reckonerLying leg curl
Lie face down, curl your heels toward your backside. It is the leg curl most gyms have and most people learned first. It works, and if a seated machine is also available there is a good reason to use that one instead.
Hips on the pad, curl under control.
- Pattern
- Knee isolation
- Trains
- Hamstrings
- Kit
- Machine leg curl
- Loading
- A weight you choose
- Reckoner prescribes
- 3 sets of 10 to 15 reps at RPE 8
- Progression step
- 5 kg once the top of the range is clean
- Skill
- Simple to learn
- Recovery cost
- Low
Muscles worked
How to do it
Line your knees up with the pivot
Lie down and shuffle until the side of your knee is level with the machine's axis. Most people set up too far forward, which puts the bend in the wrong place.
Set the ankle pad just above your heels
On the back of your ankles rather than up your calves. Too high and the lever is short and the pad digs in.
Hips on the pad, curl under control
That is the cue on your wrist. Grip the handles, press your hips down into the bench, and pull your heels toward your backside as far as they go.
Lower slowly to straight
Let the legs come back out under control until they are straight. Take longer coming down than going up.
What goes wrong
Letting the hips come off the bench
This is the fault of the lying curl. As the weight gets heavy the hips lift and the lower back arches, which gives you leverage you did not earn and puts the load somewhere it does not belong. Press the hips into the pad. If they still lift, lighten the stack.
Cutting the top short
The last part of the curl is the hardest and the easiest to skip once a set gets hard. Pull all the way to where the machine stops rather than to where the set gets comfortable.
Assuming it is the same as the seated version
It is not, and the difference has been measured directly. Over twelve weeks, the leg trained seated grew 14 per cent against 9 per cent for the leg trained prone, with the gap falling on the hamstrings that cross both joints1. This is still a good exercise. It is the second choice where both machines exist.
How Reckoner progresses this lift
Six weeks of this lift, from 35 kg, 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 at 35 kg | 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 at 35 kg | 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 at 35 kg | 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 at 35 kg | 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 at 35 kg | 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 at 35 kg | 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
Is the lying leg curl worse than the seated one?
On the one direct twelve week comparison, it produced less growth, 9 per cent against 141. That is a real difference and it is not a reason to avoid this machine, which most gyms have and some gyms only have. Use what is in front of you and prefer the seated one when both are.
Why do my hamstrings cramp on these?
It is common on leg curls and it is usually the top of the range, where the hamstrings are shortest and working hardest. Easing the load, slowing the reps down and not holding the fully curled position tend to help. Persistent cramping is worth mentioning to a doctor rather than training through.
Will Reckoner take this out of my plan for an injury?
No. The library records no restrictions at all against either leg curl. That is a fact about the record rather than a clearance for a knee you are worried about.
Similar movements
Reckoner eases the load first when this lift stalls, and offers one of these only if it stalls again after that. A lift already as light as your kit goes has no load left to ease, so the offer comes straight away. Each of them has a page.
Sources
- Maeo and colleagues, Medicine and Science in Sports and Exercise, 2021. Greater Hamstrings Muscle Hypertrophy but Similar Damage Protection after Training at Long versus Short Muscle Lengths twenty adults training one leg seated and the other prone for twelve weeks, whole hamstring volume rising 14 per cent seated against 9 per cent prone, the difference falling entirely on the two-joint hamstrings while the one-joint head grew the same either way, and protection against muscle damage being equal