TO SPEED UP YOU NEED TO OUT THE BRAKES ON!

You'll have heard me talk about about eccentric training on this blog or on my YouTube Channel. This is the type of specific work which will improve your reactivity, your sprint speed and your jump power.
Think of an eccentric muscular action as like stretching out a spring - if you did this the spring would store a huge amount of energy. Energy which will be released when the spring is let go and it recoils at super-fast speed.
In our events the stretch of the spring as noted reflects the eccentric muscular lengthening action and the release the muscular shortening concentric muscular action one.
There's much research that indicates that improving eccentric capacity will improve concentric capacity - hence it's crucial to train this muscular action.
There are lots of ways to this, for example, you can do specific drills, some being more jump orientated and some more sprint orientated.
You can also train eccentrically with weights. If you did this the focus would be on the lowering phase of the movement. For example, when performing a squat you could slowly lower for a 4-5sec count before (or not and leaving the bar in the racks and having helpers lift the bar back to the starting position) extending the thighs to return the weight.
It's actually possible to handle more weight eccentrically then concentrically - up to 25% plus more in fact.
We regularly include eccentric training in our workouts - you'll see two members of the u20 squad doing what I call "Jump forward, block and jump" jumps in the image.
The athlete performs a medium length low height forward jump and then explodes vertically upward. The girl is performing the first part and the boy the second part in the image.
Checkout the latest video on my YouTube channel to find out more and to see this drill and more - all designed to improve eccentric capacity. 
https://youtu.be/zYQRoH8Y-JM

And if you needed a reason to eccentrically train: when triple jumping out of the hop the hop leg has to withstand and return up to 20 times body weight in milliseconds. Eccentric capacity is therefore vital.
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At Coach-Athlete level there are 10 videos on various subjects that will be particularly useful to coaches.
There are videos on Training Planning, Training Transfer, Speed Phase Development, Overcoming Common Coaching issues with young sprinters and jumpers ....