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Plyometrics : Do plyometrics work for the upper body?
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Plyometric training is now a common element of elite sports training programmes. But, while its beneficial effects on the lower body are well documented, there is some doubt over how useful it is for upper body force development, writes Raphael Brandon.
First documented as an effective training method by Soviet coaches in the middle of the last century, the main purpose of ‘plyometrics’ is to increase the rate of force development, the key ingredient of power. By contrast, the main purpose of heavy weight training is to increase total force production – ie maximum strength.
It is logical for athletes to seek to increase the rate of force development, because most sports involve fast movements for which forces must be generated quickly. The foot-to-ground contact time in the high jump, for example, is less than 100 milliseconds, yet it will take around 500msec to generate maximum force. For elite performance, an athlete’s rate of force development is often more important than the maximum force he or she is able to generate.
The other advantage of plyometric training is that it comprises jumping and throwing movement patterns that involve a stretch-shortening cycle (SSC). The muscle and tendons are first lengthened with an eccentric load – eg pulling back your arm to throw a ball – which may increase the subsequent concentric force production and/or allow release of elastic energy – eg as the arm accelerates forwards to release the ball. Since most sporting movements involve sprinting, jumping and throwing SSC movements, plyometric training can be viewed as highly sport specific.
Plyometric training for the lower body nearly always takes the form of various jumping movements, such as hopping, bounding and drop jumps, while upper body plyometrics often uses medicine ball throwing movements. Both of these types of movements have been well documented (1). However, research into the effectiveness of plyometric training is less readily available than coaching manuals for the relevant exercises.
One study that raises some questions about the effectiveness of medicine ball training comes from Australia’s Southern Cross University (2). Researchers allocated 24 junior baseball athletes into three groups, one performing upper body heavy weight training, the second using upper body medicine ball exercises and the third acting as non- exercising controls.
They found that while the plyometric training – in the form of medicine ball exercises – improved strength but not baseball throw velocity, heavy weight training improved both parameters. This suggests that upper body plyometrics is not effective at boosting rate of force development.
However, these junior baseball athletes had not previously used strength training and the findings might have been different for strength- trained athletes.
Further investigation at the same institution (3) compared the different effects of upper and lower body plyometrics, this time using 41 previously trained subjects, who were assigned to weight training or plyometric training or a control condition for eight weeks.
The researchers tested their subjects’ lower and upper body strength, rate of force development and power before and after the training programme. They found that plyometric training increased leg muscle power but not the rate of force development and power in the upper body.
The effectiveness of plyometric exercises for increased leg power was established by a previous study from the same researchers (4). They found that 10 weeks of drop jump training improved counter-movement jump (CMJ) performance by 10% in previously strength-trained subjects, implying that their rate of force production, or power, had increased.
In summary, the research mentioned so far confirms the beneficial effects of jumping plyometrics for the lower body but not the effectiveness of medicine ball exercises for the upper body.
One explanation for this distinction could be that the relative loading on the legs of a jump is greater than that of a medicine ball throw on the arms.
During a jump exercise the whole mass of the athlete – say 75kg – is moved. The force required to produce this movement comes from the leg muscles, mostly the quadriceps (thighs), gastrocsoleus (calf) and gluteus maximus (buttocks).
During a medicine ball throw the mass of the ball is moved – a 5kg ball being the weight most commonly used by athletes. The force required to produce this movement comes from the arm muscles, mostly the pectorals, deltoids, triceps and latissimus dorsi.
The difference in load between jumping and throwing in this example is 15-fold. This does not mean that the leg muscles are 15 times stronger than the arm muscles. Leg press repetition maximum scores in well trained male athletes are usually 2.5-3.5 times body weight, while bench press rep max scores are 1.25-1.75 times body weight, suggesting that the legs are about twice as strong as the arms. However, in medicine ball exercises the arms are moving significantly less than half the mass moved by the legs in jumping exercises. Thus, the relative load on the arms is less than that on the legs. Theoretically, then, if you use a typical weight of medicine ball, you will not be training the upper body as hard as you train the lower body with jumping.
This conclusion is supported by recent research (5). Subjects were tested for shoulder external rotator and elbow extension power before and after a six-week medicine ball throwing programme, using one specific exercise involving both sets of muscles. They had to stand, catch a 1kg ball in one hand with the arm horizontally abducted and extended, adduct and flex the arm across the body (eccentric phase) and then rapidly abduct and extend the arm releasing the ball. This throwing movement involves the external shoulder rotators (the posterior shoulder muscles) and the arm extensors (the triceps).
Retesting revealed a significant increase in elbow extensor power, but not in external rotator power. The researchers suggested that the greater muscle mass of the posterior shoulder by comparison with the triceps meant that the training was more effective for the latter than the former.
Evidence that a heavier load upper body plyometric exercise can be effective has come from Canadian research (6). The researchers tested female subjects on a medicine ball for chest pass distance (the distance the ball can be thrown forward, measured from the athlete) and on a chest press for strength.
They then performed either a normal press-up exercise (from the knees) or a plyometric version of the press-up, as illustrated below.
The plyometric press-up
With plyometric press-ups, you start by kneeling upright, then fall forward onto the hands, absorbing the weight using the press-up lowering movement (eccentric phase), then rapidly propel yourself upwards and back to the start position (concentric phase) with a ballistic movement.
On retesting, the researchers found that both chest press strength and chest pass distance increased for the plyo press-up group. The fact that they improved their performance on the throwing test implies that they had improved the rate of force development in their upper bodies.
During the plyometric press-up a significant percentage of bodyweight – about 40% – is moved. The force for this movement comes from the pectorals, anterior deltoid and triceps muscles. For an adult weighing 75kg, this means that the upper body musculature is working against about 30kg of weight – significantly more than with commonly used medicine ball weights.
The implication of this research is that, if plyometric exercise is to be effective for the upper body, a load greater than a medicine ball must be used.
The plyometric press-up has been shown to provide such an effect for the common forward horizontal throwing movement (the chest pass). For the overhead throwing movement, which is specific to many sports, it may be worth using very heavy medicine balls or ‘powerbags’ (cylindrical sand-filled sacks with handles to hold onto).
I would suggest 15-20kg as a good (male) training load for the overhead throw movement. With this movement, you stand up, take the weight up and behind the head (eccentric phase), then rapidly pull the arms down and forward, releasing the ball or bag.
When performing such upper body plyometric exercises as the plyo press-up and overhead throw, I recommend 3-5 sets of 5-10 repetitions. To promote a high rate of force development, it is important to take 2-3 minutes rest between sets. This ensures that you do not exhaust the fast- twitch muscle fibres that are crucial to force development.
In summary, plyometrics are effective for increasing power. However, the load of the movement must be proportional to the strength of the muscles involved in the movement. Using heavy throwing objects or plyometric press-ups allows the upper body to be trained effectively.
Table 1: recommended plyometric exercise for the upper body Exercise Weight Sets x Reps Rest
Overhead med ball throw Female 10-15kg ball
Male 15-20kg ball 3-4 x 6-8 2 min
Plyo press-up (body weight) 3-5 x 5 2-3 min
Chest pass Female 10-15kg powerbag
Male 20-25kg powerbag 3-4 x 6-8 2 min
Raphael Brandon MSc is a sports conditioning and fitness specialist. He is also London Region Strength and Conditioning Coach for the English Institute of Sport
References
Donald Chu, Jumping into Plyometrics, Human Kinetics
Journal of Strength and Conditioning research Aug 1994; 8(3):198-203
Can Journal of Applied Physiology Aug 1996
Med Sci Sport and Ex 1993, 25(11):1279-1286
Journal of Strength and Conditioning Research 2005; 19(1):129-134
Journal of Strength and Conditioning Research 14(3):248–253
Plyometric Training - Part I
Plyometric Training - Part I
What it is and what it’s not.
By Juan Carlos Santana, MEd, CSCS
As a performance enhancement consultant, it has been my experience that “plyometric” training is one of the most requested forms of training by athletes. All have heard the stories of great power development accredited to this method of training. To add to the mystery, plyometrics originated as a training method in the secretive eastern block countries where it was referred to as “jump training”. As the eastern block countries rose to become powerhouses in sports, plyometric training was credited for much of their success. In the 1920s, the sport of track and field was the first to employ a systematic method of using plyometric-training methods. By the 1970s this methods of power development was being used by other sports that required explosive power for successful competition.
This article is the first of a three part series. It answers some basic questions about plyometrics and its efficacy in enhancing human performance. The second part of this series deals with lower body plyometric programming. The third and last part of this series discusses upper body plyometric training.
Plyometrics comes from the Greek word “pleythyein” (i.e. to augment or increase). However, the actual word plyometrics was first coined in 1975 by American track coach, Fred Wilt. Based from the Latin root words “plio” (i.e. more) and “metric” (i.e. to measure).
Plyometrics can best be described as “explosive-reactive” power training. This type of training involves powerful muscular contractions in response to a rapid stretching of the involved musculature. These powerful contractions are not a pure muscular event; they have an extremely high degree of central nervous system involvement. The event is a neuromuscular event! It is a combination of an involuntary reflex (i.e. a neural event), which is then followed by a fast muscular contraction (i.e. voluntary muscular event). Sound complicated? Well, it’s really not. We all have seen it, experienced it and continue to use this type of “reactive” movement pattern to develop power. We all do it everyday.
For example, every person that has been to a physician has experienced a plyometric event. When the doctor tapped under your kneecap, causing your leg to jerk, what do you think he/she was checking? The tapped caused a sudden stretch of the tendon that connects to all of the quadriceps (i.e. the muscle involved in extending the knee). Small receptors within the quadriceps create a stretch reflex, which makes the quadriceps responded by contracting explosively. The stretch reflex that caused the leg to extend is called the “myotatic reflex” and is the basis of plyometric physiology. The most common human movement, running, is completely a plyometric event. Other common plyometric events include throwing, swinging a golf club/bat, jumping and skipping!
This stretching of the muscles, prior to the explosive contraction that follows, is often called “loading”. The faster and greater the load, the more powerful the reflex and subsequent contraction. A good example of this is watching any basketball player jump. They jump higher when they can take a few steps before the jump. The reason for this is that the few steps create momentum. This momentum is used to create a bigger and faster “load” on the leg plant prior to jumping. The response to this greater load is a greater contraction by the legs and a higher jump height. The same phenomenon exists with all explosive actions.
Many times people confuse some forms of power training for plyometrics. Plyometric training is only one form of power training. A true plyometric exercise must contain a very fast loading phase. That is, for the stretch reflex (i.e. myotatic reflex) to invoke a powerful contraction, it must occur extremely fast. If the doctor pushed on the tendon below the kneecap, instead of quickly tapping it, would the knee involuntarily jerk up? Of course not, no matter how fast the doctor pushed on that tendon. Therefore, a jump (i.e. from an athletic position) onto a 24-inch box is a power exercise, but not a plyometric exercise. To make it a plyometric exercise one can jump off a 6-12-inch box, hit the ground and immediately jump onto the 24-inch box. The landing from smaller box loads the legs quick enough to create the stretch reflex needed in plyometric training. This is very demanding – don’t try it without consulting a professional!
By now you should have a better understanding of what constitutes a plyometric exercise. Hopefully, they are not as mysterious as you once thought they were. You should realize that everything we do fast has some plyometric component in it. That’s how come we can do it fast!
So, who can participate in plyometric training? The answer is everyone! With proper supervision and progression, everyone can partake in plyometric training, from children to the senior population. If you want to see the real kings of plyometric training, go to any playground and watch children play. Some of the athletes I train have performed many exercise “stolen” from six-year olds. As for my senior clients, many participate in watered down versions of hopscotch and skipping games. Seniors not only get great strength, power and balance benefits from plyometric activities, they relive great times – they love it! The only problem is getting them to stop laughing. Athletes obviously stand to gain significant power development from the prudent use of plyometrics. As with the non-athletic population, proper progression is again a key concern.
Since I’ve harped on proper progression, let’s define it as it pertains to plyometrics. First and most important, the proper strength base must be developed to support the increased force production that results from the stretch reflex. Remember that the reflex involved in plyometric training allows you to contract your muscles with greater force then you could through a voluntary contraction. Therefore, we must make sure that the musculature can support this increased force production. Secondly, a higher degree of balance and stability are also needed for the quick loading phase. Although a specific body part may seem exclusively involved, the percussive shocks that bring about the myotatic reflex are felt throughout the entire body – all structures must have good integrity to support this training. Third and last, simpler skills must be mastered before progressing to more difficult exercises.
Plyometric training has received some bad press. Inappropriate use of plyometric training has been associated with various forms of “over-use” injuries, especially in the lower extremities (e.g. patellar and Achilles tendinitis and plantar faciitis). This type of training, especially when done at a very high intensity, is a high-risk endeavor (i.e. high returns but at high risk). Like any other high-risk maneuver, high intensity plyometrics should not designed or performed without the supervision of a professional overseeing the training, and response, to the exercise protocol.
In closing, everyone should understand that like any other type of training, plyometric training is a continuum. We are all involved in plyometric events everyday. Some of us are exposed to very low levels, while others participate in higher intensities. Regardless of the level of participation, the key to safe participation in plyometrics is proper progression. I can’t emphasize this enough!
Part II of this series deals with the basic categories of lower body plyometric exercises and some general recommendations to safe programming and participation.