Welcome to the physiogain community, our today’s topic is how do you do a sit up or correct way to do sit ups.
Sit-ups or crunches target your abdominal muscles and crunches play the main role in building your abs.
They target the rectus abdominis muscle.
Crunches play a beneficial role in developing your abs and for your whole body workout.
Table of Contents
Abdominal exercise variations
Name | Description of the concentric action | Muscle group or body area | Muscles |
Bent-knee sit-up | Trunk flexion | abdomen | Rectus abdominis |
Abdominal crunch | Trunk flexion | abdomen | Rectus abdominis |
Bent-knee sit-up

Starting position
- Lie down on a floor mat in a supine position.
- Flex your hip approximately 45 degrees and flex your knee approximately 90 degrees so that your feet are placed flat on the mat, the thighs, knees, and feet should be next to each other.
- Fold your arms across the chest and start your repetition from this position.

Upward movement
- Start your exercise by flexing your neck so that your chin moves towards your upper chest and then curl your torso to lift your upper back off the mat.
- Maintain this position with the folded arms across your chest and make sure that your feet lift off the mat as your upper body is raised.
- Continue flexion or curling your torso towards the thigh until your upper back is off the mat and your elbow pointing towards your thigh.
Downward movement
- Start uncurling your torso and extending your neck in a controlled manner.
- Do not lift the buttocks off the floor to help rebound for the next repetition.
Abdominal crunch

Starting position
- Lie down on the mat in a supine position.
- Place your feet on the flat bench with the knee and hip flexed at 90 degrees.
- Hip, knee, and feet should lie next to each other.
- Place your arm across the chest and start all your repetition from this position.
Upward movement
- Start your exercise by flexing your neck and curling your torso until your upper back is off the mat.
- Maintain the same stationary position with the arms folded across the chest.
- Do not lift the feet off the bench as your upper body is raised.
- Continue curling your torso towards the thigh until your upper back is off the mat and your elbow point towards the thigh.
Downward movement
- Extend your neck and uncurl your torso in a controlled manner back to the starting position.
- Do not lift your buttocks off the floor to help rebound for the next repetition.
- Maintain the same stationary position with the arms folded across the chest.