Eccentric Overloading Methods for Jumpers: Kettlebell Swings, Part I

If you are into vertical jump training, the Kettlebell swing is a must-know,  must-do tool in your athletic arsenal.  Unfortunately, many athletes and coaches are skeptical to the idea of using kettlebell training and thus taking time away from proven standard methods, such as squats, deads, plyos, etc..  Traditional methods are certainly effective, but kettlebell swings, when performed properly are also a training tool that deserves a spot in your training program .  Here are some reasons why.

• They have high biomechanical transfer to leaping ability
• They overload the hips well when performed properly
• They can provide a strong eccentric loading of the posterior chain
• They have several variations to maximize the training effect
• They are easy to learn and the stupidity factor is low
• It is a metal ball… much easier to put in your car and work out on vacation than a barbell.

 I’ll admit, for a long time I figured Kettlebell training was something that needed to stay in the realm of personal trainers.  Obviously if the kettlebell was sissy enough to have versions of it made with pink handles, there is NO WAY me or my athletes would be caught dead working with those things.  My mind was changed after reading two excellent books describing just how potent the right use of the kettlebell can be.

I took the plunge by buying a pair of 24kg bells, and then started a daily regimen of goblet squats and swings; I didn’t really plan the training out that meticulously (as I normally enjoy doing), I just did it.  After about 3 weeks of this work, with no other power work, jumping, or sprinting… at all… one day I was walking under a basketball hoop, so as is my nature, I took a couple steps and tested out my vertical.  I was blown away as I got both hands up over it quite easily with relatively little effort.  And all this after not jumping, sprinting, or lifting anything over 100lbs for about a month!  I doubt this was my fatigue from the heavy spring training subsiding either; typically after my spring track season is done (and I take a few weeks easy to reset) my CNS dive bombs and I would be lucky to dunk a basketball.  I was amazed how well I seemed to maintain my power and strength simply from performing these swings and squats 4-5x per week.

So…. nice training method… but how does it compare to the usual squats, deads, olympic lifts, and  plyometrics and why should you be interested?

Something that I noticed about my post-kettlebell jumping as well was how fast the “loading” aka “eccentric phase of the jump was.  Hardstyle kettlebell swings are meant to be done with a FAST loading phase (you can also notice this in the video).  The kettlebell is “thrown” down, and not just “let down” by the force of gravity.  When I descended to the bottom of the jump, it was as if I was performing the eccentric/down phase of the kettlebell swing!  The difference was that now I was doing it with more power than before.  I was loading up my legs more quickly than ever!  Don’t just take my word for the effectiveness of this training; check out some of these examples of the power of the swing.

• Dan John and Master RKC, Geoff Neupert added 3 inches (8cm) to an NFL player’s vertical jump in a single morning of overspeed kettlebell swings and hip flexor stretches.
• Force plate based research has shown that athletes can produce 500lb pounds of force or more in the eccentric portion of a kettlebell swing. This happens by rapidly accelerating the bell downwards faster than gravity will typically carry it.
• Kettlebell swings and snatches may be a method of choice for athletes of low training age. Danish research by Kenneth Jay showed that two weeks worth of kettlebell snatches added 3-8cm to untrained athletes vertical leaps, which was statistically greater than another experimental untrained group who were training with depth jumps.

Add to all this, practical benefits of the bell described by RKC (Russian Certified Kettlebell Instructor) Brandon Hetzler:

“Better posture, better jumping mechanics, improved vertical jump height, improved power output, improved cardiovascular training, massive increases in grip strength, better core activation, strength gains all are typical for our athletes.  It really depends on the athletes goals. Keep in mind the kettlebell is just a chunk of iron that by itself won’t do anything, in the hands of an untrained individual will hurt or injure an individual, but in the hands of a skilled instructor can bring about massive changes.”

Are you convinced yet?  If not, I don’t blame you, after all, training fads come and go.  The difference here is that the swing is backed by science.  I strongly believe that kettlebell swings and snatches are going to be standard issue for strength programming in the future, so let’s get into what makes this such a devastating tool of training.

The science behind the swing

Benefit 1: Eccentric Force Production

The kettlebell swing produces force quickly in the eccentric/down phase.  Not a lot of weight is required either, as many great results have been achieved by athletes using bells weighing under 50lbs.  In the research done by Kenneth Jay where subjects increased their leaps by 3 inches in 2 weeks, kettlebell snatches were done by bells weighing only 18-28lbs!  The key here is just how the bells were used to  produce force.  When swinging or snatching a kettlebell, athletes will “throw” the bell downwards to produce greater amounts of force.

According to training neuro-specialist, Chad Waterbury, when you are looking to get bigger stronger or faster, you must recruit the biggest motor units.  You can do this by either lifting heavy or lifting extremely fast.  There are actually regulators in your spinal cord called Renshaw cells that will preferentially recruit the largest, fastest motor units and turn off the smaller, slower ones. To get more powerful, train either high force or high speed.  In a training setup, the traditional powerlifts can take care of the high force requirement, while kettlebells are excellent for the high speed end of the spectrum. Consider them your “dynamic day” if you are an athlete in a sport aside from powerlifting (and they can help you even if you are a powerlifter too!).

Louie Simmons of Westside Barbell puts it well when talking about fast movements with weights.  He  says: “Increasing velocity has a much greater effect on kinetic energy (KE=1/2 MV²) than increasing mass. Slowing down the motion is limiting the energy that can be stored in the muscles and  tendons”.  Along the same lines, sports science legend, Mel Siff, has stated: “One may produce the same force by moving a heavy load with a small acceleration or a light load with a large acceleration, but the training effect is very different. Explosive, low inertia training targets involuntary, neuromuscular and central nervous processes more strongly than high inertia training which has a greater effect on static strength development and muscle hypertrophy.”

So based on these experts, we can conclude that explosive, low inertia training, such as kettlebell swings, will maximize kinetic energy and target the involuntary processes (such as stretch shortening cycle) to a greater degree than moving heavy weights slowly.  (Obviously heavy weightlifting is a very important training tool, it just has a different goal) We can actually see that this type of kettlebell training is more plyometric in nature than it is a traditional weightlifting exercise.

Kettlebell training may even have some advantages over plyometric training.  In Dr. Kenneth Jay’s study, he also had a group performing plyometric exercises, along with the kettlebell group.  The kettlebell group gained an average of 3″ on their vertical leaps, while the plyometric group managed only 1″ of vertical gain.  This can be attributed to the higher velocity of the hip joint due to the weight being “thrown” down faster than the force of gravity, where in plyometric training, the maximal acceleration due to gravity stays at 1G. Kettlebells can be pushed faster than 1G.  Mel Siff referred to this type of training faster than gravity as “actively accelerated ballistics”.

In summary:

• Kettlebell swings fulfill the “high velocity” demands of motor recruitment
• High velocity movements have a greater effect on the stretch shortening cycle than slow velocity movements.
• Kettlebells can be accelerated faster than the force of gravity to place large loads on the posterior chain during swings and snatches.

Benefit 2: Targeting of the “Hip Hinge” Mechanism of Movement

There are three joints involved in the triple extension found in jumping and running; the hips, knees and ankles.  When it comes to jumping, some athletes preferentially recruit the knees (and usually end up with tendonitis) and others recruit the hips more.  So which style is better? Recent research by Patel (2010) has found that a standing vertical jump was more positively associated with work at the hip vs. work at the knee.  This study also showed that encouraging spinal stiffness along with hip dominance  could lead to improvements in vertical leap height.

In the practical realm, strength legend Dan John has stated  that “Bad jumpers start with a lot of knee bend, and then diminish the pop of the hinging hips”.  Basically, if your hips don’t pop quickly, you aren’t going to be jumping very high!  The only exception may be if you are a 2x bodyweight squatter or more, but even then, you are robbing yourself of some serious power by lack of a good hip pop.

The “Hip Hinge” is a vital movement in sport that all athletes should be familiar with.  The hip hinge simply refers to the ability of an athlete to “hinge” at the hip joint without excessive spinal flexion, particularly in the lumbar spine.  The hip hinge will show up in a variety of athletic movements, so it is important to train it.

“Athleticism comes from having great athletic hips –jumping, running acceleration, and cutting are all enhanced.  However, for the hips to fully express their athleticism, the spine or core must be stiffened.”

In regards to a training method that will teach an explosive hip hinge along with a stable core, it doesn’t get much better than the hardstyle swing or snatch! More on this stiffness through breathing tension in the next section.

In summary:

• The hip action is the most important part of a vertical jump
• Hip hinging is related to all kinds of athletics movements
• Hip hinging needs to be done in conjunction with a stiff core
• Kettlebell swings are an excellent method to teach the hinge and stiff core

Benefit 3: Improved Breathing and Tension/Relaxation Management

According to the experts,  breathing is very important in power/vertical leap training.  According to Dr.  Siff in Supertraining, “Correct breathing is important during plyometric training.  It is vital that the athlete holds the breath during the amortization and early propulsion phase to stabilize the body, offer pneumatic shock absorption and to increase the rebound force.  Forced exhalation should accompany the remainder of the propulsion phase”.

The breathing mechanism that Dr. Siff describes here is dead on with what is found in the hardstyle kettlebell swing.  In the hard-style swing, an athlete will breathe in as they swing down, and then exhale hard as they explosively drive the bell back up.  This breathing pattern will help add to the power of the  swing, and will also assist in transfer to dynamic athletic activities.

The final point of importance is that of tension/relaxation.  As previous articles of mine have talked about, relaxation is paramount in developing elite athleticism.  There has been an 800% difference demonstrated between experts and novices in terms of the ability to turn and, and then quickly relax muscles.  Learning to tense and then immediately relax a muscle is essential for high levels of performance.

Part of the reason that great athletes can achieve such high levels of relaxation is also due to the fact that fast twitch muscle has a greater capacity for instant relaxation following contraction than it’s slow twitch counterpart.  (Due to more calcium pumps in the sarcoplasmic reticulum of the FT membrane).  If you feel as if you are a slow twitch dominant person, then you may have some extra work to do when it comes to performing explosive movements with an element of relaxation.

The kettlebell swing does a wonderful job in teaching athletes to accumulate energy and then release it through breathing patterns.  Swings and snatches will allow athletes to quickly create maximal amounts of tension and then relax.  This skill can be transferred into virtually any jump, sprint, cut, throw, or demonstration of explosive power.

Summary:

• Correct breathing is an important part of dynamic activity
• Elite athletes can release tension in muscles more effectively than novices
• Kettlebells swings can teach athletes to build and release tension effectively

In closing, the kettlebell swing is a wonderful tool when it comes to explosive development of the hips.  When included in a well rounded performance program that emphasizes traditional lifting, mobility and efficiency, speed, and of course practice of the sport skill and it’s variations, it is a helpful tool in helping athletes reach their goals.

Stay tuned for part II on performing the perfect swing, along with advanced variations!

Joel

 A big “Thank You!” to my references:

Brandon Hetzler www.simplykettlebells.blogspot.com

Boston Sports Medicine and Performance Group: Interview with Stuart  McGill. http://www.bsmpg.com/mcgill-interview/

Easy Strength.  Dan John and Pavel Tsatsouline. 2011

Mike Robertson interview with Chad Waterbury https://robertsontrainingsystems.com/blog/august-4-2008/

Performance of a two-foot vertical jump, what is more important, hip or knee dominance? Master’s Thesis. 

Rupesh Patel, university of Waterloo. 2010

Supertraining.  Mel Siff, 2000.