Side Jackknife

A dynamic core exercise performed from a side-lying position where the torso and legs are brought toward each other in a crunching motion, targeting the abdominals and obliques.
Instructions
- Lie on your right side on a yoga mat or padded floor.
- Stack your legs on top of each other or stagger them for stability and support.
- Position your head on your right hand or support it with your right arm.
- Place your left hand behind your head or across your chest for support.
- Engage your core and lift your top leg while simultaneously crunching your torso forward.
- Bring your right elbow toward your top (left) knee in a crunching motion.
- Hold briefly at the contraction point, squeezing your obliques and abdominals.
- Lower back to the starting position with control and repeat.
Tips
- Move slowly and deliberately; avoid using momentum to perform the movement.
- Keep the movement controlled throughout both the up and down phases.
- Focus on feeling the contraction in your obliques and abdominals.
- Breathe steadily; exhale during the crunch and inhale during the lowering phase.
- Perform all repetitions on one side before switching sides.
Recommended starting values
Sensible novice starting points for each goal, for a lifter aged 25–40. Scale down for smaller frames or older lifters. Treat the first set of any session as a discovery set.
| Goal | Sets | Reps |
|---|---|---|
| Gain strength | 3 | 15 reps |
| Build muscle | 3 | 18 reps |
| Build endurance | 3 | 25 reps |
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