Karel and I have been doing Plyo's for a few years now. I recommend that all athletes do plyometrics, if they are injury-free and have no existing conditions that may be affected from plyo's.
I realize that jumping off and on blocks or bounding on one or two feet can be a bit intimidating. Depending on your current fitness level and experience with plyometrics, every athlete should be smart when starting something new with your body. With a little direction and help from exercise professionals, plyometrics are beneficial for athletes of all levels.
I often hear athletes saying that they are worried about hurting their ankles or falling when doing plyometrics. Sure, there is certainly a risk for injury if you are overambitious when trying plyo's for the first time. Even if you are physically fit as a triathlete or runner, you can't let your self-confidence get the best of you.
I see a big movement towards barefoot running and I just cringe when I see runners running without shoes (or with running "free" shoes). In my eyes, through evolution and changes in body structure, our ankles are not strong enough to support the body without running shoes. I know it is sad that our weak little ankles, supporting our entire body frame, may not be able to run without running shoes but in my eyes, we need to train the body to be strong enough to walk without shoes, before we can run without shoes. I love walking around without shoes but when it comes to training, I believe in strengthening the body, starting with the core, in order to build strong muscles and strengthen the weak or small muscles.
If you think you can't do plyo's, go into a YMCA and take a look at a 10am Step Class. At all levels, you will see individuals of all fitness abilities. From 20 year old's to 80 year old's, step classes are for anyone. And if you ask me, step classes are very similar to plyometrics. There is a lot of turning and moving and lots of stepping. What a great way to work on balance as well as strengthening the muscles, lungs and heart.
I try to do plyo's once a week (with plyo's being my "primary" cardio workout for the day) and I like to strength train with weights and/or machines (depending on the day, the previous workout and/or upcoming workout) 1-2 times per week. At a minimum, I am doing some type of full body strength work, at least twice a week. Plyometrics are exhausting and require no more than 30-40 minutes for an effective workout. I believe in circuit training for strength training, so aside from 10-15 min of core on a daily basis, I spend no more than 20 min strength training, per each session.
Here are two great links for some sample plyometric exercises. Remember to warm-up before starting and to start slow. Don't feel rushed when you are performing the exercises and give yourself enough rest in between exercises or sets.
Here is the workout that Karel and I did on Tues:
20 min cardio warm-up (I did Elliptical, Karel ran to the gym)
1) 30 x up and over squats (straddle step in a wide lunge and place one foot on top of step. Always keep one foot on the step as you step down with rt foot, back to center and then down with left foot. Do a squat when stepping down from the step with one leg).
2) 30 high knees (we did them on the BOSU but you can do them on the floor as well
3) 20 (10 each way, then turn around), double-leg jumps.
4) 20 (10 with rt, then turn around, 10 with left), single-leg jumps (be careful!).
5) 20 deep squat jumping jacks (hands behind the head, moving the legs like a jumping jack but going to a squat when legs are apart, then jump up with the legs together).
6) 30 push-ups (I used the opposite side of the BOSU, Karel did the push-ups with a medicine ball, moving the ball from rt. hand to left hand, after each push-up).
7) 20 partner leg drops (person on floor grabs ankles of other person, who pushes down the legs of partner. Partner doesn't let legs hit the floor)
8) 20 partner medicine ball sit-ups (stand on partners feet and toss medicine ball as partner slowly lowers body to the ground. Partner tosses the ball back to standing partner as he/she is sitting back up)
We did this circuit 4x's. We did 2 continuous circuits. Resting a minute and then repeated the 2 circuits.