A Trainer's Take on 13 of the Most Popular Abs Exercises

Updated by Melissa Rudy, 2/2/17

We often get questions about the best abdominal exercises—after all, who doesn't want to exercise their tummy muscles in the most efficient way possible? There are countless exercises that target the abs, including fitness DVDs and even the pricey machines that you often see on infomercials. But do you need a video or specialized piece of equipment to get the abs of your dreams?

A study conducted at San Diego State University's Biomechanics Lab (and published by the American Council on Exercise) says no. Their research revealed that the best exercises for your abs don't require any gizmos or gadgets, and are surprisingly easy to fit into your day.

Researchers looked at the effectiveness of 13 common abdominal exercises—everything from crunches to the "Ab Roller"  machine—and ranked them from best to worst. Using EMG (electromyography), researchers measured the muscle activity of the participants to determine which exercises best targeted the abs and the obliques, while also limiting the activity of the hips and thighs (because when an abdominal exercise is executed poorly, the hips and thighs engage to "help out" the abs).

ACE-certified personal trainer Shane McLean weighed in on each exercise and why it works so well so you can stop wasting time and start working toward the abs of your dreams.

1. Bicycle Crunches
  • Muscles worked: Rectus abdominals, obliques, hip flexors
  • Why it’s effective: This exercise is a combination of a crunch with the rotation of the opposite arm/leg, which targets most of the abdominal area. You'll feel the burn on this one. 
  • Considerations: Putting the fingers behind the ears rather than hand behind the head will prevent you from wrenching the neck, a common form mistake with this particular move. 
2. Knee Lifts on Captain's Chair
  • Muscles worked: Obliques, Rectus abdominals, hip flexors
  • Why it's effective: It works the obliques and your six-pack abs simultaneously, giving you more bang for your core buck.
  • Considerations: Keep your back against the pad during this exercise to protect the low back. Taking your knees to the opposite shoulder brings a little spice to this exercise.
3. Crunches on Ball
  • Muscles worked: Obliques, Rectus abdominals 
  • Why it’s effective: The instability of the ball assists in activating the abdominal muscles more than the floor. The ball also helps support the lower back.  
  • Considerations: Placing your feet wider apart will give you a greater base of support. Taking a foot off the ground during the exercise will increase the stability challenge.
4. Crunches with Vertical Legs
  • Muscles worked: Obliques, Rectus abdominals, hip flexors and lower back
  • Why it’s effective: This exercise is just like a traditional crunch, but with your legs extended up into the air, in line with the hips. Having the legs vertical focuses on the abs and helps in adding intensity to the crunch.
  • Considerations: Hamstrings and legs may tire before the abs. People with tight hamstrings or lower-back pain may want to avoid this exercise.
5. Torso Track Machine
  • Muscles Worked: Obliques, Rectus abdominals 
  • Why you shouldn’t bother: Although this is an effective core exercise, this machine is expensive and currently unavailable on Amazon. Using an ab roller wheel is cheaper and just as effective. 
  • Considerations: If you have shoulder issues, you may want to avoid the ab roller exercise. Make sure to engage the glutes at all times and avoid hyperextension of the back.
6. Crunches with Arms Extended
  • Muscles worked: Rectus abdominals, obliques, some hip flexors
  • Why it’s effective: This exercise is just like a traditional crunch, but you extend your arms overhead, squeezing your upper arms by your ears as you crunch up and lower down. Having the arms behind the head provides less support and a longer lever, which increases the intensity of the crunch.
  • Considerations: If you have neck or lower-back issues, you may want to avoid this exercise. Keeping the lower back neutral or pressed into the floor is recommended for this exercise. 
7. Reverse Crunches:
  • Muscles worked: Obliques, Rectus abdominals, hip flexors
  • Why it's effective: Traditional crunches cause spinal compression, which is a no-no for people with low back issues. The reverse crunch is the opposite of this, targeting the abs in a safer fashion.
  • Considerations: If you’re having to bend your head backwards while performing this, put a towel or foam block underneath your head to keep your back straight. 
8. Crunches with Heel Push:
  • Muscles worked: Obliques, Rectus abdominals, hip flexors, lower back 
  • Why it’s effective: Similar to the crunches with vertical legs mentioned above, with this move you slightly lift your hips off the ground and your feet toward the ceiling as you crunch up. The additional movement of pushing the heels toward the ceiling causes more of an intense contraction in the abdominal muscles.
  • Considerations: See reverse and vertical leg crunch. 
9. Ab Roller
  • Muscles worked: Rectus abdominals and obliques
  • Why you shouldn’t bother: This is just another piece of equipment you don't need to buy, and there are far more effective options from which to choose. Besides, not many vendors stock these anymore. 
10. Plank
  • Muscles worked: Everything, from head to toe
  • Why it’s effective: The plank is more of a total body exercise, which is why it ranks so low on this list. The plank and its numerous variations help the body to be strong and stable. They are difficult for a reason.
  • Considerations: These should form the majority of your core routine. 
11. Traditional Crunches
  • Muscles worked: Rectus abdominals, obliques, hip flexors
  • Why you shouldn’t bother: According to Men’s Health magazine, it takes almost 22,000 basic abdominal crunches to burn a pound of fat from your midsection. Who has time for that? Nobody. There are far more effective and much safer options on this list.
12. Exercise Tubing Pull
  • Muscles worked: Rectus abdominals, obliques
  • Why you shouldn’t bother: There is really nothing wrong with this exercise, other than the fact that you need to purchase a resistance band and there are far more effective options on this list. Shane recommends this far more effective core exercise to do with a resistance band. 
13. Ab Rocker
  • Muscles worked: Rectus abdominals, obliques
  • Why you shouldn’t bother: You shouldn’t have to fork out money to train your abs when your own body is a far better option. It ranks last on this list for a reason. Shane recommends trying this exercise instead. 
To view the entire study report from ACE, click here. (You will need Adobe Acrobat Reader to download this PDF.)

The big takeaway from this study is that you really don't need to buy anything special to train your abs. However, if you are going to invest in one piece of exercise equipment, a simple and inexpensive stability ball is extremely versatile for all types of exercises.

Remember, every individual performs exercises differently, and a movement that is effective for one person may be ineffective or uncomfortable for someone else. Listen to your body, work at a level that is comfortable for you and never perform an exercise that causes pain. Your abs are just like any other muscles in your body, so train them accordingly. That means one to three sessions per week, and one or two days of rest in between workouts. Also, be sure to avoid the top 10 abs training mistakes.