Tuesday, October 11, 2016

Connect Run Club podcast on the science of running

I'm the featured guest on a new podcast episode from the Connect Run Club! We talk about the science of distance running, including VO2 max, more effective training strategies, and injury prevention.  Check it out! Thanks to the folks at Connect Run Club for having me on—check out their website here.

Hope you all enjoy it! I'd like to start doing more audio and video content in the near future.  Perhaps once the fall running season wraps up I'll have a bit more time to devote to those projects!

Here are direct links to the podcast:

Monday, July 25, 2016

What does it mean to be a talented runner? Considering types of talent

Perhaps because of the popularity of David Epstein's talent-centric book The Sports Gene, much of the modern conversation about high-level distance running has turned to talent: where it comes from, how to spot it, and how to develop it. One piece often missing from the conversation is what it actually means to be talented. We speak about "talented runners" as if there is one specific set of criteria that we evaluate talent against, but in truth, there are several different types of talent which don't have any inter-dependability. By this I mean that just because one runner is talented in a certain way does not necessarily imply he or she will also be talented in another.

Broadly, I believe there are (at least) four different ways one can be naturally talented as a runner. Some are more easily assessed than others.

Natural running ability

This is what most people are thinking of when they say someone is a "talented" runner. They mean he or she has a high natural set-point of aerobic endurance, someone who can run fast times or impressive workouts without much or anything in the way of formal training. Some people like to explain this mostly in terms of genetics, while others point to an active childhood as the determining factor. Both, of course, are important, but for a coach, neither matters—you work with what arrives at your doorstop on day one. And if that newly-minted runner can already run at a high level without any history of training, that is always a good thing. This does not guarantee success, as I'll explain below, but people who start at a very high level of fitness naturally have a distinct advantage.

Natural running ability is also the easiest type of talent to identify: all it takes is a race or time trial. At the school I coach at right now, our best runner was spotted as a freshman thanks to a fitness test all sprinters on the track team undergo called the Cooper test. It was devised by Dr. Kenneth Cooper, sometimes known as the "father of aerobics" (rightfully so, given that he coined the word), for quickly and accurately evaluating the VO2 max of a large number of test subjects in the field, e.g. military recruits. The test is simple: cover as much ground as you can in 12 minutes, ideally running but taking walk breaks if needed. The distance you cover, in meters, is plugged in to a formula which predicts your VO2 max. Cooper's test is reasonably accurate when comparing test results to lab-determined VO2 max.

In our case, this freshman "sprinter" ended up finishing over 500 meters ahead of everyone else at the twelve-minute whistle. Within a few weeks he was running distance workouts with our top athletes.

For distance runners, any time trial of 1600 to 2400 meters should suffice for evaluating natural running ability. Longer tests can mask true running ability, because it's very hard to run a good 5k or 10k off natural running ability alone—these events just rely too much on training, not to mention proper pacing, which is an acquired skill.  Sprint and true mid-distance athletes should be evaluated with shorter time trials that more accurately measures the shared aerobic and anaerobic components of the specific event—a 300m time trial for the 400 meters, for example, or a 500m time trial for prospective 800m runners.

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.