Does Gaining Muscle Mass Affect Your Vertical Jump?

[EJ50]

I've been bothered about this for a while now. As a volleyball player, I am constantly looking for ways to increase my vertical. So, my question is:

Will an increase in muscle mass decrease my vertical? On one hand, I am getting stronger and therefore should be able to push harder off the ground. On the other hand, obviously, it makes sense that one would not be able to jump as high with greater mass.

Furthermore, does it matter where on my body I am putting the muscle? I would like to work on my upper body, but if the increased muscle mass lowers my vertical, then I'm not sure that that is best for me.

I've posted this question in a few different places to see what different answers I get from physicists and body-builders. I imagine the responses here would be a tad more eloquent and professional.

Any response would be greatly appreciated. Thank you in advance

 

[andrewkirk]

The right sort of muscle in the jumping muscles - mostly the quads - should increase your jump. The right sort for the occasional jump is fast-twitch rather than slow-twitch, but I don't know to what extent one can control the development of one vs the other. The extra mass of jumping muscles should be far more than offset by the extra explosive power.
In contrast, most other muscle will be a hindrance, as it's just dead weight.
There will be an optimal amount though. Muscle bulk is not the same as muscle strength, and speed of movement is important as well. Being able to squat 200KG slowly is not the same thing as lifting one's own 70kg body in an explosive movement. Bulging body-builder muscles would probably be counter-productive, even in the quads.
Why not have a close look at the legs of top-level volleyball players?