Much of this is down to the number of muscles that this exercise works. The conventional plank has more variations: marching planks, kettlebell drags, mountain climbers, and so on; the plank also works the shoulders due to how it's done in a push up position. The reverse plank, on the other hand, hits a lot of the posterior chain muscles, as the body is held up by the hamstrings, glutes, and lower back, along with the shoulders and the hip flexors (the big bonus of this hold). There are other neglected parts of the back that also get activated in this hold, like the rhomboids, the erector spinae and the middle traps.

The fundamental of this exercise is pretty simple -- just flip the plank. So now the body is facing up to the ceiling, and is supported on the heels rather than the toes which instantly kicks in the posterior chain. There aren't that many posterior chain isometric holds, and just the superman hold comes to mind as a popular one.

But one doesn't need to start off with the perfect reverse plank. The first variation might look like a glute bridge hold, but with the arms fully extended to support the upper body. The easy part in this starter variation would be to support the lower body on the soles of the feet until there is enough strength and comfort to take the weight on the heels. YouTube channel Calisthenic Movement posted a video showing the first few variations of the reverse plank and it is the only video possibly needed to learn this exercise.

One of the biggest issues while doing a conventional plank is bringing down the hips in line with the rest of the body. But there is no scope to cheat in the reverse plank, because you can see your own form instantly as you try to create a line with the body. If the hips drop, it is happening right in front of your eyes. And the body cannot extend the hips beyond a point in this exercise. So the most irritating form hack to the plank has no room in the inverted plank.

The next question is obviously the placement of the hands. Should they be facing the feet, or away from the body, or be to the sides? A Reddit thread on the community r/bodyweightfitness has a comment from an experienced gymnast who discusses this issue: "My hands are facing towards the sides on purpose. While the end goal should be hands facing backwards (forearm supination), this position along with the full shoulder extension greatly stretches the biceps. When it comes to the hands facing forward, this hand position does not lead anywhere and most people do not have the required wrist extension strength to safely hold the position. The average Joe has pain in its wrists by performing Push-Ups. At the end, the hands facing the sides is the best option and it will be the base to gradually transition towards hands facing backwards, which should take a few months for most people."

This opinion resonates with a lot of material on the reverse plank that is available online, but a first-person point of view while learning a new move is important. This is not an exercise I have seen many people try in a gym, so if you're doing it, remember that comfort comes first, before the strength to get the best position.

The final progression of this is called a Chinese plank. This can be done using two benches, or two similarly tall pieces of equipment with the feet resting on one and the head and upper back on the other while the body is suspended on a plank. There is a floor version of this as well, where the body is resting on only the head and upper back and the heels, without extending the arms.

If you are still unsure of the reverse plank, then it's worth knowing how to get the best from the conventional version. I wrote a piece four years ago in Lounge titled How to get the most out of the plank which can help build strength. The reverse plank is a must-try if you're serious about overall development.