Jackknife: How-to, Tips & More
The Jackknife is a intermediate isolation exercise for your abs. You do it with bodyweight. It is a good fit when your goal is muscle growth.
Muscles worked
Abs
Primary
How to do the Jackknife
- Lie on your back with your arms overhead and legs straight.
- Lift your arms and legs at the same time.
- Reach your hands toward your feet at the top.
- Lower both back down with control.
Jackknife tips
- Bend your knees slightly if your lower back lifts.
Sets and reps
Most lifters do well with 10 to 20 reps per set, and 10 to 20 reps is where this exercise tends to work best. Use a weight that leaves one or two reps in reserve on every set, and add weight once you can complete all your sets at the top of the range. It also works well in a superset with an exercise for the opposite muscles.
Equipment
Bodyweight
Type
Isolation
Jackknife alternatives
More abs exercises
Ab Wheel Rollout
Ab wheel
Barbell Rollout
Barbell
Bird Dog
Bodyweight
Cable Crunch
Cable machine
Cobra Stretch
Bodyweight
Dead Bug
Bodyweight
Frequently asked questions
What muscles does the Jackknife work?
The Jackknife mainly works your abs.
How many sets and reps should I do?
A good starting point is 10 to 20 reps per set, and many lifters get the best results between 10 to 20 reps. Use a weight that leaves one or two reps in reserve.
Is the Jackknife good for beginners?
It is rated intermediate, so it is better to build a base with simpler movements first and add it when your technique is solid.
What equipment do I need for the Jackknife?
You need bodyweight.
Add Jackknife to your program
Bite fills in your weights, tracks your progress and tells you when to go heavier.
Coming soon