Tip #7 Build fast twitch muscle fibers, speed up slow twitch fibers. If you want to make leaps and bounds first we have to stop the bleeding! By this I mean no more slow-twitch inducing exercises like aerobics. Ask yourself does the sport your involved with require power or endurance? If you're a football player, gymnast, or sprinter (I think you get my point) you have NO need for aerobic training. When would you use it? The more you do long duration endurance training the more your muscles will learn oxygen consuming low output slow-twitch characteristics. You want muscles that are becoming more efficient at using the creatine phosphate energy system! So without sounding like I'm hating on aerobics here, you really need to focus on those high-intensity/short duration drills like sprinting. Interestingly enough sprinters have the highest % of fast-twitch muscles of all athletes. Who do you think jumps higher the sprinter or the marathoner? One final though on this subject is recent research in Nitric Oxide (NO) supplements seems to indicate that they speed up fast-twitch muscles and seem to make slow-twitch fibers act more like the fast as well. This may make this the ultimate in vertical jump supplementation possibly rivaling with Creatine Monohydrate!