Monday, October 27, 2008

My cycling leg

This post is especially for Jason and anyone else that's interesting the the specific set up I have for cycling.

Jason commented on my previous post about his desire to tackle the Alpine challenge. Jason is a below the knee amputee as well.

The Alpine - that's awesome!! No way I could imagine doing that at this stage. I wrote about coaching a rider who did the Alpine a couple of years ago in these two posts.

You go Jason!

So, in summary, have a look at these posts which show my cycling leg set up in a little more detail:

My new leg and socket design

How my cycling leg attachment works

The cycling cleat attachment and adapter plate

The urethane adapter to provide lateral roll for out of saddle efforts

My prosthetics guy made my everyday walking leg socket with quite a shallow rear cut away with cycling in mind. The rear of the socket is such that I am able to pedal with a full length crank.

But remember I have the cleat directly at end of the pylon and so the knee doesn't need to bend quite as much as if the cleat was positioned further forward simulating an "under the ball of foot" position.

The socket also has some funky design at the front.

The other adaptation I haven't shown in pics is some soft foam-like material I place at the front of the stump below the knee, in-between the sock and liner, so that it fills the gap between the stump and top front of the socket when you are pedalling. Bend your knee when sitting and you can put your hand/fingers into the largish gap that forms betwen the stump and socket.

The gap isn't there when standing up of course but with the knee constantly bent on the bike, I found filling that gap really helped with power production and provides a much more secure feeling. I just got some off-cuts from a Clark Rubber store.

As my prosthetics guy says, the aim is to maximise the contact surface area between stump and socket. That will be something we look at when designing a dedicated bike leg socket.

Eventually I intend to have a dedicated socket / cycling leg made, however before that happens I need to further strengthen my hip so that the lateral offset of my "foot" can be brought a little more in line with the hip and knee.

For a permanent cycling leg, I envisage something like what Jody Cundy of Team GB paracycling squad had made. Anyone who can do a 65 second kilo sure has a leg that works!

See this item for more details:

Jody Cundy Interview

In there you'll see his new (the carbon leg) and old leg set ups. I don't expect to have my cleat positioned as far forward as Jody has his - he simply replicated what he was used to with his prior set up when wearing a cycling shoe over a prosthetic foot.

The one thing you have to consider with a direct cleat to pylon arrangement is that you can't walk on it. So logistics becomes a factor when planning on going for a ride.

Another thing I've noticed, since I have more than one bike, is that I am now much more sensitive to the different Q-factors of the cranks on my bikes - to the extent that I need to alter the angle of the prosthetic cleat attachment in order to ride a bike with different cranks. My two road bikes have 175 mm Campagnolo cranks however one is a Record crankset and the other a Chorus model and they have different Q-factors.

I never realised until now how much the ankles do the job for us, managing all the lateral roll when out of the saddle and coping with the small differences in positional set up.

What did Joni Mitchell say to us in that Big Yellow Taxi song?
Don't it always seem to go
That you dont know what you've got
Till its gone....

No parking lots here though!

If you want to drop me a line, just use:
alex A T cyclecoach D O T com

Anyway Jason, good luck with it!

Read More......

Saturday, October 25, 2008

3rd in line

I've been a bit busy of late, so my posting rate has slowed somewhat.

I was supporting some clients and buddies at the World Masters Track Cycling Championships last week as well as doing some other stuff. I'll write a bit more about that another day (it was a very successful championships for my club, my buddies and clients). Despite the "busy-ness", my training continues and so today I took myself down to Heffron Park for a criterium race.

Signed up for D-grade and it seems there were enough for a separate D-grade bunch today. Not sure how many we started with, maybe 12-15 riders. A moderate North Easterly wind kept the pace down on the back half of the circuit. It was a nice afternoon (race starts at 5pm), sunny and ~ 23 C.

Race is 14 laps of Heffron's 2.04km circuit.

Something new today - I bought a new leg liner during the week - that's the compression liner that goes over my stump and has the metal pin at the base that secures my stump into the socket. My existing one is tatty, worn and with holes appearing and getting bigger. So I swapped the pin over to the new liner and wore it in the race today. It would seem that cycling is quite tough on the liners.

One liner @ $1000 thank you very much. Ouch! So my first one only lasted a handful of months. It would seem the strategy is to have multiple liners, so that you can rotate them and allow each one a chance to recover properly before using it again. It looks as though I better save a few more pennies and get some more liners. That also means some getting extra pins sorted as well.

We keep learning....

So with the new leg liner on and a 20-min warm up on the circuit out of the way, I head to the start line and off we go for a 14 lap adventure.

I finished 3rd. Didn't want to leave you in suspense now, did I :)

Not entirely sure what to expect of myself, basically I was just there to see how I would fare. Pace was fairly steady, which was fine by me. A few surges by some enthusiastic souls who seemed to like riding into the wind. That was OK and at one point a lone rider put on an effort down the main straight. Seeing that nobody was going to go pull them back, I decided to try myself and it wasn't that hard to close the gap. They didn't last long anyway and soon we were together again.

So I just kept my nose out of the wind, noggin side up and never really had to work all that hard. Indeed at times I was just seeing how much soft pedalling/coasting I could do at various times, practicing basic race skills.

I unintentionally unclipped my prosthetic leg from the pedal a couple of times and I'm not entirely sure why, so I'll need to look into that. Since the pace wasn't on, it never really was a problem - I was able to calmly clip back in, but in a harder race it sure wouldn't help matters.

There weren't many left by the end, maybe a half dozen.

Duration: 50:19
TSS: 83.7 (intensity factor 0.999)
Average / Norm Power: 220 watts / 240 watts
Distance: 28.566 km
Cadence (max/avg): 109 / 86 rpm
Speed (max/avg): 50.5 / 34.0 kph

So given I didn't rate that as a super hard race and I had an IF of 0.999 for 50 minutes, then it would suggest my fitness is going along OK.

I'll probably have another crack in a couple of weeks.

Read More......

Tuesday, October 14, 2008

The Thin Blue Line

Time for a catch up on how my own training is going.

A couple of weeks ago I mentioned the results of my performance tests, namely a time trial level effort, a MAP test and some sprint efforts. Results were:

Time Trial power (20-minutes): 252 watts
Maximal Aerobic Power: 355 watts
Neuromuscular Power: 1074 watts (5-second max average with a peak of 1109 watts)

Estimated Functional Threshold Power: 240 watts.

So with those results locked away, training has been continuing. One thing to notice is the ratio of TT power to MAP. In my case, my TT power is a relatively low percentage of MAP (or if you like, my MAP is a relatively high percentage of TT power).

Hence my maximal aerobic abilities are really not a limiter (at this stage) to the ongoing development of my TT power. This helps to determine what my training focus should be for this next phase of training.

As with most cycling (except for track sprint/BMX), the focus is almost always on increasing your TT power, since it's the most import physiological marker of performance potential.

Of course rolling around the track is fun and so I will keep doing that. It also provides a safe environment for maximal sprint type efforts. Training should be hard work but it also needs to be enjoyable (mostly) otherwise we lose motivation.

So, my training will continue to be focussed on improving my sustainable TT power. Core endurance, tempo and threshold level efforts are now staples in the aerobic development diet. I'm also going to throw in a local criterium race or two as a challenge (and it's good training anyway).

My training workload is gradually increasing each week, and as I train my body is adapting to the new stress levels and responds by allowing me to continue to increase the workload. This ability to manage a continually increased workload is shown by the steady rise in the blue line in the chart below (the blue line depicts my Chronic Training Load (CTL) since I first hopped on the trainer just on four months ago).

The rate at which that blue line can rise is typically limited to a maximum of 5-8 TSS/week. Going above that rate for any length of time is usually met with an increased susceptibility for illness and possibly leads to a degrading of performance. In the opening block, I was increasing CTL at ~ 4 TSS/week and following a break from training I have been increasing at ~ 2 TSS/week. Due to the recovery from injury, it pays to be a little conservative in the rate at which CTL lifts.

Of course, for the blue line to provide such good indicator of changes in workload levels, it requires one to have an accurate understanding of their current fitness level. Hence the testing a couple of weeks ago. Not only does it set a benchmark for fitness, and provide solid data from which to determine what elements of my physiological profile need the most attention, but it also provides a sound basis on which to determine the appropriate workload and the rate at which it should be increased.

There is a period where the blue line heads south. I was having some trouble with my stump - it wasn't coping well with the stresses inside the socket and became quite sore. I thought it would need a couple of days rest but it turned out to need a lot more than that. Hence almost no training for a week and a half. It turned out that it was a technical problem that I managed to solve and so once the soreness faded, I was able to start training again and arrest that downward decline.

So far so good for the "thin blue line".

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Friday, October 10, 2008

Benefit is On!!

OK, Paul Craft has waved his magic wand and it's all systems go for my benefit night.

Date has been re-set for the evening of Friday 28 November 2008.


There should be some cracking racing, with the 3-person team format (a Sprinter, an Enduro and a Women making up each team) and teams can be club or trade-team based. It will be fast and furious fun, so if you're not racing, it will certainly be entertaining to come and watch.

Details of the racing and function are listed on Crafty's RAW Track website here:
Alex Simmons' Benefit Night

The event is now on the CNSW calendar and can be seen here:
CNSW Race Calendar - Alex Simmons Benefit

Entries via the CNSW web site.

Towards the end of the racing, I get to do another 500m TT and see how much I can beat the time I set back in August.

Once again a huge thank you to Paul Craft for putting it all together and for everyone that's helping out and/or contributing to the auction pool for the evening. There are some smashing items up for grabs.

Hope to see you there!

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Sunday, October 05, 2008

Benefit Postponed

My benefit race and function, originally organised for Saturday 1 November, has been postponed by a few weeks due to a clash of dates on the CNSW track calendar. A last minute change by the Wagga Club and CNSW sees their Cat 1 race carnival being re-scheduled to that day and so to avoid a clash Paul Craft has been asked to find an alternative date for my benefit.

I know a new date was chosen and appeared to fit in OK but I can't confirm that just yet - Paul is organising it all. It will likely be a Friday night event now, instead of a Saturday afternoon as there are now no free Saturdays on the summer calendar left.

Look out for more details directly from Paul.

I'll post an update once I have confirmed details.

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