Friday, January 6, 2017

Mike-Alex

Compensation for yesterday’s weather delivered us a perfect day for working on Slalom. Alex chose to spend nearly all of the day in race training and made an excellent choice because this permitted him to make some real progress – ending on his fastest run of the day after 26 runs. (23 filmed and three not filmed). He is now down to 23.86 seconds – reducing his record today from 24.38. That is a big margin of improvement for one day at this level.

The first video shows the fastest run – on his GS skis – and with his best technique of the day. Included are some examples of what happens when bindings are clearly not doing their job and Alex’s skilful handling of the outcome.

The second video is to let people see what it’s actually like being Alex…

 

 

 

Retraction Timing

Technically we worked on only two things today, beginning with the timing of the leg actions for leg retraction. Normal “skating” timing (which Alex still doesn’t have right) requires a flexion down into the turn and an up motion out of the turn – with the legs flexing and extending accordingly to assist this. With very high loads on the body and particularly on steep slopes this action is far too slow and there is already far too much energy in the system – so the timing of the legs reverses! The release of the turn then requires an active retraction of the legs – which lets the body come out over the skis to get out of the turn – the energy level here means that the centre of mass still comes upwards a bit . Once the skis are being crossed then the new uphill leg xetends with full force to drive the centre of mass downwards and into the new turn. We practiced this with static exercises first. When you have speed this is the fastest way to transition turns – but should only be used when there is no time for skating to increase propulsion across the hill – when there is no time for holding onto the turn during the “cross over” and using the pressure to direct momentum across the hill.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Centre of Mass

A bicycle is controlled by the motion of the centre of mass (CoM). To go left you move the CoM left and the bike acts to support this. Skiing fundamentally works the same way. Static exercises were once again used to explain CoM to Alex to make sure that he fully understood it. I showed Alex that making angulation itself – changing the body shape – does not move the CoM. Only inclining moves the CoM and during the turn the CoM must always be leading the ski. The ski will obey the CoM. I held Alex leaning over so he could see his skis and the relationship to the CoM experienced in a turn. Alex got the picture in his head – went up for his next run and demolished his prevous record – despite it being an old rutted race course. He found that most of his skidding (which caused the skis to ping off) vanished and he coud grip. This is the key to “grip”. Alex felt that by controlling the entire turn with the CoM he was now the boss of his skis (his words). Alex could now feel the slingshot effect of the skis throwing him across the slope (the horizontal component) towards the next gate – the extra grip totally changing the experience!

 

 

 

 

No comments:

Post a Comment