Crunch machines can help tone your abs.
Core training involves more than just crunches and sit-ups. For an effective workout, it's important to train your abs from all angles. Most ab exercises engage the rectus abdominis but have a negligible impact on the external and internal obliques. The ab torso machine targets these two muscle groups and improves core strength. Sometimes, its risks outweigh the benefits, though. Back pain and injuries are common concerns among those who use this piece of gym equipment.
The Benefits of Torso Rotation
A strong core can improve your physical performance as well as your stability and balance. Most workouts engage these muscles to a certain extent. For example, when you're doing deadlifts or squats, your core helps generate force. Everyday activities, such as walking, running, climbing the stairs and bending over, rely on your abdominal muscles.
Rectus abdominis, transversus abdominis, internal obliques and external obliques are the four main muscle groups of your core. They cover the internal organs, stabilize the trunk and create a solid foundation for all activities. Working your obliques is just as important as training your rectus abdominis - the so-called "six-pack."
Ab torso machines engage both the internal and external obliques. Crunches and sit-ups, by comparison, primarily target the rectus abdominis. By rotating your torso, you'll build stronger obliques and get a more balanced core workout. This will enhance your range of motion and overall fitness.
Contrary to popular belief, training the obliques doesn't increase waist size unless you use a lot of weight. Over time, these muscles will become stronger and give your abs a tighter appearance.
Torso rotation may also help realign the spine and restore proper movement in the back muscles. The problem is that your lower back muscles are designed to resist twisting, so they can be easily injured while performing this exercise on a machine.
Even though ab torso machines allow you to isolate the obliques through a stabilized motion, their risks shouldn't be overlooked. This piece of equipment goes against the number-one rule on most gym machines: to keep your back flat against the bench. As a result, it puts stress on your spine. Furthermore, it causes the spine to flex abnormally, which may lead to lower back pain. In the worst case scenario, this exercise could damage your discs.
Another problem with the ab torso machine is that it fails to engage your deep stabilizing muscles. Remember, your core is multilayered. Neglecting the deep abdominal muscles can affect core stabilization.
Additionally, many gym goers use this machine for the wrong purpose. Like it or not, you cannot spot reduce fat. Torso rotation exercises have little or no impact on body fat levels.
How to Work Your Obliques
The ab torso machine may help strengthen your obliques, but there are better options available. According to the American Council on Exercise, a good way to engage these muscles is to add a twisting motion to the traditional crunch. For overall core strength, experts recommend ab wheel roll-outs, decline bench curl-ups, bicycle crunches and stability ball crunches.
A study conducted by the Department of Physical Therapy at Korea University in Seoul point out that unilateral core training, such as rotation exercises, can improve trunk stability. Some examples include the Russian twist, the side jackknife, decline oblique crunches and seated barbell twists. Another option is the Pallof press, a cable exercise that helps develop core strength while sculpting your obliques.
At the end of the day, it's up to you whether or not to use the ab rotation machine. Weigh the pros and cons - and remember that there are safer, more effective exercises to choose from.