The original Janda crunch removes the hip flexors from the traditional crunch exercise, which forces your abs to work harder. (Activating your hamstrings and glutes limits hip flexor recruitment.)
Professor Janda originally described a process of performing a crunch while actively driving your heels into the ground. This variation below similar but you'll be coming up fully to the top, the way you would for a sit-up.
Pavel Tsatsouline recommends coming up fully to the top with these. If starting from the floor is too difficult, you can practice partial reps from the top down. The key is to maximally engage your glutes and hamstrings, which make even the simplest of sit-ups a whole different beast.
- Drive your heels into the edge of a platform to activate your hamstrings. You can also pile up a few thick mats to lay on and wedge your heels against.
- As you sit up, think about closing the space between your ribs and pelvis to fully shorten your rectus abdominis.
- Get rid of all of your air as you reach the top.
- Accentuate the eccentric, taking at least 2-3 seconds to lower.
- To make these easier, start from the top and go down further over time.
Janda sit-ups can also be done using a resistance band. In this case, an NT Loop is a comfortable setup to pull your heels against. Use the band to activate your hamstrings while working hard to keep cracking that imaginary walnut between your butt cheeks.
How to do it...
- Thread a band around a piece of equipment that's not going to move anywhere, then place each end of the band around your ankles. This will create just enough tension to lock you into position and continue pulling your heels against.
- As you sit up, think about closing the space between your ribs and pelvis to maximally shorten your abdominal fibers.
- Exhale fully as you reach the top.
- Squeeze your glutes and hamstrings throughout.
- Lower slowly. Take at least 2-3 seconds to lower yourself back down to the floor.
- To make it harder, stretch your arms up overhead on the way down to overload the eccentric.