Getting Results With Ab Crunches 

Most people include ab crunches as part of their workout, but may not be getting the results they’re looking for. People who are looking for a six-pack, or to see their abdominals, can’t expect this to happen from doing 100 crunches a day. Being able to see muscle definition, including abdominal muscles comes from a well-rounded fitness and nutrition program. However, including ab crunches in your workout is important and beneficial to losing belly fat. This exercise improves strength, burns calories, helps with posture and balance, and can reduce the risk of injury. But, you must do them correctly, for example by imagining bringing the bottom of the rib cage to the top of the hips. 

The ab crunch is a staple in strength, fitness, and weight loss programs, just like the forearm plank. However, the exercise needs to be done correctly and you need to know where it fits into your workout. Here, we’ll explore:

1. Joint motion and muscle activation in a crunch
2. Proper form and technique for doing a crunch correctly
3. Common mistakes people make with ab crunches
4. Variations and other exercises for abdominal muscles

Joint Motion During An Ab Crunch

During a standard crunch, there should be only one joint motion, spinal flexion. To perform spinal flexion, and understand the muscles, start by standing up. Then, round your spine forward so your upper body hangs over. This is spinal flexion. The spine can also perform lateral flexion (bending to the side), extension (arching backward), and rotation.

So, knowing the joint motion to any exercise is the best way to understand the muscles it uses and how to do the exercise correctly. There are over 25 muscles of the core. In fact, any muscle that crosses the hip (lumbopelvic hip complex) is technically a core muscle. However, there are only three muscles that actually perform forward spinal flexion. These muscles include:

• Rectus abdominus
• External oblique
• Internal oblique

The rectus abdominus muscle is what most people think of when they imagine having six-pack abs. It’s the most superficial muscle of the core (closest to the surface) and the prime mover in a basic crunch. The others are secondary muscles and include the external and internal oblique muscles. They run alongside the body and the internal obliques are also deeper, providing stabilization during the movement.

The transverse abdominus is one of the core muscles and important for posture and injury prevention. It is a deep muscle and wraps around the spine for support and stabilization. Although it doesn’t produce visible movement during the crunch, it activates as you pull your navel in.

Proper Ab Crunch Technique

To perform basic ab crunches, follow these guidelines.

• Lie on the floor with the right leg and left leg bent, feet flat on the ground.
• Fold the right arm and left arm over the chest.
• Pull the belly button in toward the spine to activate the transverse abdominus.
• Keep your head in a neutral position by tucking your chin inward.
• Exhale and lift your head, neck, and shoulders off the ground.
• Tuck the tailbone under and imagine bringing the bottom of the rib cage to the top of the hips.
• Pause at the top of the movement for one second, then slowly lower the upper body back to the ground in two to three seconds.
• Repeat the exercise.

To regress the crunch, you can leave your arms and hands on the floor by your side. To progress the movement and create a more challenging exercise, place your hands behind your head (elbows wide) or arms up over the head (in line with the earls). Changing the position of the hands will create a longer lever, and therefore more resistance on the abdominal muscles. 

Common Crunch Mistakes

Because the crunch is such a common exercise, it’s easy to make mistakes incorporating it into a workout. Avoid these pitfalls.

• Assuming ab crunches will get you to lose belly fat. Losing fat is part of a fitness and nutrition program. You need to burn more calories than you consume. More importantly, genetics determine where you’ll lose your fat. Exercising a specific area of the body does NOT dissipate fat from that area. 
• Doing crunches and core exercises at the end of a workout. If you’re doing a crunch as part of a core strengthening and functional training program, you should do it at the beginning of a workout. This is when you’ll have the most strength and it also fires up these important posture muscles for use during the rest of your workout.
• Try to target the lower abs. When a muscle fires, the entire muscle fiber fires or it doesn’t at all. This is called the “all or none principle” and is important in exercise physiology. You can’t contract just the top half of your biceps. The same goes for an abdominal muscle. The rectus abdomninus muscle has segmentations which leads people to believe you can activate one portion. Additionally, most people have a tough time losing fat on their lower abs. Therefore, they make the mistake of thinking a certain ab exercise will fix the problem. Instead, what usually happens, is the exercise activates the hip flexors more than anything else (not ideal).
• Using momentum to get more lift. The more you control the motion during a crunch, the better. When you start using momentum, you’re making it easier.

Variations And Other Core Strength Exercises

A well-rounded workout will include more than just crunches. Use this list to add variation to the standard crunch.

• Add weight. You can wear a weighted vest or place a weight plate over your chest. This adds more resistance and builds greater strength.
• Use a stability ball. Sit on a stability ball and roll out so it supports your middle and lower back. Then perform the crunch as usual. This increases demands for stability and strength. It also decreases pressure in the lumbar spine and tailbone.
• Bicycle crunch. To perform a bicycle crunch, lift both feet off the floor. Then extend one knee straight and crunch across the body. For example, bring your right elbow across to your left knee. Switch and repeat.
• Standing cable crunch. Using a cable machine and the cables coming from the top, hold them over your chest and do forward spinal flexion.
• Ab crunch machine. You should only use this machine if you’re trying to get those muscles bigger and have done enough core stabilization to prevent injury.
• Forearm plank. This is for stability, balance, and posture. It’s used in many core training programs, yoga, and pilates.

If you want to enhance your workout more and learn how to work out like a professional fitness trainer, check out our personal training course.

Abdominal Crunch Variations

Increase the intensity of your crunch by changing arm positions