Janda Sit-up
- Target muscle
- Rectus Abdominis
- Synergist muscles
- Obliques
- Equipment
- Body weight
- Body part
- Waist
- Type
- Strength
The Janda sit-up is a bodyweight core exercise, named after Czech physiotherapist Vladimir Janda, that targets the rectus abdominis with the obliques assisting. Actively pressing your heels into the floor contracts the hamstrings and glutes, which reciprocally inhibits the hip flexors and forces the abs to produce the movement. Use it when a standard sit-up feels more like hip work than ab work.
How to do the Janda Sit-up
- 1Lie on your back with your knees bent to roughly 90 degrees and your feet flat on the floor, hip-width apart.
- 2Rest your fingertips lightly behind your head without interlacing them, keeping your elbows wide and your chin slightly tucked.
- 3Dig your heels into the floor and squeeze your hamstrings and glutes as if you were dragging your heels back toward your hips.
- 4Hold that heel-drag contraction and exhale as you curl your ribcage toward your pelvis, leading with your chest rather than your elbows.
- 5Curl until your shoulder blades clear the floor and your abs are fully shortened, keeping your lower back in contact with the floor.
- 6Pause for a second at the top and squeeze your abs.
- 7Inhale and lower yourself one vertebra at a time under control, holding the heel-drag tension the whole way.
- 8Repeat for the desired number of reps, then release your legs and relax.
Form tips
- Set your heels about a hand's length from your glutes — any further away and the hamstrings cannot generate a strong heel drag.
- Rehearse the heel drag on its own first: press until you feel the hamstrings and glutes fire, then add the curl once that tension holds without thinking about it.
- Think of curling your ribs toward your hips rather than sitting up straight; that keeps the work in the abs.
- Move at a controlled tempo — roughly two seconds up and two seconds down — to keep the abs under tension for the whole rep.
- If your hamstrings cramp, end the set and stretch them; cramping is common while you are learning the heel drag and eases as the hamstrings adapt.
Common mistakes
- Relaxing the heel drag mid-rep, which lets the hip flexors take over and pulls the load off the rectus abdominis.
- Pulling your head forward with your hands, which strains the cervical spine and starts the rep with your arms instead of your abs.
- Swinging up with momentum instead of curling, which carries you through the range without the abs ever fully shortening and jerks the lumbar spine.
- Sitting all the way upright, which hands the top of the movement back to the hip flexors — the exact thing this variation exists to avoid.
- Holding your breath through the curl, which makes it harder to flex the spine fully and spikes blood pressure; exhale on the way up.
Frequently asked questions
What muscles does the Janda sit-up work?
It targets the rectus abdominis, the muscle that flexes your spine and runs down the front of your abdomen, with the obliques assisting to stabilise the torso. The hamstrings and glutes work isometrically to press the heels down, but they are the tool that inhibits the hip flexors rather than the target of the exercise.
What is the difference between a Janda sit-up and a regular sit-up?
In a regular sit-up the hip flexors assist heavily and often do most of the work. The Janda sit-up uses reciprocal inhibition: contracting the hamstrings and glutes while pressing the heels into the floor damps down the hip flexors, so the rectus abdominis has to move the torso on its own.
How many reps should I do per set?
Because the hip flexors are inhibited, most people find the Janda sit-up much harder than a standard sit-up. Start with 3 sets of 8–12 controlled reps and add reps only once you can hold the heel-drag tension through every rep.
Can the Janda sit-up help with lower back pain?
Janda developed the movement to train the abs without hip flexor dominance, which is a common contributor to lower back strain, so it can help restore the muscle balance that supports the lumbar spine. If you already have lower back pain, check with a healthcare professional before adding any sit-up variation.
Where should I feel the Janda sit-up working?
Mainly across the front of your abdomen (rectus abdominis), with some effort along the sides (obliques) and a steady burn in the hamstrings from the heel press. If you feel it mostly in the front of your hips or thighs, the hip flexors are still dominating — press your heels harder into the floor and stop the curl earlier.
