Often times, basketball players have used one-leg jumping their whole life. It's just a much more natural movement because it's used every single time someone goes for a layup. On the other hand, volleyball players are often used to two-foot jumping because it is the most common way to jump when trying to block or spike. So, if you have all the suppositions to be a great two-foot jumper, but you get barely of the ground this way, it's probably because of a lack of technique.
The way Arthur J. Daley and the other spectators at the Y felt when Fortenberry dunked—that’s how fans at the Oakland Arena felt on Feb. 12, 2000, when Vince Carter shoved his forearm into the rim and swung there by his elbow. What only the initiated noticed about Carter’s dunk was that if you froze him during his approach, he looked like Bob Beamon. Carter long-jumped some 12 feet, right foot leading the way, before landing for a nanosecond and blasting off into his two-footed ascent.
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.
Strength exercises include slow, controlled movements like squats, lunges, and weighted step-ups. Power exercises require explosive, quick moves like those needed for plyometrics and power cleans. Plyometrics are explosive bounding, hopping and jumping drills that blend strength and speed. Finally, practicing maximum vertical jump will increase vertical jump.
The record for the most WNBA dunks belongs to Brittney Griner. As a high school senior, she dunked 52 times in 32 games and set a single-game record of seven dunks. As a standout at Baylor University, Griner became the seventh player to dunk during a women's college basketball game and the second woman to dunk twice in a single college game. In her WNBA debut on May 27, 2013, Griner dunked twice, and as of 2014, has five WNBA dunks, including the first in a playoff game (August 25, 2014).
A second, more efficient and correct method is to use an infrared laser placed at ground level. When an athlete jumps and breaks the plane of the laser with his/her hand, the height at which this occurs is measured. Devices based on United States Patent 5031903, "A vertical jump testing device comprising a plurality of vertically arranged measuring elements each pivotally mounted..." are also common. These devices are used at the highest levels of collegiate and professional performance testing. They are composed of several (roughly 70) 14-inch prongs placed 0.5 inches apart vertically. An athlete will then leap vertically (no running start or step) and make contact with the retractable prongs to mark their leaping ability. This device is used each year at the NFL scouting combine.