Janda Sit-Up
The Janda sit-up is a regular sit-up with one specific change: before you curl up, you dig your heels hard into the floor and contract your hamstrings and glutes as if trying to drag your heels backward. That single cue shifts more of the work onto your abs and off your hip flexors, which is why physical therapists have used this variation for decades. It suits anyone who feels their hip flexors taking over a normal sit-up, or who wants a more ab-focused version of a familiar movement.
Why it works
When your hip flexors are strong and your hamstrings are relatively weak or inactive, a regular sit-up lets your hip flexors do a disproportionate share of the lifting, which is part of why some people feel sit-ups more in their hips than their abs. Contracting your hamstrings and glutes hard before curling up uses a principle called reciprocal inhibition: firing one muscle group tends to reduce the drive to its opposing muscle group, so hard hamstring activation dampens hip flexor involvement and leaves more of the work to your abdominals. The result is the same basic sit-up motion, but with a noticeably different muscle emphasis.
Set up
- Lie on your back with your knees bent and feet flat on the floor.
- Cross your arms over your chest or place your fingertips lightly behind your ears.
- Dig your heels into the floor as if trying to drag them back toward your hips.
- Hold that hamstring contraction as you prepare to curl up.
How to do it
- Keep pressing your heels down and back while you curl your torso up off the floor.
- Lead with your chest rather than yanking your head and neck forward.
- Come all the way up to a seated position, or as close as your ab strength allows.
- Lower back down slowly under control, keeping the heel pressure active the whole time.
- Reset your hamstring contraction at the bottom before starting the next rep.
Form cues
- Dig your heels in hard before you start moving, not partway through the rep.
- Keep your chin tucked slightly rather than jutting your neck forward to lead the movement.
- Curl through your spine one segment at a time rather than snapping straight up.
- Keep your feet flat and still throughout, they anchor the position but shouldn't slide.
Breathing: Exhale as you curl up, inhale as you lower back down under control.
Common mistakes
Skipping the heel dig and hamstring contraction entirely
Fix: Actively press your heels into the floor and feel your hamstrings engage before you start the sit-up, since that cue is what makes this variation work.
Yanking the head and neck forward to build momentum
Fix: Keep your hands light behind your ears or arms crossed over your chest, and lead the movement with your chest curling up instead of your neck.
Letting the heels slide forward during the rep
Fix: Keep steady pressure into the floor throughout the movement so your feet stay anchored in place.
How to program it
- Two or three sets of 10 to 15 reps work well as part of a core routine, since the added hamstring activation makes this more fatiguing than it looks.
- Two or three times a week is enough, with a rest day between sessions to let your abs and hip flexors recover.
- This is a good default sit-up variation if a regular sit-up leaves your hip flexors sore rather than your abs.
- Once bodyweight reps feel controlled and easy to complete with full hamstring engagement, add light band resistance across your chest rather than increasing reps indefinitely.
Safety notes
- Keep your lower back from over-arching at the bottom of the rep by keeping some tension in your abs even at full extension.
- Stop if you feel strain in your neck rather than your abs, and check your hand position and lead with your chest instead.
- Anyone with existing lower back issues should approach any full sit-up variation cautiously and build up volume gradually.
Exercise profile
- Force
- Pull
- Mechanics
- Isolation
- Category
- Strength
Frequently asked questions
What makes a Janda sit-up different from a regular sit-up?
You dig your heels into the floor and contract your hamstrings and glutes hard before and during the curl, which shifts more of the work onto your abs and reduces hip flexor involvement.
How many Janda sit-ups should I do per set?
10 to 15 reps for two or three sets is a solid target, since the extra hamstring activation makes each rep more demanding than a standard sit-up.
Why do I feel this more in my abs than a normal sit-up?
Contracting your hamstrings hard reduces how much your hip flexors can contribute, through a principle called reciprocal inhibition, which leaves more of the lifting to your abdominals.
Can I do this without any equipment?
Yes, the Janda sit-up needs nothing but floor space, since the key difference from a regular sit-up is the heel and hamstring cue, not any added equipment.
What's an easier version if the heel dig feels like too much to coordinate?
A tuck crunch trains your abs through a shorter range without needing that hamstring activation cue, which is a good option while you build the coordination.