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History of Educational Gymnastics in British schools
February 13, 2018
Educational Gymnastics in Britain A popular conception of gymnastics today is of young girls in sparkly leotards with hair kept up in tightly bound buns. ¬†This is a relatively new concept, with gymnastics originally being an all-male outdoor pursuit. Gymnastics has originated from several different sources, but all had the underlying principle of healthy movement. […]

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Sprint Training Mechanics: Frans Bosch

“Humans aren’t descended from apes, but are a bad crossbreed of kangaroos and horses”

kangarooFrans Bosch delivered 4 great presentations at GAIN V this year each one packed full of information and ideas.

This included two practical sessions. One was gym based and one was running based. That helped immensely with my understanding and application.

Here are some of my thoughts on his analysis of sprint mechanics, based on his anatomical model. He looks not at how the “wheels turn, but how the motor runs”. This requires an internal focus of running mechanics, not an external focus.

He uses comparisons of human anatomy with that of kangaroos, horses and springboks: the best runners and jumpers. By comparing hamstring and gastrocnemus length with tendon length in the different species, we could see how improvements could be made in speed and jump training.

He started off with 3 building blocks for improving sprinting:

  1. Muscle slack (the most important)
  2. Reactivity
  3. Reflex Patterns

Working on improving and developing these areas will improve your running speed.

What is muscle slack?

Imagine a rope dangling from one end, then being pulled from both ends: the slack has been taken out of it. Jogging is bad running with more muscle slack, removing the slack increases your speed.

Slack is not a bad thing, it helps with control of lower speeds. But, to run fast you have to eliminate the slack.

The 2 ways to do this are either:

  1. Use a countermovement, which is what less co ordinated and slower athletes do.
  2. Use pretension where the muscles are co contracting (preferred option).
Frans Bosch sprint

Reactive strength training

Bosch then explained why certain weight training exercises don’t help pretension because the bar does the work for the muscles. Instead use other exercises that allow the body to provide solutions.

(As an aside someone from the ECB told me that a cricketer I was working with who couldn’t do a body weight squat, could be tested with a barbell because the weight helped him get lower to the ground! Unfortunately he wasn’t allowed to do fielding in matches with that weight on his shoulders!).

Bosch has also eliminated the countermovement from any weight training exercises or drills that he is doing with the Welsh Rugby Union at the moment.

4 Ways to get a bouncy athlete

  1. An erect posture (max 20 degree of knee flexion when jumping). Really good jumpers have 5-9 degrees of knee amortization. These are sometimes known as speed jumpers compared to power jumpers. (Bosch said that power jumpers are just speed jumpers with bad technique!)
  2. Short contact time and little change in joint angles
  3. Pretension prior to ground contact.
  4. Drop height no higher than the jump height of an athlete (you shouldn’t store more than you can unload)

Bosch then went into more detail on the running mechanics themselves (regular readers and our athletes will have as seen this before).

I first saw Frans at the RFU speed conference 7 years ago and was blown away by the concepts. This is what we have been working towards with our athletes since then.

The bottom line is that our athletes are benefiting from this. (Jazmin Sawyers got a Long Jump bronze medal at the Junior World Championships having been trained using this methodology.)

I can’t say I grasped all of his concepts at this conference, but am able to watch the lectures back on video which helps!


  1. […] Sprint training mechanics for rugby players […]

  2. […] athletes running fast and exploring different ways of moving. Using principles I have learnt from Frans Bosch and Gary Winckler I concentrate on 2 key points in any session at the most and then find 2-3 […]

  3. […] here for more on speed training drills and here for sprinting […]

  4. Andre says:

    Do you have a copy of videos, you can share?
    Many thanks,

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James' knowledge of strength and conditioning has been a valuable resource that I have used to enhance the training programmes at 4 professional Rugby League clubs; Harlequins, St Helens, Whitehaven and Workington. He has had a positive impact on the performance of the athletes and added to the professional development of coaching staff

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