ColumbusSports.com

If you remember last week, I talked about using eccentric muscle training to improve the results of your exercise program.  If you have a really good memory, you remember me saying that generally, lifting at a slower tempo is better.  The key would here is “generally”.  Enter in plyometrics.  Plyometrics is essential for those that require fast reaction times for explosive events. 

Box jumps are a form of plyometrics.

“What is plyometrics Dan?”  Good question.  Plyometrics is another name for reactive training; it requires an eccentric deceleration, an isometric stabilization, and a concentric acceleration.  So what does that mean? 

Let’s take a look at an example of jumping off one box and then jumping back up onto another box.  When you jump off the first box, as your feet hit the ground, you start to bend your knees and your body sinks toward the ground as it tries to slow itself down and cushion itself from the jump.  This slowing down is the eccentric muscle contraction part.  (Do you remember talking about the different types of muscle contractions?)  Good thing the body knows to slow itself down; otherwise, you’d slam into the ground.  Ouch!

After your body slows itself down, there’s a moment where it stabilizes itself.  This is considered the isometric contraction phase of the jump.  Once your body gains the stability it needs, you explode up and jump up onto the next box (the concentric acceleration phase).

Putting all three of these phases into one exercise, such as a box jump, gives you plyometrics.  There are all sorts of different plyometric drills that can be done, anything from ladder drills, to skips, to jumping drills, etc.  The important thing to remember when doing plyometrics is to make sure they’re explosive.  Unlike slow eccentric weight lifting, you want to perform the different contraction phases of plyometrics as fast as possible.  The goal of plyometrics is to decrease the amount of time it takes for your body to slow itself down and explode back up (decrease the stabilization phase).

So why is plyometrics such a good form of training when it comes to improving areas such as reaction time, vertical jump, accelerating off a starting line, etc.? 
 
When you talk about improving reaction time, you essentially are looking at improving the efficiency between your nerves and muscles.  A good example of this is balance.  If your balance is poor, then your nerves aren’t telling your muscles fast enough that they need to contract to keep you balanced; there’s a lag in the time it takes for the nerve impulses to tell your brain to send more nerve impulses to contract the muscles.  It’s basically like watching news reporters reporting over in the Middle East.  There’s a lag in the time from when a question is asked at the news station until they hear it and answer it.

Remember, speed is king when working with plyometrics.

Plyometrics improves the efficiency of the nerves and muscles communicating back and forth with each other; it also increases the elastic properties of muscles.¹ This concept is very important to understand.  Your muscles have elastic properties similar to a rubber band or spring.  The amount of acceleration you get out of pushing off a surface depends on the amount of elastic energy that’s built up in the muscle as a result of the eccentric deceleration phase of plyometrics.  Just like a rubber band, the more you pull on the band, the more elastic energy is built up.  The more elastic energy built up, the farther the rubber band will fling off your finger.  The same can be said with plyometrics.  The more elastic energy that is built up through the eccentric phase of a jump, the more explosiveness there will be for the concentric acceleration phase and the faster you’ll explode up.

Another thing to understand, if the nerves and muscle aren’t working efficiently, the balance required to remain stabilized between deceleration and acceleration won’t be there.  A good stability base needs to be established in your training before moving on to reactive training/plyometrics. 

Also, if a significant amount of strength isn’t present in your muscles, you won’t be able to develop the power you need for the explosive phase of plyos.  Make sure you address balance/stability and strength before moving into reactive training. 

Remember, speed is king when working with plyometrics.  If you do plyos with a slow speed, you’ll develop slow reaction times.  If you try to get through every contraction phase of plyos as fast as possible, you’ll develop more explosiveness.  More explosiveness means a better vertical jump, a faster time off the blocks, quicker cuts on the field, faster bat speed, faster jumping out of the way of a runaway kid on a bike, and so on.

It’s important to realize that this type of training is pretty intense, and if you ever experience signs of overtraining such as decreased balance, vertical jump, or explosiveness, compared to what you normally have, it’s a good idea to stop and allow your body to recover over the next few days or even weeks.
 
Plyometrics are only one phase to a training program.  Remember, workout programs should be progressive so that your body’s always experiencing new things.  Staying in one phase of a training program for too long can lead to poor results and even injury, and when dealing with reactive training, a fitness professional is the way to go because it’s so complex.  Also, checking with your doctor before starting a workout program is a grand idea.

References:

¹ The National Academy of Sports Medicine (NASM), 2005.

Note: Your Live Trainers was featured in The Cincinnati Enquirer this week.  

Dan Falkenberg is the co-founder of Your Live Trainers. He can be reached at DanFalkenberg.com.

Tags: athletic performance, exercise selection, program design, youth sports