In Part I, I wanted to discuss that targeted deceleration training is not a good use of time. The shortened version of that is based on how isolated declaration training does not correspond to open environments. Isolated deceleration drills, such as working on stopping, may not be practical, but understanding the dynamics from a hardware or software perspective potentially is. We need inductive problem solving by looking at patterns over deductive problem solving, which isolates certain attributes to enhance COD.
In Part I, I broke down the hardware into structures that underpin the physiological characteristics of deceleration, including eccentric, concentric, and reactive strength, speed, power, movement capacity, and symmetry. I broke down the software into the cognitive aspects of deceleration, including perception, decision making, anticipation, strategy, and experience. This is an important aspect of deceleration and subsequently changing direction (COD) due to the chaotic environment our athletes live in.
As coaches, we want to break things down into simpler, more digestible parts. Unfortunately, this does not translate back into chaotic situations. Because we find that someone has a deficit in a particular attribute in either their hardware or software, and we decide to work on that specifically, it will not guarantee that we fix an integrated movement in an unpredictable environment. This is the danger of deductive problem solving or reductionism is after we break something down, the sum does not equal the parts. With unpredictable environments, you cannot put COD back together again.
But, and this is important, we need to at least try. And we need to be vigilant with our efforts to enhance our athletes’ performance, no matter how futile it may seem! With COD, we will not be able to cover everything. Isolated deceleration training is not the answer. It is hard to assess and does not directly transfer. Having a system of using standard assessments that we can find limiting factors or patterns is the best chance we have to understand transfer to dynamic environments. It is an approach of inductive reasoning through observation and pattern recognition. We are cleaving off pieces through observations during various movement strategies and reducing that limiting factor’s impact.
The thrust of this is to look at movement strategies and determine indications of what is going to limit performance.
Deceleration Indicators
Deceleration is only a prelude to acceleration in a different direction. That is what we need to think about with deceleration indicators. Stopping does not matter unless it is connected to going. That framing is significant because when we look at indicators of decelerative ability in isolation, we will miss the point. Deceleration only matters relative to the acceleration afterward.
In other words, deceleration does not matter. The total of efficiency and effectiveness during COD does.
If you look at this table, you can break this down into three primary areas: Force, Rate, and Symmetry. These are all characteristics we can quantify and determine if we have a bottleneck in the energy transfer from deceleration to acceleration.
Force is simple: if we have a force deficit, get stronger. There is a reason why strength is considered the mother of qualities. If we lack requisite strength, we will not be able to absorb the forces necessary to change directions efficiently. But this is a catch-22 of sorts, because if we lack strength, we will not be able to accelerate to a point where deceleration will be challenged. To change direction efficiently and effectively, force through the development of strength is foundational.
Strength is both neurological and mechanical. We need the nervous system to function by sending impulses, recruiting motor units, synchronizing motor units, and finally recruiting certain muscle fibers (Fast & Slow). We need mechanical to contract those muscle fibers through the sarcomeres within those fibers. The more cross-sectional muscle area we have, the more sarcomeres are contracting. So we need to get a more efficient nervous system and large amounts of muscle to create the necessary force to change direction efficiently.
But there is a point of diminishing returns from getting too big and too strong, which can compromise the rate at which we can decelerate. If we are comparing apples to apples with COD, the person who will take fewer steps or time to decelerate and can reaccelerate faster will be at an advantage. Larger body masses create more momentum and greater demand, which can elongate the decelerative period and subsequently the time and time to accelerate. So we not only need a robust muscular system, we also need a robust connective tissue system and reflexive system to control the mechanical action.
The focus is on having the appropriate amount of body mass based on sport and position within that sport, while enhancing the rate at which we move. Eccentric strength and reactive strength are all critical to equipping any body mass to be able to leverage deceleration to an efficient directional change. Rate of force development (RFD) comes down to eliciting a response from the stretch-shortening cycle. Plyometrics, both intensive and extensive, is the time-tested and proven method for enhancing RFD.
The final indicator is symmetry. As coaches, we underestimate this one quite a bit. If we are comparing an athlete to a car, we love the motor, we like the brakes, we ignore the suspension and tires. We are a bipedal-asymmetrical species. We have a dominant side and situational/user bias with the extremities we use most often. If we have a tire that is low on air or our suspension that is making us lean to one side as we move, we tend to ignore it. But we are trying to find indicators that will limit our efficiency in COD, and if we have one side that is being used considerably more, that will create a liability with COD.
If we want to be completely honest about the most efficient way to simultaneously develop strength and symmetry, unilateral strength exercises are probably more correspondent with COD efficiency. The same thing could be said about RFD and focusing more on hops and bounds over jumps. We get more from the time we have by focusing on unilateral over bilateral when we are trying to enhance COD.
Indicators related to force, rate of force, and symmetry are not trying to break down into individual parts. A myopic view on one will limit total efficiency. Abandoning the holistic development of COD to prioritize one attribute is a mistake we want to avoid. Stopping is not the goal; acceleration after stopping is. If an athlete cannot accelerate after hitting a zero velocity, that athlete is at a disadvantage.
Deceleration Tests/Metrics
I will get right to it. To assess deceleration, we will need to look at:
- Counter Movement Jump (CMJ)
- Non-Counter Movement Jump (NCMJ)
- Iso Mid Thigh Pull (IMTP)
Remember, we are trying to find indicators of how deceleration will negatively impact future acceleration. We need to find force, RFD, and symmetry. We can get this specifically from a CMJ, but we want to unpack more by using more tests.
For CMJ we we want to know how much force is going into loading and propulsion. If we see a longer amortization, we will need to increase eccentric and/or reactive strength. If we see a low peak concentric force, we will need to improve concentric strength. If we see a low RSI, we are not converting eccentric loading to concentric propulsion. If we see a gross asymmetry of 15% or more on all CMJ, we will have to address a potential energy leak during loading and propulsion. Metrics such as Peak Eccentric Force, Concentric Impulse, and Modified Reactive Strength Index (RSI Mod) are your go-tos during CMJ. A good RSI Mod is >.45m/s, which will translate to COD performance well. RSI-Mod being an absolute metric, is not so much of a range but a correlate, which will benefit from a higher number of >.6.m/s.
I personally really like Peak Power per Body Mass to determine the efficiency of an athlete’s body mass relative to the power created. We can quickly determine if the athlete is not at an ideal body mass or is not producing enough power relative to body mass. Similar to RSI-Mod, Peak Power per Body Mass (PP/BM) is an absolute metric, so the higher the better. For PP/BM >55 W/kg is good, but >65 W/kg is better.
CMJ will help us understand globablly how well we load and propel during COD.
Eccentric Utilization Ratio (EUR) is an assessment I use for Strength Deficit. EUR is used to determine how much we are leveraging the SSC during jumping. EUR can help us determine how much time we need to allocate towards eccentric or concentric strength. An athlete who has a large concentric demand will need to be between 1.0-1.1 CMJ: NCMJ Ratio. An athlete who has a large eccentric demand will need to be between 1.2-1.3 CMJ: NCMJ Ratio. For general COD, there is a sweet spot in the middle of 1.1-1.2 CMJ: NCMJ Ratio. The rationale behind the middle of the range is the balance between force and rate of force. We need to produce large amounts of force, but in a rapid manner. We cannot be too eccentric or concentric, but still need to have some development in both. When it comes to COD, we need to load and propel efficiently.
EUR will help us understand eccentric loading force and rate of force prior to COD.
The Dynamic Strength Index (DSI) is a metric we want to evaluate to determine if we need to focus more on force or RFD. By comparing the amount and rate of force we produce during a CMJ and IMTP, we can determine if we need to spend more time on strength versus ballistic exercise. The ranges are similar to EUR: <.6 means we are producing a lot of force, just not rapidly, and >.8 means we are moving rapidly, just not a lot of force. Again, similar to EUR, we want to be in the middle of .6-.8 for COD. This allows for to transfer of a high rate and high force isometrically to COD.
DSI will help us understand us understand isometric force and rate of force during COD.
Takeaways from Part I & II
I hope this was not a colossal waste of time on your part. Go back to the genesis of this blog – I was reacting to other people doing deceleration training based on not doing it myself. I wanted to articulate why, and that comes from understanding that.
My point of all this, you do not need to do isolated deceleration training to enhance COD ability. One, it does not directly translate to open or chaotic environments. The lack of predictability is more of a product of cognitive and perceptual skill than of direct physical attributes. But that is based on the logic that a reductionist approach to chaotic situations does not work. Secondly, there is not enough time to break down into microscopic details. We need to fix things through recognition that patterns are deficient in some way.
Instead of taking a reductionist approach, we should use inductive reasoning. We need to find patterns or clues to performance limiters. This approach works better than deductive because we cannot predict when and where a particular attribute will be used. It takes a particular stance of I do not know, so I will not try to manufacture an outcome with isolated drills. You are, in a sense, limiting the impact of chaos by adjusting problems through inputs and constraints.