of 6 to 8 reps per side, resting until you can reset a tight plank each time, is a sensible opening dose. Before adding this move, you should already hold a steady TRX plank for 30 seconds and control a straight TRX pike, since both the shoulder stability and the hip drive build on those two positions.

What can I do instead of the TRX oblique crunch without a suspension trainer?

A cross-body mountain climber or a plank with a knee-to-elbow drive trains a similar rotating hip-to-ribs pattern using only the floor. Neither loads the shoulders quite as hard as the suspended straps, but both build the same oblique-driven twist.

What does the TRX oblique crunch train, and when should you skip it?

It builds rotational core strength and shoulder stability together, which suits lifters who already have a solid core base and want a harder, unstable variation. Skip it if you have shoulder pain under load or cannot yet hold a strict TRX plank, since the unstable straps demand a lot from the shoulders before the obliques even get involved.

Advanced

TRX Oblique Crunch

By pulling the knees up and across toward one elbow, this move adds rotation to the pike and shifts the work onto the side of the waist. The suspended feet keep constant tension on the obliques while the shoulders stabilize a shifting base. It is an advanced rotary core builder best saved for lifters who already control a steady TRX plank and pike.

Equipment: TRX
Body part: Abs
Type: Strength
Browse by muscle: Abdominal External Oblique
Browse by movement: Rotation, Spinal Flexion

How to do it

1
Set the straps short and place both feet in the foot cradles.
2
Walk your hands out into a push-up plank with wrists under shoulders.
3
Brace the core and keep the shoulders set down and back.
4
Curl both knees up and toward one shoulder, twisting through the waist.
5
Pause briefly as the hip crunches toward the same-side ribs.
6
Extend the legs back to the plank, then repeat toward the other shoulder.

Tips

Drive the knees up and across, not just forward, to bias the obliques.
Keep the shoulders square to the floor while only the lower body rotates.
Move slowly and avoid swinging the legs into position.
Match the reps on each side to build both obliques evenly.

Variations

Common mistakes

The hips sag toward the floor in the moments between reps, turning the rest position into a loose plank instead of a braced one.
The wrists drift out ahead of the shoulders as the knees pull in, moving the base of support instead of keeping a stable plank.
Cutting the pause short at the top of the twist turns the exercise into a fast pendulum swing instead of a controlled crunch and hold.
One strap ends up shorter than the other after a few reps, tilting the whole plank and loading one shoulder more than the other.
The elbows lock out hard and lean forward to help drive the knees in, shifting load onto the shoulders instead of the waist.

Frequently asked

What is a good starting dose for the TRX oblique crunch, and what should I master first?: Two sets of 6 to 8 reps per side, resting until you can reset a tight plank each time, is a sensible opening dose. Before adding this move, you should already hold a steady TRX plank for 30 seconds and control a straight TRX pike, since both the shoulder stability and the hip drive build on those two positions.
What can I do instead of the TRX oblique crunch without a suspension trainer?: A cross-body mountain climber or a plank with a knee-to-elbow drive trains a similar rotating hip-to-ribs pattern using only the floor. Neither loads the shoulders quite as hard as the suspended straps, but both build the same oblique-driven twist.
What does the TRX oblique crunch train, and when should you skip it?: It builds rotational core strength and shoulder stability together, which suits lifters who already have a solid core base and want a harder, unstable variation. Skip it if you have shoulder pain under load or cannot yet hold a strict TRX plank, since the unstable straps demand a lot from the shoulders before the obliques even get involved.

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