"Of all the variables I’ve mentioned up to this point, you’re probably most surprised by this recommendation. Fast concentric tempos (the lifting portion of the movement) activate high-threshold motor units quicker than slow training. In fact, a trainee can achieve extremely high levels of tension within a muscle utilizing a very light load, if the speed of execution is fast enough. For further info on this statement, refer to Science and Practice of Strength Training by Vladimir Zatsiorsky.
Here’s a statement that I’ve learned to make with utmost confidence: I hate Super Slow training. Our bodies weren’t designed to perform slowly, so I don’t train it that way. I feel the future of training lies within extremely fast tempos.
But don’t read too much between the lines. I recommend that trainees execute tempos at varying speeds. Even though I usually prescribe a tempo as fast as possible, each load will mandate a different tempo. For instance, if I tell a trainee to lift a 3RM load as fast as possible, it'll be slow. If I tell a trainee to lift a 20RM load as fast as possible, it'll be very fast. Viola! One recommendation leads to different responses. Pretty cool, huh?
Bottom line: Perform concentric actions as fast as possible, and keep eccentric (negative) phases under control (1-3 seconds of lowering)."
Compliments of Chad Waterbury and T-nation. Chad is a strength and conditioning coach. In my mind, one of the best strength and conditioning coaches of all times.
http://www.t-nation.com/findArticle....4-068-training