Elbow to Knee
A floor crunch with one ankle crossed over the opposite knee, bringing the elbow across to meet the raised knee. Crossing the leg locks the pelvis so the rotation has to come from your obliques rather than from your hip swinging around, which is what separates it from a sloppy bicycle crunch.
Own the movement
Set up first, then execute. Every cue below is something you can check on your next set.
Before the first rep
- Lie on your back and plant your left foot, then rest your right ankle across the left knee so the right leg makes a figure four.
- Fingertips lightly behind your head, elbows wide — do not lace the fingers and pull.
- Press your lower back into the floor before the first rep and keep it there.
- Tuck your chin slightly so your neck stays in line with your spine.
- Pick the number of reps per side before you start, and do the same count on both.
Every rep
Breathing & tempo — Exhale as you curl and rotate, letting the exhale finish at the top of the squeeze. Inhale on the way down. Two seconds up, one second hold, two seconds down.
Sets, reps & load
Where to start, and what to change when it stops being hard.
Bodyweight to start. Once you can do 15 reps a side with a one-second top hold, progress by holding a 5 kg plate against your chest — not behind your head, which encourages neck pull. Add 2.5 kg at a time. Extending the top arm overhead is a free way to lengthen the lever if you have no plates.
What goes wrong
The errors that show up most often, and the cue that fixes each one.
Rest the fingertips behind the ears instead of clasping, and keep a fist-sized gap between chin and chest. If you cannot, do the reps with your arms crossed over your chest.
Cue the shoulder, not the elbow: drive the left shoulder toward the right hip. The elbow follows on its own.
Press the crossed ankle firmly into the supporting knee so the leg has somewhere to stay put. All the movement comes from the ribcage.
Slow to a one-second hold at the top and a two-second lower. Twelve honest reps beat fifty rushed ones, and once twelve is easy, hold a plate on your chest.
Why bother
The internal and external obliques run diagonally across the trunk, so they respond to flexion combined with rotation. Curling straight up trains them poorly; adding the twist is what puts them under real tension, and the crossed-leg position removes the hip's ability to help.
It costs nothing and needs no equipment, which is its real advantage. The limitation is that resistance is fixed at bodyweight, so past about 20 clean reps a side you are training endurance rather than building anything. At that point add a pause or load it.
Where it fits
End of a session or as part of a bodyweight circuit, two or three times a week. Pair it with an anti-extension movement — a rollout or a hollow hold — rather than with more crunches. Two rotational crunch variations in one session is redundant volume.
If this one isn't it
No kit, too hard, or too easy — here's where to go instead.
Same job, different kit
Start here instead
When this gets easy
Asked and answered
Is this just a bicycle crunch?
Close, but the crossed leg makes it stricter. In a bicycle, the legs cycle and the hip flexors do a good share of the work while the rotation gets sloppy at speed. Here the pelvis is anchored and each rep starts from a dead stop, so the obliques cannot hide.
Why does my neck hurt afterwards?
Because your hands are pulling your head instead of supporting it. Switch to fingertips behind the ears, keep the elbows wide, and initiate every rep with the ribcage. If the neck still fatigues first, cross your arms over your chest for a few weeks.
Will this get rid of my love handles?
No. Training the obliques builds them; it does not remove the fat sitting on top. Waist changes come from an overall calorie deficit. Do these because a strong rotational trunk is useful, not as a fat-loss tool.
Should I do these instead of planks?
Alongside, not instead. A plank trains the trunk to resist movement; this trains it to produce flexion and rotation. They are different jobs and a trunk that can only do one is half-trained. If you have to pick one for general strength, take the plank or a loaded carry — resisting movement is what your trunk does under a barbell. Keep this for rotational sport and for the range work carries never give you.