I have to admit...I bought this for my 5 year old son, but I found it to be just as enjoyable! Setup took a matter of minutes before he was launching his first rocket in the air. he was impressed with the THUMP followed by a dissapearing act as it launched into the sky. After he had a few tries it was my turn, I assumed it would not handle my 200lb frame very well so I started light and worked my way up to an all out double foot stomp that left craters where I landed. The SQUEEEEEL from my son as the rocket nearly "went to the moon" was priceless. We lost a few rockets that day to rooftops, damage from landing on pavement, and one down a difficult to repeat sewer drain. I advise to have the little ones wear safety ... full review
Asher Price, a reporter at the Austin American-Statesman, spent a year of his life trying to find out and chronicled his quest to jam on a regulation hoop in the book The Year of the Dunk, which comes out in May. Price, who played coy about whether he was able to achieve his goal, spoke to Science of Us about what a rec leaguer would need to do to fly like a pro. (Spoiler: lots of squats and alley-oop attempts.)
Yet, rate of force development is likely less important for vertical jumping than for faster athletic movements, such as sprinting. This is because the time that is available for force production is *ten times* longer in the vertical jump than in sprinting. Sprinters often take their foot off the ground before their lower body muscles have achieved maximum force (which takes approximately 150ms), but this early period of rising force production plays only a very small role during vertical jumping.
This is why using a slightly deeper countermovement often increases jump height, because the larger range of motion allows the muscles to exert force for a longer duration of time before take-off. Jump height *can* increase even though the force produced is almost always smaller. (Force is smaller when the countermovement is deeper partly because shortening through a longer range of motion leads to a faster contraction velocity, on account of the force-velocity relationship, and partly because the leverage of bodyweight on the lower body joints is larger with a deeper countermovement).
Finally, to make things even more complicated, it is likely that the roles of the lower body muscles may differ according to if: (1) the jump is maximal or sub-maximal, (2) long-term training has occurred, and (3) the individual has a “hip-dominant” or a “knee-dominant” technique. Indeed, the vertical jump is more dependent upon the hip extensors in maximal jumps, compared to in sub-maximal ones. And after long-term jumping training, the increase in the amount of work done in the jump by the hip extensors is related to the increase in height, while the increase in the amount of work done by the knee extensors is not.
Vertical jumps are used to both train and test for power output in athletes. Plyometrics are particularly effective in training for power output, and include vertical jumps of different types in their protocol. In one recent study, training with plyometrics (which included continuous vertical jumps) was shown to improve jump height and boost vertical jump performance to similar degrees in combination with very different resistance training protocols, indicating that the plyometric jumping contributed to the increased jump height more than resistance training. Research into plyometric jumps found vertical jumps to be among the highest in terms of muscle recruitment (as measured by electromyography), power output, and ground reaction force produced. Fatigue has been researched in athletes for its effect on vertical jump performance, and found to decrease it in basketball players, tennis players, cyclists, rugby players, and healthy adults of both genders.