Friday, March 28, 2008

Dr Smith

Anyone who recalls the 1960's TV show "Lost in Space" will also remember the character Dr Smith, who had a favourite saying: "Oh the pain... the pain!"

Usually it was a metaphorical reference to the unusual circumstances that Dr Smith and the crew of the Jupiter 2 space craft found themselves in on their jouneys, either on a strange planet or lost in space travel.

Well I can certainly attest to the sentiment lately but in my case the pain is more real than metaphorical.

I mentioned earlier about all those socks I have to use now the leg has changed size and form since starting out. Simply put it means that my leg stump is not held securely inside the socket of my prosthetic leg (Schooner) and the platform on which I bear my weight is unstable. It's a bit like having someone perform a Chinese burn on your leg each time you take a step. After a few hours you get fed up with it and take the leg off.

This has not helped with plans to pedal away on the home cycle trainer. Getting up in the morning and putting on a prosthetic only to be sore before you start the day is not conducive to any attempt to exercise and so my motivation to train has waned somewhat.

Last week it was particularly ordinary, even leaving Schooner off for a couple of days and getting about on the crutches again just so my leg could get a rest.

Now this won't last thankfully! It will be solved when my new leg is ready. Fortunately the funding approval from NSW Department of Health has come through and so next week I am going in to see my prosthetics specialist George to get measured up for the new leg. It will use a different and superior mechanism for supporting the leg, which should result in significantly greater comfort. Let's hope so!

Otherwise I'll need to get my hands on the robot!

Read More......

Wednesday, March 19, 2008

Pithy Power Proverbs

OK - I know there's a bit of tautology in the title but it sounded good, OK?

I was trying to recall all the pithy power training statements that have emerged over the years on power training forums. Last month I started a thread on the Wattage Forum with the aim of collating all those pithy little sayings.

I thought it would be a bit of fun to collect them all. Here's the result, listed in no particular order:

"It's an aerobic sport, dammit!" - Andy Coggan

"Training is testing, testing is training." - Andy Coggan

"The best predictor of performance is performance itself." - Andy Coggan

"The more you train, the more you can train." - Andy Coggan

"FTP = how fast you can go. CTL = how long you can go fast." - Rick Murphy

"The Anaerobic Threshold is neither." - unknown

"Hmmm." - Robert Chung :)

"Alls you can do is alls you can do." - Andy Coggan

"Cadence is a red herring." - Robert Chung

"If you're on the bike and the wheels are turning, you're riding" - Andy Coggan

"Specificity, specificity, specificity . . ." - Andy Coggan

"Lydiard got it right" - Andy Coggan

"All watts are not created equal." - Dave Harris

"The body responds like a Swiss watch. You just have to figure out how to wind it." - Dave Harris

"Toss that HR monitor strap!" - Charles Howe

"Power calibrates PE, PE modulates power." - Charles Howe

"It's all about the pedal force." - Tom Anhalt

"Training with a Power Meter, does it work? No, you work!" - Hunter Allen

"waaaaah my powermeter doesn't work" - first time poster ;-)

"more is more ... until it isn't" - Rick Murphy

"The best thing about a power-meter? It tells you where you are. The worst thing about a power-meter? It tells you where you are" - Bob Tobin?

"Fitness is an integral" - Rick Murphy

"For riders of every level, power is limited but speed is precious" - John E Cobb

"The less power you have the more gearing you need" - Steve Davidson?

"In God we trust, all others bring data" - W. Edwards Demings

"The plural of 'anecdote' is not 'data.'" - Frank Kotsonis

"(The) most successful riders spend the most time at zero cadence during races." - Andy Birko

"At some point, you have to increase the power" - Andy Coggan

"If it *feels* hard, it *is* hard" - Andy Coggan

"If you're wondering whether you've underestimated your functional threshold power, you probably have." - Rick Murphy

"Train, don't strain" - Arthur Lydiard

"The PowerTap is a tool, not a bolt on motor :) " - Chris Mayhew

"The PM chart is a one picture summary of the truth, as useful and brutal as honesty can be." - Alex Simmons

"Wow, I need to train more!" - Frank Overton (after looking at his previous season's Performance Manager chart)

"The (power) training levels are descriptive, not prescriptive, guidelines." - Andy Coggan

"!!!" - Hunter Allen

Read More......

Thursday, March 13, 2008

Funky things with a Power Meter #77

OK, maybe I haven't demonstrated 76 other funky things with a power meter but then I have discussed or demonstrated the following:

OK, that's only 17 dots, so this will really be Funky thing # 18. I should add that most of what I've written is based on tools and analysis developed by guys far cleverer than I but is simply there to demonstrate a number of power training ideas and principles. If anything up there sparks your curiosity, then just click on link or look it up via the index at the right to find posts grouped into various categories.

So what's Funky Thing #18 all about?

The Chung Method

Well it's linked to aerodynamic field testing but using a different methodology, known as "The Chung Method", developed by a data analysis guru and regular power training forum contributor Robert Chung. It also acts as a proxy for developing an elevation profile of a loop course without the aid of an altimeter (now that's the really funky bit). It works best when you ride a course that passes the same point more than once (the more times the better). What am I on about?

From analysing the power & speed data from a power meter file for a typical ride, estimates for both the coefficient of drag-area (CdA) and coefficient of rolling resistance (Crr) can be made. These key measures indicate the degree to which air resistance and the road surface serve to retard our forward progress or how hard we have to push on the pedals to overcome these forces at any given speed.

The method works by using the equations of motion for a cyclist (well a slightly cut down version), with a few assumptions thrown in (such as a low wind day). If we know a little more data about the course and the conditions, the estimates of CdA and Crr derived and elevation profile obtained can be pretty good. Good enough that changes in rider position, equipment (or conditions) can be readily detected and that the elevation profile be correct to within a few metres.

And it does not require the usual protocol for field testing, that of doing multiple runs under highly controlled conditions. Just use ordinary power meter data from a loop course. It helps if you have a near windless day (a little wind is OK).

Now Robert's paper which discusses
this method in detail can be found here:

So I thought I'd have a go and with the aid of a spreadsheet posted on one of the training forums I frequent, I applied it to a sample of my own data.

I picked a training file from Boxing Day 2006. Here is a pic of the training loop I rode that day, a popular local training ground - Centennial Park in Sydney. Grand Drive is a 3.8km roughly circular loop, flattish. There is also an option to climb up a hill to the Ocean Street gates, then across to the Paddington gates before descending back down to Grand Drive, which adds about 2.5km to a loop. Sydney-siders would be pretty familiar with the Park.

Here is the graph of my power and speed file for the day chosen. It was a tempo effort of 90-minutes duration where I did laps of Grand Dr with a climb up the hill to Ocean St every second lap. You can see that by and large I kept my power output within a range and let my speed vary (not that that's necessary for this method - it's just what I happened to do that day).

Using this data and the spreadsheet with the funky formulas which use the equations of motion, here is the chart produced showing the ride elevation profile of my ride in Centennial Park that day. On the chart I show the CdA and Crr estimates needed to provide a consistent elevation for the same points in the ride. Since I already knew the elevation difference from the lowest point to the highest point in the park, that helped me adjust the CdA and Crr numbers such that the profile provided an accurate representation of the course (to within a few metres).

That's quite remarkable if you ask me. Now it was just a training run, not a time trial, so I was on my training bike, probably riding with my hands on the hoods, maybe occasionally on the bar tops going up the hill. A cool morning too, so probably a bit of extra clothing on for warmth. Hence the relatively high CdA of 0.384. A Crr of 0.005 was settled on and seems to be a reasonable estimate for the mostly decent quality hotmix/asphalt surface in the Park.

You will note some variations, particularly the opening kilometres and the final lap, where the profile varies from the consistent elevations shown from km 6 to km 40. I suspect that during this middle section of the ride I was using a consistent position on my bike.

For the final lap, since the derived elevation data doesn't match the other laps, it appears that either I rode in a different position, changed clothing, conditions changed (perhaps the wind) or I was mixed in with other riders. I'm not sure, I can't recall. But the change is very distinct with this method and is one way of assessing the impact of changes to equipment and/or rider position.

The forum thread where this sparked my interest in having a look at it myself is here:
Slowtwitch Chung Method

So what's Funky Thing #19 gunna be?

As Robert Chung would say, "Hmmm...."

Read More......

Tuesday, March 11, 2008

Sock it to 'em

The socks I use in side my current prosthetic leg. Lots.
Thick cotton ply jobs (3-4 ply) about 12" (30cm) long.

So what's been happening lately?

Well the trainer project has moved along a bit. The frame is under construction and the flywheel will be machined down to size/weight. I calculated we needed to reduce the radius of the wheel by 45mm to get the weight down to an ideal mass. The SRM power meter is on its way and I should have that in a few days.

I also had a bit of fun with John playing with those uber strong rare earth magnets, rigging up a crude device to enable us to test the theory that they'll provide some form of controllable braking resistance for the ergo. It was a good enough test for us to consider the next step. I fashioned up a rough design as to how we could make it work (keeping in mind the functional but easy and cheap to rig up theme):An online discussion of the project can be found here.

As for my leg - well Schooner is now a 7 to 8 sock kind of guy (meaning I have around 30 ply of sock padding out the leg so it will fit snugly into Schooner's hard outer casing) and as a result he ain't all that comfy anymore. I used to use just one. See the picture above for an idea of how much sock that is. These are fatter than thick footy socks - more like Grandma's knitted bedsocks!

Accordingly, and following a review by my rehab Doctor at the amputee clinic, a script has been written to get funding for a new leg approved (via NSW Dept Health). Once that is cleared (about two weeks), then George at the Appliance and Limb Centre will give me a call to come in for a new sizing. Leg will then take another two weeks to make. So I'm about four weeks away from a new leg. That's about two months faster than normal I'm told.

I won't go for the bog standard (Schooner-like) leg that the subsidy covers but rather use the subsidy to go towards a better model of leg, which will also enable a cycling leg attachment. It'll cost more but it'll be worth it.

My knee flex hasn't improved much despite the best efforts of my physio. Not her fault, I simply haven't done enough regular work on it. For the first time in a long time I have not had the same motivation to do the work needed. It's part mental and part due to my current leg not being all that comfortable. When you start the day with a sore leg, there isn't much motivation to train on it. So I'm hoping the new leg will help me along with that. Everyone says "don't be so hard on yourself". But it's being hard on yourself that gets results, so I'm a bit frustrated with myself at the moment.

My cycle coaching is going along nicely and keeping me mentally active, with another coach asking me to coach them (I have several coaches as clients). Quite ironic in some ways but I suppose coaches really appreciate the value of coaching. My understanding of the ways of training with power has a bit to do with it as well ;)

Apart from my cycle coaching activities (I really enjoy my coaching work), the time has come to gradually venture back to the office and begin the process of re-establishing my "day job". So this week, after various consultations with my Doctor and the HR people at the office, I ventured in for some meetings with the leadership of the business, mainly to say hello and also to discuss what I'll be doing when I start back there next week. It's 11 months since my accident, so there's quite a bit to catch up on. I won't resume my previous duties but instead I'll move into a business improvement role and report directly to the CEO. The challenge of getting back to the work routine will take some adjustment but it'll be good for me. I'll start part-time and will ramp up the hours as I am able.

This getting up early and shaving is a bit rich though!! :)

Read More......