I recently came across a very interesting fitness challenge on the gram.

It asked people to start with 50 sit ups a day and increase it every day until they could do 500. 

I love fitness challenges. They can motivate sedentary people to get their lazy asses off the couch and start exercising. 

Having worked our ass off ourselves to get washboard abs, I know how difficult it can get to burn that last, stubborn layer of fat, which makes such challenges more appealing. 

If 50 crunches a day is all that it takes to get abs, why not! 

But there’s a lot of widespread misconception about how you can get that perfect six-pack. 

One of those misconceptions is that doing a truckload of sit ups each and every day is the shortcut that no one’s talking about.

But just how many sit ups should you do in a day to get those abs to finally be toned? 

Well, sit ups are an extremely beneficial exercise to add to a well-rounded workout program. 

It helps tone the abs and if you do it right, will even help you develop thick, round muscles on the rectus abdominis. That’s the front portion of the six-pack for you. 

But how many of these should you be doing every day? 

There seems to be no clear consensus on this. 

What I do know is that if you do more than what’s considered to be safe, there’s every possibility that you might end up with an injury. 

What Muscles Do I Work With Sit Ups

There’s no denying that the sit up targets all major muscle heads in your abdominal muscle group. 

The rule of thumb is that the sit up is used to involve multiple muscle heads on the abs, while the crunch or one of the variations of it like the cable crunch, or side oblique crunch, are used as an isolation exercise. 

Here are some of the muscles involved in the sit up.

Recuts Abdominis

The biggest muscle head in the abdominal muscle group that’s known as the famed six-pack muscle.. or in some cases, a 10 pack of abs. If you do it with a rounded back, the rectus abdominis gets one hell of a workout with the sit up.

Oblique muscles

The oblique muscles are on the side of the rectus abdominis and attach to the rib cage and to the pelvis. Sit ups are the only exercise that work both, the rectus abdominis and the internal and external oblique at the same time. To specifically target this muscle area, you can do standing oblique crunches.

Iliopsoas

One of the most beneficial traits of the sit up is that it works out the tiny Iliopsoas muscle, which is associated with lifting your legs towards the hips. Most people with sedentary jobs have very weak Iliopsoas muscles. 

Rectus Femoris

The rectus femoris is technically a part of your quadriceps muscle. But it attaches to the pelvis and it works with the Iliopsoas muscle to help the body bend at the hips. 

Stabilizers

Stabilizers are accessory muscles that also participate in the move and help complete the movement. In the sit up, your pectorals, your shoulder flexors and your neck flexors work as stabilizers. And therein lies some of the problems with the movement. 

How Many Sit Ups Should I Start off with a Day as a Beginner?

Despite looking like an easy exercise, sit ups require a fair amount of upper body strength and balance.

You may think they are just as easy as crunches but they are quite a bit more difficult, trust me.

As a beginner I would actually recommend starting off with daily crunches over daily sit ups.

The reason being if you are a beginner, out of shape, and not used to the movement there’s every possibility that you might exert more pressure than what’s needed on your neck flexors straining them. 

So, it is recommended that you start low with 2-3 sets of sit ups each day with rep ranges of 10-15 repetitions. 

If you do this right, this should be enough to torch your entire core.

At any point during the workout, if you feel an acute pain in your lower back or on the nape of your neck, chances are that you may have sprained the muscle or it may have led to a muscle tear. 

Stop and do not attempt to pull through with an injury. This almost happened to me when I did my 500 crunches per day challenge.

How Many Sit Ups Should I Do a Day to Lose Belly Fat?

Remember what I told you at the beginning about the sit up being riddled with misconceptions? 

This is one of the classic ones. Let us say it out loud. 

‘The sit up does not burn belly fat’. It is a resistance exercise, not an aerobic one. Cardio is an aerobic exercise. 

If you wish to lose belly fat, you will have to count your calories and ensure that you are consuming less calories than what you are burning off.

If you have a sedentary lifestyle, then the probability is high that you are consuming more than what you can burn off. 

Further, you will have to include cardio in your exercise routine. 

If you can do high intensity cardio, then even 70-minutes a week should suffice.

But if you cannot do high intensity cardio due to injury or some other reason, then you need to add at least 120-minutes of low intensity cardio a week. 

The sit up will work those abdominal muscles and tone them.

If you are eating the right amount of protein, then after a while those muscles will get bigger which increases their visibility even at a reasonable body fat percentage.

you do not have to be shredded and low on your body fat percentage for your abs to show. I am hovering right around 15 percent right now and my abs still look darn good.

Do 3 sets of 25-30 reps if you are or have been working out for a while. 

To Build a 6 pack, How Many Sit Ups Should I Do a Day?

If you are looking to build the rectus abdominis muscle, then you will have to mix it up with sit ups and crunches, you can also add double crunches to that mix. 

Sit ups will be like the compound lift whereas crunches will be the isolation move. 

The ideal number of sit ups that you should do to build a 6-pack varies from person to person.

If you have a toned and flat belly, then 5 sets of 25-30 reps a day will get you great results.

But if your body primarily holds fat on the abdomen, then even 3 sets of 100-reps will be what you will have to do in order to get that 6 pack set of abs. The reason you have to do this many more sit ups a day is because you have to burn that fat layer off first.

The good news is that doing this amount of sit ups a day will burn that belly fat off in no time.

Do this for a month straight and see where you are abs are at, at the end of the month and you can tone the amount of sit ups down from there.

You can also do another fun little challenge, the one punch man challenge, which consists of 100 pusups 100 sit ups and 100 squats each day for a month, this should give you a nice full body workout

What are the benefits of doing sit ups every day?

All said and done, sit ups do provide some benefits when used as a part of a well-planned workout routine. 

Builds an Insane Set of Abs – say hello to that 6 pack

Yeah, you probably could have guessed it… Doing abs each and everyday, as long as you are doing the right amount in a day will build a core that is not to be reckoned with.

There are personal case studies where people have test doing a 100 sit ups in a day everyday for a month and the amount of development that they get out of their abs is incredible.

Here is a case study that a friend of mine did. He did 100 crunches a day and it proved to be quite worth it.

Increased and Improved Core strength

While planks walk away with all the attention when you talk about core strength, the sit up is an equally good exercise to develop a strong core.

It will tighten the core girdle which in turn translates into fewer injuries during upper body work.

Also, this will improve your balance and flexibility in real life. 

Increased muscle mass

There are clinical studies that reveal that performing sit ups increases muscle mass in the abdominal section.

It can be particularly useful for women who suffer from sarcopenia as they age. 

Improves Stability

By engaging the hip flexors, your glutes and your Iliopsoas, sit ups increase the stability in your hip and lower back. With time, your mobility will increase and muscle tightness will reduce.

The reduced tightness alone leads to increased blood circulation which in turn reduces stress and boosts concentration. 

Improved Posture

The increased muscle mass, balance and strength in your core will help improve your posture. If you have bad posture, chances are that you are already suffering from lower back pain.

Do sit ups right to help restore your posture. You can also do wall angles, it helps a lot with improving posture.

Respiratory function

One of the lesser known benefits of sit ups is strengthening your diaphragm which in turn leads to an improvement in respiratory function.

The increased respiratory strength can be very beneficial to athletes who are involved in professional sports. 

Are there any benefits of doing sit ups each day before bed?

The amount of bro science being sold on the internet never ceases to amaze us.

One theory goes that any form of exercise, including sit ups when performed just before bed time can cause better recovery, as your body’s natural GH pulse is at its peak at this time.

The bro science also states that doing this can also contribute to your weight loss while you sleep. This part may partly be true.

But the theory of doing sit ups everyday before bed to improve recovery…

Well..

Sadly, this is just a myth. Doing sit ups before bed isn’t going to make your abs any bigger or stronger than any other time.

Do them at any time that’s convenient to you. 

The risk of injury

Researchers have been attempting to unravel the link between doing sit ups regularly and the increased risk of spine injury, for a long time. 

While there have been no conclusive studies yet, there’s enough research to exercise some caution while considering doing sit ups every single day. 

Here’s a clinical study for your reference: 

https://www.ncbi.nlm.nih.gov/pubmed/11114441

This study was conducted on porcine spines, or the spines of pigs because they share a remarkable similarity to the spinal column in humans.

According to this study, repeated flexion/extension movements can compress the spine to an extent that it may even lead to a disc herniation.

The caveat is that it took thousands of repetitions over a prolonged period of time for it to cause the disc herniation.

Humans typically do sit ups in limited repetitions in short bursts of time. Does that make it any safer? We don’t know. 

Here’s another clinical study. 

In the two-year Army training program where bent knee sit ups are used every day for strength and conditioning, 56% of the reported injuries were attributed to sit ups. 

https://www.ncbi.nlm.nih.gov/pubmed/16491936

The fact is that you have to perform the sit up with a bent knee for it to be effective. And this in turn can be counterintuitive, because the curved spine is pressed repeatedly against the floor.

Also, it activates your hip flexor muscles a lot and if you have tight hip flexors, those can tug against the lower spine, which is a recipe for injury.

Bottom Line

When it comes down to it, the amount of sit ups you should do a day all depends on what your goals are and just what you want to accomplish with your body.

If you want to achieve a 6 pack set of abs then you should be doing more sit ups in a day than somebody who just wants to lose some belly fat.

If you want to just look good, tone your abs, and burn the belly fat off then you should be doing around 50-75 sit ups a day every day and this will keep your abs toned and looking good after about a month of constant training.

Recommended Readings:

• Do Pull Ups Work Abs
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• Should You Squat and Deadlift Same Day?
• Crazy Muscle Growth Stories
• What Should I Workout After Chest Day? The All-You-Need-To-Know Guide