Abdominal Sit-Ups Home -> Exercises -> Abdominal Sit-Ups Primary Muscles Worked: Description: Rectus Abdominus The center, six-pack abdominal muscles. Internal and External Obliques The internal and external muscles on the sides. Transverse Abdominus The layer of muscle underneath the visible abdominals. Secondary Muscles Worked: Description: Hip Flexors The muscles that move the thigh closer to the abs. This is a sit-up movement that works the abs instead of the hip flexors. It will work all the muscles in your midsection in one exercise. The standard Crunch only addresses part of the function of the abdominals. This exercise targets the flexed (arched back) range of motion of the abs. How To Do It: Lie on your back on the floor. Roll up a towel or mat and slip it underneath your lower back, just above the waistband (the size of the towel affects your body position during this movement - use a fairly large towel). Your knees should be bent about 90 degrees. Keep your feet close together and knees wide apart. This prevents the hip flexors from having a direct line of pull, helping to minimize their involvement. Do not anchor your feet or have someone hold them down. This automatically activates the hip flexors. You will get the most out of this exercise by minimizing their involvement. The difficulty of this exercise depends on where you hold your hands. The hardest position is above your head at arms-length, then beside your head, then across your chest, then straight down between your legs or at your sides. Start with the easiest first then progress to the other positions as you get stronger. You are now ready to crunch. Keeping your torso straight and stiff, start the sit-up by tightening your lower abs. As you continue up, imagine trying to push your face up against the ceiling (think up, not around). When you reach about 25 to 30 degrees above horizontal, hold for a second and squeeze hard. Keep your back in contact with the towel at all times and always maintain tension in the abs. Lower yourself down slowly and under control. Do not just drop back to the groun. The negative portion of the crunch is extremely effective..   Tricks: 1. Hand position drop set When you get stronger at these, start with your hands over your head. When you fail with that, continue with your hands beside your head. Then continue with hands across the chest, then hands at your sides or between your legs to finish. It is a merciless drop set. 2. Working the sides To work the sides more during this movement, come up to 25 degrees then do a twisting crunch over to the side. Don't do it on the way up, just after you are up to about 25 degrees. 3. Breathe at the top Try holding the contraction at the top and breathing in and out a few times. This will really force your abs to contract. Common Errors: 1. Using momentum Do not swing yourself up to get started. Always squeeze yourself up using ab power. Start with the easiest positions first, i.e. arms down at your sides, or try these on a slant board (with your head higher) if you have trouble doing this exercise. 2. Losing tension at the top This occurs when you come too far up. Always maintain contact with the towel and keep tension in your abs. 3. Allowing the glutes to come off the ground Keep the glutes on the ground at all times. The tendency for the glutes to come up occurs at the start of the rep when your abs are first trying to get your body off the ground and your back is pivoting over the towel. It is easier to lift your glutes up at that point in order to do the exercise. 4. Coming up too far This error actually takes the tension off the abs at the point where they should be getting the most tension. Keep your lower back in contact with the towel throughout the exercise. 5. Improper towel placement The towel should be just above the waistband area in the small of the back. Placing it too high or too low will affect the exercise negatively. Variations: 1. Lower abdominal raises This variation of the Ab Sit-up exercise targets the lower abs. Start in the exact same body and towel position as the regular version. Place your hands beside the towel or beside your glutes. Now instead of lifting your torso up over the towel, raise your legs and pelvis up and over. Keep your feet together and your knees apart to minimize hip flexor recruitment. Suck in your gut to help isolate the lower abs. Your butt should come right up off the floor when your pelvis rolls up and over the towel. When you suck up your gut, imagine you are trying to suck your legs up to your chest through vacuum power alone, then rolling your pelvis over the towel. You can alternate between the sit-up style and leg raise style to hit your abs from both directions in one set. 2. Incline abdominal sit-ups This is a good starting variation of the abdominal sit-up. Set an incline board to a slight incline. If you don't have an incline board, your can use an adjustable incline bench, a decline bench, a Step platform with a riser under one of the ends or a flat bench with something under one end. The execution is exactly the same. The only difference is that the tension is much less due to the leverage, allowing even people who are relatively weak in the abs to do the exercise. It is also a very good way for advanced trainers to do high reps with this exercise. Other Abdominal Exercises Abdominal Crunches Cable Crunches Lying Leg Raises   "The Best Abdominal Exercises You've Never Heard Of" Want a wasp-tight waist? Want a six-pack that pops? Want rock-solid, steel-girder core strength and stability? In this book you will find 77 of the most unique, results- producing exercises that you've NEVER seen before... Click here to read more right now!