Just doing 30 crunches a day could sound too simple to do anything. However, depending on a few factors, this routine could offer you results.
First of all, whether this routine is enough to see ab muscle growth and strength progress depends on your current strength level.
If you can barely complete the 30 bodyweight crunches in somewhere between 2 sets of 15 repetitions or 6 sets of 5 repetitions in one exercise session, you can likely see results with this routine.
Besides that, many people will be able to recover from a workout like this in 24 hours. However, it is also possible that your ab muscles need an extra day of rest.
In that case, you don’t want to do the 30 crunches every single day.
Next, if the set and repetition ranges above are/become too easy for you, the bodyweight crunches will become more of an ab muscle endurance exercise.
If that is not your goal, you can increase the number of repetitions you do (up to a certain point) and/or use extra resistance to make the crunches more challenging.
Will 30 crunches a day make a difference for your abs?
Crunches are mainly a rectus abdominis (ab muscle) resistance training exercise. That means the main reasons why you would do 30 repetitions a day are to improve muscle mass, strength, and/or endurance in this muscle.
For these fitness goals, you have to challenge the muscles with enough pressure, do enough repetitions, give your body enough nutrients, and give your body enough rest.
What counts as enough in these categories ultimately depends on things like your body, current ab strength, how you approach the 30 crunches, and what you eat.
However, there are a few ways you can predict how much of a difference 30 crunches a day will make before implementing this exercise routine for a month or longer.
Repetitions and pressure
How much pressure and how many repetitions of certain resistance training exercises are enough for certain fitness goals are closely related.
If you can barely complete the 30 bodyweight crunches in somewhere between 2 sets of 15 repetitions or 6 sets of 5 repetitions in one exercise session, you will likely be able to grow and strengthen your ab muscles.
Once these repetition ranges become too easy, once you feel like you could do more crunches, 30 repetitions in one workout could still make a difference but mostly in terms of muscle endurance.
If you absolutely want to stick to 30 crunches per workout but don’t mind adding weights, you can hold something like a dumbbell against your chest to make the reps challenging enough for muscle growth and strength progress.
People who don’t mind adding extra repetitions and/or sets can do these things to keep seeing progress with bodyweight crunches. At least up to a certain point.
Another aspect of this crunch routine that deserves some attention is the “a day” part.
During resistance training exercises like crunches, you use your muscles so intensely that they get damaged in small amounts.
This may not sound good but it starts a variety of internal processes that can make your abs bigger and stronger in the long term.
However, your body needs some time to do these things.
There are definitely people who recover from doing 30 crunches within 24 hours. Especially since smaller muscles like your abs tend to recover more quickly than something like your glutes (butt) which are relatively big.
That being said, it is still generally not a bad idea to implement an extra rest day to make sure you are not overtraining and to have more time to do exercises for other muscles and fitness components.
Lastly, whether doing 30 crunches a day will make a difference also depends on what nutrients you eat.
Your body can not just build things without building blocks. To grow and strengthen your abs you need nutrients like protein, vitamins, and minerals.
If you are doing the crunches in the sets mentioned above, really pushing yourself enough, resting enough between workouts, and still not seeing increases in how many repetitions you can do, you likely need to take a look at your diet.
Other things that could happen
Muscle growth, strength, and endurance progress will be the main effects you can expect from implementing more crunches in your routine.
That being said, you can also expect some secondary effects from these things and more general exercise benefits to a tiny extent.
Something you do want to keep in mind is that 30 crunches will only take around a minute (+ rest time if you do it in multiple sets) to complete.
To really improve other areas of your health besides ab muscle mass, strength, and endurance, you will have to make other changes too.
Burn a few extra calories
Crunches are definitely not the best exercise option for this next effect but because burning more calories is such a popular fitness goal, it can be interesting to look at what you can expect in this area.
Exactly how many calories crunches will burn for you personally depends on things like your body weight, body composition, speed, repetitions you do, hormone levels, etc.
That being said, there are ways to make rough estimations. Let’s assume you do the 30 crunches in a minute.
With that detail, you can estimate that doing 30 crunches will burn the following amounts of calories for certain body weights:
- 125 pounds (56 kg) body weight: 4 calories
- 155 pounds (70 kg) body weight: 5 calories
- 185 pounds (83 kg) body weight: 7 calories
- 215 pounds (97 kg) body weight: 8 calories
It should be clear that just doing 30 crunches or more repetitions a day will not get you very far in terms of calorie burning.
That being said, something you have to mind for a goal like losing weight is that exercise is not the only thing that matters.
You can have a really intense exercise routine and gain weight if you have bad habits in lifestyle areas like nutrition. Similarly, you can lose weight without any exercise.
So you can still lose body fat while doing 30 crunches a day but this would be more because of your habits in these other areas.
Standing up for a long time could feel easier
Core muscles like your abs are responsible for keeping your body upright.
By improving the endurance of these muscles, activities like standing up and walking for long amounts of time could become easier and more comfortable.
One thing you do want to keep in mind with this benefit is that only training muscle endurance in your abs will likely not be enough.
Your obliques (sides) and erector spinae (lower back) likely deserve some extra attention too.
Is 30 crunches a day good?
Depending on your current strength level, ab workouts with bodyweight 30 crunches could be enough or even good to see muscle growth, strength progress, and better muscle endurance.
Additionally, it is possible that you recover quickly enough to follow this routine every day.
If both of these things apply to you, doing 30 bodyweight crunches a day can be considered to be good for you.
On the flip side, even if this is currently the case, as your abs get stronger over time, you will have to keep increasing the challenge of your crunch routines to keep seeing results.
One way to do this while sticking to the 30 repetitions a day is by holding resistance against your chest while doing the crunches. Another option is increasing the repetitions you do.