A session of crunches can feel really challenging on your stomach. Find out whether this also means you are losing belly fat and weight from other areas.
To lose weight you have to make it so your body requires more energy than is coming in from food. When this is the case, your body starts using energy stores like body fat to get the remaining needs.
The crunch exercise can help in this process to a small extent by making you move more intensely and build some muscle mass.
That being said, crunches are relatively bad compared to other exercises in these areas.
They don’t burn that many calories and since the ab muscles are relatively small, there is not a lot of room for mass increases.
Additionally, your habits in other lifestyle habits like nutrition influence whether or not and how much you lose weight a lot. It is possible to exercise often without any fat loss progress.
Something else to note is that crunches do not specifically help you burn belly fat either. To achieve this goal, you mainly have to lose weight overall.
Can you lose weight by doing crunches?
To better understand why crunches can help weight loss but are not a great choice, it is helpful to quickly go over the weight loss fundamentals.
If you want to lose weight, you need to make it so your body requires more energy to function than is coming in from food. At this point, you will start using up energy stores like body fat to get the difference.
Exercise can help with this process in different ways.
Two ways resistance training exercises like crunches can help is by making you move more intensely and building extra muscle mass. These things will burn more energy aka calories.
So it is possible to lose a tiny amount of weight by doing crunches.
At the same time, it is important to note that your habits in other lifestyle areas like your diet often play a bigger role in whether or not you will lose weight.
Especially if the only exercise you do is something like 100 crunches a day.
Additionally, as you will find out below, just because they help does not mean crunches are good for weight loss compared to alternative options.
Does that mean crunches are good for weight loss?
Basically any form of exercise can help weight loss to some extent. However, this is not the only detail that matters.
You only have a limited amount of time. How effective crunches are for losing weight compared to other exercises matters too.
How many calories crunches burn compared to other workouts
There are ways to estimate how many calories crunches burn for different time intervals and body weights.
These estimations are likely not exactly how much energy you will burn because of differences in details like body composition, hormone levels, exact speed, and weight used.
Additionally, the amounts are predictions of how much energy you use during the workout. Any extra calorie-burning from increases in muscle mass is not included.
At the same time, the estimations do allow you to compare crunches to other workouts. The amounts below are estimations for a 155-pound (70 kg) person doing the exercises for 30 minutes (1).
- Bodyweight crunches: 103 calories
- Water Aerobics: 149 calories
- Stretching (Hatha Yoga): 186 calories
- Rowing, Stationary (moderate): 260 calories
- Bicycling, Stationary (moderate): 260 calories
- Elliptical Trainer (general): 335 calories
- Running 5.2 mph: 335 calories
- Jumping rope: 372 calories
- Swimming (breaststroke): 372 calories
Even if the estimations are not perfect, it should become clear that crunches are relatively bad for burning a lot of calories in a short time frame.
On top of that, it is challenging to do crunches for long amounts of time because they are so challenging for your abs.
Do crunches help you build a lot of muscle mass?
Next, resistance training exercises typically do not look that good for weight loss because they don’t burn that many calories during the workout.
However, if you take into account that some of these movements can help you burn nice amounts of muscle mass, the conclusion changes.
How much you weigh plays a big role in how much energy you need to function. By building more healthy mass with resistance training, you can burn more calories with everything you do.
That being said, this mostly applies to compound lifts like deadlifts, squats, and bent-over rows that work big muscle groups.
It is true that crunches can help you build ab muscle mass. Even so, this muscle is relatively small so there is not a lot of room for big increases.
Are crunches good for losing belly fat?
One more detail that needs some attention is whether or not crunches are good for specifically losing belly fat.
Many people get the impression that because they feel the muscles in their stomach working hard during crunches, they are also focusing their fat loss in that area.
Unfortunately, it is generally not possible to target fat loss in significant amounts.
To lose belly fat, you need to lose enough body fat overall.
At some point, your body “decides” the fat around your stomach is next. From that point on, your weight loss efforts will work in that area.
So in theory, crunches could help you lose a tiny amount of belly fat. In practice, this will mainly be the result of making changes in other areas.
One thing crunches do deserve credit for is that they can make your abs bigger. Once you are at a low body fat percentage, this can make your six-pack more visible.
How many crunches you would have to do to lose weight
By now, it should be clear that crunches are not great for weight loss but do help in tiny amounts.
Just to show how lacking they are, it can be interesting to look at estimations of how many crunches you need to lose weight.
Assume the average person does about 30 crunches per minute.
In that case, a 155-pound (70 kg) person would have to do about 30,883 crunches to burn the number of calories in one pound (0.45 kg) of body fat (3500 calories).
The numbers will look slightly smaller for weighted crunches because they use up more energy.
However, even then, the amounts you need to do to see results will be relatively ridiculous.
Are crunches a good choice for losing weight?
Crunches help you move somewhat more intensely and could help you build a small amount of muscle mass. These things make it so this exercise can benefit weight loss to a small extent.
That being said, almost all exercises out there will help you burn more calories per minute than crunches.
Additionally, because the ab muscles are relatively small, crunches will only help you build small amounts of muscle mass.
These things make crunches a bad exercise choice if losing weight is your only goal.
Another thing to note is that other lifestyle habits like nutrition are important for weight loss too.
You can have a great workout plan and not see any weight loss results if your habits in other areas are suboptimal.
Are they good for getting a visible six-pack?
Getting a visible six-pack is somewhat related to losing weight but not entirely the same. Some of the positive effects of crunches are actually helpful for this purpose.
More specifically, doing crunches with enough resistance and in the right set and repetition ranges can help you grow your ab muscles.
If your body fat percentage is low enough, growing your ab muscles makes your six-pack stand out more.