Sit-ups vs. Crunches

[Ceicei]

What is up with the "controversy" of sit-ups and crunches? While growing up, sit-ups were very common and standard part of almost every exercise program. Now it seems as if sit-ups were practically banned and replaced entirely by crunches.

I've searched the internet. There seemed to be no scientific studies indicating that sit-ups are bad. There's a lot of stories out there for and against. If there are indeed studies, I would appreciate some links please.

I haven't had any problems doing sit-ups, but now that crunches are the "in thing", this is the question that comes to mind, "Why?" Surely the sit-ups are not equivalent with crunches. They do not necessarily work the same set of muscles, so to replace one with the other doesn't really make sense. If the purpose is intended to work the same muscles, it would make sense to replace with an exercise for the same type of muscles.

Any feedback out there would be appreciated. Thank you.

- Ceicei

 

[Monadnock]

I used to do all that. Then I saw the ab-lounge. But I'm not buying it until they come out with a motorized one

 

[MJS]

What is up with the "controversy" of sit-ups and crunches? While growing up, sit-ups were very common and standard part of almost every exercise program. Now it seems as if sit-ups were practically banned and replaced entirely by crunches.

I've searched the internet. There seemed to be no scientific studies indicating that sit-ups are bad. There's a lot of stories out there for and against. If there are indeed studies, I would appreciate some links please.

I haven't had any problems doing sit-ups, but now that crunches are the "in thing", this is the question that comes to mind, "Why?" Surely the sit-ups are not equivalent with crunches. They do not necessarily work the same set of muscles, so to replace one with the other doesn't really make sense. If the purpose is intended to work the same muscles, it would make sense to replace with an exercise for the same type of muscles.

Any feedback out there would be appreciated. Thank you.

- Ceicei

The idea is to focus on the ab muscles. Coming up past the half way mark, puts stress on the lower back. Interestingly enough, watch any gym class or LEO agility test, and you'll see the full ones. I pulled a muscle in my lower back one time, while taking one of those agility tests. Quick up and down movement, faster than you'd normally do, due to the fact that you have a minute to do as many as possible.

Here are a few things I found:

http://www.wikihow.com/Do-Sit-Ups

http://www.oaktrees.org/fitness/situps.html

http://en.wikipedia.org/wiki/Sit-up_(exercise)

 

[Jdokan]

I''ll back MJS on this wholeheartedly.....Talk to ANY physical therapist and they'll tell you....NEVER come all the way up there is no further gain to the abs...
NOW with that said do as I say not as I do....I use one of the old roman chairs for my ab & lower back workouts......

 

[Ceicei]

The idea is to focus on the ab muscles. Coming up past the half way mark, puts stress on the lower back. Interestingly enough, watch any gym class or LEO agility test, and you'll see the full ones. I pulled a muscle in my lower back one time, while taking one of those agility tests. Quick up and down movement, faster than you'd normally do, due to the fact that you have a minute to do as many as possible.

Here are a few things I found:

http://www.wikihow.com/Do-Sit-Ups

http://www.oaktrees.org/fitness/situps.html

http://en.wikipedia.org/wiki/Sit-up_(exercise))

Thank you, MJS, for the links. What I was asking for was for good scientific studies why sit-ups aren't good and should be replaced by crunches?

I do agree, however, that timed sit-ups aren't very good because it is difficult to maintain proper form when focusing upon how many within a certain time limit. This is pretty true for most of anything when time limit and/or speed are made the primary focus, proper form tends to suffer.

What I wanted to know is why sit-ups are to be "tossed out"? What scientific research/studies are out there to substantiate this?

I liked the first like that link that explained the how of doing them. The second link, while useful, does not go into the why with enough detail. The third link hints at possible research out there, but does not cite any. I did like the idea of adding on a medicine ball to the sit-ups once the muscles are already strengthened by body weight first.

Again, thank you for posting the links.

- Ceicei

 

[terryl965]

I too have to agree with Mike here sit ups are bad for th back, alot of studys have proven that also crunches works best for building abs and stronger stomach muscles.

 

[exile]

The thing about situps is, it's only the `crunch' part of the movement that stresses your abs.

Do a situp and note carefully which parts of your body are feeling the stress. You'll find 100 times out of 100 that once you're past the `crunch' part of the phase, the subsequent sit-up movement is a lower-back stressor. The abs are irrelevant. And if you want an exercise for your lower back, there are much better exercises available. So....

The best ab exercise I know of is the weighted crunch. Lie on a bench, with your hands behind your head gripping a dumbbell of suitable weight for your own abdominal strength. Do the crunch as you normally would, but making sure that the weight moves with you. After four weeks of this, twice a week, drop down to once a week with an additional 5lbs every time you work out. In three months, your abs will feel like they could stop a bullet. Disclaimer: they can't, of course. But they'll feel, and look, like they could...

 

[Ceicei]

Gosh, that's what I always wanted to do to actually stop a bullet! :angel: I suppose there is no chance in heaven of doing that with the abs...

Exile, am I to assume the dumbbell is resting on your shoulders, not on the neck, right?

- Ceicei

 

[exile]

Gosh, that's what I always wanted to do to actually stop a bullet! :angel: I suppose there is no chance in heaven of doing that with the abs...

Exile, am I to assume the dumbbell is resting on your shoulders, not on the neck, right?

- Ceicei

The way I do it, Ceicei, I'm lying on a bench, my arms are behind me, elbows facing up, and I'm grippiing one of the ends of the dumbbell with both hands. If the dumbbell (or plate) rests on your chest, there's less stress on your abs when you do the lift.

As for stopping a bullet... well, appearances will be deceiving; but as I say, if someone doesn't have a lot of abdominal fat, they will look like they're wearing armor plate on their torso. If they do have excess body fat, you won't be able to see their abs... but they'll be there, and will emerge as soon as they lose the concealing layer. That will require a fair amount of aerobic activity (as per your other thread...)

 

[terryl965]

I guess my abs are really hidden well under the coating of fat before you get to the abs.

 

[Drac]

Me, I like crunches..Got one of those "cheapie" machines from the Sporting Goods store that assist with doing crunches..I do at least 150 EVERY morning..

 

[fireman00]

I'd disagree that full sit-ups should be dismissed; their are lower back and lower ab muscles that DO NOT get fully utilized when doing sit-ups correctly. But like any exercise if they aren't done properly you can certainly injure yourself.

I have a bad back - been bothering me for about 9 years and my phys therapist told me to first build up my core ab and back muscles before resuming full sit-ups. She had me doing loads of crunches, leg lifts with my back on the ground and my knees bent fully, then after two weeks leg lifts with my knees slightly bent then with my legs fully extended then with my legs fully extended and spread apart. After three months my back felt much better and I was able to do full sit-ups with no problems.

If you have back pain get it checked out first to find out what's causing the pain.

 

[Obliquity]

As a former military person, I am thinking that if full sit-ups were bad for a person, they would not still be doing them in the military. Thousands upon thousands of sit-ups happening every day on military bases around the world. I did many over 10+ years without a hitch. In fact, my back feels way better when I am doing sit-ups with a full range of motion.

I hate to be a stickler, but it would be helpful to actually cite research rather than to merely claim that there is research "out there."

And . . . when proper form is mandated for the repetition to count while completing a timed event, one tends to do them correctly.

 

[KempoGuy06]

Ive heard that doing the cycle crunched are far mor beneficial than either. You know where you lie on your back and move you legs back and forth as though you are riding a bike. I do them and they suck, cause they work so good.

B

 

[exile]

As a former military person, I am thinking that if full sit-ups were bad for a person, they would not still be doing them in the military. Thousands upon thousands of sit-ups happening every day on military bases around the world. I did many over 10+ years without a hitch. In fact, my back feels way better when I am doing sit-ups with a full range of motion.

I hate to be a stickler, but it would be helpful to actually cite research rather than to merely claim that there is research "out there."

And . . . when proper form is mandated for the repetition to count while completing a timed event, one tends to do them correctly.

I don't know about how bad full situps are for your lower back. I do know that past the phase of the situp corresponding to the crunch, your abs are working only marginally, if at all—just as a full-depth squat will only primarily stress your quads for the first third or so of the squat; any lower and you are working lower back and glutes virtually entirely. So if it's just abs you want to work on, full situps waste time and effort, just as, if you want to work quads, full range squats are wasteful, or worse: since you can do much heavier lifting in your strongest range of motion, you actually can't overload your muscles as effectively using a full range—not just with squats, but with a lot of other free weight exercises—as you can just using a portion of the range (I recall reading something by Lou Ferrigno in which he said that he only started getting noticeable results from squatting when he cut the range down to just the very top of the squat). I think this general idea is behind a lot of the thinking about using crunches rather than full-motion situps...

 

[Brian R. VanCise]

Well I for one probably agree that if you are not in shape like most people are in the United States or the world for that matter then crunches are definately the way to go. Starting with sit ups after not having exercised or limited exercise and particularly if you are older could put alot of strain on your back. Myself I started sit ups and roman chair workouts when I was young and I have never stopped so it does not negatively affect me. I do sit ups and roman chair workouts regularly and find them to be very beneficial. The type of sit up I personally do is a modified form which does not stress my back at all and yet I get a larger movement than a crunch. Crunches on the other hand are completely a waste of time for me as they just do not stress the muscles enough.

Obliquity made a serious point in that the Military is still using them. This should tell you something. Yet remember that their personnel are generally all young in boot camp.

Having said the above I always recommend crunches for everyone based on the scientific data at hand and the numerous studies that say they are more beneficial and less stessful for you.

 

[Ceicei]

Having said the above I always recommend crunches for everyone based on the scientific data at hand and the numerous studies that say they are more beneficial and less stessful for you.

I hate to be a stickler, but it would be helpful to actually cite research rather than to merely claim that there is research "out there."

I have to agree with Obliquity.

May I ask for reference to that "scientific data" why sit-ups are bad? If done properly, I fail to see the risk sit-ups offer. I can see that benefits and stress level may differ. There are, however, some different muscles worked by sit-ups and crunches, so it would be a fallacy to say they have equal value in their purpose. Why should sit-ups be tossed out in favor of crunches if sit-ups do have some benefits?

- Ceicei

 

[exile]

Why should sit-ups be tossed out in favor of crunches if sit-ups do have some benefits?
- Ceicei

One good reason is that there are exercises superior to the part of the sit-up that doesn't work the ab. There's a big difference between a situp, which works different muscle groups serially, and something like a bench press, which as a compound exercise works several different muscle groups in tandem. The compound exercises are very efficient; but the lower-back workout you get from the situp is probably not nearly as good as the exercises you can do on the `hyperextension' back station. And if you're doing a `weighted' crunch, as I suggested for serious overload on the ab complex, having that dumbbell behind you when you come up is a bad idea—it's really easy misjudge your angle and have the dumbbell swing in your hands into your upper back, ouch! Since I always do crunches with a weight behind me, usually a dumbbell, a situp is a lot less attractive an exercise.

 

[Brian R. VanCise]

Ceicei you are welcome to go to sites like the American Sports Medicine Journal or ACSM-MSSE, etc. There you can find studies regarding sit ups and crunches. Unfortunately you will have to pay (they do not give it away for free) and you will also find when searching that science in general will side with crunches in studies but that their are also studies that will probably side with your opinion which is mine by the way. (such is how sciencetific research works depending on where the funding is coming from) Still it is pretty clear that crunches are the way that most if not all people are advising. For myself I am simply willing to take for instance what almost every Physiologist and Sports Medicine expert is saying and I know several. Having said that I know what I can do with my body and what effects it well for me which is a very demanding abdominal curriculum that simply crunches do not do well enough for me. Part of that may be my abdominal and lower back strength placing me outside the norm. (I do not know)

Feel free and look around there are lots of studies out there.

 

[jks9199]

Personally, I've found that crunches are great for the abs... alone.

Situps hit the abs, the hip flexors and more. I haven't found anything that hits all of it like the situp. In fact, if you're doing PT tests that include situps, you NEED to do situps to prepare. I learned this the hard way. Despite doing multiple sets of 50 crunches, multiple sets of leg raises and other ab exercises -- I was shocked to barely get 30 situps in a minute on a test once several years ago! (Muscle specificity rules...)