Doing crunches can be helpful but how many times you do matters too. Find out what doing 100 repetitions a day can do for you.
The first thing to note is that crunches are a resistance training exercise. Most of the effects will be related to the ab muscles.
More specifically if you are barely able to do the 100 crunches a day in 2 sets of 50 repetitions to 6 sets of 17 or fewer repetitions, this workout routine can help you get bigger abs.
When these ranges become too easy in bodyweight crunches (and even before that), you can start using extra weights to see more ab muscle growth results faster.
Besides this, doing 100 crunches a day will burn a small number of extra calories, likely improve muscle endurance, potentially give you sore muscles, and offer a few more general exercise benefits to a tiny extent.
Something important to note is that this exercise routine only takes a few minutes.
If you are interested in fitness goals like losing weight and general health, you definitely want to consider other workouts and changes in other lifestyle habits.
What will 100 crunches a day do?
You likely know that more exercise has the potential to improve your health. That being said, there are also more precise things to say about what 100 crunches will and won’t do.
These things can help you find out whether an exercise routine like this is a good choice for you and what changes would make it offer even more benefits.
How many calories do 100 crunches burn?
Crunches are mainly a resistance training exercise but you are still moving more intensely than usual. In turn, your body will require more energy aka burn more calories
There are ways to predict how many calories 100 crunches will burn. However, you do need to keep in mind that these are rough estimations.
In reality, the amounts can look different for you due to differences in body weight, body composition, hormone levels, exact intensity, etc.
That being said, the average person will do around 30 crunches per minute. With this, you can estimate that 100 crunches will burn the following amounts of calories for different body weights:
- 125 pounds (56 kg) body weight: 9 calories
- 155 pounds (70 kg) body weight: 11 calories
- 185 pounds (83 kg) body weight: 14 calories
- 215 pounds (97 kg) body weight: 16 calories
At first, these amounts may seem surprisingly low. That being said, you need to remember that it only takes around 3.3 minutes to do 100 crunches.
Even if you did more repetitions, crunches are not that helpful for burning calories compared to many other exercise options.
Will it help you lose belly fat?
Something else to keep in mind is that burning more calories alone is often not enough to lose weight and more specifically belly fat.
To start using up body fat, you need to make it so your body requires more energy to function than is coming in from food. When this is the case, you start using energy stores like body fat to get the difference.
After that, from what areas the most body fat is used depends a lot on details like your genes and how far you are on your weight loss journey.
So 100 crunches a day could help you lose a tiny amount of belly fat.
However, you likely need to pay attention to other lifestyle habits like what you eat to achieve this. And even then, your body could “decide” it wants to use body fat from other areas first.
Will you get abs if you do 100 crunches a day?
The main fitness goal crunches are helpful for is growing the rectus abdominis muscles aka your abs. At the same time, you still need to do this exercise with enough pressure and the right repetitions to see results.
Some people think that if you are able to do 100 crunches a day, this routine is not challenging enough anymore to cause muscle growth.
However, the current research suggests that doing resistance training exercises with only 30% of 1 RM can be enough to grow muscles (1). You do have to push to muscle failure enough in this type of set.
In simpler words, if you are barely able to complete the 100 repetitions a day in 2 sets of 50 crunches to 6 sets of 17 or fewer crunches, this workout routine can help you get bigger abs.
It is possible that you get to a point where these ranges become too easy with bodyweight crunches.
In that case, you can consider doing more repetitions a day or doing weighted crunches.
Besides offering more and faster ab muscle growth, a benefit of the weighted version is that you can likely do them in sets with fewer repetitions and still get similar results as 100 crunches a day.
In short, how many crunches you need to get bigger abs depends on things like your current strength level. That being said, 100 repetitions (potentially with weights) a day can be good for this goal.
Is 30 days enough?
Some people are interested in the 100 crunches a day as a temporary challenge, for example for 30 days. Individuals in this situation often wonder whether the 30 days will be enough to see significant results.
How long it takes to get visible abs when you do 100 crunches a day is hard to predict exactly.
That being said, if you are an ab exercise beginner and already at a low body fat percentage, you can likely already start to see small improvements in your ab size after 2 to 4 weeks.
At the same time, you want to keep in mind that it typically takes longer than a month to see really big changes in ab muscle mass.
Additionally, when you stop doing the crunches, the ab muscle mass you gained will slowly decrease again.
Lastly, if you currently have body fat covering your abs, you will likely not see too many visual differences by implementing more crunches.
Should you do them every single day?
During resistance training exercises like crunches you damage the muscles you work. This may not sound good but it starts a variety of processes that can repair the muscles and make them bigger.
To complete these processes, your body still needs time.
For this reason, it is often recommended to give the muscle groups you worked at least one extra day rest before focusing them again with a resistance training workout.
That being said, smaller muscles like your abs tend to recover more quickly. Many people will have no problem in this area while doing 100 crunches a day.
At the same time, doing 100 crunches fewer times a week can already offer great benefits, makes sure you stay away from overtraining, and offers more free time.
Your muscle endurance will likely improve
Even if you do the crunches with weights and repetition ranges that focus on growth and strength increases, you will likely still improve your muscle endurance to a small extent.
Core muscles like your abs are responsible for keeping your upper body upright. By improving muscle endurance in this area, activities like standing up, climbing stairs, and walking around may feel more convenient.
You do want to keep in mind that there are other core muscles too. If you are interested in this type of result, you likely want to improve endurance in your obliques and erector spinae too.
You may get sore muscles
Especially if you are new to resistance training, doing 100 crunches a day and sticking to it will likely involve getting sore muscles.
This is not necessarily good or bad for everyone. However, some people will find the muscle soreness uncomfortable in their daily lives.
Smaller benefits of doing 100 crunches a day
The 3.3 minutes required to do 100 crunches is far from the most impressive workout. At the same time, you are still moving more than usual.
This involves getting some of the more general exercise benefits of crunches to a tiny extent. Some examples include:
- Improved mood
- Better cognitive function
- Improved sleep
- Slowing down aging
Again, you should not expect too many results in these areas from only doing 100 extra crunches a day. If you are serious about these, you want to consider other workouts.
Is 100 crunches a day good enough?
By now, it should be clear that doing 100 crunches a day can be good enough to grow your ab muscles, improve muscle endurance, and burn a few extra calories.
For losing weight, doing 100 crunches will help to a tiny extent but there are plenty of better routines that will offer more impressive before and after pictures.
Next, you may also want to know how this routine compares to other options for general health. The Office of Disease Prevention and Health Promotion recommends the following exercise guidelines to adults (2):
- Moving more and sitting less throughout the day
- Muscle-strengthening activities of moderate or greater intensity that involve all major muscle groups on 2 or more days a week.
- At least 150 to 300 minutes of moderate-intensity aerobic activity or 75 to 150 minutes of vigorous-intensity aerobic activity a week. Preferably spread throughout the week.
- You can gain additional health benefits by engaging in physical activity beyond the equivalent of 300 minutes of moderate-intensity physical activity a week.
These guidelines are not perfect for every individual but it does become clear that 100 crunches a day are definitely not enough to be considered a workout routine that is good for general health.
Even in terms of muscle-strengthening activities, the ab muscles do not really count as a major muscle group.
Will 100 crunches a day do anything?
If you do them in the right sets and with enough weight, doing 100 crunches a day will help you grow your ab muscles. Besides that, you will burn a few extra calories and likely improve muscle endurance too.