Plyometrics – The good the bad and the ugly

Depending on who your source is, true plyometrics applies to exercises involving ground contact times of approximately 0.15 – 0.20 s.  The term jump training is more consistent with the type of training that Fake Ray Bans the majority of trainers/coaches will be implementing in their day to day work.

Good

Jumps have a number of benefits. They can help improve sprint, change of direction, jump and distance running performance by enhancing the efficiency of the neuromuscular system. The dynamic stabilisation benefits can reduce the risk of injury by strengthening connective tissue. Implementing jumps into a circuit format can offer a potent cardiovascular stimulus (with greater adaptations of fast twitch fibres which can be particularly important depending on your goal/sport)

Bad and the ugly

Unfortunately many individuals don’t obtain these benefits due to poor implementation.  As you may have seen, jumps can be extremely tough on the body and if not progressed according to an individual’s ability and training history can result in serious injury. The purpose of this article is to give you an idea of how to implement jumps in a safe manner, so you can experience their benefits.

How to land

Before discussing intensity or exercise selection it’s paramount to define proper technique for jumping. The intensity of an exercise can change based on how you land. Despite it being a key fundamental movement skill, it is not taught in schools. Unless I am trying to get a specific adaptation for certain sports, all of my jumps must land flat footed.  By landing on the ball of the foot the forces going through the foot-ankle- shin -knee complexes are amplified significantly. When landing flat footed, forces are absorbed much more gradually through the ankle, knee and hip. The quieter the landing, the more force absorbed by the hip. The hip is the main driver of force regulation, so this is absolutely what we want.

Some people might have some initial complaints about landing flat-footed such as a whiplash feel through their spine. This is likely because they aren’t bracing sufficiently – for example think about how you might pretense before someone hits you in the stomach. Alternatively, it’s because the exercise is too advanced. Other technical factors to look out for are posture (in terms of a neutral spine) and importantly in developing athletes and females; knee valgus (knees rolling inwards) – Which if not corrected can result in significant knee injuries.

https://www.youtube.com/watch?v=cdD_lGmHk5U

Exercise intensity
Even when you have mastered the skill of landing, jumps aren’t always appropriate for everyone. The larger the body mass of the individual, the more of a risk it becomes due to the cheap nba jerseys high forces muscles, tendons and bones are exposed to.   If the goals of your client are to lose fat/ increase lean mass, ask yourself is the risk/reward ratio really worth it.

To define exercise intensity you need to consider the following:

Height from which the Cheap Ray Bans body falls from

Take a box jump vs a regular in place countermovement jump squat (CMJ). In the CMJ the body has to fall from a greater height as there is no raised box to land on, therefore landing forces are higher. Thus, the higher you jump the greater the landing forces.

“So you are telling me the higher I put a box the lower the landing forces?”

Woah there.

After landing technique the biggest problem I see with implementation of jumps in gyms are box jumps with boxes that are simply too high! Unless it is a requirement for competition purposes, e.g. fitness-based sports (CrossFit), there is absolutely no need for doing a box jump when the landing position is more than a half/quarter squat.  

A proper test of how high an individual can jump involves measuring how far their centre of mass moves. In this respect, a box jump is not a test of how high you can jump. This doesn’t mean it isn’t useful, it means we as trainers and coaches should understand the difference. Although you have to be able to jump well to get to a high box, those who are most successful are those who are mobile and coordinated enough to pull their feet the highest. In this way, an immobile person could jump much higher than a very mobile person, but achieve a lower box jump height. Something for us all to consider.

Unfortunately, what often follows a box jump is a jump off the box onto the ground without any consideration of landing technique. This basically creates a depth landing of high intensity with poor mechanics (see vid). Jumping on a box definitely has its risks and when you start doing them under fatigue you are asking for trouble. I once saw a man catch his foot on a box, fly forward 10m under a squat rack and effectively rugby tackle wholesale jerseys china another man. All in all, I’d encourage sensible decisions when picking box heights.


https://www.youtube.com/watch?v=RPdh9fLbxKc

vs

https://www.youtube.com/watch?v=yGWqkuRfbrE


Yielding/amortisation (bending of the hip, knee and ankle upon landing)
If we are to look at a CMJ exercise, performed in such a way that you stick the landing with as minimal ankle/knee/hip bend as possible, we know this can send some high impact forces through the body. However, if landing with a gradual ankle-knee and hip bend, the forces are transmitted to the ground a lot more safely.  There are certainly situations when we would use landings with minimal yielding e.g. to improve eccentric strength for specific sports based adaptations but for the general training population this is not necessary.

https://www.youtube.com/watch?v=8k0WUKLPqYo

vs

https://www.youtube.com/watch?v=Eezc5zZgnlQ

Landing surface
Landing surfaces are another important consideration. The order of surfaces generally recommended are Gym Mats < Grass (depending on firmness) < Rubber flooring < Concrete.  I personally would never go as far as doing jumps on concrete flooring. If you don’t have access to any of the first 3 then it certainly would not be wise involving jumps in your programme.

The greater the speed from which you land from the greater intensity.

This is more relevant to sports training. It’s obvious that the greater height you fall from the greater the speed you will reach. Additionally, If you were to perform a simple hopping exercise, then perform a 5m run before starting your hops, the landing forces are amplified ~2-4 times over.

 Watch movie online The Transporter Refueled (2015)

Low Moderate Moderate-High High
Jumps onto box (double leg/single leg Box jumps, forward, sideward and backwards) In place jump variations (squat jump, countermovement jump, lunge jump, scissor jump, lateral jump) In place jumps with movement in the air (tuck jumps) or jumps with small translation( low pogo jumps , medial lateral hops) Translational jumps with great height, distance, speed and movement in the air (high hurdle jumps, depth jumps >50cm, hopping and bounding)

Intensity Chart (*Based on the exercise being executed at 100% effort)


Volume

Giving strict prescriptions for jump volumes is near impossible; it depends on so many factors. I would be lying to you if I said there was absolute set numbers. Unfortunately there are flaws in the standard tables you will see. Completing 40 depth jumps from a 1m box vs 40 box jumps are not identical. Similarly, doing 40 box jumps on a solid wooden box vs on a soft plyometric box will change landing forces and consequent volume prescriptions.

Key concepts for prescribing volumes and progressions

It is essential here to apply your common sense as a trainer and start small, while being gradual with progression. A simple analogy would be, if you had a headache and never tried paracetamol before, would you take 1 tablet or 10? Both would probably get rid of the headache but the Oakleys Outlet latter may cause further problems. It is also worth considering that tendons (which are stressed considerable more by jumps) adapt slower than muscle.

Paying attention to postures at take-off and landing can tell you a lot (is the individual maintaining flat footed landings, neutral spine, limiting knee valgus etc.). Think about how jumps complement other training components and the order of these. For example if it’s a massive squat day, the patella tendon (below the kneecap) might not respond well to doing hundreds of jumps. Similarly, performing jumps after heavy resistance exercise will take a lot of the quality away of consequent jumps.

A word on jumps for sports performance

Simplifying this as much as possible, when designing a jumps programme to enhance sports performance we firstly analyse the needs of the individual followed by a critical consideration of the key components of their sport in question.

I break my jumps down into the following categories:

  • Horizontal vs vertical dominant
  • Stiff (ankle/knee dominant) vs Deep (hip dominant)
  • Long ground contact time vs short ground contact time
  • Lateral vs linear

To understand this, let’s look at a 100m sprinter vs a netball player:

A sprinter needs to be able to rapidly apply forces over a progressively shorter amount of time. At the start of the run, the forces are largely linear, horizontal, with deeper angles at the lower body and longer ground contact times. As the sprinter progresses to maximum velocity, forces change direction to more vertical, there is less movement around lower body joints and ground contact times shorten. A set of consecutive double foot jumps up stairs vs vertical pogo jumps  (see video) would typify the different requirements between the two phases of sprinting with stair jumps transferring to the acceleration phase more and pogo jumps transferring more so to the maximum velocity phase.

https://www.youtube.com/watch?v=8INib1zE2Co

vs

https://www.youtube.com/watch?v=jdZRleEUaCU


Analysing the physical needs of a netball player, typically they will never reach maximum speed in a match, accelerations will rarely last longer than 10m and they have to make rapid change of directions from both high and low speeds. Therefore horizontally orientated/deeper jumps with some lateral emphasis and longer ground contact times might be more relevant than vertical/stiffness short ground contact time jumps. That’s not to say that those forms of jumps might not be useful for a general overload of the neuromuscular system but direct transfer and time spent using these elements should be less.
With multi-sport athletes I would rarely touch on high intensity exercises(see table), there are far more other physical capacities that training time could be distributed on which have much better risk reward contact ratios.

 Watch movie online The Transporter Refueled (2015)

Takeaway points

  • Before implementing jumps ask yourself whether it is really worth it. Are there other training methods you could use that would get you similar results with significantly less risk?
  • When implementing jumps, make sure proper landing mechanics are taught and mastered.
  • Start low volume and progress gradually with appropriate selection of exercise intensities.

With sports performers analyse the requirements of the sport first.


Ross Jeffs is an ASCA Level 2 qualified Strength and Conditioning coach and British Athletics qualified Track and Field coach. He has experience of working with professional athletes in Australia and the UK. He currently runs a performance training business in Jersey – Biography RJ Performance (RJPERFORMANCE.CO.UK) working with some of the best local athletes Knowledge in a vast range of sports. You can contact him at Ross.Jeffs@Bath.Edu.

 Watch movie online The Transporter Refueled (2015)

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