For a long time sit ups (or crunches) had been the ab exercise of choice for anyone wanting to work their stomach muscles. But in recent years more and more experts suggest that you should never do a sit up again.
So which is it and what should you do?
It really depends on 2 main factors.
1/ What are you trying to get out of your training?
Sit ups and crunches only work the outer abdominal muscles (rectus abdominus) not the deep core muscles (such as the transverse abdominus) that other exercises such as the plank would work.
So if you are trying to lose weight I would make sit ups a very minor part of your training (if at all). You get a much better core workout, engage many more muscles, and therefore burn more calories, from other exercises.
If however you are looking to build muscle and get more definition on your outer core/six pack muscles, i.e. look better with your top off, sit ups are one of the best exercises for working that specific area. The crunching motion targets them more specifically than any other exercise.
But you need to have little or no body fat on your stomach for this to work. You will not burn fat off your stomach by doing sit ups. You will just be building the muscle.
So if you are slim/skinny already they will work. If you have a little fat on your stomach and want to get rid of it so your abs show more, sit ups arenít the best choice. You are much better of doing a combination of total body weights/circuit training and cardiovascular work. You canít spot reduce body fat, i.e. burn fat off a particular area by exercising it. Fat is burned by your body as an overall process.
In addition you need to get your diet as good as possible. I.e. keep the refined/processed foods, sugars, carbs (all things that lead to body fat storing) to a minimum and eat a healthy, high protein, fresh food diet that is calorie controlled.
This will lead to a lower body fat, which in turn will lead to a more defined midsection.
2/ If you have any pre-existing back/core injury issues.
If you suffer from a sore lower back, sit-ups are probably best left out of your routine. The rounded posture you need to adopt to do them does put strain on your lower back. And therefore is likely to exacerbate any existing problem you may have.
Sit ups close up the facet joints in your back and put a strain through them. And they can also lead to tight/stiff shoulder and neck muscles as well.
So if you have a back problem, even if itís not that bad, the benefits of doing sit ups are outweighed by the negatives.
If however you have a strong, healthy lower back without any issues, I donít see any reason why sit ups canít be part of your routine IN MODERATION and in conjunction with other core exercises. Thatís the key point.
For years and years a lot of people did 1 core exercise, I.e. sit ups. No deep core work such as planks whatsoever. So of course your inner core will be weak and you will develop problems if thatís what you are doing. You core and body would be totally out of balance strength wise.
But if you do a balanced program working the entire body with many different core exercises included, there is no reason why you lower back should develop problems. Quite the contrary you should have a strong core from outer muscles through to inner muscles.
I think sit ups get an overly bad rap these days. It has become trendy to harbour on all the negative points they can bring. But in my view (unless you have a pre-existing back problem) there is no reason why you canít add in a couple of sets of sit ups at the end of your workout to work on your outer abs.
It doesnít have to be either a great exercise or an awful one. It can just be an okay exercise which is okay to use by the right people in moderation.