Flexion Leg Sit up (bent knee)

Strengthen your rectus abdominis with the bent-knee flexion leg sit-up. This bodyweight exercise builds core endurance and improves spinal flexion for a

IntermediateWaist Body weight

Movement: Compound
Force: Pull
Per set: 1 min
Rest: 30s

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Variations of Flexion Leg Sit up (bent knee)

Compound

Flexion Leg Sit up (straight arm)

Waist · Rectus Abdominis · Body weight

Intermediate

Description

A sit up variation where the legs are bent at the knees, focusing on the core muscles.

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How to do Flexion Leg Sit up (bent knee)

01
Setup
Lie on your back with your knees bent at approximately a 90-degree angle and your feet flat on the floor, hip-width apart.
02
Setup
Position your hands lightly behind your head with elbows wide, or cross your arms over your chest.
03
Exhale as you slowly curl your torso upwards, initiating the movement by lifting your head, then shoulders, and finally your upper back off the floor.
04
Continue to flex your spine until your chest approaches your thighs, keeping your feet grounded and maintaining a controlled motion.
05
Inhale as you slowly reverse the movement, uncurling your spine segment by segment until your shoulders and head gently return to the starting position.

Tips

Focus on a smooth, controlled spinal flexion and extension rather than using momentum to lift your body, ensuring continuous abdominal engagement.
Keep your gaze directed towards the ceiling or slightly forward throughout the movement to help maintain a neutral neck position and avoid strain.
Engage your transverse abdominis by gently drawing your navel towards your spine before you begin to lift, providing greater core stability.
Avoid pulling on your neck with your hands; if you feel neck strain, place your fingertips lightly behind your ears or cross your arms over your chest instead.

Common mistakes

Using momentum to sit up rather than core strength will reduce muscle activation; instead, perform a slow, controlled curl through your spine.
Pulling on the neck with your hands can cause strain; instead, use your hands only for gentle support or cross your arms over your chest.
Lifting your feet off the floor indicates an over-reliance on hip flexors; instead, keep your feet firmly planted by focusing on core engagement.

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Questions

What muscles does Flexion Leg Sit up (bent knee) work?

Flexion Leg Sit up (bent knee) primarily targets Rectus Abdominis. Secondary muscles include Iliopsoas, Obliques, Quadriceps.

Is Flexion Leg Sit up (bent knee) good for beginners?

Flexion Leg Sit up (bent knee) is rated intermediate. Beginners can still attempt it with lighter weight and careful form, but it's best to master easier variations first.

What equipment do I need for Flexion Leg Sit up (bent knee)?

You need Body weight to perform Flexion Leg Sit up (bent knee). If you don't have this equipment, look for variations that target the same muscles with what you have available.

What are the best tips for Flexion Leg Sit up (bent knee)?

Focus on a smooth, controlled spinal flexion and extension rather than using momentum to lift your body, ensuring continuous abdominal engagement. Keep your gaze directed towards the ceiling or slightly forward throughout the movement to help maintain a neutral neck position and avoid strain. Engage your transverse abdominis by gently drawing your navel towards your spine before you begin to lift, providing greater core stability. Avoid pulling on your neck with your hands; if you feel neck strain, place your fingertips lightly behind your ears or cross your arms over your chest instead.

What are common mistakes when doing Flexion Leg Sit up (bent knee)?

Using momentum to sit up rather than core strength will reduce muscle activation; instead, perform a slow, controlled curl through your spine. Pulling on the neck with your hands can cause strain; instead, use your hands only for gentle support or cross your arms over your chest. Lifting your feet off the floor indicates an over-reliance on hip flexors; instead, keep your feet firmly planted by focusing on core engagement.