During pregnancy, most women develop a split in their abdominal muscles. Sit-ups increase the abdominal pressure and encourage the split between the abdominal muscles, making the recovery of these muscles after childbirth slower and problematic.
Sit ups do NOT strengthen the core stabilisers. It does NOT work the core stabilisers, the transversus abdominus and multifidus. These muscles need to be trained to help with the recovery of the split in the abdominal muscles.
Sit ups is a dynamic exercise, specifically training the prime movers which often inhibits the activity of the core stabilisers from working. Without the strong base of core stability, sit ups can cause back pain, as it puts extra pressure on the discs of the lower back. It also increases the risk of injuring the discs and causing long term lower back pain.
It is a commonly held belief that performing abdominal strengthening exercises such as sit ups reduce abdominal fat and give the appearance of a flat stomach. However this theory referred to as Spot Reduction, is an absolute myth where people believe they can lose fat from a particular area of the body (such as the abdominal’s) by performing exercises specific to that area (sit-ups).
Abdominal exercises have benefit to increase the strength and tone of abdominal muscle, but they do not directly decrease the amount of fat which is above them. To reduce abdominal fat, or fat from any part of the body, the overall equation is fairly simple in that total energy expenditure must be higher than total energy intake. All forms of exercise increase energy expenditure, whether it be cardiovascular exercise or resistance training. Performing resistance training can increase the body’s lean tissue (muscle) which in turn increases our energy expenditure through and increase metabolic rate.
That being said, having good core stability and strength is important and helps to reduce back pain and improves the overall muscular support of the body, which helps to make exercise easier. However, exercises such as sit ups and crunches place a heavy load on the back which can lead to soreness and injury. Try doing a more gentle core exercise such as the one demonstrated below.
So, the next time someone tells you that sit ups will reduce that unwanted abdominal fat, don’t believe them!