Instructions

1

Lie supine on a flat surface with your back and head resting comfortably on the ground, knees bent at approximately 90 degrees, and feet flat on the floor hip-width apart.

2

Place your hands behind your head with fingers interlaced for support, keeping elbows wide. Engage your core by drawing your navel toward your spine.

3

Slowly extend one leg forward in a controlled manner, straightening the knee while keeping the other foot planted on the ground. Lower the extended leg back toward the starting position without fully relaxing.

4

Drive through the planted heel and engage the quadriceps to return the extended leg to the bent knee position. Alternate legs in a rhythmic pattern, maintaining constant tension throughout the movement.

PRIMARY MUSCLESRectus Femoris

SECONDARY MUSCLESVastus Lateralis, Vastus Medialis, Iliopsoas, Rectus Abdominis

EQUIPMENTBody weight

DIFFICULTYBeginner

Overview

If you want to isolate and overload the Rectus Femoris, the Crunch leg raise is an excellent addition to your routine. The mechanics of this Strength, Cardio 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 Femoris and associated synergists.
Reduces the likelihood of Waist injuries by reinforcing connective tissue strength.
Utilizes Body weight to create sustained mechanical tension, forcing deep muscle adaptation.

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 Femoris.
Using excessive momentum to swing the Body weight rather than controlling the eccentric phase.
Rushing the repetition tempo instead of focusing on the mind-muscle connection with the Waist.

Pro Tips

If you feel this primarily in your joints rather than the Rectus Femoris, instantly lower the weight and readjust your Body weight setup.

Muscle Anatomy

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

Exercise Variations

Dumbbell Crunch leg raise
Cable Crunch leg raise
Banded Crunch leg raise

Beginner Tips

If you are new to the Crunch leg raise, focus on mastering the movement pattern with zero weight before adding Body weight.

Crunch leg raise