Key words to remember "Just About Everything" but still, this exercise is one of the best for overall health but it also is tough to do at first and makes you focus on so many things it's not even funny. It's the Gymnastic Bridge or as it's called in Yoga, Chakarasana or the Wheel Pose. It truly is one of the GOATs in fitness and Physical Culture in general.
When I first learned it many moons ago, it was just doing the Push-up version of it or as they were called Reverse Push-ups. They're tough to do when they're part of a routine in your arsenal but once you get the idea and hold the top position, you're going to feel one of the biggest stretches ever. Regardless of what size you are, it takes strength to get into and it takes even greater strength just to hold for a period of time. I remember the first time holding it and 10 seconds felt like an eternity. Have no idea what my longest time is in that thing but I do know that in my early 20's, I went to a party once for a cousin of mine at her house and kids were roaming around, so I decided in her living room to hold the Gymnastic Bridge and a number of kids were crawling under me back and forth for a period. Thought that was going to kill me LOL.
The Gymnastic Bridge is just another variation in a series of Bridging Exercises that target multiple muscle groups and forcing the body to work as a single unit. You see this exercise a lot in Yoga circles or in Gymnastics (obviously) and in Wrestling. Guys like Karl Gotch and Billy Robinson would teach this exercise to students to get them in amazing condition in addition to Hindu Squats, Push-Ups and the Wrestler's Bridges. It is a favorite that's for sure.
The idea of it as an Isometric Exercise is to hold it essentially with just the hands and feet on the ground. At first, having the heels up is a good starting point and as you progress, lower the heels until you're completely flat footed. Just the hands and feet alone would be enough but some have been strong enough to take away limbs and hold the exercise with one arm and both feet on the ground, one arm and one leg or do a sequence called Around The Clock which I learned from Logan Christopher. This is more of a skill than anything and yeah it's cool to do if you can do it but the point of the exercise is to feel the stretch, the full body concentration and breathing as naturally as possible.
Once you get the hang of it and can hold it, so many benefits are being thrown into the mix: Control Over Your Body, Strength that is functional, Spinal Health, Agility, Flexibility, The Opening Of The Lungs and hits the Core Muscles unlike any other exercise. Some powerful stuff comes out of doing this exercise. You can do the Reverse Push-ups and get benefits from them too but once you're able to hold it for even 30 seconds to a minute or more, you're getting far better benefit out of it in my opinion.
I would consider this exercise for the most part a Yielding Isometric meaning that you're fighting gravity in order to hold it. Although I'm a bigger fan of Overcoming Isometrics, some Yielding ones are just awesome and this is one of them. I would sometimes use this exercise as a finisher or as part of my Isometric Training to hit the muscles from everywhere I can think of. Practice this with intent and do a little dynamic "warm up" to help with easing into the exercise like working the wrists, shoulders and hips. These areas are essential to getting into the position because if they're weak, you won't get very far and you'll just be stuck but hey, we all start somewhere. Here's a Demo of what the Gymnastic Bridge looks like.