By Coach Kristen
Plyometrics is a fancy way of saying “jumping movements” in regard to exercise. In other words, your body leaves the ground. In CrossFit, you may recognize these movements as box jumps, squat jumps, jump lunges, or the plyometric pushup. Love them or hate them, these exercises are important and can not only help improve your cardio fitness and endurance, but can also have a big impact on your Olympic lifting. Let’s break it down.
Fast-Twitch Muscle Fibers
Fast-twitch muscle fibers are your body’s strongest, largest fibers and contribute to absolute strength. (In contrast, slow-twitch muscle fibers are typically used in endurance training.) These fast-twitch muscle fibers are strengthened and made more efficient through plyometric movements. So how does this translate to your success in and out of the box?
The stronger and more efficient your fast-twitch muscle fibers (remember, we increase this by plyometrics), the easier you can recruit (use) these fibers in your Olympic lifts and heavier weight sets. Your body can better recognize the need to engage those muscles to help you do what you are asking it to. All of this increase in strength and efficiency translates into an increase in power as well. Power is simply converting strength into speed. Ever hear the term “speed under the bar”? Or what about “fast elbows”? Ummm…yeah. We hear that a lot. And for good reasons. Having this power (speed) allows you to again, perform your Olympic lifts in a better / faster / bigger way. Another way of looking at is:
Stronger Fibers à Faster Muscle Contractions à Increased Power
It may seem counterintuitive that plyometrics can reduce the occurrence of injury versus increase it, but it’s true. As your muscles become stronger and more powerful, you need stronger, more supportive tendons. (Tendons are the flexible, but inelastic cord of tissue that attaches your muscles to your bones.) Plyometrics not only strengthen the tendons, but they also improve their elasticity. As you are lifting the barbell, or even doing burpees, these tendons need to respond just as efficiently as your muscles. When you are doing plyometric exercises, you can improve the function of these tendons in a controlled way, therefore decreasing the propensity of injury when doing non-plyo movements.
It makes sense that if plyometrics increases the efficiency of producing muscular force (strength), muscular endurance is also improved. The body learns to increase production and reduce energy expenditure. Want to improve your performance in some of the more “enduring” workouts or benchmarks? Plyos can help with that. Studies have also shown that endurance athletes (long distance runners, triathletes, etc) perform better and recover faster when including plyometrics in their training.
Ok so maybe increasing your bone density isn’t as sexy as increasing your deadlift, but it’s still important. For women AND men. And if you’re able, jumping, or plyometrics, is the single best way to increase bone density. Introducing stress to bones in the form of jumping prompts them to add mass – or at the very least, reduce the rate at which they lose mass as people age.
So basically…the question you should be asking yourself isn’t “why we jump”, but “why shouldn’t we jump”? As long as your current health permits some form of plyometrics – go for it! And if it doesn’t, or if jumping makes you uncomfortable, start small. There are always modifications to reduce the impact on your joints until you are ready for the next level.
Happy jumping, friends!