You can switch up your core workouts in many ways. Find out how to do straight leg crunches and whether they are any benefits.
Some people give different movements the same name but this article considers straight leg crunches to be a crunch variation where you keep your legs stretched and on the ground.
Compared to the regular version, straight leg crunches tend to be more uncomfortable on your back and tend to work your hip flexors more.
While straight leg crunches can still grow and strengthen your ab muscles, they are typically not recommended.
Regular crunches and other variations just tend to be better.
If you do decide to do straight leg crunches anyway, make sure you implement optimal set and reps ranges and enough weight to see results.
How to do a straight leg crunch
While it will likely not resolve all the uncomfortableness, using a yoga mat during straight leg crunches can make the exercise more convenient.
That aside, take the following steps to do a straight leg crunch:
- Lie down on the ground with your legs slightly less than stretched and together on the ground. Keep your arms against your chest.
- Raise your shoulders as far as comfortable in a controlled motion. Keep your lower back against the ground and keep your neck in line with your upper body.
- Slowly lower your shoulders back to the ground.

You don’t want to swing your head forward to create momentum in straight leg crunches.
Instead, make your abs generate the power for the controlled movements and keep your neck in line with your upper body.
Straight leg crunches muscles worked
The main muscles worked in straight leg crunches are your abs and more specifically the muscle fibers in the upper part.
Additionally, this variation will likely engage your hip flexor muscles just a bit more than regular crunches.
To actually grow and strengthen your abs, you still need the right crunch exercise reps and sets. Additionally, you need enough weight to make these ranges challenging enough.
This means more advanced lifters may need weighted crunches but that many people will be able to grow and strengthen their abs with straight leg crunches.
Straight leg crunches benefits
The different leg and foot position does change things but the positive effects will be similar to the regular crunch benefits. Some of the most important ones are:
- Stronger muscles: Straight leg crunches are a resistance training exercise. In combination with enough pressure and movements, you can use this exercise to grow and strengthen your abs.
- May reduce or prevent back pain: Making your abs stronger with straight leg crunches can reduce and prevent back pain (1, 2). You do want to keep in mind many people will find straight leg crunches less comfortable in this area than the regular version.
- Can make your six-pack stand out: If your body fat percentage is low enough, growing your ab muscles can make your six-pack stand out more. Many people like the look of this.
- No equipment or location required: You don’t need any equipment or a specific location to do straight leg crunches. This can save you money and time.
Even if straight leg crunches are not the number one ab exercise, these benefits do show the potential of movements like this.
Straight leg crunch alternatives
By now, you may wonder what some of these more effective straight leg crunch alternatives are. Additionally, you may want to work different muscles or work the same ones isometrically.
Some examples of straight leg crunch alternatives include:
- Other crunch variations
- Ab wheel roll-outs
- Hanging knee raises
- Bicycle crunches
- Sit-ups
- Lying leg raises
What alternatives you prefer depends on why you are interested in leg crunches, why you don’t like them, and what fitness tools you have.
Are straight leg crunches a good exercise?
Straight leg crunches can still be a good exercise to grow and strengthen your ab muscles.
The main thing to note is that straight leg crunches can be uncomfortable for your back and work your hip flexors slightly more.
Regular crunches and other variations can offer the ab muscle engagement without these things and are typically recommended instead.
No matter what crunch variation you choose, you want to keep in mind that you still need enough reps and sets for training goals.
Additionally, advanced lifters could benefit from crunch equipment options like a dumbbell, heavy backpack, or other weights.
Lastly, personal preference still matters too. If you happen to like doing straight leg crunches more, you can consider this movement too.
Related posts:
- Reverse Crunches: How To Do, Risks,…
- Lying Leg Raises: How To Do, Benefits,…
- Bicycle Crunches: How To Do, Are They Good,…
FAQ
Are straight leg crunches effective?
Straight leg crunches can still be effective but the regular crunch is typically better.
Are straight leg crunches harder?
Straight leg crunches can be the suboptimal kind of harder on your lower back. For this reason, regular weighted crunches are typically recommended if you want an extra challenge.