High Reach Jumps – with your feet shoulder width apart, bend down into a comfortable squat position and then jump up as high as you can reaching for the sky! This drill is great to do under the basketball goal or near a wall so you can have a visual of how high you’re jumping – or how low you jump once you start getting tired. Try to reach the same height through all your reps.
An important component of maximizing height in a vertical jump is attributed to the use of counter-movements of the legs and arm swings prior to take off, as both of these actions have been shown to significantly increase the body’s center of mass rise. The counter-movement of the legs, a quick bend of the knees which lowers the center of mass prior to springing upwards, has been shown to improve jump height by 12% compared to jumping without the counter-movement. This is attributed to the stretch shortening cycle of the leg muscles enabling the muscles to create more contractile energy. Furthermore, jump height can be increased another 10% by executing arm swings during the take off phase of the jump compared to if no arm swings are utilized. This involves lowering the arms distally and posteriorly during the leg counter-movements, and powerfully thrusting the arms up and over the head as the leg extension phase begins. As the arms complete the swinging movement they pull up on the lower body causing the lower musculature to contract more rapidly, hence aiding in greater jump height.[5] Despite these increases due to technical adjustments, it appears as if optimizing both the force producing and elastic properties of the musculotendinous system in the lower limbs is largely determined by genetics and partially mutable through resistance exercise training.[6][7]

An alley-oop dunk, as it is colloquially known, is performed when a pass is caught in the air and then dunked. The application of an alley-oop to a slam dunk occurs in both games and contests. In games, when only fractions of a second remain on the game or shot clock, an alley-oop may be attempted on in-bound pass because neither clock resumes counting down until an in-bounds player touches the ball. The images to the right depict an interval spanning 1/5 of a second.
As an athlete pushes off the ground, he or she must overcome his/her own body weight. The lighter the athlete, the less force is necessary to do this. Imagine trying to jump as high as you can and then immediately repeating this same test wearing a 20-pound vest. It's obvious that the second jump will be much smaller. Now, imagine how much higher you could jump if you were 20 pounds lighter.
Janik was available by text whenever I needed him, like my very own dunk training app. The important thing, he said, was to work out hard and smart. When my knees or back were sore, he advised lowering the weight for a few sessions and eliminating depth jumps. "Listen to your body," he told me. And I did: I took a day off here or there if I needed it; I added more weight when I felt good. When, after five weeks, I started to worry that I wasn’t going to dunk again, he kept me motivated. "Leg strength is the key. Squat deep. Ass to grass," he told me, unsympathetic to the known fact that squats are fucking terrible.
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.[8][9][10] 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.[11][12][13]