Crunches are not the most impressive-looking exercise in the gym but they can still offer benefits that could make them worth it to you.
You will get more general health benefits to a tiny extent but this article will mainly focus on the more specific aspects of crunches.
Something you do want to keep in mind is that some people find the spine moving in crunches uncomfortable. These individuals may need to start with isometric (static) core exercises like planks.
1. Crunches can benefit your ab muscles
Crunches are an isolation exercise that works your rectus abdominis aka ab muscles.
In simpler words, they have the ability to grow and strengthen the ab muscles that run along your stomach.
Because they are so isolated, crunches tend to be better than something like sit-ups for growing and strengthening these muscles (1).
Many people like the visual aspect of bigger abs but these muscles also help you keep your upper body upright.
One important thing to note is that just working your ab muscles every once in a while will likely not be enough to see results.
You still need to implement effective rep and set ranges of crunches with enough resistance.
Since the ab muscles are relatively low, most people will be able to see nice results with just bodyweight crunches. Something like doing 100 crunches a day can actually help.
That being said, weighted crunches could offer more and faster results in a more comfortable way when you reach a certain strength level.
Especially for goals like improving ab muscle strength instead of size.
2. Crunches could help you avoid back pain
Growing and strengthening muscles is not only useful for improving performance and visuals. It can also help you avoid pain in a variety of areas.
More specifically, core exercises like crunches can potentially help you avoid back pain.
One review of studies concluded that core muscle exercises can help reduce lower back pain (2).
A more specific study with 120 people observed that a core muscle stabilization exercise program was more effective for reducing lower back pain than routine physical therapy exercises (3).
This benefit of crunches can be helpful because aches and pains are somewhat common in modern life. Especially in the lower back area.
3. Crunches are a budget-friendly exercise
Investing in your health can be a great idea but many people want to keep their fitness budget at least somewhat reasonable.
Luckily, it is often possible to get nice amounts of benefits without spending a lot of money.
The crunch exercise is a good example of this.
Because the ab muscles are relatively weak, many people will be able to work these enough with just their body weight.
Even if you are at the strength level where you need some extra resistance, you can do crunches with household objects like a heavy backpack against your chest.
In turn, these things free up resources you can invest in other areas of your health (or other things).
4. Crunches could flatten your stomach a tiny amount
While crunches are definitely not that effective for this next benefit, you can still say that they help you flatten your stomach aka help you lose weight to a tiny extent.
This is mostly because the movements involved are just a bit more challenging and require just a bit more energy than daily activities where you sit still like watching TV or working at your desk.
In turn, this makes it just a bit easier to get in a situation where your body needs more energy than is coming in or makes the difference just a bit bigger.
However, it is important to make it clear that how many calories crunches burn is not that impressive either.
The average person will only burn around 41 to 71 calories while doing crunches for 15 minutes.
Since one pound (0.45 kg) of body fat is about 3500 calories, it is fair to say that while crunches can help weight loss, they are definitely not a great exercise choice if this is your main goal.
5. Crunches can grow different muscle fibers
The muscles in your body, including your abs, can actually consist of different ratios of muscle fiber (4).
A potential benefit of crunches is that you can easily do them in different ways that focus on growing different types of muscle fibers.
For example, if you do many crunches with just your body weight, you will likely focus on type 1 muscle fibers which are so-called slow-twitch muscle fibers.
These tend to be good at exerting force for extended amounts of time.
On the other hand, you can also do your crunches more explosively and with extra weights. This will be better for growing type 2 aka fast-twitch muscle fibers.
Many people don’t need to worry about this benefit but for example athletes in specific sports may find the adaptability of crunch workouts useful.
6. You can do crunches almost anywhere
To do many sports and exercises you need a specific sports field or fitness equipment that is not always at-home-friendly.
This is not ideal since it means you will have to spend time going to certain locations and back.
At first, this may not sound that bad. However, even if your car ride only takes 10 minutes and you only work out 3 days a week, that is an extra 30 minutes per week.
Additionally, this extra time can make it a bit easier to skip your workouts.
That being said, crunches allow you to forget about these things (at least for your core workouts). You can do them basically anywhere.
In turn, you could easily get in a few sets of crunches every day at home if this aligns with your training.
7. Crunch technique is easy
Another potential downside of many sports and exercises is that you have to spend a good amount of time learning how to do them good enough.
In turn, you will not be able to get the full health benefits and/or have a higher injury risk until this point.
Additionally, some people do not like this initial learning period and just want simple activities in their workout programs.
On the flip side, there are exercises like crunches that basically everyone can do right the first time.
You only have to pay attention to keeping your lower back against the ground and not swinging your head back and forth too much and you can start growing and strengthening your abs.
8. Crunches can make your six-pack more visible
On top of the physical health benefits, growing and strengthening your abs can also make your six-pack more visible.
Not everyone cares as much about this but it is fair to say that six-packs are typically considered to be visually appealing.
Additionally, many resistance training exercises do not work your abs that much.
These things could make it worth implementing crunches to get a more balanced look.
It is worth briefly mentioning that many crunch alternatives can be useful for this benefit too. You could prefer these for a few reasons.