Quarter Sit-up

Instructions

1
Lie supine (flat on back) on a mat or floor with legs extended straight and arms positioned alongside the body with palms down
2
Press palms into the floor for stability and core engagement. Ensure lower back maintains contact with the floor throughout the movement
3
Slowly lower both legs toward the floor in a controlled manner, maintaining a neutral spine and keeping lower back pressed to the ground. Stop before legs touch the floor to maintain tension
4
Drive through the core and return legs to the starting position by contracting the rectus abdominis. Complete the rep with legs extended and slightly elevated above the floor
PRIMARY MUSCLESRectus Abdominis
SECONDARY MUSCLESIliopsoas, Rectus Femoris, Serratus Anterior
EQUIPMENTBody weight
DIFFICULTYIntermediate

Overview

If you want to isolate and overload the Rectus Abdominis, the Quarter Sit-up is an excellent addition to your routine. The mechanics of this Stretching exercise specifically bias the Waist, while the use of Body weight allows for a smooth, natural resistance curve.

Benefits

  • Promotes balanced muscular development by effectively recruiting the Rectus Abdominis and associated synergists.
  • Improves overall Waist stability and proprioception during heavy loads.
  • Reduces the likelihood of Waist injuries by reinforcing connective tissue strength.

Common Mistakes

  • Losing core tension, leading to poor spinal alignment and reduced power output.
  • Shrugging the shoulders or compensating with secondary muscles rather than isolating the Rectus Abdominis.
  • Rushing the repetition tempo instead of focusing on the mind-muscle connection with the Waist.
  • Using excessive momentum to swing the Body weight rather than controlling the eccentric phase.

Pro Tips

Think about pulling from your elbows rather than your hands to better isolate the Rectus Abdominis and minimize bicep/forearm takeover.

Muscle Anatomy

The primary driver is the Rectus Abdominis. However, the movement also recruits Iliopsoas, Rectus Femoris, Serratus Anterior to maintain control of the Body weight.

Beginner Tips

If you are new to the Quarter Sit-up , focus on mastering the movement pattern with zero weight before adding Body weight.

Frequently Asked Questions