Wednesday, August 25, 2010

Moved Art of Coaching Speed to new home

Moved the blog Art of Coaching Speed so I can manage it better.

http://artofcoachingspeed.com/

What started as an exercise in gathering my thoughts for training my own staff has grown.  I look forward to helping many coaches develop their skills and training techniques.  Hopefully I'll provoke some thought along the way.

Tuesday, August 17, 2010

Woodway Speedboard

I have long been a fan of the Woodway FORCE treadmill.  It is a self propelled treadmill. This has been for several reasons;
  • Encourages FOOT CONTACT under COG
  • Encourages HORIZONTAL PROPULSIVE FORCES
  • Allows VIDEO ANALYSIS of multiple strides easily
  • Provides easier accel bounding learning and resisted bounds
  • ...and in the case of a FORCE 2.0 or 3.0 provides data on actual forces and gait analysis between left and right legs
Last year Woodway introduced the SPEEDBOARD.  We  had the chance to recently evaluate it with athletes of different calibers and experience. 

Another self propelled treadmill, this one uses a low friction belt, and curved surface so that no harness is needed.  A bit scary for many when first stepping on, it ends up being very easy to get used to.

We have done some rudimentary video analysis comparing athletes over ground and on the Speedboard.  Although  not complete, I can say that differences in most kinematics are minimal.  Below are some comparison shots.  Although limited by using 60 frames of video, their was not difference in stride frequency in this analysis.

TOE OFF
THIGH BLOCKING
GROUND PREP
GROUND CONTACT
MID STANCE

TOE OFF 2 

Our coaches have generally found that athletes feel like it "makes them go faster."  In our trials and observations, it seems to encourage better recovery and step over mechanics.   This has been consistent among many different athletes.  Put them on their and we have seen residual phase get cut dramatically and a better step over action.  The step over may be encouraged by the slight angle of the tread in front, encouraging them to step up to it. 


One area where we have found we had to really coach well and watch is ground contact.  I encourage dorsi-flexed ground contact and this becomes even more important on the Speedboard.  When coached and executed, ground contact is good and many athletes have actually felt increased gastroc soreness after sessions.  This makes sense as they are making contact with slight angle and therefore potentially loading in a more stretched position.  This would also be something to consider if an athlete is returning from a foot/lower leg injury or has problems there. 

If an athlete tends to overstride and does not understand to try and footstrike under the COG they may be encouraged to overstride or even heel strike in lower level athletes.  The key was coaching.  It is very easy to hear the difference and we found even more than on the ground that if given as a cue, athletes could hear the difference themselves.

These are a bit in contrast to the FORCE treadmill.  I have found it encourages better ground prep and footstrike mechanics by its nature to require additional force production.  Any overstriding on it will not drive the belt backward. 
All in all we are finding it extremely useful. 

  • Takes up a lot less space than 60-100 yards of track/turf. 

  • It allows us to provide video feedback and analysis over multiple strides. 

  • Encourages good recovery mechanics.

  • Allows a natural running motion.

  • Allows IN/Outs indoors

  • Useful for repeat sprint intervals with active running recovery between.

Wednesday, August 11, 2010

Increasing Speed - Interview with Jon Goodwin

Here is the beginning of a great interview with Jon Goodwin, that was done by Patrick Ward on his blog. 
http://optimumsportsperformance.com/blog/

Increasing Speed – Interview with Jon Goodwin
by Patrick on August 9, 2010

Last month I attended the NSCA National Conference and watched a lecture on sprint biomechanics given by Jon Goodwin. The lecture was easily the best of the weekend and I jotted down a lot of notes. Jon was nice enough to take time out of his busy schedule (as both a coach and researcher on sprint biomechanics) to do this interview and I am very excited to present it to you.
1. Thanks for taking the time out of your day to do this interview, Jon. Could you please tell the readers a little bit about yourself.

Essentially, I’m a frustrated athlete. Injury ended my involvement in athletics and like many, coaching was my next avenue to stay involved in the sport I loved. I started coaching in 1997 and from there my coaching interest progressed from athletics to strength and conditioning. Whilst this was going on I completed a BSc in Sport Rehabilitation and an MSc in Biomedical Engineering before progressing from teaching biomechanics at undergraduate level to validating both a BSc in Strength and Conditioning in 2006 and a distance learning MSc in Strength and Conditioning in 2008 at St Mary’s University College in the UK. I now run these programmes whilst continuing some coaching and starting studies towards a PhD in sprint mechanics.

2. Your presentation at the NSCA National Conference on sprint mechanics was excellent. In that presentation you talked a lot contact length and contact frequency in attaining high velocity. Can you please talk a little bit about this? More specifically, why is contact frequency so important and what can we do about it?

The mechanical relationship here is real simple and governed by real simple rules.

Firstly, obeying simple laws of mechanics our motion is only altered by forces. We are subjected to 2 important forces when we run – gravity vertically and air resistance mostly horizontally. If not for these 2 forces we would just continue throught the air at a constant velocity forever. The job of running at max velocity is then to apply forces in such a way that we overcome the changes in motion that these forces create. i.e. when we land we need to arrest the downward velocity we have accrued during freefall and also overcome the loss of horizontal velocity we are subjected to due to air resistance.

Next, we need to think about when we are able to apply the forces that can do these jobs. The answer to that is simple too. The only time we can express these forces actively is when we have a surface to push against. i.e. when we are on the ground.

So now we’re left to consider; what are the variables we have access to while the athlete is on the ground? What things can a coach enable an athlete to change to apply force in a more effective way to allow faster top running velocities?

There are 2 variables we have access to here.

The first is contact length, the distance travelled by the centre of mass whilst the athlete is in contact with the ground. This is controlled by how long your legs are and how far you reach in front of your mass and/or push off behind.

The second is contact time, the time you take in contact with the ground. This is controlled by how long it takes the athlete to apply enough impulse (force x time) to halt their downward velocity and reaccelerate themself back into the air for the next flight phase.

You should be able to see here, we have the components of our standard equations for velocity; a displacement and a time taken to cover that displacement. This leaves us with a fundamentally important relationship for speed (and acceleration and agility) coaches to keep in mind.

Velocity = Contact length / contact time

Obviously our leg length isn’t something we’re actively going to change (not ethically anyway) and wide contact positions such as reaching in front or pushing off a long way behind have been demonstrated to become progressively more ineffective mechanically. Whilst there is likely to be some plasticity in contact length, possibly controlled by athletes strength around the hip, contact length probably only offers small opportunities for change. i.e. getting stronger might enable you to handle longer contact lengths (so allowing faster velocities) but we certainly aren’t going to cue athletes technically to reach out in front or push off further behind.

Contact time on the other hand has been shown to be a huge variable of importance. The primary thing faster sprinters do differently is they generate much higher peak leg extension forces on the ground and they do it much more quickly. This means they can overcome gravity and project themselves back in to the air in less time (air time being virtually almost constant across runners of different ability). With this capability they are able to cover their contact length in less time. So what happens to our equation? Contact time gets smaller, so velocity gets larger. This is the primary mechanism by which faster sprinters travel at faster velocities than slower ones.

read the rest here...

Sunday, August 8, 2010

10 % Rule of Speed Training

If you’ve read speed training articles, or watched most presenters and dvds, and even if you’ve gone through coaching education you’ve heard it.

10%

That’s the most you want to load according to conventional wisdom, 10% of bodyweight. Of course that’s a bit arbitrary because are we talking a sled or parachute. Grass or track or turf? So it’s evolved a bit to be no more than 10% decrement in speed.

Only 10%

It’s been handed down over the last few decades like a prized heirloom from mentor to apprentice, coach to athlete.

10%. No more or else! If you use more, you risk detriment to sprint technique.

Almost all coaches will agree without thinking twice. This is blanket rule for sleds or other resistance training and it’s applied broadly to both acceleration and maximum velocity.

Why?

I stuck to this 10% rule in my early sprint training days because it’s what other track coaches taught me and made some sense. However, over time, I couldn’t find the full logic and my background as a weightlifting coach probably made me biased toward more load. As I did graduate work in biomechanics I developed a new lens to analyze it. For many years now, I have used heavy resistance (50% to > 100% Bodyweight) to improve acceleration in team sport athletes.
One way to add weight for Mark Sanchez?

If you ask most proponents of the 10% limit why, you won’t get many solid answers, because people aren’t asking the right questions. Let me help ask some.

Are you training acceleration or maximum velocity?
Big difference. The kinetics and kinematics are not the same in acceleration and max velocity.

Quick Review: Kinetics is about motion and causes (torque, force, impulse, rate of force development, etc…) and kinematics (velocity, acceleration, joint angles, alignment, etc…) describes the motion. From a technique standpoint, it’s chicken and egg. Each impacts the other.
In terms of force production what we know today is that the HORIZONTAL component is large in pure acceleration, but the VERTICAL component is dominant in maximum velocity. A heavy sled provides horizontal resistance. Makes sense why a heavy sled wouldn’t translate to max velocity sprinting.
It can be argued that in most team sport settings, it is acceleration that is more common and therefore more important. Right now what I’m talking about is focusing on improving acceleration. Since we are talking about acceleration, and most of the research on resisted sprinting is on max velocity, THROW IT OUT.
So what, if it acutely changes some kinematics?
Sprinting with resistance changes the kinetics and kinematics. So what? Is that inherently bad? Isn’t that often a goal of training drills?

In coaching athletes I am often trying to change kinematics. That can be the main point. I may be trying to develop a greater arm action, or a larger horizontal force component, or a higher stride frequency. It’s not whether or not heavy sleds changes things. For the coach it’s a question of; is it the change you want?

Speaking of different kinematics, what about some other drills that we use? Wall drills change the upper body kinematics, but we decide that the value of training the core and lower body motion is worth the temporary change in the upper body. Plyometrics have different kinematics as do many “technical” drills. Why are those OK but, heavy resisted sprinting is not?

Remember also, of the little data there is on acceleration, this is an acute change while doing the resisted run. The question is what does it do to the actual acceleration mechanics without resistance?

What are you using it for?
This is a key question that should drive our decision to use any drills. I like to classify drills as technical, training, or applied. This helps guide our selection based on athlete and training session goals.

Technical drills are designed to improve motor control, build kinesthetic awareness and teach the athlete how to move. Training drills are designed to elicit a training effect such as force characteristics, or energy system development. Applied drills are intended to add variability and let the athlete discover the movement solutions to different problems.

In a movement training session we will have some of each, but with a focus on one area more than others. I think resisted sprint drills can be used in different ways.

An athlete may get a technical benefit out of heavy sled resistance if it brings about kinesthetic awareness, helps them understand the feel of driving back. In working on 40 yd dash starts, I’ll use that heavy sled to build awareness of what it feels like to have tension in the start position.

It also can be a training drill. We can use it to build special strength and work on the impulse components. When used in a contrast method (which for me is almost always) it has a potentiating effect on the following un-resisted accelerations.

What research says it’s detrimental?
There is research, almost all of it on maximum velocity sprinting, which shows changes in kinematics with heavier resistances. Does that mean it causes negative adaptation?

I don’t care if the athlete’s time over a distance is 1000% longer if the technique is right. Lets imagine I have a very heavy load on the sled. The athlete goes for 6-10 steps. If it only moves a few inches on each stride, so what? As long as the mechanics are right and the contact time is good, why not? You are getting a stimulus even if it didn’t move.
Not exactly what I had in mind.

I definitely think you can cause detriment to acceleration technique if you use it poorly. Add a lot of resistance to the athlete and their form could fall apart. Allowing this while yelling “Drive harder!” isn’t what I consider good coaching.

Tips to best use heavy sleds for acceleration
Enough questions already. Bottom line, I question the proposed rationale for limiting sleds resistance to 10% when training pure acceleration. You might want to question it too. Here are some tips I use for sled resisted acceleration.

Use heavy sleds for pure acceleration.
After using these techniques and analyzing video I advocate using loads greater than 50% and sometimes up to 100% for the first 5 steps of acceleration and that’s it. If you are getting into longer distances I think you need lower resistance. As a matter of fact, we barely ever use any horizontal resistance during max velocity. I might be more inclined to add a weight vest to influence the vertical component.

Make sure you get the effect you are looking for.
Heavy sleds are going to change something. Whether its kinetics or kinematics, consider how the change will influence the adaptation you like. If I have a very strong athlete, who is a plodder with long ground contact times already, I need to be wary of very heavy sleds because the change may not be what I was looking for.

Contrast with free accelerations
Always follow heavy resisted acceleration with free acceleration. If you are using it as a technical exercise than this clearly makes sense. If you are using it for a training effect, it may not be as clear cut, but I still follow with free accelerations.

I advocate a “guided learning” approach to movement training. I introduce technical and training effect elements, then allow the athlete to solve movement problems. These applied drills are key for the individual to adapt the technique to their personal and environmental constraints. I think it’s a key to get a transfer effect into actual sport competition and preventing that robotic look to movement.

Use waves for more reps.
With an athlete that can handle a higher training load and will benefit from more reps, use contrast waves. Just increasing volume, you could add more reps in each set of resisted runs and then go to more reps of un-resisted accelerations.

Instead I would suggest doing multiple waves. Each wave would include 2-5 reps with resistance and then doing at least as many un-resisted. These contrast sets can then be repeated by going back to resistance and finishing with un-resisted. I find this helps with the motor control adaptation better and prefer a series of waves where each wave has fewer resisted reps.
Go Use It
So now it’s time to figure out what you are going to use. Ask the questions, analyze the acute effect. Review training adaptations and decide what works. That’s what coaches do!