reckonerDecline sit-up
The sit-up on a bench tipped head down, with your feet hooked under a pad. The slope makes each rep harder than one on the floor3, and the hooked feet let the hip flexors pull harder too2. So it is a hard abdominal exercise that is also a hard hip flexor exercise, and a fine way to make a sit-up heavier without holding a weight.
Feet hooked, curl up, lower slowly.
- Pattern
- Core flexion
- Trains
- Abs, hip flexors
- Kit
- Bodyweight, decline bench
- Loading
- Your own bodyweight
- Reckoner prescribes
- 2 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
- Lower back
Muscles worked
How to do it
Hook your feet and lie back
Set the bench at a slope you can control, hook your feet under the pad and lie back with your knees bent. Cross your arms over your chest or rest your fingertips at your temples.
Peel your shoulders up first
Start each rep by rounding the top of your spine and lifting your shoulders off the bench, so the abs take the first part. Only then let your hips fold to bring you up.
Curl up until your chest is over your thighs
Keep coming until your chest is over your thighs, and stop there. Your hands stay off the back of your head the whole way. Laced fingers turn into a lever on your neck the moment the set gets hard.
Lower slowly
Go back down slower than you came up, reversing the fold and then the curl, until your shoulders touch the bench. The slow way down is where the slope earns its place.
What goes wrong
Hauling on the back of your head
The set gets hard, the hands take over and the chin drives into the chest. It buys reps and it loads the neck. If your hands are helping, the set is already over.
Dropping back to the bench
Gravity is on your side going down, so it is easy to fall back and bounce into the next rep. That throws away the half of the rep the slope makes hardest. Lower under control every time.
Setting the bench steeper than you can handle
A steeper bench is a heavier sit-up, so it is tempting to start at the steepest notch. If you cannot lower slowly or you need your hands to get up, flatten the bench a notch and keep the reps clean.
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 | 2 x 10 | More reps 10 → 11 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 2 | 2 x 11 | More reps 11 → 12 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 3 | 2 x 12 | More reps 12 → 13 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 4 | 2 x 13 | More reps 13 → 14 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. |
| 5 | 2 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 | 1 x 14 | More reps 14 → 15 repsYou finished every set with three reps left in the tank (RPE 7) and room left in the range, so the reps climb before the load does. The lighter week is over, so this is back to two 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
Is a decline sit-up better than a crunch?
Not for the abs. The crunch measured among the highest exercises for both halves of the rectus abdominis and for both obliques, while the bent-knee sit-up drew the most from the hip flexors of the group1. The authors flag that as a possible problem for people with low back pain, so if your back is sore the decline crunch asks less of it.
Why do I feel this in my hips?
Because the hip flexors are what bring you upright once the curl is done, and hooked feet let them pull harder. Holding sit-up positions with the feet fixed lowered abdominal activity and raised hip flexor activity in one study2. That is the design of the exercise, not a fault in how you are doing it.
How does Reckoner progress a bodyweight sit-up?
It only reaches your plan if you choose it, in the movement picker, a swap offer or search. With no weight to add, Reckoner moves you up through the rep range, and once you top it at the effort it asked for, it adds a working set, up to a ceiling. It cannot see your bench, so making the slope steeper is your call.
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, Journal of Orthopaedic and Sports Physical Therapy, 2006. An electromyographic analysis of commercial and common abdominal exercises: implications for rehabilitation and training fourteen participants across nine abdominal exercises, with the crunch among the highest for upper and lower rectus abdominis and for both obliques, and with rectus femoris activity greatest in the bent-knee sit-up, which the authors say may be a problem for people with low back pathology
- Parfrey and colleagues, Applied Physiology, Nutrition, and Metabolism, 2008. The effects of different sit- and curl-up positions on activation of abdominal and hip flexor musculature fourteen subjects holding sit-up and curl-up positions, where fixing the feet produced significantly lower activation at every abdominal site measured and higher rectus femoris activation; isometric holds on the floor, not reps on a decline
- Monfort-Pañego and colleagues, Journal of Manipulative and Physiological Therapeutics, 2009. Electromyographic studies in abdominal exercises: a literature synthesis a synthesis of eighty-seven EMG studies naming spine flexion without hip flexion, and inclined planes or added load to raise contraction intensity, among the main factors in choosing abdominal exercises; a synthesis, not a meta-analysis