All data were analyzed according to the intention-to-treat principle. Differences in the primary outcome were analyzed with the use of an unadjusted chi-square test. Results are presented as absolute and relative risks and 95% confidence intervals. Kaplan–Meier curves for estimated survival were compared with the use of a log-rank test. A Cox proportional-hazards regression model was used to evaluate the influence of potential confounding factors on the outcome (factors were selected if the P value in the univariate analysis was <0.20).

Exactly which muscles are most important for improving the vertical jump is still relatively unclear, and may differ between individuals. Clearly, the spinal erectors, hip extensors, quadriceps, and calf muscles are all involved in the jumping movement, and the hip extensors and quadriceps are likely the prime movers, but which of the hip extensors is the primary muscle is very unclear. Importantly, since force production is required right up until take-off, the lower body muscles must produce force from moderate through to short muscle lengths, which differs from the barbell back squat exercise.
4. verb By extension, to achieve a forceful, dramatic success or accomplishment handily or easily, often at the expense of someone or something else. Sometimes hyphenated. The incumbent president has slam dunked his opponent in every televised debate so far. If we can slam-dunk this proposal, we'll get enough funding to see us through to the end of next year.
To begin, go up without a ball first. This will give you a great idea of where you’re at and just how close you are to being able to dunk. For beginners, you should focus on dunking with one hand. Your other hand should stay by your side to balance your body while you’re in the air. The two-handed dunk is awesome, but is surprisingly more of an advance dunk and should be an approach you build up to as you work on your dunking.
Keep your upper body straight and your arms relaxed at your side. Extend your left leg straight out behind you with a slight knee bend. Place your right leg in front of you with your knee bent at a 90-degree angle and your thigh parallel to the floor. This is your basic lunge position. From this position, slightly lower your entire body, and jump to the opposite lunge position with your right leg extended behind you and your left leg in front of you. Repeat 25 jumping lunges in a row for three sets with a 1-minute break between sets.
Because jumping ability is a combination of leg strength and explosive power, jumping can be developed in the same fashion as any other muscular activity. The ultimate limit to how high any athlete can jump will be determined to a significant degree by the distribution of fast-twitch versus slow-twitch fibers present in the muscles of the legs. This distribution is a genetic determination. Fast-twitch fibers are those whose governing neurons, the component of the nervous system that receives the impulses generated by the brain to direct muscular movement, fires more rapidly, which in turn creates the more rapid muscle contractions required for speed. As a general proposition, an athlete with a greater distribution of fast-twitch fibers will be able jump higher than one with a preponderance of slow-twitch fibers.
Perform the routine every second day to give your body a days rest in-between workouts. This means that on week one you’ll be training 4 times a week, week two you’ll be training 3 times per week, and on week three you’ll be training 4 times per week. That ends up being 11 workouts per phase for a total of 33 workouts in the program. Also, during this program you will be taking one week off between each phase to let your body completely recover. You need to give your muscles time to fully repair in order to grow stronger and more explosive.