Kettlebell Reverse Crunch
The kettlebell reverse crunch is a floor-based core exercise where you curl your hips off the mat while holding a kettlebell above your head as an anchor. It builds strength in your abs and obliques, with your quadriceps helping to hold your legs in position. It suits beginners who can already do a basic crunch or knee raise, and it's a good way to add challenge without needing much space or kit.
Muscles worked
The Kettlebell Reverse Crunch mainly works your abs and obliques, with your quadriceps helping.
Setting up
- Place a kettlebell on the floor above your head, on a mat if you have one. Choose one heavy enough that it won't slide when you hold it, such as 8-16 kg. It's there as an anchor, not something to lift.
- Lie on your back with the bell just beyond your head, then reach back and hold the handle with both hands. Keep your arms long but not locked.
- Bend your knees to roughly 90 degrees with your shins parallel to the floor and your feet together.
- Press your lower back gently into the floor before you start, so there's no gap under it.
How to do the Kettlebell Reverse Crunch
- Lie flat, grip the kettlebell handle firmly and bring your knees above your hips with your shins parallel to the floor.
- Breathe in, then as you breathe out, draw your lower ribs down towards your hips and press your lower back into the floor.
- Keeping that brace, curl your knees up towards your chest and lift your hips and lower back a few centimetres off the floor.
- Pause for a second at the top and squeeze your abs and obliques. Your tailbone should be the only thing travelling upwards, not your whole body.
- Slowly lower your hips back to the floor over about three seconds, keeping your knees bent and your lower back pressed down.
- Stop with your feet hovering just above the floor, or let them lightly touch, then go straight into the next rep without relaxing your abs.
Form tips
- Think of curling your pelvis towards your ribs rather than throwing your knees at the ceiling. The movement is small and controlled.
- Grip the handle and keep your arms long to give yourself something to brace against. Pull the bell lightly towards you without moving it so your upper body stays still.
- Count a slow three seconds on the way down. The lowering phase is where most of the work happens.
- Breathe out as you curl up and in as you lower. If you hold your breath, your brace usually slips.
- Keep your knees bent throughout. Straightening your legs makes the exercise much harder and tends to make your lower back arch.
Common mistakes
Swinging the legs for momentum
Pause for a second at the top and lower for three seconds. If you can't control the descent, reduce the range or the reps.
Lower back arching off the floor
Press your lower back into the mat before every rep and stop the lowering phase when you feel it start to lift. Bending your knees more also makes it easier.
Lifting the hips too high
You only need a few centimetres of lift. Rolling up onto your shoulders means you're using momentum rather than your abs.
Dragging the kettlebell
Choose a heavier bell or place it against a wall or a sturdy object. Hold it to stay steady, not to pull yourself through the rep.
Sets and reps
| Build strength | 3-4 sets of 6-10 slow reps with a 3-4 second lowering phase and a one-second pause at the top, resting 90 seconds between sets. |
|---|---|
| Build muscle | 3 sets of 10-15 controlled reps, resting 60 seconds between sets. Stop a rep or two before your form breaks down. |
| Fat loss and general fitness | 2-3 sets of 12-15 reps within a circuit with other exercises, resting 30-45 seconds between exercises. Keep the reps controlled, not rushed. |
Pick a weight where the last rep or two of each set is hard but your form stays clean. When every set feels easy, it's time to go up.
Kettlebell Reverse Crunch alternatives
Machine taken, or want some variety? These work the same main muscles.
Kettlebell Reverse Crunch FAQs
How heavy should the kettlebell be for a reverse crunch?
It only needs to be heavy enough to stay put when you hold it, so 8-16 kg suits most people. Because it's an anchor, a heavier bell doesn't make the exercise much harder. Make it harder by slowing the tempo, pausing at the top or adding reps.
Why do I feel the kettlebell reverse crunch in my lower back?
This usually means your lower back is arching away from the floor as you lower your legs. Press it into the mat, bend your knees more and shorten the range until you can keep it down. If you feel pain rather than muscle effort, stop and get it checked.
How many reverse crunches should I do?
Most people do well with 3 sets of 8-15 slow reps. Pick a number where the last couple of reps are tough but you can still lower with control. Quality matters more than count.
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