According to this article, all forms of crunches are bad for your back, because they flex the spine.
Regardless of whether or not this is 100% accurate, I would like to know if there are any ab exercises I can perform which involve little-to-no flexion of the spine, yet still exercise the muscles enough to achieve a toned look.
The article mentions these exercises which are safe for the back:
- Bridges
- Planks
- Leg extensions ? (Side note: does anyone know which exercise they are referring to?)
- Bird dogs
- Stir the pot
In all of these exercises, it looks like the rectus abdominis muscles are exercised isometrically. Is that really enough in order to achieve a toned ab look? If not, can you recommend any alternative exercises which don't involve spinal flexion?
Say I do use an exercise which tones the abs without requiring flexing the spine, would it take a lot longer to build muscles than the traditional way (i.e. sit-ups, crunches, etc.)? Also, would it be more likely that I would plateau a lot sooner?
Note: I realize that in order to get toned abs, you need a combination of very low body fat in addition to significant abdominal muscle mass.