Monday, 1 April 2013

TORQ Trail Team Assessment Day - Loads of Positivity


Hopefully just a quick post tonight, commenting on an excellent day I attended yesterday at Parliament Hill, London.  You may have seen my Trail Running Sussex launch blog post last week.  Well yesterday was the first outing for Trail Running Sussex.  I had been invited to do a talk to around forty keen, ambitious trail runners who were hoping to get selected for the newly formed TORQ Trail Running Team.  These runners had been shortlisted from apparently loads of runners that had applied after seeing the following information:
TORQ is looking for runners who will join the TORQ Trail Team for 2013 and enjoy many of the benefits of a professional running team.

Anyone who is committed to running on the trails and exploring the outdoors - as well as their own limits - is encouraged to apply to be part of the team: this is not just for elite runners.
Those successful in being selected for the team will spend a year as part of the TORQ Trail Team, with many of the benefits usually only available to professional teams, including:
  • A nutritional assessment and nutrition products from TORQ Fitness
  • Team-branded kit for training and racing
  • A three day training and preparation trip running in the Alps on the UTMB course around Chamonix from Thursday 20th to Sunday 23rd June 2013
  • Appearances in features in Trail Running Magazine
  • Support and advice throughout the season
As you can see, with the team not focusing on elite runners, it created quite a bit of interest.  There is also a second assessment day in Shropshire in two weeks time for around another forty runners, and I have been invited to do a talk there as well.

The day was a great opportunity to meet and chat to loads of super positive trail runners.  It was also really nice to have an audience paying full attention, listening and interacting with me during my talk. (Just a wee bit different to lecturing biomechanics to University students!)  Unfortunately I really enjoyed their enthusiasm for my 'words of wisedom', that I went on, and on, and on!  The amazing thing was that they didn't seem to wilt, a true demonstration of ultra endurance qualities!

Rather than me describing the overall day, one of the runners has provided a well written summary on his blog.  Click this link to read Chris' blog post.  As Chris describes, the day consisted of three talks and then an easy off road run up Parliament Hill, with some awesome views of the high rise buildings of London.

During my talk I covered quite a few topics. One or two of these topics I was quite vocal in terms of that what I was saying had been clearly demonstrated either within the academic literature or as evidenced during running races. I have since thought, that for these topics where I was more certain of my ideas, that perhaps I should provide a little bit of evidence to substantiate my statements.

Firstly, my statement that dehydration is not the problem in relation to decreasing performance that it is made out to be!

The first talk of the day was a talk on nutrition by Martin from TORQ.  By the way I haven't actually mentioned who TORQ are.  In a sentence they are a company that produce nutritional products, and are well used within the Mountain Biking community.  I have tasted their TORQ bar, and it tastes good.  But haven't yet tried their gels, although Luke my physio uses them and states that they are really good.

I spent quite some time checking out the TORQ website last week, and overall I was pretty impressed with the website, the material they present, and how the science is translated into their products.  Similarly, the talk by Martin was very good, and he clearly explained the purpose and benefits of adopting an appropriate nutritional strategy.  However, there were two small aspects of Martin's talk that I wasn't in total agreement with, and a little unfairly I highlighted my concerns regarding these two aspects during my talk, without providing the opportunity for Martin to reply, sorry Martin.

So, with regards to dehydration,  Martin put up the following slide.
Now this slide corresponds to data from the eighties which has since been clearly shown to be totally flawed when it comes to real life marathon running!  The following is the abstract/summary from a scientific journal article from 2012.
Drinking Behaviors of Elite Male Runners During Marathon Competition

Author(s): Beis, LY (Beis, Lukas Y.)[ 1 ] ; Wright-Whyte, M (Wright-Whyte, Moray)[ 1 ] ; Fudge, B (Fudge, Barry)[ 2 ] ; Noakes, T (Noakes, Timothy)[ 3,4 ] ; Pitsiladis, YP (Pitsiladis, Yannis P.)[ 1,5 ]

Source: CLINICAL JOURNAL OF SPORT MEDICINE Volume: 22 Issue: 3 Pages: 254-261 Published: MAY 2012

Participants: Ten (9 winners and 1 second position) male marathon runners during 13 major city marathons.

Main Outcome Measures: Total drinking durations and fluid intake rates during major city marathons.

Results: The ambient conditions during the 13 studied marathon races were 15.3 degrees C +/- 8.6 degrees C and 59% +/- 17% relative humidity; average marathon competition time was 02:06:31 +/- 00:01:08 (hours: minutes:seconds). Total drinking duration during these races was 25.5 +/- 15.0 seconds (range, 1.6-50.7 seconds) equating to an extrapolated fluid intake rate of 0.55 +/- 0.34 L/h (range, 0.03-1.09 L/h). No significant correlations were found between total drink duration, fluid intake (rate and total), running speed, and ambient temperature. Estimated body mass (BM) loss based on calculated sweat rates and rates of fluid ingestion was 8.8% +/- 2.1% (range, 6.6%-11.7%). Measurements of the winner in the 2009 Dubai marathon (Haile Gebrselassie) revealed a BM loss of 9.8%.

Conclusions: The most successful runners, during major city marathons, drink fluids ad libitum for less than approximately 60 seconds at an extrapolated fluid ingestion rate of 0.55 +/- 0.34 L/h and comparable to the current American College of Sports Medicine's recommendations of 0.4-0.8 L/h. Nevertheless, these elite runners do not seem to maintain their BM within current recommended ranges of 2%-3%.
So it is quite clearly demonstrated that elite marathon runners experience dehydration well in excess of 5% bodyweight, which according to the above figure would correspond to performance well less than 70%, but yet Gebrselassie set the world marathon record, also with a similar 9 - 10% dehydration that he had at Dubai!

But, the above article refers to elite marathon runners.  Does the same findings apply to the non-elite?  Well there is another recent 2011 article, that investigated this and here is the abstract/summary:

Inverse relationship between percentage body weight change and finishing time in 643 forty-two-kilometre marathon runners Hassane Zouhal, 1 Carole Groussard,1 Guenolé Minter, 1 Sophie Vincent, 1 Armel Cretual, 1 Arlette Gratas-Delamarche, 1 Paul Delamarche, 1 Timothy David Noakes 2

Objective The purpose of this study was to determine the relationship between athletic performance and the change in body weight (BW) during a 42 km marathon in a large cohort of runners.  Methods The study took place during the 2009 Mont Saint-Michel Marathon (France). 643 marathon finishers (560 males and 83 females) were studied. The change in BW during the race was calculated from measurements of each runner’s BW immediately before and after the race.

Results BW loss was 2.3+2.2% (mean + SEM).  BW loss was -3.1+1.9% for runners finishing the marathon in less than 3 hours; -2.5+2.1% for runners finishing between 3 and 4 hours; and -1.8+2.1 for runners who required more than 4 hours to complete the marathon. The degree of BW loss was linearly related to 42 km race finishing time.  Neither age or gender influenced BW loss during the race. Conclusions BW loss during the marathon was inversely related to race fi nishing time in 643 marathon runners and was >3% in runners completing the race in less than 3 h. These data are not compatible with laboratory-derived data suggesting that BW loss greater than 2% during exercise impairs athletic performance.
They match an extensive body of evidence showing that the most successful athletes in marathon and ultramarathon running and triathlon events are frequently those who lose substantially more than 3–4% BW during competition. So the issue of dehydration severely affecting performance at even 5% dehydration clearly doesn't seem to occur!

So even for non-elite runners, it appears that dehyration of 3.1% results in a better performance than dehydration of only 1.8% of bodyweight!

My second point of concern regarding Martin's presentation was the issue regarding how much carbohydrate does one need to consume during an ultra trail race.  Martin clearly explained the latest research that has demonstrated that with the use of a Maltodextrin (glucose polymer): Fructose blend, at a 2:1 ratio, the amount of carbohydrate that can transported across the intestine is increased from the previous thought maximum of 60 grams per hour, up to 90 grams per hour.  The real issue what was being discussed yesterday was, is there really a need to consume 90 grams an hour during an ultra trail race.

Well, I am pretty confident in stating NO!  My reason for this is that the intensity one runs at during an ultra trail race, say of 100 miles, is so low, that the body is not consuming much carbohydrate.  This relationship between exercise intensity and utilisation of fat or carbohydrates comes mainly from the nineties, but is still regarded as being correct.

Below are some figures that illustrate how the percentage of fuel from carbohydrate decreases as the exercise intensity decreases.

So these two figures above show that as the intensity of the exercise decreases more energy is created through the metabolism of fat, not carbohydrate.  The figure below clearly illustrates this relationship.

Now during the second half of a 100 mile ultra, and I guess for those runners that attempt to try to run at a constant pace/effort, then during the entire race, the intensity is going to be rather low.  For me, with a maximum heart rate of around 185 bpm, and a resting heart rate of around 45 bpm, during the last 50 miles of the Lakeland 100, my heart rate is typically at only around 120 - 125 bpm which equates to around 54 - 57% of heart rate reserve (HRR) which is max HR - rest HR, which equals 140 bpm.  It has traditionally been thought that the %HRR corresponds reasonably closely with %VO2max, so it would indicate that for the second half of the race I am exercising at only around 54 - 57% of my VO2max. (Although the latest research suggests that the % HRR would more closely equals the %VO2 reserve, either way the value will be reasonably similar.) Which from the figure above would give me a fat:carbohydrate ratio of around 65% fat and only 35% carbohydrate. It is therefore clearly obvious that there is no need to consume 90 grams of carbohydrate per hour, as the body isn't using carbohydrate at a high rate!

The final aspects from my talk yesterday that some evidence may be useful to demonstrate the point I made, is to do with slowing down during ultra races, and marathons.  I discussed this in some detail in a previous post back in December 2011, after I raced Martin Yelling from Marathon Talk at the Endurancelife Dorset Coastal Trail Marathon, and I raised this aspect of him getting it totally wrong regarding pacing!  He wasn't convinced.  I'll present the key figures and some text from my previous post that clearly demonstrate that the concept of the negative split is totally wrong, and leads to 'failure' for over 95% of all marathon runners.

To help provide evidence for the flawed concept of the negative split, back in December 2011 I looked at the results from that year’s Virgin London Marathon. Perhaps as one would expect, based on the status the negative split has, both the male and female winners ran negative splits. So therefore why have I wasted all of this time typing up this blog post, attempting to get you to consider that the negative split isn’t what it is made out to be? But let’s look a little deeper at the results. How many of the other 99 runners in the top 100 in the massed start race also achieved a negative split? Remember these runners are the very best, at the very front of a field of over 35,000 finishers. Surely then one would expect around half of the top 100, or at least a third! No, only seven other runners in the top 100 finishers ran a negative split. This ‘strange’ result could however be because at the front of the race many of the runners went out with the pace makers at nearly world record pace, in the hope of hanging in there to the finish, they therefore were never going to achieve a negative split. So if I look at how many within the next 100 places from 101 – 200 achieved a negative split, this would give perhaps a more true representation of the frequency of the negative split occurring. These runners from 101 – 200 are still top quality runners, and in relation to the overall field, very, very fast runners, with an average finish time of 2 hours 39 minutes. The results show that there were only 6 negative split runners from the 100.

If you look at the graph above, it shows the number of runners that negative split from samples of 100 runners at different time gaps for the first 10,000 finishers, then you will see that there is ABSOLUTELY no relationship at all between the finish time of the runners and the percentage that achieve a negative split. If running a negative split was a quality of being a good runner, of a good performance, then surely one would expect that further towards the front of the field there would be a higher percentage? With a correlation of pretty well zero, one shouldn’t need any more evidence that the negative split is NOT something to aim for, NOT something that indicates that you performed well!

Another key statistic is the percentage of runners within the first 10,000 finishers that actually achieve it, being only 5.8%. With this evidence it therefore still amazes me that there seems to be the message ‘out there’ that the negative split is something all runners should aim for. If we look at a 10% sample, in batches of 100 runners, spread throughout the 23,600 runners that finished within 5 hours at London, then the percentage that achieve a negative split drops even lower to only 4.3% of finishers! The graph above also shows how the positive split slowing down time increases as the finishing time increases.

A real issue that needs attention, is in terms of the potential effect this low percentage of negative splits may have on the marathon finishers, when 95.7% of them do not achieve probably the number one goal that is drummed into them apart from finishing! Remember the message ‘out there’ that the negative split indicates that you ran well, probably even more important than your actual finishing time. So 95.7% of runners are potentially disappointed because they didn’t achieve one of their goals.  No wonder most endurance runners think negatively towards themselves!

The above figures relate to a road marathon, what about some ultra trail race data?  Well I dug out some results and did some analysis.  Hopefully it makes some sense.

Data from the 2012 Montane Lakeland 100:

So, even the widely regarded 'super human' performance by winner Terry, still involved him slowing down during the second half of the race by nine percent!  In comparison to Gancho, who obviously took it really easy during the first half of the race, being over an hour and a quarter behind me at Dalemain.  He still slowed down during the second half of the race by twenty one percent.  Yes, a reduced slowing down rate, in comparison to Paul (and Barry 2nd=, same slowdown as Paul, and also 4th place Ian with 33% slowdown) and me, with a massive 42% decrease in pace!  So only Terry slowed down less than Gancho, but Gancho only finished in 6th place.  Did his attempt to run even pace, cost him second place?  Did he gain back the time he lost during the first half of the race when running purposely slowly, by going faster in the second half of the race.  An interesting question?  I think not!

Just one last example to finish with, this time from the 2011 IAU World Ultra Trail Championships in Connemara, Ireland.  Comparing my slowing down during the second half of the race, with Julian Rendall from GB, who finished one place behind me in sixteenth place.

With regards to the percentage slowdown at the Worlds, it is much smaller than the Lakeland 100, as the first half of the Worlds course involved two very tough steep climbs of Diamond Hill, of around 400 metres climb each time!  Again the question could be asked, did Julian manage to run that much substantially faster during the second half of the race, significantly faster to gain back all of the time he lost during the first half of the race by purposely running slowly?  Again I think not!

Just to conclude "Run as fast as you can, while you can!"  The negative split is a flawed concept!

I hope that the above information has helped provide some evidence for some of the statements I made during my talk.  However, as I mentioned yesterday, the majority of the content of my talk are my views, so it doesn't automatically mean that they are correct.  The main goal from my talk was to get the audience to start questioning their ideas to training and racing.  Is there an alternative approach?

Time to sign off, and I think the words from Tom at Marathon Talk are quite appropriate.
“A large amount of what we achieve is governed by our mental state and how we see ourselves. (It is) a lot about opening the mind to what might be possible when we throw away the self imposed limitations of our mind.” Tom Williams, 2011.
To those of you that attended yesterday's TORQ Trail Team Day, thanks for making the day an enjoyable experience.  To everyone else, hopefully the above information makes some sense, even without the context of my TORQ talk!

I hope to see you all 'positive splitting' in the future,



  1. Excellent and interesting article Stuart, thank you for the post. Very well articulated and argued cases which are informative and stimulating. Without as much in-depth knowledge or stats, drawing upon my own experience and looking back to years ago when distance runners drank and eat a lot less than we do today (and which I was used to as a long distance runner and cyclist in my youth) shows that many ran much quicker than today's top marathon runners are able to do. At that time, with much less liquid or food consumed, you could run well under sub 2.30 and not be in the top 20 or 30 in small but very competitive fields. Research I have read suggests that for well trained athletes in particular, significant dehydration is not a performance limiter. The effects of glycogen depletion are more significant it seems, but your evidence on those two subjects is really interesting and very persuasive, if not conclusive. However, as a market researcher, I think your observations on negative splits are not conclusive because they do not answer the question whether, in individual cases, more would not in fact actually have performed better if they had consciously run negative split paces for long races of marathon or more. In my own case, for instance, having experimented on pace, when I am fully fit (a key requirement to not slowing down naturally I'd say!) all my best personal performances have unquestionably come off pacing strategies aimed at a negative split (in the Comrades marathon for instance). I also remember once questioning Bill Adcocks of Athens marathon fame, when I was wondering which was the best pacing strategy to adopt for long distance races, which pacing strategy had produced his best performances and he was unequivocal; his best results came on 'relatively' steady starts and getting faster towards the end. That's not say you should start 'slowly' so as to be well behind the leaders with no chance of catching up in later stages as in your examples, but a more measured early pace may still be best. I am sure you would agree that a correct pacing strategy is key to optimal performance, but I don't think your stats prove the point on negative splits. They may prove that most people do not adopt a negative split strategy, or maybe that they are not capable of doing so, but I think they do not actually prove that a target negative split performance at a given fitness for any individual is not the best likely way to get an optimal time for a given long distance event for that individual? I'd say a lot more research is needed on the same people adopting different strategies and comparing their results over time before we can be more specific on the subject?

  2. I absolutely agree with the comments on hydration. Glycogen stores are associated with quite a lot of water - so, I am not sure that loss of body mass is really a good measure of dehydration. If you use glycogen and sweat you will lose weight and remain hydrated.

    I am not so convinced about the comments concerning negative splits. Slowing down has a very profound effect on finishing time, so a near flat pace theoretically produces the fastest result. Going out too fast certainly hastens the slowing. Whilst I like the idea of; "Go as fast as you can for as long as you can" it rarely produces a good result. Realistic planning and a gradual increase in effort with a near flat pace (on flat terrain) must surely still be the best advice.

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  4. Thanks for the Blog.

    On Hydration:
    The authors of the paper on hydration have worked extensively with the very best runners in African nations such as Kenya and Ethiopia. My understanding is that they developed their original hypothesis based on what they saw i.e. that nutrition and hydration "strategies" were not consistent with the conventional recommendations from sports science. Yet, they were the best runners in the world. Things to think about include:
    1) That Kenyan/Ethiopian runners have adapted to their diet so are not limited by the same factors those in the UK....
    2) That the scientific literature is wrong. One of the author's Tim Noakes is always challenging things based on a superb intellect but he's not always backed up by the evidence.
    3) Many studies published in nutrition are supported directly or indirectly by those with vested interests.
    4) The body fat of the runners in the study is far lower than for even normal athletics populations.

    One thing that is often not considered, but is very pertinent to ultra running is gut health. Lots of carbs during a race can and do result in GI issues.... good "neutral" diet pre-race is important as is training the gut to be able to handle carbs during exercise. 60g of CHO per hour during exercise (depending on BM) can be challenging for very many people.....90g may be 'optimal' from a theoretical perspective but it's unachievable for most.

    On the negative split debate....I'm not sure if there is much debate if you go back to 1st principles:

    Mathematically and energetically, even splits are best. If you do a negative split, then you will have been losing time in the 1st half of the race. A positive split and you'll be losing time in the 2nd. Fact. Additionally, any variation in pace will generally result in poorer running economy. Of course, things are never as simple as that and tactics, course and environmental conditions will all have an affect on what is the ideal pace.

    No inferences can be made from meta-analysis. My experience in cycling shows that only a tiny minority get their pacing right. I've got the advantage of using (absolute) power data here though.

    Of course, there is the psychological aspect of racing. I think a slower start could be of some benefit to most here as it simply prevents runners going off too fast and the result is a less precipitous drop in pace later in the race. This is still sub-optimal though.