The sliding knee tuck is a plank-based abdominal exercise performed with the feet onsliding discs, drawing the knees under the hips to train the lower abs and hip flexors. It is the same tuck as thesuspended knee tuck, but the discs keep the feet on the floor, so friction replaces the pendulum and nothing swings when a rep is rushed. The resistance is steady across the whole path instead of peaking. Coaches program it as a core finisher after pressing work.
What Muscles Does the Sliding Knee Tuck Work?
- Primary: Rectus abdominis (lower abs), iliopsoas (hip flexors)
- Secondary: Rectus femoris, external obliques
- Tertiary: Serratus anterior, anterior deltoid, triceps
How Do You Set Up for the Sliding Knee Tuck?
Place two discs on a hard, smooth floor about hip width apart. Kneel behind them, set the ball of each foot on a disc, then walk your hands out until the wrists sit under the shoulders and the body forms one line from head to heels. Spread the fingers, press the floor away and tuck the chin. Push the discs back an inch so the abs are loaded before rep one.
How Do You Perform the Sliding Knee Tuck?
- Set the plank with wrists under shoulders, hips level and the discs still.
- Exhale and pull the discs forward, curling the pelvis so the knees track under your body.
- Stop with the knees beneath your hips, the lower back rounded and the shoulders stacked over the hands.
- Hold that tuck for one count, pressing the hands down so the plank does not fold further.
- Push the discs back slowly over two seconds, keeping the toes weighted so the slide stays smooth.
- Finish in a straight plank with the hips no higher than the shoulders, ready for the next tuck.
What Are the Key Form Cues?
- Pull the hip bones to the ribs: begin every rep by shortening the abs, so the discs follow the pelvis rather than the feet dragging first.
- Weight the balls of the feet: even pressure on the discs keeps the slide silent and stops one foot from stalling.
- Keep the shoulder blades spread and the elbows locked through the whole slide.
- Feel the lower back flatten out gradually as the discs travel back.
- Breathe out on the way in and in as the legs extend.
What Are the Most Common Mistakes?
- Piking the hips high on the tuck: the hips rise on hip flexor pull and the abs never curl, so keep the hips only as high as the pelvis lifts them.
- Sagging the hips as the discs go back: the lumbar spine takes the body weight in extension, so stop the slide when the plank is straight.
- Yanking the discs in and letting them shoot back: momentum does the rep, so cap the return at two seconds.
- Sliding on carpet or a sticky mat: the discs catch mid-rep and the shoulders lurch forward, so use a hard floor.
- Letting the hands creep behind the shoulders: the wrists load and the plank shortens, so reset the hands each set.
What Are the Best Sliding Knee Tuck Variations?
- Sliding oblique knee tuck: the knees track toward one elbow so the obliques turn the pelvis.
- Single-leg sliding knee tuck: one foot on a disc and the other lifted, an anti-rotation demand.
- Sliding pike: legs stay straight and the hips rise, a longer lever and more shoulder work.
- Plank jump in: the same tuck jumped instead of slid, faster and less controlled.
- Towel knee tuck: a folded towel under each foot on tile, the same slide without discs.
How Do You Progress the Sliding Knee Tuck?
- Raise the feet onto a low step before adding anything else; the load is bodyweight, so leverage is the lever.
- Build from 8 reps up to 15 per set with the discs stopping between reps.
- Add a set per week from 2 up to 4 while the plank holds through the last rep.
- Slow the return to four seconds, or hold the tuck three counts, once 15 reps are routine.
How Should You Program the Sliding Knee Tuck?
Put the sliding knee tuck at the end of an upper body or core session, once the shoulders are warm but not spent from heavy pressing. Train it two to three times a week for 3 sets of 8 to 15 reps, resting 45 to 60 seconds. Pair it with a dead bug or a side plank so the trunk also trains resisting extension and rotation.