What Are Double Crunches And Should You Add Them To Your Workout?

Crunches are a staple of most fitness routines for good reason: Core muscles keep us stable and balanced. The stronger they are, the more our bodies are capable of, and the less likely we are to injure ourselves, as the Mayo Clinic explains. Crunches are a sure-fire way to work the core muscles without extra equipment or a lot of space.

But it turns out there is something even better than a standard crunch: a double crunch. A double crunch is essentially a crunch blended with a knee-to-chest exercise. If you don't love ab work, this might sound like a bad joke, but there is nothing funny about how effective these exercises are. They work both the main abdominal muscle as well as the muscles of the upper thigh.

Double crunches, like standard crunches, require no equipment and very little space. They're perfect for apartment workouts since they don't require jumping. They fit easily into a busy schedule, and everyone from beginners to athletes can do them. There's only a few things to be cautious of before you add them to your routine.

When doing a double crunch, make sure your back is flat to the floor when you start, and that you engage your core before every crunch. This will keep strain off your lower back and prevent arching that may lead to injury, per Women's Health Magazine. The same can be said for putting too much strain on your neck, so be sure not to grab at or push your neck with your hands.

If you know how to do a crunch, some of the steps to a double crunch are going to be very familiar. You'll still want to read through the steps to ensure you're hitting all the safety points and to spot the differences between a standard crunch and a double crunch.

1. Start on your back with your fingertips either lightly touching the sides of your head or your arms at your sides.

2. Engage your core. (This is the most important step to avoid injury.)

3. Brace your feet on the floor, knees bent, then slowly raise your feet so they are a few inches off the floor, and hold them there.

4. Raise your chest and head off the floor and curve your chest in as you do in a standard crunch. At the same time, raise your knees and bring them toward your chest.

5. When your face and knees are about six inches apart, hold the crunch for a few seconds, then slowly release back down. Release the tension from your abs before re-engaging them to repeat the exercise.

You might find that your back starts to ache, or you cannot properly engage your core for very long. If this happens, take a break and work another muscle group, then come back to the double crunches. Pushing yourself to continue may strain your lower back and cause injury.

For an excellent video example with a slightly different approach, check out this tutorial.