Building the Armor: Sit-Ups May Not Be the Answer

         Sit-ups and crunches have been the staple-mark core exercises used to build core strength and endurance. They are easy to implement; you don’t need equipment or a lot of space to perform them. But, are they really the most efficient exercises to target core strength and endurance?

            In order to better understand which exercises we should do to strengthen our core muscles, we must first define “core.”. For this blog’s purpose, when “core” is referenced it is referring to the musculoskeletal region around the lower back (quadratus, back extensors, transverse abdominus, etc.), abdominal wall (internal and external obliques, rectus abdominus etc.), and all the ligamentous structures surrounding the torso and spine. Something that is interesting to understand is that the core isn’t just made up of abdominal muscles. When we hear “core,” the first connections we make are usually in regards to the abdominal muscles, which is partially accurate, however numerous muscles make up the core. For example, the latissimus dorsi muscle (lat. muscle) is considered a core muscle because it connects to the thoracolumbar fascia (lower back), an area that plays an important role in lumbopelvic movement.

            When we talk about core training, we also need to look at how much stress is being placed on the spine. The muscles provide necessary support as we move through flexion, extension, and rotation, but as we go through the different ranges of motion the disks and ligamentous tissues of the spine end up taking on more responsibility (McGill, 1998).  Since the core directly connects to the spine, picking exercises that also places the spine in the best position to reap the benefits is very important as well. For example, when performing a bent knee sit-up, there are 3,350 Newton’s of compression on the spine (Axler and McGill, 1997). That is over 740lbs of force being placed on the spine. Instead, consider a side plank or side bridge exercise. This exercise targets more core muscles, yet puts >200lbs less compression force on the spine. Picking core exercises that have high muscle activation and lower compression forces is important in the longevity of spine health. 

          Building a strong core is important. The core isn’t just the abs you see or don’t see when you lift-up your shirt or flex in the mirror. They are a web of muscles and connective tissues that structurally hold your body together to protect your spine from external compression forces. Building this foundational structure through exercises, such as but not limited to curl-ups, side planks, birddogs, suitcase carry, and farmer carry, will introduce more effective core training carry over compared to sit-ups and crunches. The harmony of muscle activation created during bracing exercises like planks and farmer carries, develops armor around the core to reduce the risk of injury, improve the transmission of compression forces around the spine, and give the breathing muscles a stronger base to help the lungs with ventilation.

Birddog

            We can learn a lot from our past and over the years, exercise research has shown that sit-ups and crunches do not give the best risk to reward benefit when targeting the core. Remember, the core is more than just the superficial muscles around the abdominal region you see every day in the mirror. They do more than give an aesthetic meaning in life. They drive performance, aid in breathing, and build armor around the spine to protect the spine from unwanted forces. Build your armor with exercises that have more carry over.  

References

Axler, C. T. & McGill, S. M. (1997). Choosing the best abdominal exercises based on knowledge of tissue loads. Medicine & Science in Sports & Exercise, 29, 804-811.

McGill, S. M. (1998). Low back exercises: Evidence for improving exercise regimens. Physical Therapy, 78(7), 754-765.

For more exercise content check out our YouTube Channel: Cystic Fibrosis Fitness Institute 

More From THE Blog