The traditional sit up, curl up, or crunch has been a staple in the fitness industry for years. Some fitness experts advocate to never, ever use these exercises to train the core, while some feel it is ok to add in occasionally. Regardless of the controversy, there are 3 populations that will absolutely not benefit from the standard sit up or crunch.
People with Osteoporosis.
Bending and twisting movements such as sit-ups and crunches, are two movements that should be avoided if you have osteoporosis. Some yoga poses and sports like tennis and golf, which are very dynamic in their rotation and flexion, should be used with caution. These movements can increase the risk of compression fractures in your spine. Also use caution with daily activities such as bending over to pick up object.
Pre and post natal women.
Pregnancy puts so much pressure on the belly that it can sometimes lead to a condition called Diastasis Recti, which is the separation of the rectus abdominal muslces. This can affect both prenatal and postnatal women depending on how far along you are in your pregnancy and the quality of your tummy tissue post pregnancy. You will want to refrain from any movements that put pressure on that area, such as crunches and sit ups, ( and eventually push ups, front planks and, down dogs).
The desk jockey.
Think about the position you are in when you are sitting at a computer for an extended period of time. Your hips are bent at 90 degrees, your spine is flexed forward and your shoulders are rounded. What does this position resemble? Perhaps a sit ups or crunch? This position (especially when repeated over and over again) could potentially lead to pain and perhaps bulging discs. When we sit so often, it makes no sense to continue to train this way.
DISCLAIMER: I am not doctor or registered dietician. The information provided on this site is based on my own experiences, and should NOT be taken as medical advice. Prior to starting any new exercise or nutrition program consult with your physician or other healthcare professional to determine if it is right for your needs.