Why are you doing plyometric exercises?

This is a post is actually a discussion post that I wrote for my master’s program, so it may be a little science heavy for some of you. Over the next 10 weeks I will examining in depth the implementation of plyometric exercises, and this was the first post of the quarter. I felt I got my point across pretty well and want everyone to consider the points about “why are doing plyometric exercises?” and “how are you doing them?”

Take home points:

1. Plyometric exercises are meant to work on the ability to move with more force and speed while performing high velocity movements.

2. High intensity plyometric exercise ,just like anything else that is high intensity, is anaerobic exercise (done with out the use of much oxygen) by nature. Additionally, it benefits anaerobic alactic performance the most (e.g. sprinting, jumping high, quick changes of direction, balance, running economy – endurance related – but not endurance).

3. STOP doing high intensity plyometric exercises for anaerobic lactic conditioning (breathing hard and burning legs)! More than likely, you are ingraining bad habits while under fatigue because because the quality of work SUCKS; therefore, you are using the exercises for the wrong reason.

Anyways, here is the post.  

Plyometric training is a training modality that is predicated on a series of activating and lengthening a muscle group followed by immediate shortening of the active muscles. This definition describes the stretch-shortening cycle (SSC), and over all plyometric training allows the SSC to increase power production either from enhanced speed of movement or force production or both. Baechle and Earle (2008) describe plyometric training using the mechanical and neurophysiological models and surmise that both models are at play in during plyometric training. These definitions are the basis for which coaches and trainers prescribe plyometric exercise. However, in my experience I have noticed many marketing campaigns and individual trainers use plyometric training as a modality for increasing endurance at all times of the year with a very wide range of clients with little to no individualism. This may be due to the over stated idea of train slow be slow, but force velocity continuum works in both directions: If you apply more force, you can create more power. If you get more speed, you can create more power that way too. The ideal way of going about it would be to do both with progression and periodization.

The promises of enhanced athletic abilities run rampant. Indeed, the research on plyometric training clearly support those claims, especially regarding sprinting and power production for adults and children (Rimmer & Sleivert, 2000; Meylan & Malatesta, 2009). Although, I do not believe volume and intensity are prescribed correctly or for the correct metabolic conditioning purposes by many products and by some coaches. The idea of simply taking a high intensity exercise modality that has been shown to enhance some athletic qualities, namely anaerobic qualities, and prescribe it for long amounts of time or for rounds of time to turn it into a “ all energy system conditioning session” seems unwise to me because there is no specific purpose.

What does the research say about using plyometrics under fatigue rather than power production other technique oriented goals such as reduced contact time (Rimmer & Sleiver, 2000)?

Moran et al. (2009) examined tibial peak impact acceleration and knee kinematics during drop jumps (DJ) from 3 varying heights (i.e. 15 cm, 30 cm, 45 cm) in a non-fatigue state and in a fatigue state, after an incremental treadmill run. The reason the author’s performed this study was to evaluate the premise that significant increases in tibial impact accelerations will increase the risk of injury. The authors noted that “excessive” impact accelerations have the potential to cause an assortment of injuries. It was hypothesized that lower drop heights would produce greater relative tibial impact accelerations compared to higher drop heights because as the drops get higher the neuromuscular system’s ability to control tibial impact acceleration is reduced regardless of being fatigued or not. Moran et al. (2009) revealed that in a fatigued state impact acceleration was increased by 32% for the 15 cm drop, 17% for the 30 cm drop and 2% for the 45 cm drop; therefore their hypothesis was confirmed. Over all the study revealed that as drops get higher there is more danger for injury regardless of fatigue. The main take away is that in a fatigued state the lower drops caused significantly more strain to the lower extremity than when un-fatigued (Moran et al., 2009, Figure 1).

Moran et al. (2009) kept repeating the principle of specificity regarding athletes’ need to produce power even in a fatigued state, and while I can definitely understand what they are saying, I do not agree with the idea of purposefully training/practicing at a high intensity in a fatigue state. Is the goal to practice not getting injured? I can get on board with some technique work after working on the “money exercises” for the day, but not an entire day dedicated to wiping an athlete out and then seeing how far (i.e. time/density) he can push into it. The actual sports athletes play do not even do that. If someone is fatigued they are subbed out; in something like soccer on the professional stage if they get subbed out they do not come back in!  In the simplest of terms it always comes back to “what are you doing “this” for; what is the purpose?” Plyometric exercises are known to be great for explosive movements like jumping, sprinting, agility and balance, and quickness and reaction time (Makovic, 2007; Rimmer & Sleiver, 2009; Brown & Ferrigno, 2005) and for development of children’s fundamental movements (Johnson, Salzberg, & Stevenson, 2011), I do not see much in the way of performing an assortment of specific and high-intensity plyometric exercises for the purpose of strictly trying to tire someone out.

References:

Baechle, T. R. & Earle, R. W. (2008). Essentials of strength training and conditioning. Champaign, IL: Human Kinetics.

Brown, L., & Ferrigno, V. (2005). Training for speed, agility, and quickness. Champaign, IL: Human Kinetics.

Johnson, B. A., Salzber, C. L., & Stevenson, D. A. (2011). A systematic review: Plyometric training programs for young children. Journal of Strength and Conditioning Research, 25(9), 2623-2633.

Markovic, G. (2007). Does plyometric training improve vertical jump height? A meta-analytical review. British Journal of Sports Medicine, 41, 349-355.

Meylan, C & Malatesta, D. (2009). Effects of in-season plyometric training within soccer practice on explosive actions of young players. Journal of Strength and Conditioning Research, 23(9), 2605–2613.

Rimmer, E., & Sleivert, G. (2000). Effects of a plyometrics intervention program on sprint performance. Journal of Strength and Conditioning Research, 14(3), 295-301.

 

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