You can do the best weight training or vertical jump program, but without enough recovery, you won't be able to realize your potential results. For example, if you train hard and consistently, but you go out for parties every night, you probably won't notice any results. Probably, your performance will decrease.
Or if you train like a Navy Seal or a French Foreign Legionnaire, you'll be in super shape, but probably you won't notice any gains in your vertical jump. It's due to the very high training volume, you simply don't let your body to recover from the training.
Both your muscles and your central nervous system needs recovery. During a training session you break down your muscles and nervous system. Your gains in muscle, strenght and/or plyometric ability happens during the recovery period, as your body tries to adapt the stress. It's true either you train for body building, strenght or athletic performance.
Here are two articles about recovery:
Recovery FAQ (Higher Faster Sports)
Central Nervous System Recovery (VerticalJumping)
