Tuesday, June 21, 2016

Grandma's Marathon 2016: How much did the heat slow your time? A statistical analysis


Photo: Drew Geraets
The 40th annual Grandma's Marathon was held this past weekend in Duluth, Minnesota.  Grandma's is a staple of the Midwest marathon scene and is perennially praised as one of the best races in America.  The point-to-point course is a beautiful route that starts in the north woods of Two Harbors and follows the shore of Lake Superior into downtown Duluth.  With a slight net elevation loss and very few hills, the course is also usually a fast one.

This year, however, many participants were disappointed with their times.  Warmer than average temperatures and clear, sunny skies caused many runners to finish well back from their goals.  Since several runners that I coach or advise ran the race, I was curious to see how much of an effect the temperature had on their finish times.  So, as I often do, I started crunching some data.

Fortunately, I was able to stand on the shoulders of some Big Running Data giants—a 2012 scientific paper by Nour El Helou and other researchers in France already laid the groundwork for disentangling the effects of climate on marathon race times.  In their paper, El Helou et al. analyzed ten years' worth of results from six World Marathon Majors (London, Berlin, Paris, Boston, Chicago, and New York), resulting in a data set of 60 marathons.  These totaled almost 1.8 million marathon finishers.  El Helou et al. ran statistical analysis on each year's results, trying to find the correlation between ambient temperature during the race and the distribution of the finish times.

El Helou et al.'s methods

Because El Helou et al. (correctly) hypothesized that temperature would have varying effects on runners of different abilities, they analyzed several levels of performance for the top one, 25th, 50th, and 75th percentiles of male and female finishers.  So, for example, if the 2010 Chicago Marathon had 21,000 male finishers, the authors looked at the finish time for 210th place—that's the "one percentile" time.  This marker is more useful than looking at the winning time or 10th place, because those can be affected by things like the quality of the elite field, the tactics employed by the lead pack, and so on.  After extracting the various levels of performance for the 60 marathons in the data set, El Helou et al. then consulted meteorological records to find the ambient temperature midway through each of the 60 races. 

Doing regression analysis allowed El Helou et al. to correlate the ambient temperature with the distribution of finish times.  The broad trend in the results was not surprising: marathon times are slower when temperatures are too hot, and they are also slower when temperatures are too cold.  What was surprising, at least to me, was the optimal temperature for marathoning.  El Helou et al.'s data robustly shows that the ideal temperature for running a marathon is pretty chilly—39 degrees Fahrenheit (3.8° C) for a 2:40 marathon! Race times follow a parabolic curve, slowing significantly on either end of an optimal temperature. 

Click to enlarge

Tuesday, April 26, 2016

Training for talented but injury-prone distance runners


Are you looking for a shortcut? Are you not very talented? Maybe you should read this article instead! Five steps to success at high school distance running

Writing the perfect training plan is easy.  There are plenty of philosophical debates on the internet about the finer points of workouts, paces, etc., but most coaches can come to some agreement on what works—on paper, at least.  The problems arise when you try to take these perfect training plans and start using them in the real world.

Will most 5k and 10k runners improve if they could run 100 miles a week with a 20mi long run, a 10mi tempo run, and a long interval session every week? Sure.  But the problem is that most can't do this without getting hurt.  Too many runners get caught up trying to emulate a perfect training plan, then get frustrated when it doesn't work out.  If you've been in the sport long enough, you've probably known several talented runners who keep banging their heads against the wall, trying the same training plans over and over, hoping that if they can just stay healthy for once, they'll get really fast.  Strictly speaking, this is true: if you're really talented, and if you get a long block of great, uninterrupted training in, you're going to get very fit.  It's that second "if" that's usually the problem.

Especially if you are a naturally talented runner—and by this I mean that your baseline ability to cover long distances at great speeds is strong, i.e. your natural aerobic fitness is good—nothing matters if you can't stay healthy.  If you or a runner you coach is very talented but also very injury-prone, what is the right way to approach training?

Training for the injury-prone talent

The first thing you need to do is forget everything you've learned about normal training.  Pretty much any book on training for distance runners (including mine) will lecture you about the importance of a big aerobic base, usually built from high mileage and prodigious high-end aerobic workouts.  Again, if you're a very talented runner, you benefit a lot from this, but if you can't run 40 miles a week without staying healthy, forget 80 miles a week for now.

I recall advising a DI runner who had suffered ten stress fractures in five years of running.  Despite this, he'd managed to run 2:25 in the 1000m and under 8:30 in the 3k.  Though his mileage was, overall, fairly low—50-70 miles a week—he nevertheless suffered constant bone stress injuries.  If you were his coach, wouldn't it make sense to try something different after stress fracture #3 or 4?  On paper, yes, 50 miles a week isn't enough to run a great 3k or 5k.  But no matter how much you run, you'll never race well if you are injured.  Is there another way?

A better approach is to return to a first-principles approach to understand what you need to run fast.  In a standard training methodology, a large volume of easy to moderate running allows you to do faster high-end aerobic workouts, which in turn enable you to run race-specific workouts and the race itself.  Renato Canova illustrates this simply and beautifully:

If I use fast intervals, I train for improving my race performance

If I use long fast run, I train for becoming stronger in my specific training

If I use long run at moderate speed, I train for increasing the base that makes me able to run long and fast

For a very talented but injury-prone runner, you can significantly cut injury risk by using talent as your base—instead of running high mileage and a lot of aerobic workouts, you can very low mileage and only sparingly (but not never!) go for aerobic workouts, relying instead on your high natural aerobic level to enable your race-specific work.  You can supplement this by doing easy to moderate cross training workouts, e.g. on the bike or in the pool, to improve your basic aerobic abilities.  All distance runners need to be able to run continuously for a long time, but the talented-but-fragile runner don't need to actually do it on a regular basis.

Let's look at a concrete example.  A standard sub-16 high school cross country runner's schedule during the early pre-season might look like this:

Saturday, January 23, 2016

What's the point? Considering the various reasons to go for a run

Do you understand why you go running? I don't mean on a philosophical or motivational level; I mean on an actual performance-related day-to-day level: do you know why and how going for a regular run (as opposed to an interval workout or a specifically-paced tempo session) helps you run faster?


If you know your physiology— or if you've read my book, Modern Training and Physiology—you can probably rattle off a number of reasons.  Increased red blood cell count, more mitochondria, deeper capillary beds, et cetera, et cetera.  All of this improves your aerobic capabilities, and this is why the first thing to do in order to get faster is to run consistently, and run more.

If you approach the question of why you should go for a run with the mindset of a complete novice, you'll realize there are some obvious points to consider.  How far should you run? How fast should you run? Should you run the same speed every day, and the same speed year-round?

"Going running" is the staple starch of a distance runner's training.  But I've come to realize that a lot of athletes can't articulate what purpose the plain old boring run serves in training.  They know VO2 max, they know lactate threshold, they know marathon pace and critical velocity and hill sprints and creatine phosphate sprints and any number of other highly technical tools of training, but have only a vague inclination of the purpose of just going for a run.

Part of why this question is a little tricky to answer is because the standard run has a number of different uses.  This leads to confusion about how fast to run, how far to run, and so on.  In order to get a better intuition about the purpose of running generally, and easy running specifically, it will be instructive to look at the range of uses of the "regular run."

Going for a run to improve your aerobic fitness

First, a thought experiment: If a total newcomer to the sport—say, a high school boy who runs 5:30 for the mile in gym class with no running-specific training—starts running 30 minutes at an easy effort every day, will he improve? Certainly, yes.  The new stress on his body will stimulate a physiological response in the form of improvements in the "oxygen delivery system"—all those physiological markers of performance that you read about in textbooks.

The same high school runner, a year later, decides to start training harder.  He still runs 30 minutes per day, but increases the effort level, running at a moderate to fast pace at least 4-5 times per week.  Will he improve? Again, yes.  Though the volume of training is the same, the intensity is higher.  This, again, creates a new, stronger stimulus on the aerobic system, which responds in turn.

Now consider an alternative: Instead of running faster, our runner decides to run 60 minutes per day, still at the same easy effort as before.  Will he improve? Yes.  A new and greater stimulus leads to a proportional increase in fitness.

Finally, a third situation: our runner, a year after starting his training program, decides instead to keep doing the same thing—running 30 minutes per day at an easy effort.  Will he still improve? Maybe a little bit...but eventually, his aerobic fitness will not get any better.  This is one mistake that die-hard Lydiard fans often make—believing that the same training (e.g. 100 miles a week) can produce improvements in aerobic fitness forever.

In reality, of course, high schoolers often do continue to improve year after year with the same training, because they're maturing and developing, which also contributes to performance.  And our simplistic thought experiment doesn't take into account the effects of workouts and races.  If your workouts are progressing over time, in volume, speed, intensity, or some combination thereof, you can improve your performances even if your off-season training is the same, but that's outside the scope of our topic for today.

So, we might conclude that the purpose of running—in the off-season at least—is to produce a new stimulus on the aerobic system in order to improve our fitness.  This is correct, but it's only part of the purpose of the easy (or not-so-easy) run in training.

Sunday, January 10, 2016

How to break the marathon world record in Atlantic City, New Jersey



Welcome to our special coverage of the "World's Fastest Marathon" presented by Johnson & Johnson, I'm host Tim Hutchings here with co-commentator Stuart Storey, broadcasting live from beautiful Atlantic City, New Jersey.  Conditions could hardly be better—as we approach our 8 p.m. start time, the temperature has sunk to a chilly 36° Fahrenheit, and there's hardly a ruffle of wind blowing off the ocean.  Runners from the 10k community race held earlier tonight are touring the newly-revitalized Revel Resort, enjoying the post-race entertainment and placing their bets on the outcome of the upcoming professional races. 
 Floodlights illuminate the ten-kilometer loop course, which the competitors will run criterium-style—four laps for the full marathon distance. 
 The start of our men's race is only a few moments away; the women's field will start two minutes later.  The men's pacers will look to hit halfway in sixty-one minutes flat, and the women have asked for just over sixty-seven minutes at the half.  The goal for both races: the fastest marathon in history...

Does this sound like an impossible dream? Well, read on, and let me convince you.

We are currently living in a golden age of marathon running.  Paul Tergat's 2003 world record has been bested forty-one times in barely twelve years—an unprecedented occurrence, especially considering that top marathoners typically only race one or two marathons per year.  Performances that, only a decade ago, would be earth-shattering are now relegated to also-ran status.

There are a number of reasons why elite marathon times are routinely three to four minutes faster than a decade or two ago: more young, talented runners are moving to the marathon in their prime running years; prize money and appearance fees have never been higher at big-city marathons; track 10,000m events are rare and not profitable to run anymore; and top African runners and their coaches have discovered new training methods that push the body to find new sources of energy, creating a breed of what coach Renato Canova calls "turbo-diesel" runners. 

The relative importance of each of these explanations for the current banner crop of sub-2:05 marathoners is up for debate, but analyzing these is not my goal today.  Instead, I want to outline how current champions can go even faster.

It doesn't involve drugs, and it doesn't involve any changes in training.  Instead, making a number of alterations to the actual marathon event itself should do the trick.  Modern marathons are still conducted according to the logistical needs of a big-city event that caters to the general population, and sometimes, this doesn't result in ideal circumstances for running as fast as possible. 

Attempts at distance world records on the track are planned months in advance: the entire field consists of world-class runners, expert pacers are enlisted to ensure the pace is spot-on, and the venue is selected only after careful consideration of things like temperature, wind, and quality of the running surface.  In the future, marathon world record attempts will look very similar.

Big-city marathons that have played host to world record attempts, like Berlin, London, and Rotterdam, still have a number of deficiencies which could be costing elite marathoners precious seconds over the course of the race.

Wednesday, December 16, 2015

How much easier is running on an AlterG? Developing equal-intensity curves for anti-gravity treadmill running


Have you ever run on an AlterG? Once firmly in the realm of space-age gadgetry only available to professional athletes, AlterG anti-gravity treadmills seem to be cropping up everywhere nowadays.  College athletic departments, physical therapy offices, and even the occasional high school are purchasing AlterGs for their widely lauded ability to allow runners and other athletes to continue to train pain-free even with significant injuries.  By reducing your effective body weight, the AlterG allows you to run at normal training speeds with drastically reduced impact and active forces.  With careful modulation of the body weight settings, you can often maintain running fitness even during the rehab period of formerly season-ending injuries like a stress fracture. 

The AlterG achieves its anti-gravity effects using a pressurized "bubble" that encapsulates the runner's lower body.  Special compression shorts with an airtight skirt zip securely into a thick vinyl bubble that surrounds a standard running treadmill.  The heart of the AlterG, a computer-controlled air pump, inflates the bubble to above atmospheric pressure, applying an evenly-distributed force from air pressure to the runner which counters the force of gravity.  By adjusting the air pressure inside the bubble, the AlterG can adjust your effective body weight. The AlterG uses a force plate to correlate changes in the bubble's internal air pressure and your effective weight while standing on the treadmill.

In the past few months, I've been fortunate enough to have access to an AlterG.  I've also been fortunate to not have to use it for any injuries (knock on wood...), so I used the opportunity to look into a question that I've been wondering since learning about the AlterG: How much easier is running on an anti-gravity treadmill compared with running on land?

Because the majority of the metabolic cost of running comes from absorbing impact and accelerating your body weight against the force of gravity to propel yourself forward, it's axiomatic that reducing your effective body weight while maintaining the same running speed will reduce the energetic cost of running.


Notably, this is not the same situation that occurs when a runner loses weight normally—if a 150 lb runner decreases his weight to 140 lbs by restricting his caloric intake, muscle loss is inevitable (this is part of the problem with the idea of "racing weight").  Though he now weighs less, and thus the energetic cost of running a given speed is decreased, he has also lost some muscle, so his ability to produce energy is reduced as well.


There's no good bio-energetic equation to predict the metabolic cost of running; the only way to get a good answer would be with an experiment, which I set out to conduct. 

Friday, August 7, 2015

Designing a general strength circuit for distance runners



Weights, general strength circuits, plyometrics, and hip/core strength exercises all have their place in the training of a distance runner.  Today, I'd like to focus on general strength circuits specifically. 

Each word in that phrase has a particular meaning.  General means not specific. i.e. not exercises that are very similar to running or that involve running.  An example of a more specific strength exercise might be uphill sprinting or bounding.  Strength means more or less what you'd expect it to be—resistance exercises for muscular strength.  Finally, circuits denotes that we're talking about a high-intensity strength routine with many different exercises and short recovery. 

Why should a distance runner do this type of strength work? There are three reasons, and each of them illustrates one of the three domains from which a good coach will draw wisdom.

Why do strength circuits?

1.  Anecdotal observations on strength

The first domain is anecdotal observation.  Subjectively, I (and a lot of other coaches) have noticed that fast, injury-resistant runners tend to be stronger and more athletic than their slower, injury-prone counterparts.  Of course, there are exceptions—a skinny, uncoordinated kid who wins the state meet, for example—but if you spend enough time around budding distance runners, you'll find the general trend is undeniable.  This alone is reason enough to do some type of work for improving strength and general athleticism, since it's also evident to any experienced coach that "just" running won't make you strong and athletic.

2.  A physiological argument for strength circuits

The second is drawing from physiology and training theory.  In distance training, we know that it is advisable to build a base of general, less-specific running before moving to race-specific workouts.  We can apply the same principle to both strength work in general and to high-intensity circuits in particular.  Before we start doing any heavy weight lifting, high-intensity plyometrics, or hill sprinting or bounding, it makes sense to improve our general strength and athleticism so we're better-prepared for higher-intensity, more running-specific stimuli further down the road. 

Additionally, there's a general-to-specific argument to be made for high intensity circuits with regards to development of a finishing kick.  Think about what happens when you kick at the end of a race: you call upon your fast-twitch fibers to work at a high intensity, even though they're already awash in acidosis.  We can train this in a specific way by doing certain workouts (or just by racing), but how could we train, in a general, non-specific way, the ability to recruit fast-twitch fibers in a fatigued state? A general strength circuit is the perfect solution.

 3.  Scientific research on strength circuits and hormone levels

If you keep up with pro running news, you'll know that there has been a lot of buzz recently about the possibility of illegal doping being much more widespread than was previously thought.  There are three go-to pharmacological aids for drug cheats: EPO, which boosts your red blood cell production, testosterone, which boosts muscle growth and recovery, and human growth hormone, which also aids in muscle growth and recovery.  Wouldn't it be great to be able to boost levels of these hormones naturally?

With EPO, we're out of luck unless we live at altitude, but with regards to hGH and testosterone, the situation is a little more interesting.  Scientific research shows that a general strength circuit designed with a couple of guidelines in mind will boost levels of human growth hormone and testosterone in the blood for several hours post-exercise.1

By now, it should be clear that strength circuits should be a part of any competitive 800m to 10,000m runner, and should be a serious consideration for long-distance runners from a recovery and injury-resilience perspective too.  The next question is how to actually design a general strength routine.  To do so, we'll look to the scientific literature for guidance. 

Wednesday, August 5, 2015

My history with loss of leg coordination while running




I try to avoid anecdotes and personal histories when dealing with running injuries.  They're fraught with the dangers of recall and confirmation bias, and worse, people seem hardwired to give more credence to a personal story than reams of scientific data.  But in the case of loss of leg coordination, I don't really have a choice—the scientific data is extremely sparse, and there aren't even any case studies in the medical literature describing anyone with the hip-centric loss of leg coordination symptoms that seem to be a variant of "runner's dystonia."  On top of that, I know of only a handful of people who claim to have made full recoveries from the loss of coordination problem—and I'm one of them.  As you read my account, remember that I'm not a doctor, and I'm also not an unbiased observer.  My views on solving loss of leg coordination are no doubt informed by my own experience.  For a more objective review of the problem, see my extensive article on loss of coordination published last week, or the executive summary.


*   *   *

Background

To understand my story about loss of leg coordination, it will help to have a bit of a background on my journey as a runner.  I started running cross country and track as a freshman in high school, having done a little bit of each sport in middle school.  I didn't become a runner until my sophomore year of high school.  Until then, my times were decidedly unimpressive, and I did not train in the offseason or take the sport seriously.  Starting in fall my sophomore year, I began running year-round.  I was not particularly athletic, so I did not have other sports to do in the winter and summer anyways.  Plus, I wanted to see if I could improve.

And I did—I dropped from 5:40 in the mile as a freshman to 4:40 as a junior.  During those two years, I started experimenting with doing longer runs (12+ miles), and even ran Grandma's Marathon after my sophomore and junior years.  I did not start doing what I would now consider "high mileage" until before my senior year; that summer, I had a few weeks around 80 miles, and that winter, I averaged over 70 miles a week for almost three months, with a high of 90.  Again, this paid off, and it set me down the path of being a high mileage runner.  Throughout high school I was eminently healthy; I never missed a single day due to injury.

I ran in college, and continued improving thanks to high mileage training.  A few 100-mile weeks my freshman year dropped my times further, and going into my sophomore year, I logged eleven weeks in a row over 100, including several at or above 120.  This culminated in probably the best race of my career, a 25:34 cross country 8k in Wisconsin.  I missed that winter for a non-running-related injury, but with that exception, I did not miss much time due to injuries until my junior year.  Starting that summer, and for the rest of my college career, my progression was interrupted by overuse injuries, mostly in my hips and feet.  Later, I would realize that a lot of these were likely the result of not enough hip strength work, but that's a story for another time.

In many ways, my background fits the typical profile of a runner who develops loss of leg coordination: young, fairly serious and competitive about training, and a history of high-volume training.