Archive for half-marathon

Argentan half-marathon

Posted in Running with tags , , , , , , , , , on October 5, 2019 by xi'an

Today is the day of the Argentan half-marathon which I will not run this year as I have not yet fully recovered from my Achilles tendinitis. (If running too many days in a row, as I indulged in while in Salzburg, inflammation is back!) Frustrating, as this is my “race of the year” in the Norman countryside. But another break also occurred ten years ago, when I missed the 2009 and 2010 episodes. And somehow this is the “best year” to miss as I am switching to the next age group, V3 or grand-master!, in less than a month, and will thus end up as one of the youngsters in the next race I run! As an indicator, in the 5km trail I ran last Sunday in the Parc, I ended 4th (by one position and 6 seconds!) in my category and 2nd (by three positions and 16 seconds, plus a month!) in the following one.

running shoes

Posted in Books, Running, Statistics with tags , , , , , , , , , , on August 12, 2018 by xi'an

A few days ago, when back from my morning run, I spotted a NYT article on Nike shoes that are supposed to bring on average a 4% gain in speed. Meaning for instance a 3 to 4 minute gain in a half-marathon.

“Using public race reports and shoe records from Strava, a fitness app that calls itself the social network for athletes, The Times found that runners in Vaporflys ran 3 to 4 percent faster than similar runners wearing other shoes, and more than 1 percent faster than the next-fastest racing shoe.”

What is interesting in this NYT article is that the two journalists who wrote it have analysed their own data, taken from Strava. Using a statistical model or models (linear regression? non-linear regression? neural net?) to predict the impact of the shoe make, against “all” other factors contributing to the overall time or position or percentage gain or yet something else. In most analyses produced in the NYT article, the 4% gain is reproduced (with a 2% gain for female shoe switcher and a 7% gain for slow runners).

“Of course, these observations do not constitute a randomized control trial. Runners choose to wear Vaporflys; they are not randomly assigned them. One statistical approach that seeks to address this uses something called propensity scores, which attempt to control for the likelihood that someone wears the shoes in the first place. We tried this, too. Our estimates didn’t change.”

The statistical analysis (or analyses) seems rather thorough, from what is reported in the NYT article, with several attempts at controlling for confounders. Still, the data itself is observational, even if providing a lot of variables to run the analyses, as it only covers runners using Strava (from 5% in Tokyo to 25% in London!) and indicating the type of shoes they wear during the race. There is also the issue that the shoes are quite expensive, at $250 a pair, especially if the effect wears out after 100 miles (this was not tested in the study), as I would hesitate to use them unless the race conditions look optimal (and they never do!). There is certainly a new shoes effect on top of that, between the real impact of a better response and a placebo effect. As shown by a similar effect of many other shoe makes. Hence, a moderating impact on the NYT conclusion that these Nike Vaporflys (flies?!) are an “outlier”. But nonetheless a fairly elaborate and careful statistical study that could potentially make it to a top journal like Annals of Applied Statistics!

semi-marathon d’Argentan [1:27:27, 22/356, 2/65]

Posted in Kids, Running, Travel with tags , , , , , , , , on October 2, 2017 by xi'an

As a new anniversary of the beginning of this ‘og, here comes and goes my yearly half-marathon in Argentan, Normandy, which was the 33rd edition of the race and my 19th participation there…

“Ah, le fameux Robert de l’INSEE qui vient faire chier chaque année!”

This was not one of my best races, by far, and the [fake] news that this was going to be the last edition did not help. There were fewer runners than in the earlier races, meaning no protection on most of the route from what seemed like a constant headwind, as I ran by myself from the third kilometre. And I was tired from too much training (and not enough sleeping) the past week in Warwick. Or not enough training the previous week in Vienna. Anyway, this was not a great race and the local V2 [Grand Master] runner who greeted me with the above good-natured apostrophe when I passed him on the second km ended up one minute ahead of me. I could have even stopped at mid-race, were it not for a deficient watch operation, that kept me thinking I could keep with my earlier time [3:39 – 3:50 – 3:59 – 3:53 – 4:00 – 4:28 – 4:11 – 4:06 – 4:04 – 4:07 – 4:24 – 4:39 – 4:01 – 4:12 – 4:05 – 4:14 – 4:03 – 4:16 – 4:17 – 3:58 – 0:25] till the finish line when I found a 4mn difference with the official time! Despite the low participation of 356 runners, and with the support of runners from England, the town of Argentan has vowed to keep the race on for next years, calling for volunteers to man the route and the arrival hall. Till next time, then, hopefully!

male masters

Posted in Running, Travel with tags , , , , , , , , on November 5, 2016 by xi'an

Yesterday, I received this wood plaque from the organisers of the San Francisco Marathon! Nice, as I had not expected them to deliver abroad. And with this surprising title of second place in the male masters. After checking on Google (and avoiding a long list of SM sites), it appears that this means the above 40 category, which I had never heard of before. (I would have preferred an above 50 category, obviously! Which appears to exist in some races as the Grand Master category, even better!) Looking further at some of the (running) links, it also appears that categories by weight have been introduced in some races… Not that I can expect to benefit from that further division!

Argentan half-marathon 2016 [1:23:28-23/380-V2 2/74-16⁰]

Posted in Running, Travel, Wines with tags , , , , , , , , , , , , on October 2, 2016 by xi'an

And yet another Argentan half-marathon! Which started this blog, so to speak, 8 years ago… Although I could not repeat my feat at the San Francisco half-marathon, as I had lost my high altitude benefits, I managed well enough, with a good overall time of 1:23:28 and a second place in the V2 category, once again. I gained more than one minute from last year time, despite a strong face wind and thanks to sticking to a small group of younger runners. This is one of my best times since the start of the blog in 2008, so I am clearly very happy with the result. And plan to celebrate tonight with a top Montpellier wine!

San Francisco ½ marathon [1:26:32 – 15/7533]

Posted in Kids, Running, Travel with tags , , , , , , , , on August 2, 2016 by xi'an

Just completed the 2016 San Francisco ½ marathon. And this despite Air France’s best efforts to keep me out of it (and thanks to my son!), a long flight and hardly any sleep before the 5:30am start. This is the most brutal, unforgiving, relentless ½ I ever ran, with a significant positive differential of more than 700 feet (215 meters) and according to other runners with tracking devices possibly 0.3 miles extra (close to 500 meters). And fierce winds on the Golden Gate Bridge, both ways! So I am utterly flabbergasted by the outcome, which sees me arriving 15th altogether and first in the over 50 group [and third French!]… race_2167_photo_39804811Even though I presume the training for Monte Rosa, the (unsuccessful) attempt at Monte Rosa, and the additional bike rides the previous month helped, although I did very little speed sessions. The race got hard the moment we started climbing, first a little hill near Fort Mason, then the slope to the bridge that truly slowed me down. Crossing the Golden Gate Bridge both ways was exhilarating, although I could not see one pile from the previous one, being in a cloud the whole time and Sun being not up yet. And although this section of the race was the most exposed, with no runner around to run in packs. Thankfully, there was one big downhill run around the 11th mile (that I passed in 1:11:11!) which helped me gaining back some time if no position, and facing the last climb, which seemed to last till the finish line in the Golden Gate Park… My overall time of 1:26:32 is surprising in itself if I account for the elevation: by Naismith’s rule, that would brings the time on a flat terrain under 1:20, a feat I only achieved once. And many other things are just weird in this race, from the 7500 runners I never saw, many of which finished over 4 hours, to the number of young winners (the third male runner is 17, the first female runner 20, a 14 year old came 22nd and even weirder the second female in the 5k is 8 year old!). And to the fact my ranking changed several times from 18th to 16th, 15th, 17th, and eventually 15th again.  [Congratulations to the organisers, by the way! The whole race was brilliantly organised with all kinds of amenities I had never seen before. And thanks to the supportive Erythrean taxi who took me from the airport and offered me a free ride back if I ended up in the top ten! It sounded like a joke at the time….]

cheating in long-distance running

Posted in pictures, Running, Travel with tags , , , , , , , , on April 10, 2016 by xi'an

This morning, I was reading at breakfast a NYT article on a presumed cheat by the winner of the 2015 Ironman Canada race, in the category of women ages 40-44… (This gruelling race takes place around Whistler, with a 2.4-mile swim, a 112 mile bike race with a huge differential, and a complete marathon!) Leading to reassess earlier victories by the same runner and ending up by her being barred from running in Ironman and Triathlon Canada races (and loosing her title for the 2015 race as well). This reminded me of Darren Wraith pointing out to me an article in Runner’s World where an independent volunteer was checking times of road-runners across the US towards detecting inconsistencies in split times and between races, or in pictures at alleged split times, eventually exposing a significant number of cheaters that had been undetected by the organisers. While I find the temptation to cheat less of a surprise than the article authors, even when nothing more than local and much temporary fame is at stake, and particularly so when a podium or a selection for a more prestigious race is at stake, the limited involvement of race officials is an issue, given how easy it is to spot those inconsistencies. Actually, it is ridiculously easy to cheat as well: when I ran the last Gertrude Cox scholarship race at JSM in 2009, my wife and I picked our tags together and ended up switching them by mistake. Which made my wife the female winner of the race until I pointed out the switch later that afternoon to the organisers. And spoke with the true winner who was surprised but unsuspecting at not being the winner. This may well be a reason for the phenomenon to be so widespread, namely that it does seem to make sense to try to cheat for a middle-of-the-pack rank, so little sense that one does not bother to voice suspicions to course officials. For instance, when I ran my most recent half-marathon in Argentan, I crossed a runner coming backward on the course route around the 11th kilometre and thought he had either given up or was acting as a pacemaker for another runner. Later I however spotted him during the awards ceremony in the first ten runners of the half-marathon! But did not do anything as I was not 100% sure it was the same runner and as being on the podium was the only reward of a possible cheat… In addition, there was no split time and hence little if any hard fact to back up my story. Maybe I’ll pay more attention on the next race!