Side Jackknife

What it is

This bodyweight core movement targets your oblique muscles, helping to strengthen the sides of your torso. You lie on your side and simultaneously lift your upper body and legs to bring them together. It effectively engages your entire abdominal wall for improved core stability and definition.

Technique tips

• Keep your supporting arm extended for balance.
• Engage your core before initiating the lift.
• Exhale as you lift your body and legs together.
• Control the descent slowly to maximize muscle engagement.
• Avoid pulling your head with your hands; lead with your shoulder.
• Focus on a strong contraction in your side abdominals.

How to track your progress

Log reps, and add the extra load if you wear a belt or a vest. Straddly counts your bodyweight in the estimated max, so added weight and extra reps both show up as progress, and new records are flagged during the session.