reckonerHanging knee raise
Hang from a bar and bring the knees up. It is the abdominal exercise most likely to be done badly in a busy gym, because a swing looks like a rep and nobody can tell from the outside. Done still, it sits among the highest exercises measured for the whole of the rectus abdominis and the internal oblique1.
Raise the knees, stop the swing.
- Pattern
- Core flexion
- Trains
- Abs, hip flexors
- Kit
- Bodyweight, pull up bar
- Loading
- Your own bodyweight
- Reckoner prescribes
- 3 sets of 10 to 15 reps at RPE 8
- Progression step
- Nothing to add, so the sets climb instead
- Skill
- Some technique
- Recovery cost
- Low
- Not prescribed if you have declared
- Shoulder, lower back
Muscles worked
How to do it
Hang and get rid of the slack
Overhand grip a bit wider than the shoulders, arms straight. Pull the shoulder blades down away from your ears so you are hanging from your back rather than swinging from your joints. Wait until you are completely still.
Tilt the pelvis before the knees move
Curl the bottom of your pelvis up toward your chest first. That tilt is the abdominal part. Without it, the knees still come up and the hip flexors do all of it.
Bring the knees to the chest
Raise them as high as the tilt lets you, with the legs together. When the pelvis stops rotating, the rep is over, whatever the knees could still do.
Lower slowly and stop the swing
Come down under control until the body is straight and still again. If you have to wait a beat before the next rep, wait. A rep started from a swing is a rep you did not do.
What goes wrong
Kipping once the set gets hard
A small swing arrives around the fifth rep and the ones after it are a different exercise done faster. The honest number is the rep before the swing started.
Lifting the knees without tilting the pelvis
The knees travel a long way and it feels productive, but a pure knee lift is hip flexion, and the abs are only holding the ribs in place. The tilt is the part you came for.
Gripping until the hands give out first
If your hands quit before your trunk does, the set ended for the wrong reason. Straps are a reasonable answer here, and so is doing your grip work somewhere else.
How Reckoner progresses this lift
Six weeks of this lift, run through the real engine. Nothing below was typed in: the prescription, the decision and the sentence beside it all come from the same code that writes your week.
| Week | Prescribed | What it did |
|---|---|---|
| 1 | 3 x 10 | More reps 10 → 11 repsYou finished every set at RPE 7, with room left in the range, so the reps climb before the load does. |
| 2 | 3 x 11 | More reps 11 → 12 repsYou finished every set at RPE 7, with room left in the range, so the reps climb before the load does. |
| 3 | 3 x 12 | More reps 12 → 13 repsYou finished every set at RPE 7, with room left in the range, so the reps climb before the load does. |
| 4 | 3 x 13 | More reps 13 → 14 repsYou finished every set at RPE 7, with room left in the range, so the reps climb before the load does. |
| 5 | 3 x 14 | Deload 40% of sets offFive weeks of building, then one week lighter. About 40% of the sets come off. The load holds and your reps stay where you earned them, so you keep the strength and lose the fatigue. |
| 6 | 2 x 14 | More reps 14 → 15 repsYou finished every set at RPE 7, with room left in the range, so the reps climb before the load does. The lighter week is over, so this is back to three sets. |
Real engine output, not an illustration. Every row was produced by running the engine itself when this page was generated.
The full rule, and why the reps move before the load does, is in how Reckoner decides to add weight.
Questions people ask
Knee raise or leg raise?
Knees first. Straight legs make the lever much longer and almost everybody buys that extra range by swinging or by arching the back. Get the knee version still and controlled before you lengthen the lever.
Does this work the lower abs specifically?
Not in the way the phrase suggests. When the hanging knee-up was measured it was among the highest exercises for upper rectus abdominis and lower rectus abdominis alike1, which is what you would expect from a muscle that mostly contracts as one sheet. It is a good abdominal exercise. It is not a way of picking a region.
How do I make it harder once I can do plenty?
Add load rather than reps forever. The vest version of this movement is in the library for exactly that, and Reckoner will prescribe weight on it the same way it prescribes weight on a bar.
Similar movements
There is no load to ease on this lift, so Reckoner offers one of these the first time it stalls. Each of them has a page.
Sources
- Escamilla and colleagues, Physical Therapy, 2006. Electromyographic analysis of traditional and nontraditional abdominal exercises: implications for rehabilitation and training twenty-one healthy adults across traditional and nontraditional abdominal exercises, with the wheel roll-out, the pike, the knee-up, the hanging knee-up on straps and the inclined reverse crunch highest for upper and lower rectus abdominis, internal oblique and latissimus dorsi, and with the wheel pike and knee-up, the inclined reverse crunch and the bent-knee sit-up also highest for rectus femoris, which the authors note may be a problem for some people with low back trouble