Racewalking: The hidden flight path

Anyone who has watched racewalking intuitively knows it's different from running, hence it has as much credibility as classic technique in XC skiing, or the butterfly stroke event in swimming. And anyone who's tried race-walking knows it's very hard to do well, painful (especially the shins) and frustrating (especially if you get DQd moments before finishing). For most of its contemporary existence it has been a maligned sport.

What are the technical differences between walking and running? According the official rules,

• Racewalking is a progression of steps so taken that the walker makes contact with the ground so that no visible (to the human eye) loss of contact occurs.  

• The advancing leg must be straightened (i.e., not bent at the knee) from the moment of first contact with the ground until in the vertical position.

We know there is a flight phase with each running step. Walking, by contrast, both your feet should never both leave the ground. Rule #2 is less intuitive but in fact a better way to differentiate running versus walking. Interestingly this rule only came into effect in 1995.

There are another technical differences. For instance in a runner's mid-stance phase, i.e. when the foot swivels under the hip, the body's centre of mass (COM) is at its lowest. For walkers, because of the straight knee, their mid-stance COM is at its highest point. I only mention this because because I find that both running and walking, when you really think about them, are weird, complex movements.

Returning to rule #2, it is easy enough to visualize (and enforce) to make it a fair visual criteria in a judged sport. However there is a fundamental problem with Rule #1 that I will now explain. There is already plenty of research that observes a flight phase in race walking. For instance in a recent (2014) literature overview, Pavel et al note

From an overall view, race walking athletes seem to adhere to the ‘straightened knee’ rule, but at race speed they do not observe the ‘no-flight time’ rule. 

Admittedly flights times spoken of are small; Pavel estimates between they range 0.01 and 0.05 seconds. But those small flight times add up. Moving at 4 m/s, a single 1/100th second of "flight time" can earn a bonus distance of 4 cm (after all, distance = speed x time). So in a 50 km walk race, given a stride frequency of 3 steps/s (180 steps/min), one takes over 37,000 steps. That tiny flight time and 4 cm per stride adds up to a total distance gain of 1.5 km! Importantly the human eye cannot visually process a flight time of 10 milliseconds yet a race walker is less likely to win without this clear flight-time advantage. Indeed, in one study flight times were found positively correlated with speed.

Video of a race-waller leaving the ground (at 0:13):


Unlike some judged sports where small "cheat" advantage stay small (such as making a single illegal V-shape move with your skis in classic racing), because of the cumulative effects of undetectable millisecond flight times, we now know a completely honest race walker is at a permanent disadvantage over one who can eke out a bit of air time for each stride.

Rum runner's relay and the personal trophy

On the weekend I was part of the winning team for the Rum Runner's Relay (A Few Good Men). The team award has gone to HRC (Halifax Running Club) for ten years straight so yes, we are breaking history.

Ultimate prize: A rum barrel! (sadly it contains no rum) 

Since my time in Halifax is growing limited (assuming I find work in Montreal next spring), it was a good time as any to experience part of the coastline on foot from the HRM to Lunenburg. Beautiful weather and a fun 12-hour day overall. I'd like to be back, if possible. We'll see.

Science of running: a hierarchy

Listening to Steve Magness' podcast on the topic of Systems vs Process methods to coaching got me thinking about my own take on the subject.

By and large I agree with Steve's message, which boils down to acknowledging coaches can't expect long-term development from their athletes if they follow a pre-ordained workout recipe. This makes perfect sense, as so many factors go into choosing a proper working, to declare your original plan unassailable is tantamount to fortune telling.

But I was irked (as always) when Nassim Taleb's cursed Swan quoted. It is true that "One cannot understand a macroscopic system by appealing to its components in isolation" when making final decisions. But it is also true that isolating certain components can be helpful. That's why we have the Large Hadron Collider. That's why our minds do not benefit from unnecessary multi-tasking. That's why workouts often focus on one type of running (easy, tempo, distance, speed).

Isolation is, in essence, good. Then as athletes grow in complexity, so do the workouts. Each workout component is equivalent to a keyed note. The totality of multiple workouts with many such keys is music.

To illustrate this complexity, I made a diagram with the various internal levels within each of us. To avoid over-generalizing I focus on running.

A season summary: Tely 10, Calgary, and more

I'm not as much a fan of posting too many details about my own races. My favourite thing is to take a step back and see a larger picture. But as this season has been a busy and productive one, it seems disingenuous to ignore all people and places that have been part of 'my' running this season. My season started in April (not counting two indoor 3k races), and is taking a pause in August. In fact right now I'm on a work trip, writing this in Indiana of all places. First to boil down the facts, here's my races from the season.

 My 2015 Spring-Summer Road Races

Date	Location	Distance	Place & Time	Rating*
April 25	Grande-Digue	15 km	2nd in 48:45	★★★★
May 2	Lung Run	5 km	1st in 15:08 (PB!)	★★★
May 23	Cabot Trail Relay (Leg 17)	18.7 km	2nd in 1:02:05 (PB?)	★★★½
May 31	Calgary Half Marathon	21.1 km	8th in 1:09:14 (PB!)	★★★★
June 21	Halifast Track Event	5000 m	1st in 15:15	★★
July 10	Antigonish Highland Games 5 Miler	8 km	2nd in 25:32	★★★
July 26	Tely 10	16 km	2nd in 51:04 (PB!)	★★★★
Aug 3	Natal Day 6 Miler	9.6 km	2nd in 31:15	★★★

*Rating (out of 4 stars) is a subjective combination of my feelings about my performance and the race itself. At the end of the day, it's hard to disentangle the two.

Some of the best season news is that I had no terrible races and no serious injuries. I never came close to dropping out or running hurt (running sore, well yes). Must be all those training heuristics I use (FYI: I don't keep a mileage log). Also one thing is for certain, I got real comfortable finishing behind the winner. On top of that, both of my victories were only 10 seconds ahead of second, so there was a real possibility of landing 7, let alone 5, runner-up positions. Fun fact: I finished behind a Matt (McNeil + Loiselle) a total of 4 times. Matts are fast!

Estimating Calories from random foods

Every piece of food you buy in Canada is equipped with a Nutrition Facts label.

This label presents an data total Calories, Fibre, Fat, Sodium, Carbs, Protein and micronutrients per serving. Of those, only protein, fat, and carbs contribute meaningfully to total calories. There are some odd trends in the labelling practises. For instance "Fat" and "Carbohydrates" have a "% Daily Value" (%DV) associated with them, but not protein. This is odd, since recommended protein intake is much easier to estimate a priori than either carbs or fat (more on that later). It's also odd that %DV of total calories is not given, since fat and carbs (whose recommended percentages are given) make up the bulk of food calories. Yet so much data is given, seems we could figure this out. Is it possible to reverse engineer the nutrition data given, make some simple assumptions, and sneakily obtain total recommended daily calories?

My Goal: using only the packaging of random food items (and one assumption about protein intake), I will determine the tacit daily caloric intake made by Health Canada.

(Questionable) ideas for promoting road races

In the USA, for the year 2014, total marathon and half marathon participation numbers are at an all-time high. There are almost 100 races across the US with more than a thousand participants. All good news so far.

We've come a long way from the niche sport that was marathon racing 40 years ago; total numbers have since increased 20-fold. There is no reason to suspect a collapse of the system, as races require little capital investment compared with, say, a soccer stadium or an NHL-worthy ice rink. But there are hints that 2015 will see an absolute peak in race numbers. This could lead to a small, but noticeable, chain of events.

Drugs in sport: a manifesto of sorts

Here are some propositions for putting drugs in context with the broader definitions in sport.  There are no hyperlinks to news articles. There are no equations. There are no scientific articles and few drugs are actually mentioned in context. We assume the drugs work as prescribed. Anyone reading this far already has opinions on the matter of drugs in sport, therefore I am avoiding superfluous quotes from other op-eds.

I am searching for beginnings, rather than ends to the conversation on drugs in competition. We already know 'getting caught' is 'bad'. But why? What starting point brought us to this conclusion? These are seven propositions that seem, collectively, like as good a starting place as any. Basically I have assembled collection of (what appear to be) generally-true statements about drugs. Some statements are trivial, others contentious, some others vague. I'm curious what others see in them.

So here are the seven propositions for what we consider when bettering oneself at a sport: