TRX Alternating Knee Tucks

TRX Alternating Knee Tucks challenges the abdominals and hip flexors while the trunk resists arching or rotating.

Primary muscle

Abs

Primary musclesRectus abdominis, Iliopsoas

Secondary musclesObliques, Rectus femoris, Tensor fasciae latae

Equipment

TRX

How to perform TRX Alternating Knee Tucks

Follow the sequence in order, paying attention to the starting position, movement path, and finish described in each step.

For TRX Alternating Knee Tucks, place the feet securely in the TRX cradles and build a high plank with the hands below the shoulders.
Brace before moving and keep the ribs, shoulders, and support points still.
Draw the knee or legs toward the torso without swinging or allowing the lower back to arch away from support.
Pause when the pelvis begins to curl or the legs reach the strongest controlled position; keep the shoulders still.
Return the legs slowly without losing trunk position. Complete the planned repetitions evenly on both sides.

Bend the knees or use a smaller range as soon as the lower back starts to lift or arch.

Pause between repetitions and initiate with the abdominals instead of momentum.

Press the floor away and keep the shoulders above the hands while the feet remain in the cradles.

Lower the legs slowly. The lowering part of the repetition still trains the muscles.

Lower back arching: Bend the knees or use a smaller range as soon as the lower back starts to lift or arch.
Shoulders losing support: Press the floor away and keep the shoulders above the hands while the feet remain in the cradles.
Stop when the exercise produces sharp, catching, radiating, or increasing joint pain rather than the expected muscular effort.
Alternative Bent-Knee Raise: Bend the knees to make the raise easier while keeping the hips and ribs still.

Place TRX Alternating Knee Tucks after the main compound lifts, in a focused core block, or beside an exercise that does not require a fresh trunk.

Use two to four times per week while accounting for trunk work already supplied by squats, hinges, carries, and overhead lifting.

Goal	Sets	Reps or time	Rest	Effort and execution
Control / technique	2–3	5–8 reps per side	45–75 sec	Stop well before position changes
Strength / endurance	2–4	8–15 reps per side	60–90 sec	Stop while 1–3 good-form reps are still possible

Use TRX Alternating Knee Tucks after Deadlifts or Barbell Back Squats so abdominal fatigue does not affect the main lift.
Pair it with Bird Dog or Cable Pallof Press for a focused core block.

Scale the movement