COD Considerations For Youth Athletes

Rich Clarke

Let’s say you have the opportunity to work with an athlete from 10-16, or from pre-peak height velocity (PHV) to post-PHV. As we know, there are a number of changes in anthropometrics and coordination throughout that time.


  • Low body mass
  • Short stature
  • Low speed capabilities


  • Heavier
  • Taller (higher COM)
  • Faster

Think about this from a multi-directional speed perspective…

If an athlete is light and short (COM low to the ground) we would consider that advantageous for COD movements. Of course, they are relatively slow so let’s say they are slow but adaptable.

If the athlete then becomes heavier, taller and faster. They now become fast and less adaptable.

They key change is momentum. Momentum = Mass x Velocity. They have more of both components when post-PHV.

To change momentum requires more impulse. Which means more force (they might have this) applied effectively to the ground (they probably don’t have this).

So they have naturally developed all the negative impacting stuff, but none of the useful stuff.

It is common for us to use jump height or linear speed as our performance measures at all stages of development. But is it really appropriate to measure the success of our programme by something that changes with maturation anyway? They will get faster or stronger without us doing anything, so it is much more difficult to identify what added benefit you have had.

In contrast, COD ability doesn’t naturally improve because maturation is working against it. If you are really confident in your impact on an athlete’s athleticism, it might be humbling to look at a COD outcome. But, remember that a total time measure (such as 505 time) is still heavily bias by linear speed. COD deficit is a much better measure here.

I actually completed a pilot study and compared COD variables between a pre-PHV and a post-PHV group. Linear speed, total 505-time, approach speed and entry speed of the 505 were all significantly faster in the post-PHV group. But exit speed wasn’t (athletes unable to use faster entry speed on exit due to poor positioning) and COD deficit was actually worse in the post-PHV group. This was a small group, but I would put money on the same thing with more participants.

If you fancy downloading my full slide deck from when I presented about this pilot study, click here.

The analogy I use is when athletes are pre-PHV, it is like driving a Go Kart. You don’t go that fast, but you can throw it into corners, barely touch the brakes and have a great time with very little risk. Then PHV comes along and they transfer into driving a Range Rover. Heavier, taller and more speed. Suddenly they can’t throw it into corners or avoid the breaks because trouble awaits.

The key additions here are multiple planes of motion and increased deceleration requirements. So, this gives us insight into the key area where you need to focus.

There are a few things which interact here.

  • Braking strength
  • Movement skills
  • Affordances/understanding

If you go from the Go Kart to the Range Rover engine, you need to ensure that the brakes get upgraded, you learn to deal with the different gears and you change your expectations of what you can do.

So the recommendation is that we need to ensure that braking strength improves. This is likely the easiest as strength levels will naturally increase with age. Of course, this could be eccentric focussed but don’t get too cute here. They are youth athletes and you neither want to start thinking about optimising physiology or using all your tricks at this point. Good overall strength levels are your focus and remember it is a long-term game.

Yet, we can be a little more direct with movement skills and affordances. The most important thing is they learn how to lower the COM. Remember it is now heavier and higher up. So, they need to be competent in triple flexion and being able to do this during vertical, horizontal and a medial-lateral deceleration. So, lots of variations of reducing momentum in different tasks is ideal.

Affordances and understanding are the main component people overlook as it is less physiological. When you have spent a few hours racing a Go Kart, you get back into your car to drive home and it feels weird. You can’t slam your foot on the accelerator anymore, you need to brake earlier before corners and generally can’t be as much of a manic. It is the same for the youth athlete, but they have been Go Karting for the past 10 years. This means they have no memory representation of how to drive a bigger car to click back into. Think back to when you learned to drive, a much bigger learning curve.

Because of the youth athletes’ constraints (short, light and slow), they have adopted a movement strategy to suit. One paper has even shown children use a deceleration strategy where the COM stays high and steps are both longer and less frequent vs adults. Quite simply, they do this because they can. They have no reason to adopt a strategy which is any different.

So as these constraints change, we need to expose them to tasks with feedback to let know that this isn’t possible anymore.

The key here is systematic variation of drills which require braking. Decelerate to turn 180 degree, 90 degrees or 60 degrees. All with various approach distances which allow the athlete to get up to different speeds. I would also add don’t wait for post-PHV to do this, expose them to this from day 1. If the feedback is clear and they can learn, you’ll set them up effectively for the future.

Oh and of course, consider a performance measure such as COD deficit. It will give you some insight you don’t get elsewhere.


Rich is the founder of Strength Coach Curriculums and an S&C coach who specialised in multi-directional speed. He runs the S&C provision for Bristol Flyers Basketball and consults with clubs across the globe while also leading the MSc programme at the University of South Wales