Reverse Crunch
Trains the abs from the bottom up, which most people never do.
Setup
- Lie flat, hands by the hips or holding something behind your head.
- Knees bent, feet off the floor.
How To Do It
- Curl the knees toward the chest by lifting the HIPS off the floor.
- The movement is the pelvis tilting, not the legs swinging.
- Lower slowly until the hips return to the floor.
Breathing
Exhale as the hips lift.
Common Mistakes
- Swinging the legs and letting momentum lift the hips.
- Only moving the knees while the pelvis never leaves the floor.
Programming It
| Goal | Sets | Reps | Rest |
|---|---|---|---|
| Strength | 3–5 | 4–6 | 2–3+ min |
| Muscle | 3–4 | 8–12 | 60–90 sec |
| Endurance / Conditioning | 2–3 | 15–20 | 30–45 sec |
Why This Exercise Works
This movement trains the abs, hip flexors through a controlled range under load. Progressive tension over time is what produces adaptation — not novelty.
Where It Fits in a Program
Trains the abs from the bottom up, which most people never do. Train it when you are fresh enough to execute it well — compound work early in a session, isolation and accessory work after. This is an appropriate entry point. Learn the movement with a load you can control for every rep before adding weight — technique acquired early is technique you keep.
Progressing and Regressing It
To progress the reverse crunch: add load in the smallest increment available, or slow the eccentric to three seconds. To regress it: reduce range to what you can control cleanly, or use a supported version of the same pattern. Change one variable at a time or you learn nothing about which change worked.
Equipment and Substitutions
This version needs no equipment. If the pattern is not available to you on a given day, choose another exercise training the same muscles from the list below — the pattern matters more than the implement.
Related Exercises
- Hanging Leg Raise — Abs, Hip Flexors
- Hanging Knee Raise — Abs, Hip Flexors, Grip
- Bicycle Crunch — Abs, Obliques
- V-Up — Abs, Hip Flexors
- Hollow Body Hold — Abs, Deep Core
- Kneeling Cable Crunch — Abs
- Ab Wheel Rollout — Abs, Lats, Shoulders
- Body Saw — Abs, Core, Shoulders
Common Questions
What muscles does the reverse crunch work?
The reverse crunch primarily trains the abs, hip flexors. The listed muscles are highlighted in the animation above so you can see where the work should be felt.
How many sets and reps should I do?
For strength, three to five sets of three to six reps. For size, three to four sets of eight to twelve. For skill or capacity work, keep the reps well short of failure and repeat the quality rather than chasing the number.
What are the most common reverse crunch mistakes?
Most often: swinging the legs and letting momentum lift the hips; only moving the knees while the pelvis never leaves the floor. Both are easier to catch on video than in the moment — film one set from the side and watch it back.
Can I do this without any equipment?
Yes — this version needs no equipment at all. It trains the abs, hip flexors using bodyweight alone, which is why it travels well and works as a warm-up, a substitute, or a full session on its own.
Is this safe if I have an existing injury?
The reverse crunch loads the lower back and hip directly, so an existing problem there is the one to be careful about. If a rep reproduces your pain rather than producing normal training discomfort, stop the set and get it assessed. This is general fitness information, not medical advice.
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Form guide for educational purposes — not medical advice. New to training or working around an issue? Apply for coaching and get a plan built for your body.