September 2021 - Athletic Performance Academy

Pacey Performance Podcast REVIEW- Episode 361 John Wagle

This blog is a review of the Pacey Performance Podcast Episode 361 – John Wagle

John Wagler

Director of Performance Science and Player Development, Kansas City Royals (MLB)

Website

Background:

John Wagler

Previously, he earned his PhD at East Tennessee State University, worked at DePaul University as a strength and conditioning coach, and spent some time prior to that as a baseball coach.

Discussion topics:

What are the benefits of eccentric training?

”The benefits of eccentric to me really comes down to the fact the force production isn’t constrained by the lengthening velocity. We can produce really high forces at really high speeds, which happens to occur quite often in sport. That pairs pretty well with how we need to adequately prepare athletes for the demands of sport.

A lot of the tangible benefits are with longer term applications of eccentric training in programme design:

Fast fibre cross sectional area changes
More explosive performance
Longer fascicles
More sarcomeres in series
Stronger anabolic signals
Stiffer muscle tendon units

I think the commercialisation of flywheel has been a big part of the resurgence in interest in eccentric training, as well as researchers who have done a lot of research in this space (Dr Haff, Jamie Douglas – see his review paper below ?, Melissa Harden)

Chronic Adaptations to Eccentric Training: A Systematic Review

Direct links to dynamic athletic performance, what kind of benefits are we going to get from eccentric training?

”On the shortening velocity side that’s where the sarcomeres in series come into play for performance, and from the injury risk side we are getting longer fascicles as well, so something like the Nordic leg curl is very well supported in the literature especially when you do add eccentric overload, and it really seems to have an influence on muscle architectural changes within the muscle.

There does seem to be a preferential hypertrophy to fast fibres which can help us in a couple of ways, obviously we are going to have bigger and faster fast twitch fibres, but there is also a potential or theoretical situation where we have less drag from the slow twitch fibres just because the fast twitch fibres are making up a larger relative proportion of the whole muscle cross sectional area. And you do have a stiffer muscle tendon unit which is going to lend itself very well to dynamic athletic performance.

You have stronger anabolic signalling with eccentric training and more satellite cell activation which in theory is going to get you some more muscle size change at the fibre specific level rather than whole muscle, and then more voluntary agonist activation and down regulation of any inhibitory response of the nervous system. That’s not to say because of that list I should only focus on eccentric training as it’s only a piece of the puzzle but I do think it’s an under appreciated programming variable especially with its versatility.”

With all its benefits why would coaches not take this on board, and implement some of it into their training programme?

”Some of it is on the athlete safety side with the supra-maximal eccentric loading, and that all gets bucketed into eccentric training, although eccentric training does not necessarily have to be supra-maximal, but I do think there is a stigma that this a very stressful stimulus, and it is, like even in the sub-maximal versions of it, there is certainly some physiological stress associated with this that doesn’t necessarily appear with other training methods. But I do think there is a way to programme in it, with the acknowledged apprehension because of the potential implications of recovery status of their athletes.

People point very readily to the repeated bout effect and that’s certainly something that we need to consider, but you are still going to be disruptive to the recovery status of the athlete if you are progressing and providing adequate overload and variation regardless of what you are doing with the eccentric training side so the repeated bout affect doesn’t absolve us from considering the stress induced from eccentric training.

The repeated bout effect refers to the adaptation whereby a single bout of eccentric exercise protects against muscle damage from subsequent eccentric bouts. … There is some evidence to suggest that the repeated bout effect is associated with a shift toward greater recruitment of slow twitch motor units

For anyone who hasn’t introduced eccentric focused training before, where would you start and what would you recommend for people to progress through?”

”Level zero for me would be the tempo or movement cadence manipulation with eccentric training. There is actually not a tonne of support for it, especially in terms of strength and power adaptations which is pretty logical if I slow the eccentric phase down I’m not going to be able to use as much weight, and that intensity down shift has implications for strength and power changes.

There has certainly been some studies that have shown muscle size changes but my interpretation of literature is that I have yet to be convinced that slowing down the eccentric phase is superior to regular ol resistance training without a targeted approach to movement cadence. But that being said, I do think there is a lot to be gained to revisit technique and make sure that those things are really sound and to make sure you are stressing tissues the way that you intend.

I like flywheel as the next logical progression.

There is a little bit of elongation, let’s call it, between the eccentric and concentric phase when you have to overcome the inertia at the bottom of a squat for example, where it can give people time to produce a lot of force but they are not necessarily ready to produce that force rapidly, so the flywheel lends itself well next, plus there is a little bit more [research] support on the hypertrophy side, and especially for the lesser trained athlete so you’ll also see some strength, power, and change of direction changes as well.

Then you get into things like accentuated eccentric loading (AEL) and you might progress into that from sub-maximal to supra-maximal and things of that nature, and because of the higher eccentric rate of force development (eRFD) most notably, that lends itself really well to progress to plyometrics and top speed sprinting, which are kind of the tail end of what you would want to expose that athlete to in terms of the highest level of eccentric stress. Whether you want to bucket plyometrics into eccentric training is up to your interpretation, but to me that’s kind of the end of the road, and AEL does a good job of setting you up for some of those more advanced plyometrics.

Tempo training
Flywheel training
AEL
Plyometrics and sprinting

All that being said, I think it’s important too that it’s more about the blend of these methods, that you’re not going to do one of these methods in isolation, and you would do elements of each no matter what stage of training you are in, and that’s important to be able to set you up for success in progression.”

How can people progress their use of flywheel to then progress onto AEL?

”Flywheel has a longer transition between the eccentric and concentric phase, to give them more time to produce force. There is also an element here where the athlete can control the intensity. A lot of the eccentric overload present in flywheel training is mediated by the concentric velocity. So although there is an element of progressive overload in absolute terms with the size of the wheel, a big chunk of that is mediated by the athlete. So you have a bit more versatility to meet the athlete where they are at, and progress them accordingly.

Accentuated eccentric loading (AEL) prescribes eccentric load magnitude in excess of the concentric prescription using movements that require coupled eccentric and concentric actions, with minimal interruption to natural mechanics.

Eccentric load is in excess of the concentric load– doesn’t need to be supra-maximal, which automatically makes it different from tempo training where you have the same load on the way down and the way up, and makes it distinct from flywheel training where you have the same inertial load on the way down and way up.
A coupled eccentric and concentric action– which makes it distinctive from negatives (eccentric only training).
Minimal interruption to the natural mechanics of the selected exercise– which further differentiates it from flywheel training, a lot of times you are wearing a harness, and if anyone has ever been on the flywheel device, it’s a great training tool so this isn’t a criticism, if you squat on a flywheel it’s different than if you squat with a barbell in terms of the mechanics which will stress tissue differently.

To do this you can use manual resistance from a partner (push ups and nordics etc), weight releasers, hold dumbbells especially as it applies to plyometrics.”

What are the specific benefits of AEL outside of what we have spoken about with eccentric training?

”There does tend to be an acute testosterone and growth hormone response that persists a little bit longer than with traditional loading, and possibly some alterations in glycolytic enzyme production and lactate clearance ability with AEL which could have some advantages for sports that have a large endurance component (soccer, 400m runnner). AEL was typically reserved for strength/power type athletes but that may not be the case with that new research that while it is pretty thinly supported in the research it is intriguing enough to continue to explore.”

Can lower end athletes benefit from some of the AEL methods?

”In terms of loading and the stimulus you are providing, there is not really a barrier to entry besides obviously you have to consider eccentric training is pretty stressful so they are probably going to take a little bit longer to get through the recovery process from that training.

I think too if you are looking to apply AEL for potentiation you have a much narrower window to operate with to actually induce that potentiation. You are walking a tight rope between fatigue and potentiation, and those weaker or less trained athletes, that tight rope is just going to be much thinner. So those that are stronger probably have a little bit more margin for error on programme selection.

I thought for sure with the mechanistic underpinnings there would be a potentiating effect with AEL, such as the muscle is in a greater active state, more calcium sensitivity etc, but it’s actually a really mixed bag [in the research] especially when it’s narrowed to resistance training such as bench press or squatting with weight releasers, there’s just as much research that shows that it is detrimental as it is beneficial to that acute performance, and there appears to be a pretty big sensitivity in programme design and load structure.

Plyos vs. Resistance Training (Short-term acute effect)

So if you were going to do it, and to make sure you are not burying the athlete, it would be best to do it alongside some sort of augmented feedback such as a velocity measurement or a between set counter movement jump. But on the plyometrics side, it is still a little bit of a mixed bag, but there seems to be a little bit more clarity in terms of what is going to work and what isn’t going to work. The studies that do have a favourable acute effect from AEL tend to be ones that have a conservative loading (holding a pair of 10kg dumbbells and also plyometrics that have a lesser centre of mass displacement (AEL doesn’t tend to work with a really large displacement like a deep squat which causes a fatigue effect). But a tight coupling, the rapid eccentric action with an eccentric overload does appear to be where you can induce some potentiation.

I would tend to put my more stressful content at the beginning of the week so I can provide my athletes with the recovery at the back end of the week. So for me AEL to me fits better at the beginning of the week particularly in season, so for players that have a high speed running demand especially upright top speed type running, having an AEL exposure early in the week to expose them to some higher eccentric rate of force developments but not necessarily what they are going to encounter in sprinting. And then have a top speed exposure later in the week, where it is an emphasis in their training, acknowledging that if they are training in their sport in between they will still do some high speed work between those sessions as part of their sports practices.

A nice progression could be:

AEL counter movement jump (with dumbbell release at bottom)
Depth jump (shock method)
AEL depth jump (with dumbbell release at bottom)
Repeat serial hurdle jumps

Where does this fit into the bigger programme?

”With AEL specifically I do feel it fits very neatly at the tail end of a cycle where you do have a demand to develop some maximal strength or retain the maximal strength you have already developed but stage some of those higher power output or higher velocity efforts, where you are trying run your fastest, jump your highest, be at your best, kind of staging a taper, would be where I would put AEL, in terms of what it can retain and what it can expose the athlete to in terms of high eccentric RFD.

If you are going to follow AEL with a taper you are okay with the intentional high stress nature of that eccentric training, so if you are going to pull training content away to promote that recovery AEL fits really well as part of a over reach to stage taper, or the block prior to set that taper up.”

Top 5 Take Away Points:

The benefits of eccentric training is that the force production isn’t constrained by the lengthening velocity.
Eccentric training progression: tempo training, flywheel to AEL and finally plyometrics and sprints.
Less advanced athletes will need more time to recover from high stress eccentric training.
There may be a more clearly defined benefit of AEL with plyos for potentiation.
In annual planning AEL will fit more towards the end of a training cycle with the goal to develop some power prior to a taper.

Want more info on the stuff we have spoken about? Be sure to visit:

Twitter:

@DrJohnPWagle

Pacey Performance Podcast REVIEW- Episode 362 Matt Van Dyke

This blog is a review of the Pacey Performance Podcast Episode 362 – Matt Van Dyke

Matt Van Dyke

Director of Sports Science for the Houston Texans

Website

Background:

Matt Van Dyke

As the Director of Sports Science for the Houston Texans, Matt is responsible for the management of training loads and other performance aspects implemented to each individual athlete in order to maximise performance and readiness. Prior to this, Matt has worked at the University of Texas and University of Denver, designing and implementing speed, strength, conditioning, and mobility training programs for men’s lacrosse, alpine ski, baseball, tennis, swimming and track and field.

Discussion topics:

Tell me a bit about your background

While I was getting my Masters I did two summer internships and six months full time working for Cal Dietz at University of Minnesota. Then I moved to University of Denver as Head of Strength & Conditioning for 2.5 years, where I also met Dr Nick Studholme (he runs a system called FNOR – Functional Neural Orthopaedic Rehabilitation). I transitioned to more of a sports science role at University of Texas looking at the athlete through a holistic lens.

I now work in an NFL setting and being part of a sports performance team where I sit in the middle of Strength & Conditioning staff, Sports Medicine Staff and Nutrition & Wellness, and from my perspective providing the best insight that we have available from the testing and monitoring into athlete availability for our coaches and management.

How do you decide what to test, and what metrics to evaluate within those tests?

You first have to evaluate what you as an individual or you as a staff VALUE, because you need to have a system and process of testing sports performance. Understand that the context of it is king, as we all understand that an athlete isn’t great because their jump metric is ‘X’ and there is way more that goes into it.

What aspects do we feel are valuable linked to on field performance?
Link between positional demands and physical preparation
What is our end goal of change and did we create that change?
In season is really about fatigue management, and that’s where auto-regulation comes into play
We have to be able to have actionable data- we don’t just want to collect data
Create buy in, which ensure that the athlete gives effort in their testing.
How can we help them recover more and create that unbreakable athlete?

Would you mind taking us through the six pillars of athletic performance?

”I would say that those six pillars in some combination or other create every single athlete movement goal or process that an athlete can produce on the field.

(taken from article: Athlete assessments: evaluation of more than just athletes)

Now it’s all about fitting the training programme that you are going to implement based on the context that you have available; so if you talk to Cal he is going to use block periodisation for all of these; well he is going to have his athletes for 40 something weeks of the year potentially so that’s going to be a different model than a group that potentially has 8-10 weeks with their athletes out of the year, and obviously as you progress through different levels of sport the availability to them changes pretty drastically.

Repeat sprint ability is truly your end goal for the majority of team sports.

This would look different for a cyclical sport like track & field or swimming etc. The speed component is ultimately what we are chasing after but if we are only going to see our athletes at certain times throughout a year and they are get a lot of that from on field then we are going to focus on the pieces that will move the needle that they are probably not getting. But again, it entirely depends on the context of the situation that you are in, of how you would programme to achieve each of those.

In terms of the energy system work for repeat sprint ability the oxidative system is not going to be specifically trained like it would in a block periodisation system, but it’s going to be more like a repeat sprint ability, we’re not going to go out and train the glycolytic system and run 300 yard shuttles because that’s not beneficial to them. They need to produce intense amounts of force and energy in a matter of 4-6 seconds, sometimes as short as 2-5 seconds, and then recover from that. So in the couple of weeks we have with them we are going to make sure that we are preparing them for those demands and not just necessarily the long slow aerobic work.”

How would you programme for those demands of the key 3-4 second bursts before the sub when you have those constraints?

”The more I look at it, the more I’m going to err on the side of quality training. If I’m looking at velocity drop off in the gym or the field we don’t want to see ever greater than a 10% drop, then we are training in a fatigued state. There are times in a game when you are going to need to do that, but if you use the analogy of the heavy slow back squat versus the drop jump, the impulse is going to be significantly higher in the drop jump even though the total force over the two jumps may be similar. So we want to look at the impulse and the quality of that foot strike with limited time, and once they can do it once, can we get them to do it repeatedly.

Early on in the off-season will have days designed specifically for acceleration, change of direction, some type of volume training so it’s going to be a little bit more the conditioning side of things and then as we gear towards the season it’s going to be more of a repeat sprint ability. It’s almost like a high to low approach but then as you get closer to the season it’s going to be more like a high to moderate approach as the lows aren’t really lows anymore, as if you are going to practice for 3-4 days in a row the athletes have to be prepared for that.”

Let’s dive into the strength pillar. Tell us a little bit more about the triphasic method and your take on it

”The big pieces of it are the 6 physical components that we have spoken about already, but then really it’s about how can we take the work that Cal has done and then restructure it slightly to fit into the context that we were in at Denver.

The most important take away is that people want to talk about just the eccentric, the isometric and the concentric and say okay well that’s the triphasic system, but the way I look at it is, yes the muscle action is a component of the triphasic system but when you really get into it there is also that modified undulated block within the week that he is going to do, and the block periodisation. Cal has undulated the programme in order to ensure that there are never too many training qualities trained in the same block. And so that block periodisation piece is going to break up each of those physical performance qualities and train them based on how long they are retained within the athlete’s body.

The eccentric, isometric and concentric pieces are obviously key and people understand that and implement that the most. Realistically it is shifting into that power and speed, creating more of an elastic tensile system and now can I do that under high velocity conditions which are going to be required in sport. Now the majority of time is going to be spent in that strength component because you never really know what an athlete has done when they come to you, and the motor learning from eccentric and isometric is going to play a key role as well.”

Daz comment- Matt wrote a fascinating article as a guest post on Max Schmarzo Blog ‘Programming Application to Match Desired Adaptations, (October 2017).’

He talks about how he integrates the Joe Kenn Tier System to improve basic strength and then uses the Triphasic system to peak his athletes and improve reactive strength (what Matt calls his ”Tierphasic” system).

Increase fitness and function
Improve basic strength (Tier system)
Improve reactive strength (Triphasic system)
Increase power and speed
Maintain physical attributes throughout competitive season

The Triphasic system takes the newly developed force producing capabilities and increases the use of that strength in a reactive manner. It is in this phase the three muscle action phases are individually trained as this continues to allow adaptation to both the nervous system, muscle tissue as well the biomechanical efficiency of that movement. The stretch-shortening cycle is the focus of Triphasic training, and the goal of triphasic training is to train and optimise each component of the stretch-shortening cycle separately. In the final concentric phase timed sets become particularly important (around 55-80% 1RM, mean bar velocity 0.67-1.0 m/s).

The final off-season primary goal consists of training that improves the athlete’s power and speed. I believe this is the most critical aspect for the transfer of training onto the competitive field in many sports as they are completed at the highest velocities (around 55% 1RM or less, mean bar velocity 1.0 m/s). This is known as the ‘below 55’ method. It can use light weights, at body weight, and accelerated speeds.

Oscillatory training is utilised in this block to prepare your muscles to fire as rapidly as possible, and also train your antagonist to relax more quickly, allowing an even faster contraction.

French contrast training is utilised throughout all of the triphasic blocks. These series of styles of plyometrics, including weighted, body weight and accelerated, prepare them for the below 55 training block.

How did you programme oscillatory training into the triphasic method?

Oscillatory (OC) training is implemented throughout the Triphasic Training Method. To the untrained eye, these brief, 3-4 inch movements applied with well trained athletes can appear gimmicky and useless, this could not be further from the truth. The OC methods utilised are able to improve strength within specific movement ranges, and involve a rapid ‘push-pull’ motion in an attempt to maximise the ability of an athlete to reverse the muscle action phase at high velocity.

When we actually get into the strength it does depend on how many days you have to train but typically about 2 days or so of eccentric training is going to give you a good stimulus, and same for isometrics. Based on the context of how you are implementing it whether you have 3 or more days training, if you had three days then we would typically implement it in the strength block. So if you have 3 days of training, days 1 (medium intensity-medium volume) and 3 (lower intensity and high volume) would be whatever muscle action you are in (eccentric, isometric, concentric), and then that middle one would be the reactive day (high intensity low volume) so we are going to potentially do timed sets there to match the weight room to the demands (such as 5 seconds get as many reps as you can).

Tissue tolerance using OC

Tissue tolerance is created through the use of 30 second OC work in the general preparation training block. In this phase the athlete is introduced to the OC methods through a moderate intensity and increased volume. It is through the increased volume that strength and skill learning within specific ranges of motion take place, while also maximising the metabolic requirements of the general preparation block.

Strength and power blocks

You are typically going to train that in a disadvantageous position so you are going to train that in your weakest range of motion with high loads above 80%. Bear in mind 80% 1RM is only 80% of your strength at your weakest position, and so that oscillatory method puts you at that sticking point for the entire 5 seconds so now you are talking about training strength at their weakest position.

Speed phase

As you progress through the blocks you can switch that oscillatory into more of an advantageous position now its about more about speed, or a critical joint angle that you might be in during acceleration or top speed. With the goal of maximising neural drive in the speed phase the advantageous position can be utilised, with moderate loads of 45-55% 1RM.

The ultimate goal of the entire system is this thought process of contraction and relaxation agonist and antagonist working together, and there is a huge component of motor learning.

That’s why eccentric to isometric to concentric (reactive), and then power and speed (which are commonly left off because we are focused on the strength component) is important to remember that the firing patterns are most changed by the high velocity movements.

So with this skill learning of this speed training programme did we create a change in that relaxation- as the only difference between Matveyev’s fourth and fifth level classification of athlete was how fast they can relax their antagonist.

Progress throughout the Annual Cycle

As increased data is collected within the annual cycle, the time of year also becomes important in the evaluation process. With the understanding of athlete progression from general to specific throughout the annual process, it should be accepted they will not perform at the highest level on all testing metrics throughout the entire year. Rather, there should be key milestones within the annual training process that an athlete should aim for based on their individual results from the previous year and the positional baseline requirements.

If each group (sports coaches, medical team and S&C team) has a different goal for an athlete that does not work in synchronisation, the athlete will not experience the full benefits of the program being implemented. This misalignment could happen anywhere in the organisation and create a situation that could have easily been avoiding with communication.

This becomes particularly important in transition periods within the annual cycle. All groups must understand the goal and outputs required of athletes when a new phase begins. The example in the Figure below represents those phases and how the consistent building for “what is next?” is critical for athlete performance and reduced injury risk. When this pattern is understood by everyone involved, athlete assessments and progress become increasingly important as the ultimate question is asked “is this athlete prepared to tolerate this new training/practice/competition phase?”

Top 5 Take Away Points:

Testing/metrics- You first have to evaluate what you as an individual or you as a staff VALUE.
Repeat sprint ability is truly your end goal for the majority of team sports.
The stretch-shortening cycle is the focus of Triphasic training.
Oscillatory training is utilised to prepare your muscles to fire as rapidly as possible, and also train your antagonist to relax more quickly.
In annual planning the ultimate question to ask is “is this athlete prepared to tolerate this new training/practice/competition phase?”

Want more info on the stuff we have spoken about? Be sure to visit:

Twitter:

@Matt_Van_Dyke

Pacey Performance Podcast REVIEW- Episode 359 Damien Harper

September 14, 2021/in APA Blog, Pacey Performance Podcast Review /by dazdrake

This blog is a review of the Pacey Performance Podcast Episode 359 – Damien Harper

Damien Harper

Lecturer at the Institute of Coaching & Performance (UCLAN)

Research Gate

Background:

Damien Harper

Damian is currently working in the Institute of Coaching and Performance at UCLAN, supervising students on professional masters and doctorates in elite performance. He’s also a member of UCLAN’s newly developed football performance hub, developing the human braking research group following his PhD.

Prior to his time with UCLAN, Damian lectured in exercise physiology at York St John University, coached at the Bobby Charlton Soccer School, and earned his master’s degree while working with sports clubs in his local area. One of which was St. Albans Rugby Club, where he developed the 10/05 repeated jump test.

Discussion topics:

Why is deceleration so important?

In terms of what we are talking about when we are referring to deceleration it’s horizontal deceleration, so the opposite of horizontal acceleration. What we are looking at is how quickly the athlete can reduce their speed with respect to time. So we want to improve the ability of the athlete to reduce their speed as quickly as possible. This is important from a movement outcome perspective and deceleration capability, and in addition to the mechanical aspect of deceleration we also want to look at the intricacies of the movement skill. Deceleration is a highly complex interaction of the limbs to ensure that the athlete can apply those braking forces effectively and orientate those forces effectively.

So in essence there are two key components when we look at deceleration; one how well they can control the braking forces and two is how well they can attenuate and distribute those forces throughout the lower limbs. Therefore braking force control and braking force attenuation are the two key components that I look at.

Bill Knowles first came up with the mantra ”Don’t speed up what you can’t slow down.”

If an athlete hasn’t got that deceleration ability alongside that acceleration and top speed capability, then they are going to take a longer time and longer distance to slow down.

It is perhaps more accurate to say an athlete will not speed up what they can’t slow down, and there is probably a self regulatory mechanism there which is the athlete will reduce their speed knowing that they have got a deceleration at the end of it. So they won’t speed up what they can’t slow down to try and protect them from potential tissue damage which could occur in deceleration, which consumes some of the highest mechanical loads on the lower limbs.

Athletes who can decelerate more rapidly can enhance their COD ability so in essence they can hold off their brakes for longer because they can reduce their speed over shorter distances and times, so they can access a greater percentage of their top speed potential during the COD task. That deceleration capacity becomes absolutely critical in terms of enhancing overall speed potential.

In addition to performance enhancement with COD, an individual who has got better deceleration ability can actually reduce the amount of mechanical load that is going to be exposed on the plant step where we see all these ACL injuries and potential lower limb injuries.

You wouldn’t get in a super car that has amazing top speed capabilities if you knew that the brakes were warn and not working very well, you just wouldn’t put the accelerator down because in any set distance you know it is going to take longer to brake.

The problem with the super car analogy is that until recently we haven’t really been able to get a good indication of an athlete’s deceleration capability, so we don’t know how that interacts with the acceleration and top speed; we don’t know how good the brakes are as such.

What are the options for testing deceleration capability?

One of the problems we have had with advancing deceleration has been linked to the difficulty we have in measuring it, as it is much harder to measure than your acceleration and top speed capability but the good news is I can now see more options that can be applied on the field, which is great. In terms of measuring deceleration there are two options; one to measure it during a change of direction task (such as a 5-0-5 test) which requires the athlete to bring their momentum to zero before changing direction so there is a really big deceleration demand within a 5-0-5 test. Generally angles less than 60 degrees are no good because they are focused on maintaining speed.

The other option is Horizontal acceleration to deceleration in a linear path; you could get the athlete to stop at a pre-set distance- where the athlete has to sprint and then come to a stop at that [20m] line. The other option is to commence deceleration at a pre-set distance. So at the [20m] mark they have to put on the brakes and try to stop as quickly as possible; we refer to that as the Acceleration-Deceleration-Ability (ADA) test.

So then the question is how do you measure deceleration during those tasks? It took me about 12 months to arrive at the conclusion that we need to have instantaneous velocity throughout the task using radar, or laser or high speed video or electro-motor devices like the 1080 sprint. It surprises me that even today there are only a couple of studies that have attempted to capture instantaneous velocity during a change of direction task. I refer to these as ‘direct methods’ of measuring deceleration.

There are also ‘indirect methods‘ of capturing deceleration such as the ‘change of direction deficit’ and the ‘deceleration deficit, but they are only an estimation, we don’t know at the minute if they actually give you an indication of an athlete’s deceleration capacity which in essence is metres per second squared (m/s 2).

We selected 20m at the time because we wanted to select a distance which allowed the athlete to get near to their maximum velocity, so therefore we challenged their deceleration capacity. The greater the speed they approach the deceleration the greater the demands on their deceleration demands are going to be. We wanted to ensure we capture their maximum deceleration ability. You could adapt that distance to the demands of the sport.

You can look at AVERAGE deceleration (taking all the instantaneous values over the entire deceleration phase and getting an average of their deceleration values) and Peak deceleration (which is a single value), but I’ve tended to think that this isn’t the best measure of an athlete’s deceleration ability as this doesn’t really account for the entire deceleration phase.

There is a possibility that athletes with high peak deceleration may be obtaining them because they are not able to spread the deceleration across the entire deceleration phase. Therefore there are high peak values occuring particularly near the back end of the deceleration.

What tech do you need to be able to capture those measure?

”I used a radar gun (Stalker) but you can also use laser devices, which have a higher sampling frequency such as ergo test laser speed device, (which I believe has the ADA test built into the software).

But you could also obtain instantaneous velocity with high speed video such as dartfish or some of the newer devices such as 1080 sprint.

If you don’t have a budget for high tech equipment there is an option to look at some indirect indication of an athlete’s deceleration ability by looking at some of the underpinning qualities connected to the physical qualities that are needed to decelerate. This could include drop jumps and counter movement jumps, and use some of the specific metrics within them.

With the drop jump reactive strength index (RSI) was proposed as a key physical quality for deceleration, originally proposed anecdotally by Marc Kovacs. Recently we found quite large associations with RSI from either 20cm or 40cm and deceleration ability. When we broke the deceleration into early (50% Vmax) and late deceleration phase (50% Vmax to zero) we found that drop jump RSI had a greater association with early deceleration phase- shorter ground contacts and really high impact peaks when there is perhaps more of a heel strike and there is a transition from that top speed to the first few steps of deceleration phase.

Athlete’s who could put the brakes on quicker could achieve greater deceleration ability across the whole deceleration phase. So greater drop jump RSI could be important for tolerating the higher forces during the early deceleration phase, and ability to reduce the mechanical loads in the final foot contact and have better change of direction. This could also be linked to ability to pre-activate prior to ground contact, and therefore pre-tension prior to hitting the ground.

Can you speak to us about strategies to actually improve deceleration?

I have already mentioned about reactive strength as possibly one key quality. The other qualities that Mark mentioned at the time was:

Eccentric strength
Dynamic balance
Power – which includes rate of force development (RFD)

Eccentric strength is quite a wide area. By identifying some of these specific eccentric qualities we can help then to target our training strategies. Of the eccentric qualities we looked at during a counter movement jump, it was the ones linked to eccentric deceleration phase – eccentric peak force and eccentric RFD which had the biggest difference between those who had low and high deceleration abilities. Now that gives us a little bit better insight and these qualities have been linked to an athlete’s stretch load tolerance or limb stiffness capabilities. They are also under reasonably fast joint angular velocities- the downward phase round about 200 degrees/second- so they are having to produce those forces pretty quick- with highest rates at the ankle and knee as much as 500 degrees/second.

In terms of eccentric maximum strength we have seen most evidence to target the quadriceps which is perhaps not surprising as the quadriceps are absolutely critical in terms of resisting that knee joint flexion/controlling that yielding during the braking step and also critical for attenuating the forces when we brake. The knee and the ankle will attenuate (dampen) about 70% of the force during deceleration so before it gets to the hip the majority of force has already been dampened and reduced. You could also look at muscles such as the rectus femoris which because of the trunk position, places quite a big demand on that muscle, so you do see exercises like a reverse Nordic being used with an upright trunk.

A lot of my ideas about means to develop solutions, a lot of these ideas have come off the back of the work I did with the Football Association looking at development of a braking strength framework to prepare international footballers for competition demands.

Braking ELEMENTARY exercises – have highest level of tissue/neural overload (single joint, unilateral)
Braking DEVELOPMENTAL exercises
Braking PERFORMANCE exercises – have highest level of coordination overload (small sided games or utilizing unanticipated decelerations to target really high forces that are highly specific to what the athlete is going to face in competition).

To increase the players damage resistance to high deceleration loads.

An example of a method such as ‘rapid eccentrics’ would probably fit in the braking developmental exercise category. We are increasing their eccentric peak force, eccentric RFD and also ability to switch off quickly to unload the centre of mass quickly and could include exercises such as squat drop, or snatch drop and then arrest that movement at the bottom. You can look at a fast eccentric squats which is an eccentric only exercise, where we emphasise the speed of the downwards phase (40-70% 1RM).

Drop jump type activities- and activities which may accentuate that component. You can also do activities such as dropping from a relatively low height with an additional load, and then the concentric phase has a lower level of load than the eccentric phase. It can be done with dumbbells, hex bar, elastic resistance (loaded on the downwards and then explode on the upwards phase). He bar is preferable to dumbbells as the athlete is not worrying about landing on the dumbbells.

How can you manipulate SSG in order to target deceleration?

I’m finding the 4 vs 4 and 5 vs 5 (smaller SSG) really stresses the frequency of decelerations, high frequency of velocity changes which may help develop the enduring nature of decelerations. It may be larger SSG that are needed to develop the maximal deceleration capabilities where there are opportunities to attain higher movement velocities, which has important implications for managing the microcycles, particularly in the competition phase.

A constraint is whether you utilize goals or not, and with the goals in place research suggests there is more linear running and transitions whereas the possession only SSG doesn’t achieve that as much. You can also use different numbers such as a 4 vs 5 to offset the numbers could be another option.

Where is the research going in the future?

Resisted/assisted concepts with 1080 motion device to develop deceleration and COD
Advancing the assessment of deceleration including limb to limb demands across a period of time
Training interventions to develop deceleration capabilities – very little research been done here

Top 5 Take Away Points:

Deceleration definition- how quickly the athlete can reduce their speed with respect to time.
Braking force control and braking force attenuation are the two key components of deceleration.
Deceleration capacity becomes absolutely critical in terms of enhancing overall speed potential
To measure deceleration we need instantaneous velocity throughout the task
In order to improve deceleration capability there are a number of components that can be enhanced (reactive strength, eccentric strength, dynamic balance and power).

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