Tag Archives: running science

Another Brick in the Wall

Hitting The Wall.  Those words strike fear in the hearts and minds of marathoners.  In the marathon it is the point of almost no return, the point at which you question your will and ability to go on.  Or so I’m told.  Boston marathon winner (and Canadian marathon record holder) Jerome Drayton once said “To describe the agony of a marathon to someone who’s never run it is like trying to explain colour to someone who was born blind.”  I don’t think I have ever hit the wall.  I’m not sure how I will respond if I ever do.  I hope that I have the resolve to tear it down brick by brick, in Run Fatboy Run style.  To my endless amusement, race directors build symbolic walls at the 20-mile mark for marathoners to run through.  I look upon those giant inflatable archways as life-sized placebos – if I can run through it I won’t hit it.  Maybe the inflatable placebo works, maybe that’s why I’ve never hit the wall.  Or maybe I have hit the wall and I don’t know it.  Like Drayton said, some things can’t be explained.  I’m going on faith that I’ll know it if it happens, but will I?  What is it like?  I get tired, my pace may ebb and flow, my legs feel heavy, running becomes more difficult as the miles go by … is that a bonk or is that a marathon?

Bonking.  I’m not alone in my confusion.  Scientists hotly debate what the wall is and why we hit it. Many point to physiological causes like muscle glycogen depletion, low blood sugar, dehydration and general fatigue, but plenty of studies have shown that the wall strikes before true depletion. Others argue that we hit the wall when our brain starts telling us that we can’t (or shouldn’t) go on, even though we have not hit our physiological limit.  In truth bonking may not be one thing.  There may be a body-bonk, a brain-bonk, and an ultimate-bonk when both the brain and the body put on the brakes.  Although much ado has been made as to why we hit the wall and how to avoid hitting the wall, considerably less scientific attention has been given to the actual experience of bonking. What does the hitting the wall feel like?  Perhaps the occurrence is so gruesome that marathoners won’t talk about it and therefore researchers can’t study it.  Buman and colleagues set out to try. Their objective was to assess the frequency of hitting the wall among marathoners and to identify salient phenomenological characteristics of the experience.  The runners who reported bonking were presented with a list (see below) of the 24 most commonly reported characteristics of hitting the wall and they indicated if the experience exceeded that of a typical race or training run, specified when the effect became significant, and rated the impact on overall performance.

The List.  The 24 characteristics commonly reported as part of the experience of hitting the wall: generalized fatigue, loss of running form, renegotiating performance standards/race goals, muscle cramping or muscle pain, unintentionally slowing pace, difficulty breathing, loss of concentration, deliberate direction of attention away from race, increased motivation, increased effort, clearer focus on race objectives, confusion, decreased motivation, irritability, lightheadedness, decreased sense of pace, nausea, dehydration, limb heaviness, increasingly negative attitude, desire to walk, shifting focus to surviving race, intentionally slowing pace, and desire to quit.  This does not sound good.  Not good at all.

The Facts.  Only 43% of respondents in Buman et al’s study reported hitting the wall.  I say “only” 43% because many studies report a bonk rate of closer to 55%.  I’m astonished that around half of all marathoners bonk – I guessed in the neighbourhood of 25%.  The upside is that almost all go on to finish the race.  Although more men reported wall hitting than did women (45% versus 37%, this gender pattern is consistent with other research), all who hit slammed into the wall around 19.72 miles.  Finish times did not differ between those who did and did not hit the wall – so the faster are not more immune to bonking.

The Bonk, defined.  From the list of 24 bonking characteristics, four things differentiated those who hit the wall from the non-bonkers: (i) generalized fatigue, (ii) unintentionally slowing of the pace, (iii) a desire to walk, and (iv) shifting focus to surviving the race.  The remaining 20 characteristics were reported by both bonkers and non-bonkers alike, although bonkers may have experienced those characteristics more intensely or felt more impacted by them.  So how do we save ourselves from this fate?  The authors found that the odds of hitting the wall were about 1.82 times higher for males than for females.  So Step 1: be a woman.  They also found that a greater distance for the longest training run was associated with a reduction in the odds of hitting the wall.  Step 2: Don’t forget the long run.  I like a few of my long runs to be within 30-minutes duration of my expected marathon finish (for instance, if you expect to run a 3:30 marathon a few long runs in the 3-hour range may help you push back the wall).  Expecting to hit the wall, surprise surprise, increased the odds of hitting the wall.  It’s a self-fulfilling prophecy.  Step 3:  Fill your well to boost your confidence.  Hitting the wall in a previous marathon also upped the odds of doing so again.  Step 4:  See Step 3.

The Lesson.  I think Yogi Berra said it best: “Baseball [running] is 90 percent mental; the other half is physical.”  Poor math skills aside, I think this quote and this study reinforces what we already know about running a marathon: prepare your body, prepare your mind, then step on the starting line full of confidence.

Study RefBuman, M.P., Brewer, B.W., Cornelius, A.E., Van Raalte, J.L., & Petitpas, A.J. (2008). Hitting the wall in the marathon: Phenomenological characteristics and associations with expectancy, gender, and running history. Psuchology of Sport & Exercise, 9, 177-190.

Title Ref:  Pink Floyd – Another Brick in the Wall (Part 1).  From the album The Wall.  1979.

Now Face North

I have this weird sense of direction.  Deep in the secluded woods my husband will spin me around until I get dizzy, randomly stop me, then ask me which direction I am facing (we’re on hiking trips, so it’s not as ominous s it sounds).   I have an uncanny accuracy within the 16 directions of the compass rose – I wouldn’t just say NE, but NNE.  I’m almost* always right (as validated by our trusty GPS).  [*I lose all sense of direction underground; a situation that greatly agitates me.  This may not seem like much of an inconvenience, but as amateur spelunkers we often go underground during hiking expeditions.  Side note: I normally do not spin around to the point of dizziness during a cave descent.].  During one test, based on the GPS coordinates, he pronounced me wrong.  I was flabbergasted because my internal directional reading felt so right.  About 10 seconds later the GPS refreshed and voila, I was correct.  I’m faster and more reliable than the gadget.  That’s about as technical as it gets – I sense the direction.  Like some sort of navigational mystic.  I would have been a real assest to Columbus – Chris, I sense the New World is that way.   Over the years I have come to discover that this sense of direction while certainly not rare, is definitely not common.  Runners, in particular, are often quite hopeless with directions.  I’m sure it is some combination of inability, disinclination, fatigue, distraction, and glucose depletion. 

My run club typically distributes maps for long runs.  Even so, about 90% of the runners will get lost at least once during a training cycle.  Packs of runners will get lost as group, not a one seemingly able to navigate through the city maze.  Orienteering on the run is not an easy feat.  Although frustrating, the silver-lining side of me actually thinks it is good training – getting a bit misdirected is a psychological challenge as quite a bit of mental fortitude is required to keep going when you’ve gone a klick (or a few klicks) out of the way.  Running a marathon takes a lot of will, so it’s good to face some challenges during training.  Expect the unexpected, as we runners are apt to say.  Heck, people have gone the wrong way in races and exhausted runners have momentarily forgotten the location of the finish chute.  It’s surprisingly easy to do, especially when you are following the crowd. 

Sometimes the route maps will say things like “follow the blue line through the cemetery”.  Sounds easy enough.  Hilariously, I will enter the cemetery, point out the blue line, actually stand on it and say here is the blue line – follow this line for the next 2K, and 5-minutes later a flock will, without warning, suddenly deviate from the line.  As though there are being pulled in the wrong direction by some invisible force.  Never mind when we don’t actually have a blue line to follow.  I even have reports of people getting lost on the return portion of an out and back route.  Luckily, within each group someone with a keen sense of direction usually emerges and becomes the default compass for the group.   I have come to suspect that, perhaps not coincidentally, this is the only person to ever look at the aforementioned maps.

I’m the kind of runner who becomes the default compass for the group.  It is a task I embrace.  Wayfinding fascinates me.  However, my orienteering nature runs (ha) somewhat counter to my (mostly failed) quest to be a zen runner.   Maybe next run I will leave the map at home and just go where the wind takes me.  Maybe next time I will follow the group wherever they may lead.  Maybe next time I need to get lost.

Are you a human compass or have you mastered the fine art of getting lost?  Take the test below to calculate your sense of direction. 

Title Reference:  REM – Stand. From the album Green. 1989.

The Santa Barbara Sense of Direction Scale

This questionnaire consists of 15 statements about your spatial and navigational abilities, preferences, and experiences.  For each statement select the number that indicates your level of agreement with the statement.  Select “1” if you strongly agree that the statement applies to you, “7” if you strongly disagree, or some number in between if your agreement is intermediate.  Select “4” if you neither agree nor disagree.

strongly agree    1   2   3   4   5   6   7    strongly disagree

1.  I am very good at giving directions.
2.  I have a poor memory for where I left things.
3.  I am very good at judging distances.
4.  My “sense of direction” is very good.
5.  I tend to think of my environment in terms of cardinal directions (N, S, E, W).
6.  I very easily get lost in a new city.
7.  I enjoy reading maps.
8.  I have trouble understanding directions.
9.  I am very good at reading maps.
10.  I don’t remember routes very well while riding as a passenger in a car.
11.  I don’t enjoy giving directions.
12.  It’s not important to me to know where I am.
13.  I usually let someone else do the navigational planning for long trips.
14.  I can usually remember a new route after I have traveled it only once.
15.  I don’t have a very good “mental map” of my environment.

For Qs 1, 3, 4, 5, 7, 9, 14:  1=1pt, 2=2pts, 3=3pts, 4=4pts, 5=5pts, 6=6pts, 7=7pts
For Qs 2, 6, 8, 10, 11, 12, 13, 15:  1=7pts, 2=6pts, 3=5pts, 4=4pts, 5=3pts, 6=2pts, 7=1pt

The lower the score the better the sense of direction (minumim=15 and maximum =105).  In the interest of full disclosure, I scored a 20.

Ref:  Hegarty, M., Richardson, A.E., Montello, D.R., Lovelace, K., & Subbiah, I.  (2002).  Development of a self-report measure of environmental spatial ability.  Intelligence, 30, 425-447.

Confessions of a Wannabe Morning Exerciser

A morning workout.  The concept holds great appeal to me – wake up early to exercise, go to work, then enjoy a rare quiet evening at home.  There is no good reason why I can’t manage a morning swim, spin, or yoga class.  There are reasons, just not good ones.  About once a week I get the notion that I will wake up early to get in my workout.  About once a week I fail to follow through on these grandiose plans.  It goes something like this: The alarm bells sounds earlier than usual.  I press that magical button that grants me nine extra minutes of sleep.  Repeat.  Repeat.  At some point I become partially roused.  Roused enough to generate a pillowcase full of (lame) excuses.  I’m tired.  The extra sleep will benefit me more than a swim.  If I go after work I won’t watch as much TV tonight.  I’m too stiff in the morning to get much benefit out of my yoga class.  Better to wait until the evening session.  By the time I get to the gym I’ll just have to leave to get to work.  After work I’ll have more time.  I feel a cold coming on.  And the excuse making continues until I run out of time (or fall back asleep). 
I do manage one early morning workout per week(end) – my long run.  I won’t define “early” because I’m sure at least 50% of you will scoff.  Let me just say that I get up earlier for my long run than I do for work.  Attendance at my early morning run is more out of habit than out of any sort of natural inclination towards the am. I run with a group and every Sunday morning I drag myself (make that drive myself, because no way I’m getting up early enough to walk) to run club bleary-eyed and incoherent.  I’m not the only one.  A friend once arrived still in her pyjamas and fuzzy-pink slippers.  True story, except for the slippers part. 
I blame chronobiology.  I am a slave to my biological rhythms.  Your chrono-type is revealed in your sleep patterns.  We all know that there are owls (evening-types) and larks (morning-types) and those birds that can tweet anytime (neutral-types).  Although much of our tendencies are determined by genetics, age and lifestyle are factors as well.  For instance, the young and the old are more likely to be morning types and college students tend toward the evening side of the scale.  Morning and evening types represent about a mere 15-20% of the population; the remainder are swingers.  Where do you place on the lark-owl spectrum?  Unusually, I was an evening-type even as a child (I didn’t – still don’t – wake up spontaneously on Christmas morning) and post-university I’m still an evening type, even though my occupational demands lend themselves more fruitfully towards morning productivity.  I can’t shake my nocturnal tendencies.  Owls, like me, naturally waken about 2 hours later than the majority of the population and don’t feel sleepy until sometime around 12 midnight and 2am.  We like to stay up late and wake up late.
Did you know that your chronobiologic rhythms can effect your running speed, strength, and endurance (not to mention your cognitive state – which in my experience can influence all of the aforementioned variables)?  You may want to time your workouts to your chronobiology.  Or perhaps not. If your race is ill-timed for your rhythms some practice running out-of-sync might be beneficial.  Like me and those early morning races.  I need to train my legs to move two hours before they’d prefer to wake up.  There is research to suggests athletes may perform better in the late afternoon, but for practical reasons (like increasing temperatures) marathons rarely start at 4pm.  The afternoon advantage is reflected in improved strength, anaerobic performance, and aerobic capacity, and decreased risk of injury.  On the flip side, other research shows that morning exercisers are more likely to stick with a routine.   Hard to reap the rewards of an afternoon run if you drop out of training in week three.  Fortunately though, the time-of-day impact is less dramatic during moderate intensity aerobic activities, like in jogging, than it is on other sports requiring more explosive power.  Unfortunately, I do not consider running a marathon to be equivalent to a moderate-intensity jog. 
So what’s a runner to do?  When to run is determined by your personal circadian clock, biological changes across the day that culminate in a 4pm boost, your lifestyle and preferences, and considerations like the race start.  Timing may be everything, but I’m of the mindset that any time is better than no time.

It’s the final countdown

29 Days until the Boston Marathon.  29 days and 11 hours and 40 minutes.  That’s less that a normal-sized month (oddball February excluded) away.  But who’s counting?  Me, that’s who.  Gulp.

Why is it that winter, which usually seems so endless, felt so short?  Wasn’t it just yesterday that I started my training? And now I’m almost out of time.  I’m a winter runner and I’m not ready for my cold weather training to end.  In a choice between +20C and -20C I’ll pick the latter every time.  I revel in the sub-zero training and the near-zero racing.  But suddenly spring is in the air, the layers off winter are coming off, and Boston is less than a normal-sized month away.  I have precious few days of cool training weather left before the hot humid haze takes over.  I have precious few days of training left before my running quadfecta begins.  I’m feeling the heat, in more ways than one.

I’m not alone in my love of the cold.  A study pulling together years of marathon results and weather data concluded that 41F/5C is the ideal marathon temperature.  As the mercury rises to 10C performance drops by 1.7% and at 15C performance is down 2.5%.  And it just keeps getting worse as the temperatures soar.  Those results – totally me.  So, until the heat wave begins I’m taking full advantage of the last chill of winter.  The gloves aren’t off, yet. 

Title Reference: Europe – The Final Countdown. From the album the Final Countdown. 1986.

She’s got legs; she knows how to use them

I often feel like my long limbs get in my way.  There is a certain lack of coordination that comes along with extra-long legs – think Bambi learning to walk.  As a runner though, many people view my long skinny gams as an asset.  I’m not convinced.  Clearly they’ve never gone shopping for full-length running tights or “capris” as I call them.  I have a permanent ring of frostbite in that space between the end of my socks and the start of my so-called pants.

Let’s look at the reigning marathon champions.  At 5’8, Paula Radcliffe is taller than the average woman, but she’s barely model tall.  Haile Gebrselassie, at 5’5, is below average height, but not dramatically so.  I read somewhere (source unknown) that most elite marathoners tend to be of average height and below average mass.  Maybe distance runners look so tall because they are so lean.  Like an optical illusion.  Long legs may sound good, but a short lean person does have less mass to carry around for 42.2K than a tall lean person.  The shorter runner may also have a flexibility advantage that could benefit running – more efficient stride, less injury susceptibility, and so on.  I don’t know for certain that taller folks are less-flexible;  I’m just saying that you don’t see many sky-scraping gymnasts.

The ‘tall is better’ theory seems to centre around the hypothesis that longer legs means a longer stride, which in turn means fewer steps over the same distance.  Presumably, over the long run (ha ha), fewer steps are more economical.  However, longer limbs may also have a greater moment of inertia, which requires effort to overcome – which is not so economical.  Anthropologically speaking, as with shorter toes, increased lower-limb length is thought to have coincided with other morphological changes observed with the appearance of Homo species.  These changes are consistent with the view that daily movement distances were much more extensive for Homo than for earlier hominins.  When the movement territory was small the cost of less efficient shorter lower limbs would have been minimal, especially in light of other advantages (like climbing).  But as the need for endurance locomotion arose, fuel-efficient long limbs became an asset.  Perhaps a must.  Or so the theory goes.

Steudel-Numbers, Weaver, and Wall-Scheffler tested whether leg-length did impact running economy.  When controlling for body mass, they found that increased lower-limb length did result in a lower cost of running.  It’s true; there is a long-legged advantage, at least in terms of locomotor economy! Long legs are more efficient, although it isn’t clear why.  It is interesting, though, that this increased efficiency was not related to stride length. The tall (or, more precisely, the long lower limbed) do have an advantage, but not because of their increased distance between footsteps.   So don’t envy the stride, envy the ride.

Ref: Steudel-Numbers KL, Weaver TD, Wall-Scheffler, CM. The evolution of human running: Effects of changes in lower-limb length on locomotor economy. J Hum Evol. 2009. 53:191-196.

Title Reference: ZZ Top – Legs. From the album Eliminator. 1983.

Running Is Its Own Reward

Time and time again it comes to my attention that a sizeable segment of the population are under the impression that people run for one reason and one reason only: to lose weight.  As a slender gal, I’m often asked why I run when I don’t “need” to run.  Why would I exert the effort if not for reasons of appearance?  It’s madness.  Based on the “skinny = why bother to run” theory, health is irrelevant.  Afterall, it’s all about the number on the scale.   Perhaps I should just enjoy my genetic blessings, flop myself on the sofa, eat bonbons, and watch TV.  Ok, I do that too.  There are many reasons why I run and weight control does not make my top ten list.  And given the amount I eat during training, it would be a doomed endeavour anyway.

I find this personal experience interesting in light of recent research conducted by Havenar and Lochbaum.  They studied individuals training for their first marathon to assess differences in motivation between the successful rookies (those who ran the marathon) and the dropouts.  Perhaps not surprisingly, 70% of the original participants quit during training and did not run the marathon.  Using the Motivations of Marathoners Scale (MOMS) the authors found three measures that differentiated the finishers and dropouts: weight concerns and social motives (social recognition and affiliation).  In all cases the dropouts rated those motivators, especially weight concerns, more highly than did the finishers.  The results “suggest that weight concern and recognition motives among first time marathoners are possible predictors of premature disseveration from the training program”.  That is, they dropout.  It seems that the will to get skinny isn’t enough to get you across that finish line.

Ref: Havenar, J. & Lochbaum, M. (2007).  Differences in participation motives of first-time marathon finishers and pre-race dropouts.  Journal of Sport Behavior, 30, 270-279.

The Long and the Short of It

I have long slender fingers.  People tell me they are perfect piano playing fingers.  With no musical gifts whatsoever, those fingers are wasted potential. I also have long(ish) slender toes.  They are a genetic gift from my father.  Beyond intense frustration when trying to buy flip-flops or the occasional post-race toe rehab, I don’t spend much time thinking about my toes.  I especially don’t spend time thinking about how my toes may be negatively impacting my running.  Or I didn’t, until now.

In a recently published article in the Journal of Experimental Biology, Rolian and colleagues found that a mere 20% increase in toe length over average leads to greater mechanical work in stabilizing the metatarsophalangeal joints and controlling the forward motion of the centre of mass during propulsion.  They presume (but didn’t directly test) additional mechanical work translates to increased metabolic costs of locomotion.  In practical terms the reduced mechanical performance and higher metabolic costs of long toes are suggestive of injury susceptibility.  The authors specifically point to situations in which the toes are loaded for long periods of time – such as during a marathon.  The extra forces could accelerate the onset of muscle fatigue, which tends to lead to alterations in loading (we change our biomechanics slightly so as to reduce pressure on the fatigued areas).  Possible long term outcomes include metatarsal stress fractures and increased wear and tear on the tendons culminating in microtraumas and tendon failure.  The latter issue, tendon stress, fatigue, and failure, has plagued me through the years.  Perhaps my little piggies are to blame.

The authors place this research in the context of evolution.  Short human toes (or more precisely, the phalangeal portion of the forefoot) differ from extant non-human hominoids (like chimps, gorillas, orangutans, gibbons) and earlier hominins.  Presumably a set of physical and behavioural adaptations for endurance running, including short toes, were selected for over the course of human evolution.  Our short-toed ancestors would have been more efficient runners, a fine skill when running was critical to survival.  Poor Australopithecus, with their long lateral toes, could not forage as far or as long as their shorter-toed brethren.  Modern humans with Australopithecus-like toes (approximately 40% longer than average) are similarly disadvantaged.  Somehow surviving natural selection, we still face an increased risk of injury during distance running.  I suppose non-running modern humans with long toes aren’t bothered much by the ends of their feet.  My anthropology loving friend has awesomely dubbed my disadvantaged digits “Lucy Toes”.   Those of you with more evolved Lilliputian-sized toes – rejoice, advantage one.

Epilogue:  Since originally posting this article I did what any good scientist would do.  I measured my toes. To my surprise, my increase over average is a mere 10% — less than the 20% found to mess up running.  I’m on the search for a new evolutionary excuse for my less than elite times.

Ref: Rolian C, Lieberman DE, Hamill J, Scott JW, Werbel W. Walking, running and the evolution of short toes in humans. J Exp Biol. 2009. Mar;212(Pt 5):713-21.