There are many exercises you can do to lose weight both at home and the gym. What about crunches, do they help you lose weight and belly fat?
Crunches are a relatively well-known bodyweight exercise that focuses on working out your ab muscles.
Compared to most exercises, crunches don’t burn that many calories during the workout. In addition, crunches are not as good for building muscle mass as weight lifting workouts with external weights and many other bodyweight exercises.
Even if you are looking for a no-equipment, at-home exercise, something like lunges will likely help you more with weight loss than crunches.
In fact, crunches are one of the worst exercises for losing weight and belly fat. If you are already at a low body fat percentage you can use crunches to make your abs stand out more but besides that, they are not very useful.
Keep in mind that your diet and other lifestyle habits are important when trying to lose weight no matter what exercise you do.
What exactly are crunches?
Crunches are a type of calisthenics, which means bodyweight, exercise. One repetition of a crunch involves the following steps:
- You also start lying down on your back with your legs bent at the knees and your feet flat on the ground.
- You can place your hands behind your head, cross them over your chest, or put them anywhere else. The point is to not really use your arms or move them during the exercise.
- Raise your head and shoulders from the ground as much as possible while keeping your lower back on the floor. Make sure you don’t use your arms but your ab muscles to do this movement.
- Lower your head and shoulders until you are back in the starting position.
You can describe the crunch more or less as half a sit-up.
Cardio versus HIIT versus muscle building
All forms of exercise can be divided into 3 main categories. These 3 categories are cardio, high-intensity interval training (HIIT), and muscle building. In terms of what parts of your body they mainly impact you can bucket cardio and HIIT together.
Each workout will inevitably use both your cardiovascular system and muscles. However, usually one of the two really stands out.
The way cardio and HIIT help you lose weight are slightly different from how more muscle helps you lose weight. One or the other can be better depending on the situation.
You do train your cardiovascular health to some extent but crunches are mainly a muscle building workout.
Muscle building helps you burn more calories by increasing muscle mass. How much you weigh is an important factor in how many calories you burn each day. That’s how many weight loss plateaus happen, you lose some weight and you start burning fewer calories with the same habits.
Building more muscle helps you add healthy weight. A certain amount of muscle also burns slightly more calories than the same amount of fat. This means that by spending a little time building muscle you can increase the number of calories you burn 24/7.
Crunches will mainly benefit your upper ab muscles which are unfortunately not a very big muscle group. This means you won’t build a lot of muscle mass with crunches which in turn means they won’t benefit weight loss as much.
Muscle-building exercises with external weights generally allow you to build more muscle mass in a shorter amount of time compared to bodyweight exercises like crunches. Even within the bodyweight workouts category, there are many better exercises to build a lot of muscle mass.
Cardio and HIIT
Cardio and HIIT mainly help you burn more calories by increasing the intensity and quantity of movement right now.
This makes those kinds of exercise great for short term energy usage. The flip side of the coin is that once you stop doing these kinds of exercise the extra calorie burning will stop fast.
HIIT is basically cardio but faster. So depending on your tempo you are doing one or the other. The higher the intensity of the exercise you are doing, the more calories you burn.
HIIT can also cause something called “afterburn”. This is basically having an increased metabolism for a while after you stopped the exercise.
Do this for long term weight loss
So cardio and HIIT are good for fat loss in the next hour or so.
For long term weight loss muscle building is usually more time and effort efficient.
You can also do both. The extra muscle will help you get more out of your cardio workout by increasing the amount of mass you have to move around.
Often people forget that your choice of exercise isn’t only about how efficient the calorie burning is.
A full-on weight lifting workout might be more time-efficient for long-term weight loss but if you don’t like that kind of workout, chances are you won’t stick to that. The workout that doesn’t get done doesn’t burn any calories.
How many calories do crunches burn?
You have to keep in mind that the amount of calories burned by exercising depends from person to person. Things like age, weight, activity levels, and more influence it.
That being said, there are still approximations for how many calories you can burn by doing crunches. You can also see the calories burned for different kinds of exercises to see how all the workouts compare.
The following numbers are an estimation for a 155-pound person doing the exercises for 30 minutes (1).
- Crunches: 165 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
Not a lot of people can do crunches for 30 minutes. Nonetheless, this does give you a perspective on how effective this exercise is for calorie burning compared to others. You can check out the specific article on how many calories crunches burn for different time intervals and bodyweights.
The thing with these numbers is also that the more intense and the longer you do your exercise, the more calories you will burn. For example, if you do your crunches at a faster pace, or wear a weighted vest, you can burn more calories in less time.
The numbers above are great to get an estimation but you can’t rely on them being the exact same for you.
The amount of calories you can burn with crunches during the exercise is not great. If you want to burn a lot of calories during the 30 minutes of your workout there are many better exercises.
Often muscle-building exercises have the benefit of burning extra calories in the long-term due to all the extra muscle mass. However, crunches don’t really build much muscle mass.
How long does it take to see results from crunches?
One pound of body fat is about 3500 calories (one kg +-8000). How long it takes to see weight loss results from crunches will also depend on the number of calories in your diet.
One person might eat more than the other. This might make it so they need to exercise longer or more intense to see the same weight loss results. You can even lose weight without exercising so there are many factors that influence it.
15 minutes of crunches a day could help you burn an extra 825 calories in 10 days which is about 0.24 pounds of body fat. 30 days 2475 calories and so on…
Keep in mind that losing weight too fast can be harmful. In general, a 500 calorie deficit per day is considered to be a healthy weight loss rate.
Because of the small amount of muscle you may gain from crunches your weight might not move that much initially. That does not mean you are not losing fat. If you lose inches but not weight when you start doing crunches you are most likely gaining some muscle weight and losing body fat weight.
Should you do crunches for weight loss?
The number of calories burned during the workout per minute of crunches is rather low compared to many other exercises and workouts. On top of that crunches will not help you build a lot of muscle mass.
Even if you are specifically looking for a no-equipment, quick & convenient, exercise at home something like lunges may help you build more total muscle mass and burn more calories during the workout, and thus help weight loss more than crunches.
If you don’t mind going to the gym you can certainly find exercises that benefit weight loss more.
All in all, crunches are one of the worst exercises for weight loss.
Keep in mind that the things you eat and other lifestyle habits stay important no matter what exercise routine you’re following. It’s hard to out-exercise a bad diet.
Do crunches burn belly fat?
The main reasons why people look into exercises like crunches are trying to get a flatter stomach and/or getting visible abs.
The first thing you need to know is that you generally can’t target fat loss significantly in specific body areas. In other words, exercises that target your ab muscles don’t necessarily burn belly fat. Even exercise itself in general is usually not the area of health where you get the most fat loss results from.
However, where crunches can help anyway is by making your ab muscles bigger.
To get visible abs you want to combine getting to a low body fat percentage, basically losing body fat, and getting bigger ab muscles. So crunches can help you get to your ab goals but you likely have to focus on other exercises and health areas, like your diet, too.