Thursday, November 16, 2017

Trabecular paper published; blog tab updated

Our paper in PLoS ONE describing my master's project research is now published, and I've updated the blog tab "trabecular bone project" with a summary.  Links below.

Best A, Holt B, Troy K, Hamill J (2017) Trabecular bone in the calcaneus of runners. PLoS ONE12(11): e0188200.

Sunday, November 12, 2017

Paper recap- "Short Trail Running Race: Beyond the Classic Model for Endurance Running Performance."

Thanks to Kim Nedeau for sharing a spanking new paper with me that I likely wouldn't have seen otherwise.  I thought I'd share it here with a brief summary (though really it should go on my neglected/never started "mountain running science" blog page).  Nothing evolutionary here-- this is pure exercise physiology, and will likely only interest trail runners, but for this demographic it's a great read.

The research: Testing was conducted on 100+ competitive French trail runners before a 27k (16.8 mile) singletrack, technical mountainous trail race with 4,000+ feet of elevation gain.  (Only figure 1 in the paper lets the reader infer that this is an up and down race, not up only...I digress.)  The researchers asked whether the "big 3" factors that predict traditional endurance running performance apply to trail racing, which is quite different.  The 3 factors are:

1) VO2 max: the maximal amount of oxygen an athlete can take in and use to do muscular work.  Essentially, this is a measure of how big the engine is: how well the cardiovascular system can deliver oxygen to the muscles and the capacity of the muscles to use this to power contractions. 

2) Perecent VO2 max at Lactate Theshold: essentially, how much of your oxgyen delivery/usage capacity you're using while running at a pace requiring a slight anerobic energy contribution, which corresponds to about 60 min race effort  You may have a huge VO2 max, but a guy who can race a given distance at a lower relative percentage of VO2 max is more efficient than you and has reserve capacity.  I don't think this is too different than #3:

3) Running economy: the energy required to run a given distance. This is a measure of efficiency. This tends to matter more for longer races where total on-board fuel is an issue (races of 2 hour or more), but a more economical runner can better translate muscular work into forward motion, making her faster over shorter distances too. 

These 3 factors are strongly predictive of running ability in traditional running races-- road races, etc, run on level or mostly level ground, and on pavement/grass/anything homogenous.  That is, an athlete with superior numbers in these 3 tests will probably win (excluding, of course, the impossible-to-quantify factors of toughness and focus.) The researchers suspected that maximal muscular strengh in the legs might be a factor for trail racing, as this has been shown to improve running economy in level and inclined running, and it has predicted race performance in a 26 mile all-uphill mountain race.  (As an aside, that's the main reason I lift: to improve uphill running economy by building a "stiffer spring". Aside aside: this is why flexibility/muscle length in many muscle and tendon groups is inversely related to running economy. The best runners aren't great yogis.) 

The results: The traditional model (the big 3) DID NOT predict race performance in a 16.8 mile mountainous trail race.  Nor did maximal knee extensor strength. The model that best predicted performance was a combination of 3 variables:

1) VO2 max.
2) "Fatigue index". Runners performed 40 maximal reps on a knee extensor machine, which isolates the quadricep muscles.  Fatigue index is a ratio of torque produced during the last 5 reps divided by the first 5 reps. So, fatiguing less in this test means a better fatigue index. 
3) Running economy at a 10% incline.  

This is all very interesting.  Take aways:
--I'm not surprised that VO2-max was predictive of trail racing performance.  It predicts performance in every running discipline.  To race trails and mountains, work on getting a big aerobic engine with short and hard intervals.
--Fatigue index of the quadriceps makes sense too-- extreme uphill/downhill racing is very dependent on these muscles.  For a race with climbs and descents that are moderate in length (but not endless), the quads need to be conditioned for anaerobic energy production, which is what a 40-rep exercise is testing.  And as the authors infer, higher fatigue resistance means that muscle fiber recruitment needn't increase to permit continued force production. Because energy cost of running is dependent entirely upon volume of muscle activated, this is a big deal.  I am surprised, however, that a test isolating the quadriceps was so predictive, as mountain running requires really almost every muscle in the body and especially plantar flexors (calves etc) and hips muscles (all of the glutes, etc). 
--Running economy at 10% incline matters, but running economy on a flat surface was not correlated with trail racing performance. Another study found that flat and uphill running economy are not realted-- again, as I've been saying, don't train for flat running and expect to be good at uphill running, or vice versa. Even in a race that is only (at most) half climbing, running economy while climbing is a highly predictive factor in determining race performance. (Suck on that, downhill specialists!). The authors suggest that the observed fatigue resistance in the runners' quadriceps is resultant from their uphill training and also their cycling (which most performed as cross traning). Therefore they recommend that trail runners should perform uphill training and cycling to improve quadriceps fatigue resistance and therefore trail racing performance
--The authors were surprised that maximal force production wasn't a significant factor in race performance. But their test isolated the quadriceps, and as I just mentioned, the quads are only part of what it takes to run fast up and down mountainous terrain for 3 hours.  I don't think they looked at this, but I bet if they compared the running economy measures of their runners to the runners' quadriceps maximal strength tests, there'd be a strong correlation, as has been found in other studies.  So don't take this as evidence that you don't need to do strength training to be a mountain or trail runner, and to their credit, the authors remind us of this. Lift weights and/or do plyometrics to improve your uphill running economy and therefore to kick ass up mountains.

Anyway, this is the first paper I've seen that investigates factors determining trail/mountain running performance vs. level running, and it's nice to see some experimental articulation of how they're different. To wit: "The flatter the running surface (i.e., road) the higher the relevance of laboratory-based phyiological measures of relative VO2 max, %VO2 max and runnig economy".  

Ehrström, S., Tartaruga, M. P., Easthope, C. S., Brisswalter, J., Morin, J. B., & Vercruyssen, F. (2017). Short Trail Running Race: Beyond the Classic Model for Endurance Running Performance. Medicine and science in sports and exercise.

Link to abstract (full text is behind a paywall):
Message me if you'd like the full text. 

Tuesday, October 17, 2017

2017 racing season reflections

It's been a long time since I blogged about my running and biking. But if training like this is still worth doing at 35 years old, then it's also worth reflecting (even publicly) from time to time.  So... read on if you can handle the self indulgence and probably typos too, beacuse I don't have time to edit this!....

I managed to win my first two mountain races of the year-- Wachussett and Ascutney, short paved courses up these mountains-- but with times slower than years past. This wasn't a problem, nor much of a surprise... whether due to age, training or both, my VO2 max probably isn't what it once was.  This proved to have little bearing upon my big goal for early summer, the Mt. Washington Road Race, which at over 1 hour is long enough to forgive a lack of top-end aerobic capacity, favoring instead the specific ability to clear lactate while running straight uphill nonstop.  I'll avoid the details because I feel increasingly protective of my training, and it could drone on forever, but the short version is I figured out how to train for and race Mt. Washington.  On my 3rd try, I scored a slight PR in 1:08:35, good enough for 6th place (results).  I really feel like this was my best result: 6th against that field feels legit, and it was the warmest (slowest) day of the 3 years I've run it. I still want to run 1:06, and on a perfect day I think I would have. So, I will likely try again, though part of me wants to be done with this race because it is a devestatingly intimidating and painful challenge.

Scott Mason Photography
Bike for Bovines. Photo- Scott Hussey.

My favorite mountain bike race was a week later-- Domnarski Farm.  I raced Category 2, unsure if I had become fast enough to race Cat 1.  I won by 5 minutes I think, catching people from the waves in front of me and getting hung up on them in the singletrack but still setting a Cat 2 course record.  I
was "encouraged" by several in attendance (and later on Facebook) to move up to Cat 1, which I did for my late August race, Bike for Bovines.  The longer courses of Cat 1 racing seem to suit me and I finished 2nd in the 30-39 Cat 1 group, with the 4th fastest overall Cat 1 time, 2 seconds out of 2nd overall.

Oh, I should add that UMass brought back their old mountain bike race, across the street from my house, in April.  That course didn't suit me but it was fun as hell.


Just as in 2016, I worked myself into great shape by August.  And just as in 2016, this did not result in multiple satisfying race results.  This stung even more this year than last. After the Mount Washington Road Race in June, I averaged 14 hours/week of running and mountain biking, with lots of quality...15,000' feet of climbing, hard workouts, and hard rides each week.  This proved to be a bit overzealous and I aggravated an Achilles
RTTVT. Photo- Lee Krohn.
tendon problem, forcing me to skip my August mountain running race (Race to the Top of Vermont) and focus only on the bike portion of this event, in which I finished 4th, with some dissapointment.  With lots of arrogance I was sure I'd win this race. Not even close! I'm a runner who mountain bikes; I'm not a cyclist.  Aaron Stone was the most impressive of the day, faring well (top 10) in the run, racing back down the mountain, and riding up in the bike race, following in Josh Ferenc's footsteps (which are not easy steps I can tell you from experience).

In September I got healthy and kept training.  Well, my Achilles got healthy, but a cold and sinus infection coupled with being busy (wah wah, lots of complaints here) set me back a step.  Actually all of that was fine- the problem was that when I lined up for my last mountain running race of the year at the Race to the Summit (Stratton Mountain) in October, I didn't focus.  I didn't want to hurt.  Halfway up the mountain, in 2nd place, Ferenc passed me and...I just let him.  Spending mental energy on so many other things this fall (like work-- imagine that) left me unfocused.  It's no excuse, I just got my ass kicked. Third overall, 1 minute slower than last year in a short race (23 min).  We did have a great time with the winner, a Latvian (now American) 4:01 miler, on the right of this picture.

At least then I could focus on the race I looked forward to most: Circumburke, a mountain bike race over a 27 mile loop around Burke Mountain in the Northeast Kingdom of Vermont.  The course was about half doubletrack and fireroads, half super-flowly new-age style singletrack.  LOTS of climbing-- 3,500' feet of it.  I went hard from the start.  Constant lactate in the legs; scary at minute 1 of a 2.5 hour race.  But I felt better and better as the race wore on and was top 10 (and moving up slowly) at mile 16, when I hit a waterbar on a fast descent and blew out my tire. I'm to blame here; higher tire pressure could have prevented this.  Three minutes later I had fixed the flat by putting in a tube, but one CO2 cartridge wasn't enough, and eventually another rider gave me one so I could get back on my bike.  I lost 11.5 minutes, spent the next 10 riding modestly, and then got back up to near-race effort.  Those 11 minutes cost me, at least on paper and by doing maths, a 6th place finish. Factoring in the time I spent pedaling easy and feeling sorry for myself, I potentially could have finished 3rd.  But wishes are ponies and that didn't happen, and my result was 20th (out of ~385- results) so I have to own that.

Circumburke Start. credit: Burke Mountain
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Reflections on the year

Other than 3 race results I'm happy with-- Mt Washington, Domnarski and Bike for Bovines-- 3 great things happened this year because of my racing.

1) I was fortunate to test my limits with great athletes, many of whom I now call friends.  The mountain running and mountain biking scenes are loaded with positive energy.  I can't even begin to summarize these stories in this post, though you've probably seen some of them on my Facebook, as I can't help but share the overwhelmingly positive vibes that these people have given me. You know who you are!  From the races, to the big training runs I've done with you guys this year....thank you.  And thank you to my team, acidotic RACING, for your support and all that you do for endurance sport.

Race weekend camping with Stoneman and Wifey. 
2) I had the luxury (and it is a luxury!) of spending LOTS of time with two of my favorite people: my
wife Michaela, and Aaron Stone, both of whom joined me for many of these races, which really are weekend adventures in the woods and mountains.  The memories from this year, and the last few years with them, are my fondest from all of my competitive years.

3) I confirmed a hypothesis this year, one that will keep me motivated for a few more years at least: Mountain running and mountain biking at the highest levels possible (for me) are wholly compatible, even complimentary.  I could (and may) write a post concerning my training philosophy here.  I don't think that mountain bike training is compatible with, say, road running, but for the running races I do now, these things go together like peas and carrots.

My dad reminded me last night that 35 is past your prime for mid-distance endurance sport.  Of course I know this is true-- or at least, 35 is the upper-end of prime time.  I've always said that when I no longer get faster at a discipline I'll stop, and I've been doing this, switching first from road running to trail and mountain running, and most recently placing more emphasis on mountain biking.  I'll have some of the same goals in 2018 as I've had the last few years, but I'll set a few new goals too.

 I can't wait to get back to hard training again, because this stuff makes me feel alive.