Question: I am a high school athlete who would like to increase my vertical jumping ability for basketball. Would you discuss this topic in your column? I think that there are athletes in many sports who would like to be able to jump higher. Thank you.
Answer: Actually, there are several factors that play a role in your vertical jumping ability. The first is muscle strength. However, according to a review of research on jumping in the Gatorade Sports Science Exchange (No. 6, Volume 7, 1994), whether or not jump performance will be improved by increasing muscle strength depends on how strong the athlete is before beginning the strength program. Thus, vertical jump performance improves markedly following strength training in people who begin training with only average strength but very little in people who are already very strong in the muscles that contribute to jumping.
The second factor relates to how fast you can contract your muscles. For example, a very strong individual who tried to smoothly execute a vertical jump movement over a period of 10 seconds would never even leave the ground. It is not surprising to me, understanding the principle of "specificity of training," that squat training with heavy loads is not a very effective way to increase vertical jumping ability. In fact, such training might even reduce the ability of the muscles to develop force rapidly, especially if the athlete was already very strong.
A third factor in jumping well relates to your ability to coordinate the movement effectively. The ability to create power is affected by the interaction of all the muscles that are involved in any movement pattern. When the primary mover muscle contracts, muscles on the opposite side of the joint must completely relax. That is why certain training techniques are better than others - they help muscles coordinate for maximum performance.
So, what type of exercise should you do to develop jumping ability?
The answer to this depends on how strong you are in the jumping muscles. If you are not very strong, you should begin a program to develop strength using traditional squat-type exercises with fairly heavy loads. If you are stronger (and as you gain strength), you can do some type of loaded, explosive jump training to increase the ability of muscles to contract faster and to learn coordination.
Use fairly light loads - about 30 percent to 60 percent of your 1-RM - so that you can complete the jump movement in a rapid and accelerative manner. The "counter-movement" type jump would have you perform a rapid crouch, and then jump as high as you can with about 30 percent of your 1-RM.
You can also use "plyometric" training to increase the overall neural stimulation of the muscle. However, jumping from a platform should not be done until your muscles are strengthened by regular weight-training techniques to the point that you can squat at least 150 percent of your body weight.
Remember, to jump well, you have to jump (specificity principle). So, be sure that you use a combination of training methods, as well as jumping with body weight only (e.g., rebounding drills, etc.) as part of your regular practice routine.