At a glance
- Main muscle
- Quads
- Equipment
- Machine
- Rep range in Mitta
- 10 to 15 reps
- Skill level
- Beginner
- How tiring
- Low
- Weight step in Mitta
- 2.5 kg
How to do it
- Set the backrest as far back as possible.
- Control it deep into the bend.
- Pause briefly at the top.
Pick a weight you can lift for 10 to 15 reps with good form, and stop each set with a few reps left in the tank.
Why rating A
Grows the rectus femoris, which squats barely do; leaning back produced even more growth there, and partials in the stretch gave extra growth.1,2,3
Mitta rates every exercise from S to C, based on research where it exists and on how the exercise loads the muscle. When Mitta builds your plan it picks from S, A and B exercises and prefers ones that load the muscle at long length. C exercises are never picked automatically, but you can still choose them yourself.
Alternatives
These train the same muscle. Use one if you lack the equipment, if this exercise does not feel right, or for some variety.
- Reverse Nordic · Bodyweight · rating B
- Sissy Squat · Bodyweight · rating B
- Hack Squat · Machine · rating S
Keep learning
- What is progressive overload, and how do you do it?
- How many sets per muscle per week?
- What is RIR, and how do you estimate it?
- One-rep max calculator: your max from any hard set of the leg extension.
Let Mitta set the weight.
Mitta plans the leg extension with a weight and rep target for every set, worked out from your last sessions.
Questions about the
leg extension
What muscles does the leg extension work?
The leg extension mainly trains your quads.
How many reps of the leg extension should I do?
Mitta plans the leg extension at 10 to 15 reps per set. Most sets should end with only a few reps left in the tank.
What can I do instead of the leg extension?
Good alternatives that train the same muscle are the reverse Nordic, sissy squat and hack squat.
Is the leg extension good for beginners?
Yes. It is easy to learn, so it suits people who are new to lifting.
Why does the leg extension have rating A?
Grows the rectus femoris, which squats barely do; leaning back produced even more growth there, and partials in the stretch gave extra growth.
Sources
- Kubo et al. 2019, EJAP (diepe vs halve squat: meer bil- en adductorengroei, quads gelijk) doi.org/10.1007/s00421-019-04181-y
- Larsen et al. 2025, J Sports Sci 43(2):210-221 (leg extension 40° vs 90° heupflexie: meer rectus-femorisgroei bij achterover leunen, vastus gelijk; ongetrainde mannen) doi.org/10.51224/SRXIV.407
- Larsen et al. 2025, J Sports Sci (rugleuning naar achter, 40° vs 90° heupflexie: meer RF-groei, vastus gelijk) doi.org/10.1080/02640414.2024.2444713