Starfish to Jack Knife
CoreMuscles worked
corehip flexorsobliques
- Equipment
- No equipment
- Level
- Advanced
- How much to do
- 8–12 reps per set.
How to do it
- Lie on your back with your arms and legs spread wide into a star shape.
- Press your lower back gently into the floor and brace your abs.
- Lift your arms and legs together, folding into a jackknife with your hands reaching toward your shins.
- Open back out to the wide star shape with control.
- Keep each fold smooth without swinging your limbs.
How to breathe
Breathe in as you lower, out as you push. Never hold your breath at the hardest point.
Common mistakes
Swinging into it. If momentum is doing the work, slow down until the muscle has to.
Letting your lower back peel off the floor. Press it down, and end the set the moment you cannot.
Rushing. Speed hides the range; slow down until the last rep looks like the first.
Frequently asked questions
- Which muscles does Starfish to Jack Knife work?
- Starfish to Jack Knife mainly works your core. It also engages your hip flexors and obliques.
- What equipment do you need for Starfish to Jack Knife?
- None — Starfish to Jack Knife is a bodyweight move you can do anywhere.
- Is Starfish to Jack Knife good for beginners?
- Starfish to Jack Knife is an advanced move. Master the basics before you try it.
- How many reps of Starfish to Jack Knife should you do?
- 8–12 reps per set.