They are key at developing explosiveness and athleticism and should be an important component of a well balanced strength training program. You will need this explosiveness when trying to build strength for the heavy barbell lifts like the bench and deadlifts. Plus they are vital in developing general physical preparedness and work capacity that will allow you to increase your training volume as you progress.
There are a ton of jump variations you can do, but for most of you these 3 will do the trick.
#1: Box Jumps
Most gyms have some sort of box you can jump on. Nothing complicated here. Just jump onto the box. Jump higher and higher as you progress.[tube]http://www.youtube.com/watch?v=WPMqixXXsIA[/tube]
#2: Hurdle Jumps
This simply means jumping over things. In a standard gym sitting, you can jump over benches or boxes. If you are training outside, this is where park benches and other objects come into play.
#3: Long Jumps
These are the most advanced because they require a great deal of explosiveness and athleticism already. You have to be very careful on cushioning your landings, and be aware of the pounding your joints, knees, and legs take in the process. I do not recommend this for beginners, but as you progress, you can work these in. Make sure your technique is sound and you have a strong core before doing these.
Knowing you need to focus on these 3, how do you incorporate them into your training?
I’d treat them just as any other exercise. They count towards your overall training volume and the higher/further you jump counts towards your training intensity. The higher/further you jump, the less reps per set you should perform. Fifteen or less total reps split up among 3-5 sets would work.
I tend to work my jumps in at the end of my workouts or after my big compound lift. If I’m jumping for a low vertical, I’ll use them as a conditioning finisher. If I’m going for high verticals, I’ll make them a focal point of my training after heavy squatting for example. One thing you can do to work in jumps mid-training is superset heavy squats with box jumps to really build up your explosiveness and leg strength.
One important distinction here is to not treat jumps as high-intensity cardio alone. While they do make a kick ass conditioning exercise, you also need to treat them as a way to develop explosiveness. The more explosive you are, the better you will perform on your big lifts. That’s why it’s important to test yourself and continually try to jump higher and further, not just for reps and time.
As far as frequency goes, you could jump a couple of times a week. Work in your plyos on the same days you are training lower body if you can. If you must jump the day after lifting heavy squats or deadlifts, crank your intensity (height/distance) down to no more than 75% of your max effort. Just like lifting weights, jumping for prolonged periods at 100% max effort can be stressful on your central nervous system (CNS).