Responding to everything:
1. Is this better than traditional power exercises?
No. But I believe it can be very effective if the right loading is used. It can at least be a supplement, for now. A 24kg kettlebell is still very light. I have used 100lb DBs before and have found that it hits my legs a lot harder, and there is more extension because the DB does not swing and add momentum.
2. Is this a maximal exercise?
No. If it was I would be jumping further and would have difficulty initiating jumps in succession. However it is quite challenging.
3. Why is there no hip hyperextension or full triple extension?
Partly because this is not a maximal exercise, and partly due to the nature of the equipment used there is no hip hyperextension or full triple extension. If this was a maximal exercise, there would be hip hyperextension and full triple extension just like in a broad jump or a standing vertical jump. Now there are other common power building exercises that can improve leaping power that also do not involve full extension of the hips, knees or ankles.
Olympic cleans, a similar exercise, also do not involve full triple extension or hip hyperextension (the last one is debatable however). Overhead throws involve hip hyperextension but do not involve knee extension in the way it occurs in a vertical jump. Both of these exercises are great for building power, like the kettlebell swinging jump but do not mimic a vertical jump more than this exercise does. Full triple extension or hip hyperextension are not required for this exercise because the power is coming from the bottom of the range of motion, mostly, but not at the top as in a jump squat.
I believe this exercise is much more specific and useful than cleans or overhead throw, but not better than a jump squat. (that's complicated though so let's not discuss that, yes the clean is great for building front squat strength too, an overhead throw hits the hips well... arguing about the specificity of the exercise is probably meaningless, as long as you are jumping and getting stronger in a fashion similar to jumping and are consistent the marginal differences in different power building exercises are not too significant imo, so i'm not saying it's necessarily better but I would do it certainly over cleans or overhead throws anyday).
Due to the nature of the kettlebell, it swings forward upon jumping which allows the athlete to jump further more easily. Thus this exercise certainly is not training the toe-off portion of a jump in the same manner as a jump squat. However, the added momentum of the kettlebell allows the athlete to lift more weight just as in reverse band set ups for any lift, such as the squat. Thus that factor is somewhat irrelevant. Also since the loads upon landing are high, I am not swinging the weight forward with my arms, I am using the power in my legs to lift my body up and forward slightly without allowing the kettlebell to swing forward in a manner that is dangerous and prevents a safe landing and initiation into another jump.
4. How can this exercise benefit athletes more so than other exercises?
Amortization and rate of force absorption in the bottom position of a jump, and rate of force development and power development.
The hardest part about this exercise is not the jump, the hardest part is absorbing force properly in the "hole," at the bottom of the range of motion, the half squat position. Unlike a regular jump, the arms do not swing down as vigorously since there is a kettlebell in the hands, nor do they swing forward aggressively; the momentum of the kettlebell helps drive the body forward, but it is really the hips that are doing most of the moving of the weight. Since the arms cannot swing behind the body like a regular vertical jump, the legs aren't absorbing a s much force as possible, however with the right size kettlebell, it will be a challenge that can provide an overload that can improve vertical jump just as well as other exercises. The jumping portion of the exercise is not easy either; the athlete should expect to feel fatigue in all parts of the quads, as well as the glutes, in a manner that I would guess is similar to the overhead med ball throw.
With a dumbell the exercise I would argue is more difficult on the concentric phase, but easier on the eccentric force absorption phase. Balancing is also more difficult with the kettlebell upon landing.
5. Key tips about performing this exercise correctly:
Raptor mentioned something about me initiating a "pull the torso up" movement. I do not quite follow but this is how I perform the exercise so that it hits my legs and hips in a manner that is very specific to vertical jumping, and is MUCH better than just jumping vertically as someone else suggested (which will not provide the same training effect at all, or train the hips as well, but it would be decent like jump squats I suppose, again the swinging nature of the KB makes it GREAT for improving rate of force absorption and overall force absorption).
Progression of movements from start to finish:
1. start with kettlebell near hips, with arms touching the body, in a wide enough stance so that you can comfortably swing the arms behind you.
2. Bring hips back while simultaneously squatting down slightly and swinging KB behind body, but allow the natural backwards motion of the hips (hip flexion and the knee flexion) to assist the swinging of the kettlebell.
3. (this step is the key here) As you are transitioning from force absorption to production, with the kettlebell getting ready to swing forward and still being behind the body, jump using the hips first by swinging them forwards (as if you were going to do a hip hyperextension, JUST LIKE in a clean... so no there is no hip hyperextension but if the weight hadn't gone upwards or forwards, there WOULD HAVE been hip hyperextension so that is certainly irrelevant), the arms are not important at all as in an overhead throw or a vertical jump here (one reason why it's not maximal either). As the weight passes forward you should feel your hips acting first then the knees/quads, and the jumping should have happened.
4. Land then start over at 1.
Make more sense? It's really simple. You swing a weight behind you and jump forward with it. Since the KB swings, it helps the legs absorb more force and absorb it faster, while jumping with the weight. I do certainly focus on my hips almost as if they were a hinge joint, swinging them back and forwads throughout the movement. The forward swing probably has nice potentiation too because it makes you feel like you are jumping far when it's pulling you forward, almost like reverse band squats.
Much more than just a GPP exercise. If it was just GPP this exercise would train the anaerobic glycolytic system more than just the anaerobic system, like higher rep stuff. But it's not easy to do this for high reps even though it is submaximal. I can't do more than 6 reps without losing power with 24kg. I only did a few per set here as you can see. I think it can be GPP, but also more than that with the right loads.