If you had to cut down a tree, would you use a baseball bat to cut it down? Of course not, a baseball bat will cause damage to the tree by causes huge dents, but it’s not going to cut a tree down with an ax. When a lifter goes to the gym, they have to use the right tools to get the most effective results. You should be looking for the exercises that cause the greatest amount of activation during a movement or much like a person using the wrong tools to cut down a tree; you’re going to be wasting lots of time and energy.
The seated ab crunch machine is a common exercise machine that many people use to activate the abdominals. Many trainers don’t know this but the abdominal crunches performed on an exercise machine, in a seated position may not be desirable for individuals with lumbar disk pathologies, low back pain, or weak abdominal musculature due to high rectus femoris (thigh muscle) activity that’s involved when you have to bring your legs forward.
The Swiss ball crunch is an abdominal exercise that has been widely used in both rehabilitation and clinical settings for balance and stability. Swiss ball training is therefore only recommended as a low threshold modality to improve joint position, posture, balance, and neural feedback. Both Swiss ball and machine crunches work the abdominals, but what works the best?
Swiss Ball Crunches
Researchers wanted to compare the abdominal during abdominal crunches performed on a Swiss ball with added elastic resistance and an abdominal training machine. The researchers hooked electrodes all over the stomach of the subjects to measure the abdominal activation.
The researchers found that sitting crunches in an exercise machine designed to isolate the abdominal muscles does not target the abdominals to the same extent as the supine crunch on the Swiss ball although both exercises caused high activation of the abs. In contrast, the flexed hip position during the seated crunch in machine resulted in higher rectus femoris (quads) activation as compared to the Swiss ball crunch.
Key Points: The Swiss Ball is a better exercise for the abdominals than the seated ab machine.