Many athletes are in pursuit of “ripped” abs and methodologies like CrossFit often emphasize movements like GHD sit ups and toes-to-bar. But these exercises emphasize hip flexor muscles and may put the low back at risk. Janda or Hardstyle sit ups might be a better alternative that target the abs more directly and protect the back.
What Is a GHD Sit Up?
The glute hamstring developer (GHD) can be used for many great exercises, such as the glute hamstring raise. The glute hamstring raise develops the glutes and hamstrings and is a great accessory exercise.
Flipping over on the GHD allows you to do a full-range sit up where you touch the floor with your hands and then come all the way up to touch the toes. CrossFit teaches an explosive version of this exercise as seen in the video below:
Potential Issues with GHD Sit Ups
In general, full-range movements are an excellent practice. But critics of the GHD and traditional sit ups on the floor indicate that the lower back is stressed. In a 2014 interview for Stack, Stuart McGill, an expert on low-back disorders, describes how the discs in the low back are vulnerable to damage when they are put into position in the GHD sit up. As told to Stack.com:
With repeated full range motions, combined with the loads experienced in this type of exercise, our work shows the fibers of the disc slowly delaminate, accelerating degenerative disc disease. The scaffolding holding the fibers together soften with each repetition, reducing the resilience of the disc to loading…There’s quite a high velocity and substantial force through a big range of motion in this exercise. You can’t perform exercises with high spine power and expect it to stay healthy. When you repeat high force and velocity through collagenous disks, they will delaminate and bulge.
Another potential issue with the GHD sit up is the excessive recruitment of the hip flexor muscles. This problem plagued regular sit ups and is one of the reasons crunches became recommended over sit ups. Crunches were thought to focus more on the abdominal muscles without activating the hip flexors. But crunches are still not a perfect solution as they do recruit the hip flexor muscles to some extent and the low resistance requires many repetitions.
Enter the Janda Sit Up
Professor and neurologist Vladimir Janda came up with a solution for hip flexor recruitment by using the principle of reciprocal inhibition. Reciprocal inhibition is when one muscle contracts and the antagonist relaxes.
“GHD sit ups are advantageous in a competitive framework as we can easily see the start and end positions. But Janda sit ups might be a better alternative to GHD sit ups for long-term health.”
In the case of the Janda sit up, if we contract the hamstrings and glutes, our hip flexors will relax. By engaging the hamstrings and glutes, we better isolate the abdominal muscles and take strain off the lower back. Furthermore, we increase the difficulty of regular crunches, so we don’t need as many repetitions to tire the muscles.
In this video I discuss both the GHD and the Janda/Hardstyle sit up:
How to Do a Janda Sit Up
The tricky part of a Janda sit up is how to activate the glutes and hamstrings. Janda described a process of performing a crunch while actively driving the heel into the ground. One issue with this method is that there is a fine line between driving the heel back and down (to activate the hamstring) and straight down (which will activate the hip flexor).
Another way to think about the movement is to imagine the leg curl machine and try to pull the foot back and toward you (while the heel on the ground is providing resistance). It is also important to stabilize the neck and upper back. Try to keep the neck and upper back in the same position, rather than using the neck to generate force.
“Crunches were thought to focus more on the abdominal muscles without activating the hip flexors. But crunches are still not a perfect solution.”
- Have a partner wrap a towel around back your calves and pull with about ten pounds of force. You will be tempted to release tension from the hamstrings, but a good partner will pull your legs out if you do so.
- Wrap a band around your legs (or even better, something that won’t provide variable tension, such as the Ab Pavelizer).
The goal is to activate the hamstrings and glutes as much as possible in any of these variations.
An Advanced Janda Sit up Variation
The original Janda sit up was more like a crunch with the body coming only slightly off the floor. Pavel Tsatsouline in his book Hardstyle Abs, added a variation where you would come up into a complete sit up. As these are very difficult, he suggested starting in the upright position and doing the negative portion of the sit up until you get stronger.
GHD sit ups are advantageous in a competitive framework as we can easily see the start and end positions. But Janda sit ups might be a better alternative to GHD sit ups for long-term health. They focus more on the abdominal muscles and, with the involvement of active glutes, take tension off spinal discs.
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