23 August 2014

PTL is approaching

I am since yesterday in Chamonix preparing for Petite Trotte a Leon (PTL) which will start on Monday 5:30 pm CET. The UTMB start arch is built, but besides that there are not many signs that the town is going to be turned into the trail and mountain running capital next week. The sales exhibition start not until Tuesday, when we will be somewhere in the Swiss alps, and starting PTL feels little like jumping the gun.
On the other hand is PTL more aligned with the other activities here and I had an interesting discussion today with some climbers regarding some of the more technical glacier passages at PTL. It has been a very strange summer here in Chamonix with cold weather and plenty of rain and snow and the organizers have therefore shortened the track a little bit and taken away the passages to Cabane du Trient and Cabane de Valsorey. I think it is a very good decision and it will certainly still be a formidable challenge to finish the route, which still is 294 km with 26557 meters D+. The two late glacier passages at Col de la Sassiere (after 206 km) and Col de l'Argueray (after 231 km) is still retained and we can now only hope the weather will be good enough to enable us to run the intented original course. Regretfully it looks like we might get some rain and snow during Tuesday/Wednesday, but it might be local and more in France than in the Swiss and Italian parts of the tour where we hopefully will be then.

Mont Blanc over the clouds today seen from Aiguille du Midi

I am much less nervous before PTL than I was before Tor des Geants (TDG) last year for three reasons. Firstly, obviously, I now know much more what is waiting and hopefully I will have learnt something from my mistakes at TDG. It is still going to hurt immensly, however, and I do realize that PTL is much more challenging due to the technical non way-marked course and the need to plan for food yourself to a great extent. I just read an excellent and insightfull comparison between PTL and TDG by Jill Homer and I cannot say that I did not felt my heart-rate increase and thought once again what I have signed up for. Secondly, I am much better trained this year. I have had a great pre-season both with regards to milage and aerobic speed/hill training. The last few weeks have also been great, I have had a slight cold, but nothing interferimg with my form and my legs feel absolutely great. Today and tomorrow I am adjusting to the altitude at Aiguille du Midi at 3800 meters to avoid the onset of Acute Mountain Sickness I had early on before adjusting in TDG. Finally, and most importantly, I am now part of a team and it will be great to run with Otto Elmgart. He is an outstanding ultra-runner with great results from for instance Badwater last year and previously Sparthatlon and I am sure I will learn a lot from him during the coming week.

The only sad thing, besides of course being away from the family for more than one week which indeef is painful, is that our original teammate Tobias Lindström, who was the first Swede completing PTL last year, cannot be running with us. He is not unhappy himself however as he is embarking on the bigger life adventure of becoming a father any day now. He has, as Stefan Andreazzoli did before TDG last year, been tremendously helpful in providing valuable tips and support and his spirit lives on in the name of the team which he coined; "Living the dream".

For security reasons each PTL team has to carry a GPS transmitter/beacon and this also mean that it is possible to follow the progress of the teams live at http://www.nexxtep.fr/UTMB/EN/ and http://utmb.livetrail.net. Information will also be provided at the UTMB homepage. I have race bib 10601 and Otto 10602. I will probably post something more before the race start, but now I need to continue eating and sleeping to make up for some the deficiencies in both next week.

05 August 2014

Summer vacation training

It has been quiet here at the blog as I have been on a two week vacation with my family in Antibes in southern France along the Mediterranean coast. I thought it would be a repeat of the tapering/recovery vacation I had last year in Sicily in Italy where my legs got a well needed rest as I only spent limited time on the hotel treadmilland also did some water running. However, it was not to be as we found an excellent 800 meter long uphill road on Cap d’Antibes with just the perfect slope and inclince grade to enable speed aerobic repeat hill training. It was certainly not like running in the technical steep hills further inland, but felt great to get some speed in the legs after a summer of long slow distance training mixed with slower much steeper hill repeats. So, in the end we spent almost every morning on this road before going to the beach or doing excursions in the area.

The slope looks gentle, but really hurt both lungs and legs
On the beach I got plenty of time to read books and also mentally train and prepare further for Petite Trotté a Leon (PTL). Naturally, with the mountain run adventure PTL less than a month away I was drawn to books about mountains. It was quite surrealistic laying down in the warm pleasant sun hearing the waves meet the sandy shore and read about things going terribly wrong in cold snowy harsh conditions in the Alps, the Colorado 14ers and other mountains. However, I hope it will be valuable to mentally prepare for both the objective and subjective dangers of the mountains – it would of course have been better to learn by being in the mountains to experience difficulties first hand, but without the time this is better than nothing. And, as most of the disastrous mistakes I read about was fatal I rather learn about them second hand by reading about them than experiencing them myself. I am now really longing to Chamonix, only 20 days now until the start of PTL.
Screenshot of some of my summer Kindle reading on my iPhone

17 July 2014

Learning from past experiences

One of my main guiding principles is that you can learn something from everything and, not surprisingly, some of my best learning experiences have happened when things have not gone as planned and when I have had to face and overcome problems and obstacles. Based on that the exercise yesterday when my teammate Otto and I was out the whole day running, testing our gear and getting to know each other better was a poor learning experiment because almost everything went very well. The sweet and sour chicken pre-cooked meal ready-to-eat (MRE) warmed with a water-activated chemical heater was actually quite tasty, I got no blisters or chaffing, no stomach issues, I have no muscle soreness today, and most importantly, Otto and I had great discussions and share the similar thoughts about the experience that awaits us at PTL (Petite Trotte à Léon).  Of course, we made some navigation mistakes, got a little bit thirsty due to the heat before we found water at a farmhouse, and I got annoyed with the Garmin GPSmap 64s more than once, but overall we could have hoped for more difficult challenges, but it was not to be this beautiful summer day.

We ran a small section of Sörmlandsleden, a lowland trail path of more than 1,000 kilometers close to Stockholm. It brought forward some nice memories as my first trail Ultra was actually a 50K race in 2002 called Sörmland Ultra Marathon along another section of this trail. I ran at a rather modest 4:35 and remember that I could barely walk for a week afterwards (the world is indeed small – Otto also ran this race in 2002 at a time of 4:23 – at that time none of us could know that we 12 years later would head out for PTL together). The picture below from Whatifultra entitled “My family watching me try to get around the house the day after my first marathon” really captures this.
Picture from Whatifultra
Yesterday we ran of course slower, but were out for a much longer hike, and I was actually quite surprised that I did not feel any muscle soreness when running to work this morning. It appears the body is really adjusting and learning to cope with physical stress. One of the most profound experiences I had a Tor des Geants (TDG) last year was that the healing process was remarkably and that I could have quite severe pain for some hours, but that that was transient and abated either when the course changed character (i.e. less downhill running sections) or when I rested and slept for one hour. So I am much less nervous for my physical condition before PTL and I think yesterday’s test run was a very good answer that my preparations up until now has been good and paid off.

I had not tapered anything before the run yesterday and that might be one reason that my legs felt quite heavy and slow during in particular the more technical downhill sections. Another reason might be the quite heavy backpack. In any case one of the learning experiences was that I know most focus much more on downhill running the next few weeks. That much can be gained in downhill running technique was something I most painfully learned at TDG last year. It can also be learned watching this video of Kilian Jornet, Timothy Olson, Julien Chorier and Dakota Jones descending the north side of the Grant-Svamp pass early in the Hardrock 100 race this evening. As the video photographer taking it said “What the hell”. Completely amazing and certainly a downhill running technique to strive for (or at least dream about).

Mentally I also think it was a good preparation yesterday discussing some of the premises we will be faced with during PTL. One thing we can be certain about is that, unlike yesterday, things will not go as planned and this is also a driving theme in most race reports from this long race. Unlike the plentitude of videos frompast editions of the race (see previous blog post), there are not many race reports from PTL in English. Some of the one’s I have found are listed and linked below. I think that some of them definitively are providing some good thoughts and the second best thing to learn from your own experiences is really to learn from others.

PTL race reports in English:


11 July 2014

Thoughts about Hardrock 100, Adventure racing and Though Mudder when running a Fartlek

Today I had hoped to be on the starting line in Silverton, Colorado, but as so many others I will have to wait for my luck. There are only 140 runners at the Hardrock 100 mountain ultramarathon trail race each year and so far there have been no Swede on the starting line. This year’s elite field is probably the strongest ever seen with the possibilities for Kilian Jornet, Seb Chaigneau, Julien Chorier, Tim Olsen, Dakota Jones, Jared Campbell and Joe Grant to be the first runner to kiss the Hardrock at the finish line. One of the few elite runner’s missing this year, Anton Krupicka, but who I guess anyway will be there pacing his friend Joe Grant, has written a great pre-race review of the runners. As always, good pre-race analysis and interviews are available at www.Irunfar.com , where it is also possible to follow the race live later today.

I have instead run a Fartlek in the certainly more modest hills around Uppsala this morning. When I woke this morning I was quite sore and I had no motivation and no ideas what to run today but when I finally put on my shoes and went out the door it quickly felt great again. This is something very liberating with running – to just put on your shoes and go out without any careful planning beforehand what to do and without any expensive equipment and gear. My wife is an avid road cyclist and my 8-year old son is really into alpine skiing and it is amazing how much more the equipment mean in these sports – not only the bike rig itself or the skis, but all other things around these sports as well (not to disrespect the importance of having the right running shoes, but...). For me personally one of the drawbacks of running longer races like PTL (La Petite Trotte à Léon) is all equipment needed – it is not only expensive, but also quite time consuming to plan and gather.

This aversion for being dependent on gear is one of the things that make me hesitate to try for instance triathlon or adventure racing. Having just read the old book “The Thrill of Victory, The Agony of My Feet: Tales from the World of Adventure Racing “ edited by Jamison, Moslow-Benway and Stover I see a lot of similarities between PTL, where we will be orienteering for over five days in teams along a not way-marked track, and multi-day adventure racing. Indeed, in adventure racing there are appear to be a lot of "retired" ultrarunners. I am also intrigued that there are multiple sports combined into one event. During my high school and early college years I competed in military pentathlon, a very small sport in which the main ingredients is that you have to be a good runner and a good swimmer, which I was with a background in both sports (for a good introduction video to military pentathlon see below). And, if I know myself well enough I would not be surprised if my curiosity made me try at least one adventure race and a triathlon sometime in the not to distant future.


However, I think there is a fine line between it being a challenging sport and being a fun spectacle, and, looking at the development of obstacle race competitions like Though Mudder or Though Viking, I think the line has been crossed with these events, at least for me personally.  Having spent numerous ours on the obstacle course used in military pentathlon and gained respect for each and every of the twenty obstacles, I am not at all attracted to the more theme park oriented obstacle courses in these other events. It is evidently also quite dangerous to run these courses as discussed in two new articles by Eichner ER “Tough mudder injuries, triathlon drownings, and team rhabdomyolysis in the Navy” Curr Sports Med Rep 2014; 13: 66-7 and Greenberg et al “Unique obstacle race injuries at an extreme sports event: a case series” Ann Emerg Med 2014; 63: 361-6. On the other hand, I know others who really like these events and who have started to train harder just in order to be able to complete on of the courses, much like I am training to be able to complete the PTL, and hopefully someday also the Hardrock 100 course, so why not. But I guess my personal reaction if an ultrarunning friend said to me that he/she had signed up to "run" a though muddler would be as captured by the whatisultra animation below.

07 July 2014

Iron deficiency, anemia and supplementation in ultramarathon running

The summer training is progressing well and I have this week returned to spending more time in the local ski slope to get more long-distance vertical meters in my legs. I have been slightly bothered by my torn left knee – only a superficial skin wound, but rather large and as it also got somewhat infected it will certainly leave an impressive scar. There are now exactly 49 days (7 weeks) until the start of Petite Trotte à Léon (PTL) and I have reached the stage in the training where it feels like I would be able to do it reasonably well if the race would occur within the next few days. Now it is more a matter of sustaining rather than improving my form. Still, I will have some more weeks of really hard training before going on a short vacation which also will be the start of more technical speed and aerobic training.

I have also started to prepare by increasing my iron stores through both food and supplementation. I have, probably for genetic reasons, always had a borderline hemoglobin value of around 14 g/dL (140 g/L) and my iron deposits have also been rather low with borderline serum ferritin values. Not that I have a clinically significant iron depletion/deficiency (sideropenia), but when I have started to run longer races at high altitudes I think it important to have as optimal values as possible. Normally, I am not using any supplementation, but before TDG last year and now before PTL I will try to optimize my oxygen transporting system not only by training to increase my VO2max, but also by iron supplementation.

I would not use iron supplementation if I had better hemoglobin and iron values. I was therefore quite surprised to see in study of 489 100-mile mountain ultramarathon trail runners that over 75% use vitamin and mineral supplementations (Hoffman & Fogard “Demographic characteristics of 161-km ultramarathon runners” Res Sports Med 2012; 20: 59-69). I think that this not only is unnecessary, but perhaps even damaging – I just read an article describing the results of a double-blind randomized controlled trial of 54 healty volunteers receiving either vitamin C (1000 mg) and vitamin E (235 mg) or placebo daily for 11 weeks while undergoing an endurance training program (Paulsen et al “Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial” J Physiol 2014; 592: 1887-901). In this study vitamin C and E supplementation hampered cellular adaptations in the exercised muscles, and although this did not translate to less improvement in VO2max and endurance testing, the authors advocate caution when considering antioxidant supplementation combined with endurance exercise. On the other hand there are indications that vitamin C supplementation is beneficial for prevention of upper respiratory tract infections (colds) and exercise-associated bronchoconstriction in association with long endurance races (Hemilä & Chalker “Vitamin C for preventing and treating the common cold” Cochrane Database Syst Rev 2013; 1: CD000980; Hemilä “Vitamin C may alleviate exercise-induced bronchoconstriction: a meta-analysis” BMJ Open 2013; 3: pii: e002416).

While there clearly are some doubts whether supplementation of vitamin C is beneficial or damaging there are more and more data indicating that iron supplementation is benefical in athletes with low iron deposits and iron deficiency anemia. A recent PhD graduate thesis by Dr Sandström from Gothenburg University showed that the prevalence of iron deficiency in young female athletes, for instance the Swedish female national soccer team, was over 50%, despite better diet and less loss by menses than a control group (and also controlling for other risk factors such as Helicobacter pylori infection and vegetarian diet) (thesis available online at https://gupea.ub.gu.se/handle/2077/35460 ). He found higher values of the inflammatory protein serum hepcidin in the athlete group compared with the non-athletes and, as hepcidin downregulates the protein ferroportin important for dietary iron absorption this could be a mechanism beind so called “sports related iron deficiency”. There have been a number of studies in recent years showing up-regulation of hepcidin in response to endurance training in general and running in particular (see for instance Kong et al “Hepcidin and sports anemia” Cell & Bioscience 2014; 4: 19; Peeling et al “Iron Status and the Acute Post-Exercise Hepcidin Response in Athletes” PLoS ONE 2014; 9: e93002; Auersperger et al “Exercise-Induced Changes in Iron Status and Hepcidin Response in Female Runners” PLoS ONE 2013; 8: e58090). However, these findings are still from small early studies and further data is needed to certainly show that this is the mechanism behind sports anemia and it is probably not relevant for all athletes as, for instance, one study of six males running a 100-km ultramarathon failed to show any changes in hepcidin values (Kasprowicz et al “Running a 100-km ultra-marathon induces an inflammatory response but does not raise the level of the plasma iron-regulatory protein hepcidin” J Sports Med Phys Fitness 2013; 53: 533-7).

The relation between exercise and hepcidin (From Sandström's thesis)
Ultramarathon runners are probably at higher risk of iron deficiency than other endurance athletes for several reasons. Firstly, the inflammatory reaction/acute phase reaction in response to injury in ultramarathon running has consistently been shown to be very high and this would probably lead to high hepcidin values (see articles refered to above). Secondly, while most hematologic paramaters appear normal after ultramarathon training and racing, there appear to be changes indicating induction of some kind of changes in the iron metabolism (see for instance Dickson et al “Effects of ultra-marathon training and racing on hematologic parameters and serum ferritin levels in well-trained athletes” Int J Sports Med 1982; 3: 111-117; Fallon et al “Changes in haematological parameters and iron metabolism associated with a 1600 kilometre ultramarathon” Br J Sports Med 1999; 33:27-32; Fallon & Bishop “Changes in erythropoiesis associated by reticulocyte paramaters during ultralong distance running” Clin J Sports Med 2002; 12: 172-178; Banfi et al “Behavior of hematological parameters in athletes peforming marathons and ultramarathons in altitude (‘skyrunners’)” Clin Lab Haematol 2004; 26: 373-377). In contrast, contrary to common belief, the effects of foot-strike haemolysis on red-blood cell count and haemoglobin values appear to be negligible after ultramarathon running (Lippi et al “Foot-strike haemolysis after a 60-km ultramarathon” Blood Transfus 2012; 10:377-83). Furthermore, even though ultramarathon running clearly induces gastrointestinal bleeding that might be associated with nausea, diarrhea, abdominal cramping and bloating, it appears neither to influence RBC count or haemoglobin values (Baska et al “Gastrointestinal bleeding during an ultramarathon” Dig Dis Sci. 1999; 35: 276-9; Thalmann et al “Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study” Br J Sports Med. 2006; 40: 359-62).

There are of course no good large randomized-controlled trials studying iron-supplementation in ultramarathon running, but in running there are some smaller studies indicating a positive effect in iron-deficient, non-anemic male and female runners (for instance Garvican et al “Intravenous iron supplementation in distance runners with low or suboptimal ferritin” Med Sci Sports Exerc 2014; 46: 376-85; Hinton & Sinclair “Iron supplementation maintains ventilator threshold and improves energetic efficiency in iron-deficient nonanemic athletes” Eur J Clin Nutr 2007; 61: 30-39). One reason that studies of iron supplementation in sports anemia historically has yielded small or diverging results might be due to the exercise-induced inflammatory reaction with high hepcidin leading to decreased gastrointestinal uptake of also supplemented iron. It is therefore probably important to time to iron supplementation so that it is not occurring at the peak of the inflammatory reaction and hepcidin rise after training.

In the end, I think no supplementation can replace a healthy diet and this time of the year it is easy to find good sources of healthy nutrients both in the food stores and close to the trail. I am particularly fond of blueberries, as I have written in a previous blog post. Even though the health effects of supplementation with polyphenols found in blueberries still needs to be investigated further (see for instance the recent study by Nieman et al “Influence of a polyphenol-enriched protein powder on exercise-induced inflammation and oxidative stress in athletes: a randomized trial using a metabolomics approach” PLoS One. 2013; 8:e72215), I love the taste and what better to eat after a long trail run than a piece of blueberry pie?
Blueberry pie


29 June 2014

25 June 2014

Petite Trotte à Léon (PTL) videos

Time passes quickly and this time of the year before summer vacations can be quite busy. It has been reflected in the lower activity here at the blog, but fortunately not in my training as I have had two good volume weeks with over 100 km each and as an extra flavor a couple of fast hill-repeat or fartlek bouts in hilly terrain. The logistic planning for Petite Trotte à Léon (PTL) is also progressing well. For instance for food we will complement what we can get at Refugios and life-bases with the same pre-cooked meals ready-to-eat (MRE) warmed with a water-activated chemical heater used by the Swedish Armed Forces.

What we have not found time for is recon runs on the PTL track. I have therefore tried to “dry run” by looking at videos from previous editions of PTL. There are some overlaps with regards to courses and some of the mountain passes/Cols will be the same, but more importantly it is good to mentally prepare by forming pictures of the varying alpine conditions we will face. There are, with the new possibilities to film by handheld video records like GoPro, plenty of movies from the last year’s races and below are some of the films I have found. This list is by no means comprehensive and I have probably missed plenty of videos. Some of them are really good and inspiring in general for not only PTL, but for mountain ultramarathon trail running in general. I have ordered them below based on year and for reference I enclose an overview map of the planned original course for each year. I really hope we will be able to run the full course this year as it really look like one of the most beautiful and challenging:
Planned PTL course 2014


PTL course 2013

La Petite Trotte à Léon — The long way around Mont Blanc
Filmed by Beat Jegerlehner ( Team "Too Dumb to Quit”, USA) Edited by Jill Homer
Length: 4 minutes 56 seconds

By Janne Marin (Team “North Js”)
Length: 4 min 57 seconds

By Michel Eugene
Length: 16 minutes 48 seconds

By Unicaela Gabriela Monti
Length: 16 minutes 14 seconds

PTL 2013 by cotentrail part1
By Lord-Mac-Guigui
Length: 22 minutes 40 seconds

PTL 2013 by cotentrail part2
By Lord-Mac-Guigui
Length: 16 minutes 50 seconds

PTL 2013
By Jean-Luc Gillet
Length: 7 minutes 46 seconds (Mostly still pictures)

Auot 2013 La petite Trotte à Léon
By RacingClub Nantes
Length: 9 minutes 58 seconds (Mostly still pictures)

UTMB – PTL 2013
By Tobias Lindström
Length: 5 minutes 46 seconds (Mostly still pictures)


PTL course 2012

PTL 2012
By Pascal Bourquin
Length: 3 minutes 27 seconds

PTL 2012
By Janne Marin (Team “North Js”, Finland)
Length: 11 minutes 02 seconds

By Cedric Baud
Length: 53 minutes 47 seconds

PTL 2012: la course au long cours
By Serge Hardy
Length: 13 minutes 51 seconds




PTL 2011 Rando Running Team
By Franck Bourasseau
Length: 16 minutes 23 seconds

PTL 2011 Partie 1
By TeoTouraine1
Length: 14 minutes 08 seconds

PTL 2011 Partie 2
By TeoTouraine1
Length: 10 minutes 31 seconds

PTL 2011 Partie 3
By TeoTouraine1
Length: 8 minutes 19 seconds

La Petite Trotte à Léon (PTL) 2011 - D-run Fortitech Brasil
By Luis Mazzotini
Length: 35 minutes 10 seconds

PTL 2011-1
By Thierry Bravard
Length:  5 minutes 35 seconds

PTL 2011-2
By Thierry Bravard
Length:  7 minutes 28 seconds

PTL 2011-3
By Thierry Bravard
Length:  4 minutes 21 seconds

PTL 2011-4
By Thierry Bravard
Length:  5 minutes 51 seconds

PTL 2011 partie  1
By Serge Adam
Length: 43 minutes 0 seconds (Mostly still pictures)

PTL 2011 partie  2
By Serge Adam
Length: 39 minutes 57 seconds (Mostly still pictures)


PTL course 2010

Survivre à la PTL 2010 - Part. 1
By UTMB organization/Gabriela Monti
Length: 12 minutes 17 seconds

Survivre à la PTL 2010 - Part. 2
By UTMB organization/Gabriela Monti
Length: 12 minutes 12 seconds

PTL 2010 Bowie
By Pierre Aupaix
Length: 5 minutes 17 seconds

Bénévoles Petite trotte à Léon 2010
By benevolePTL
Length: 4 minutes 26 seconds (Mostly still pictures)

13 June 2014

The limits of human running endurance

It has been another good week from a running perspective. I have shifted focus from building on my aerobic capacity with hill repeats to longer distances and a lot of long back-to-back runs. The reasons for this are two-fold. Firstly, I got a muscle strain last week in an abdominal muscle when doing core exercises; actually quite annoying as I now really feel how much you use also the abdominal muscles when running on technical paths. In order to give the muscle time to heal I decided to refrain not only from directly hurtful activities, like further core training and sit-ups, but also from mildly uncomfortable activities like trail and downhill running. And, the muscle appear to quickly be getting better. Secondly, I would like to prepare better for the difficult task of starting a run when feeling really stiff and sore. During Tor des Géants last year it was sometimes really hurtful to go out in the cold and darkness after having slept for a short period of time and it took a while until the muscles had getting used to running again. With longer back-to-back runs I imagine I will prepare myself a little bit for this before PTL.

However, compared to what waits the 14 runners starting The Sri Chinmoy Self-Transcendence 3100 Mile Race on Sunday, my longer back-to-back runs seem like sprint distances. For those of you who have not heard about this almost 5000 kilometer long race I can strongly recommend the book “Running Beyond the Marathon: insights into the longest footrace in the world” by Grahak Cunningham. The runners are given 18 hours a day between 6:00 am to midnight, seven days a week, for 51 days to complete 5649 laps around an 883 meter block in Queens, New York. They need to run a minimum of 60 miles (96 km) a day to complete the distance. Grahak’s book is a really great and fascinating account of both the physical and mental struggles to complete this race and it is really inspirational. It also gives good practical tips about blisters, chaffing and other ailments that will be experienced at magnitude at such an extreme ultra event like this. To me, what is really fascinating about this race is that it really shows what the human body and mind is capable of. Interestingly, there are not many runners not finishing the race and those who are forced to a DNF appear quite often to be suffering from issues with infected blisters.

In reading the literature about what limits human endurance I came across the papers “The limits of human endurance: what is the greatest endurance performance of all time? Which factors regulate performance at extreme altitude?” and “The limits of endurance exercise”  by Tim Noakes in Adv Exp Med Biol 2007; 618: 255-76 and Basic Res Cardiol 2006; 101: 408-417. In these papers he discusses the energy expenditure of ultra endurance activities and classifies endurance performances based on the required energy consumption. That would make Robert Falcon Scott's Polar party during the 1911/12 British Antarctic Expedition the greatest endurance performance of all days as, for most of 159 consecutive days, Scott's team man-hauled for 10 hours a day to the South Pole and back covering a distance of 2500 km with a predicted total energy expenditure per individual of about 1 million kcal.

However, in line with the histories of runners in Grahak’s book on the Self-Transcendence 3100 Mile Race it appears not to be primarily the negative energy  balance which limits the endurance performance for these long races, even though that it partly determines the possible running pace during these herculean runs.  I have previously mentioned the findings from the 4487 km long Trans Europe Foot Race 2009 (TEFR 2009) for instance in a blog post about the effects caused by this race in the 44 participants on the brain and the pain perception and personality traits of the runners. This race has now been described in a number of fascinating scientific articles and confirm that most runners complete the race despite the massive negative energy balance  that they lost more than half of their adipose soft tissue and even lean tissue volume decreased (mainly skeletal muscle tissue). For further reading I can recommend the articles listed below, most of them actually freely available through Pubmed. I certainly think we will learn much more about human physiology from studies of longer races like this in the future.

·      Schütz et al “The TransEurope FootRace Project: longitudinal data acquisition in a cluster randomized mobile MRI observational cohort study on 44 endurance runners at a 64-stage 4,486 km transcontinental ultramarathon” BMC Med  2012 10:78

·      Freund et al “Substantial and reversible brain gray matter reduction but no acute brain lesions in ultramarathon runners: experience from the TransEurope-FootRace Project” BMC Med 2012; 10:170.

·      Freund et al “Ultra-marathon runners are different: investigations into pain tolerance and personality traits of participants of the TransEurope FootRace 2009” Pain Pract 2013; 13: 524-32

·      Schütz et al “Characteristics, changes and influence of body composition during a 4486 km transcontinental ultramarathon: results from the TransEurope FootRace mobile whole body MRI-project” BMC Med 2013; 11: 122

·      Freund et al “Regionally accentuated reversible brain grey matter reduction in ultra marathon runners detected by voxel-based morphometry” BMC Sports Sci Med Rehabil. 2014; 6:4