Monday, 29 April 2013

A weekend at the Races, Part 1: Highland Fling

Mid week I took the difficult decision of pulling out of Highland Fling due of lingering foot injury, and following a phone call from  race director John Duncan the easy decision of helping out with a spot of Marshalling. While I felt I couldn't risk running 53 miles, to compensate slightly for this loss I decided to enter the Sunday's Balfron 10k, it was my first 10k race three years back so held fond memories.

Saturday Morning : Marshalling the Fling @ Drymen

While I was surprised to get the call from John Duncan, just a few minutes after emailing my withdraw, it was really great to have the opportunity to still be actively involved and witness the great race unfold. My post was about half a mile before the Drymen checkpoint, at the right hand turning off the road and into the field that leads up to the checkpoint.

The half hour drive from Callander to Drymen was really beautiful, cold and clear with fresh covering of snow ontop of the higher peaks.  My thoughts were with the runners now a half hour into their adventure, the clear conditions took me back the stunning conditions we had in last years Fling.  I arrived at Drymen checkpoint at 7am and introduced myself to the BOSS (Mary Connelly) collected my red bib with black trim, Mary complimented my matching Trailroc 255's - by bizarre coincidence black shoes with red trim. All set I headed down to my post.

At around 7:18 I heard the first rapid foot steps through the trees and three lead men appeared abreast, looking fresh and completely comfortable as if in a gentle morning jog with friends.  I am always amazed by just how comfortable the elite runners make it look, it was a real privileged to witness great runners doing what they do best.  A few minutes past then a second wave of elite's arrived and I started to recognize a few faces.  Again they all looked effortless, just gliding smoothly downhill, disappearing into field and uphill as quickly as they came.

As an avoid follower of Stuart Mills' blog I was surprised to not seem mixing it up with lead runners and a little concerned to see him at the back of the second  wave and not looking as comfortable as runner I'd expect of his calibre and competitive instinct.  Ultra-marathoning can be a fickle sport, some-days you fly others the cylinders don't all fire up and respond.   While Stuart's day was unfolding quite to plan he still went on to post another great performance and second sub 8 hours time.  Ohhh what I'd give to have that ability.

Shortly after I spot Richie Cunningham in small group pass and do my Marshalling duty and call out to go right, pointing out the hole in the  hedge you go through.  I do feel a bit of tit telling this to a Grand Master of the West Highland Way!

In the wave of runners was Tracy Dean, the leading lady gliding past and up the hill.  Within a few minutes other ladies appeared. A few minutes and call out to go right and Caroline McKay appeared looking fresh and enjoying the day.  I recently had done analysis of the fat burning on carbohydrate needs during Ultra's and used fitness data of Caroline's so was really curious how she would do, I was expecting here to race well and likely go sub 10hour.  She was ahead of Drymen splits for 10 hours, and so it would stay that way with her finishing in 9:36, a PB by over an hour.  If you ever want proof that Paleo diets and a good training plan work look no further than this astonishing improvement.

I knew John Kynaston's splits so was expecting him to turn out shortly before 7:50 and right on cue her turns out, great big smile and blethering away to what seems to be an entourage around him - all cribbing off his splits no doubt!

Originally I had a plan of trying to take photo's but runners now started pouring past with only a few moments between the gaggles so never had a chance.  My left pointing arm was now feeling rather over-used, not quite the workout I had been planning for 5 months to do on the 27th of April but you gotta take whatever you can to keep fit when injured!

What really impressed me is the good cheer that almost all the runners passed by with.  It was glorious day on beautiful course and no doubt this nourished the great atmosphere amongst the runners and Marshals.  I have to admit pangs of jealously watching the runners head uphill and further on to big adventure along the West Highland Way, I too wanted to amongst them.  Had I been over cautious in pulling out?

My own injuries woes felt rather pathetic when Rhona of RedWineRunner blog came through, despite a painful knee injury she was looking strong and running what looked to be pretty smoothly.  Running with injury requires a lot of grit so I have a huge amount of respect for the fact that she completed her mission finishing in 13 hours.

With the tail end of the runners coming through the field was spreading out and at around 9:20 the last of the relay runners came through and it was time for me to head back up hill to the Dymen checkpoint, give back my big and collect a surprise bottle of bubbly!

All through the day I followed twitter updates from spectators, runners and the organizers and was amazed by the course record being broken, and what an amazingly close finish from the two leading ladies!  And all those other great adventures that runners undertook - I look forward to lots of interesting blog posts in the coming week.

It was privilege to have played even a tiny part of the great day, the organization from the top down was really impressive.  As runner you rarely get to see all what the race organizers have to plan for and coordinate.  Being on the other side marshalling brought it home to me how much ultra running is family that love running and love where we run, whether it's helping run events or taking part, what  makes it's special is the spirit of goodwill that infused the day and will linger long after.

Friday, 26 April 2013

2013 Londom Marathon Elite demonstrate folly of a Positive Split

Positive splits in Marathon and Ultra distances are not only typical for masses but also very common in the Elite runners as well.  Does this mean that Positive Splits are best or does this just illustrate how hard run Even or Negative Splits when trying to run the perfect race? 
In Stuart Mills recently blog post "A Tiny Bit More on Pacing, and Trail Running Sussex Develops" he analysis the results for recent 2013 London Marathon both the Elite and masses and with it shows just how few people achieve a Negative Spit.  Stuart also goes further and suggests that this is proof that a positive split is a good thing and that a negative split just leads to a sub-par performance.  Is this suggestion sound?  

The fact that this years Elite marathon were at marathon pace at the half way point but the race winner ended being the slowest in 7 years suggest that Positive Split is actually detrimental.  To explore this further I'll look at the splits and finishing times the last four years of the London Marathon that I could find record of, and the also for comparison look at the Marathon world records and the London Marathon Winners Personal Best.

Last four years of London Marathon Winners

Tsegaye Kebede 2010 London Marathon 02:05:19 01:03:07 01:02:12 -1.45%
Emmanuel Mutai 2011 London Marathon 02:04:40 01:02:45 01:01:55 -1.33%
Wilson Kipsang 2012 London Marathon 02:04:44 01:02:12 01:02:32 0.54%
Tsegaye Kebede 2013 London Marathon 02:06:04 01:01:34 01:04:30 4.76%

What clearly stands out is this years race Positive Split of 4.76% was huge compared with the previous 3 years, and the finishing time was the worst.  The course record of 2:04:40 was set with a -1.33% Negative Split, while Wilson Kipsang's time of 2:04:44 was with a modest 0.54% Positive Split.  This data suggests that this years large Positive Split was significant factor in the slowest winning time at the London Marathon in 7 years.  A quote from the  winner says it all : "It was too quick," said Kebede of the early pace.

Personal Bests of London Marathon Winners and World Records.

Paula Radcliffe 2003 Womens's World Record 02:15:17 01:08:02 01:07:15 -1.15%
Haile Gebreslassie 2008 Men's World Record 02:03:59 01:02:03 01:01:56 -0.19%
Emmanuel Mutai 2011 London Marathon, PB 02:04:40 01:02:45 01:01:55 -1.33%
Tsegaye Kebede 2012 Chicargo Marathon, PB 02:04:38 01:02:53 01:01:45 -1.80%
Wilson Kipsang 2011 Frankfurt Marathon, PB 02:03:42 01:01:40 01:02:02 0.59%
Patrick Makau 2011 Men's World Record 02:03:38 01:01:43 01:01:55 0.32%

Here the range of are from -1.33% Negative Split to a 0.59% Positive Split, with the average a -0.59% Negative Split  Even the largest Positive Split still was only a slowing of 22 seconds over second half marathon distance, which really is incredibly even split.

These are the very best performances of the very best of  marathoners, they are the  absolutely pinnacle of human distance running and clearly demonstrate that a Negative Split  will more often deliver a personal best performance than a Positive SplitAnything more than running a very modest Positive Split is detrimental to performance as the London 2012 result show.

These figures really show the importantance of starting out at a pace that you feel is sustainable for the whole race:  "Start out steady and Finish Strong" wins the day.

Wednesday, 24 April 2013

Highland Fling : Runner to Marshal Transformation

In the middle of last night I awoke with the simple but profound realization that I love running more than racing, and racing in the Highland Fling this weekend was just going to exacerbate my foot injury and delay the day what I can get back enjoying the freedom of injury free running. 

The Fling is an awesome event and one I've been wholly focused on for the last five months so making a decision to pull out is a hard one.  I really, really wanted to be out there on Saturday, but my realization is that I want even more to be out everyday on the hills, be it in an event, training for an event, or just for the plain joy of running in the beautiful countryside.  Having been sidelined by various injuries and illness over the last 6 weeks has brought into focus how frustrating it is to be injured, the physical pain of injury is far less than the loss of not being out there running and the frustration of not making progress in training for a big event.  The thought of making myself more injured on this occasion just doesn't seem to justify what I might gain in single days running, even when day is out on the beautiful West Highland Way with great likelminded company.

While my subconscious made the decision last night I couldn't quite bring myself to officially withdraw till the end of the working day, so just after 5pm I sent off an email to race organize John Duncan.  Minutes later I picked up the phone to John, who politely inquired about my withdraw and then seamlessly moved onto asking if I was now available to help out with Marshalling...

Over dinner I explained my withdraw and the idea of Marshalling on the Fling to my three girls and each one came up with a different plausible excuse I should have used to get out of Marshalling :-)  I'm not sure they have quite grasped the idea that volunteering to help in events is both crucial to the smooth running of events and it's rewarding seeing others safely on their way.

So.. now I'm a longer running in the Highland Fling, but I'm still part of it. Current plan is for me to be stationed at Drymen directing runners off the road and right into the field that takes you up to the check-point.

Sure there is part of me that will be wishing I was passing through as a runner at 7:55am and bang on my splits on route to a PB, but this year it wasn't to be.  There are plenty more days of running and more great races this year for me to look forward to so I won't be dwelling on might have been.  Instead I'll be there to point runners in the right direction and soak up the atmosphere and inspiration that can be gained by witnessing nearly 600 runners embarking of something that most people would consider impossible - two marathons on rugged terrain in one day, that's just plain awesome!

Good luck to all those running on Saturday, see you at Drymen!

Monday, 22 April 2013

Anti-taper : Ben Ledi and Callander X 10km race report and Fling Prospects

My preparation for the Highland Fling has gone off the rails due to injury so for the last 6 weeks have done little running, and none of the key long training runs.  To try and maintain some semblance of fitness have been on the bike and up the hills walking as cross training with a few short runs thrown in.  With conventional training thrown out I've also given up on textbook taper and rather than take it easy this weekend did two tough workouts back to back.

On Friday the weather was brilliant, warm, sunny, light winds, in theory I should have been resting but the days was just too beautiful to squander so I cycled to Stank Glen Car park and walked/run up Ben Ledi and ran down, 2500ft ascent/descent in 1hour 25minutes.  Not racing but brisk enough to get the HR up on ascent and to stress the quads a bit on the descent.
Approach Ben Ledi summit from the south, with views looking west towards Ben Lomond
The next day was the Callander X 10km race, it's a great local event so just had to enter as a competitor.  Last year the race was the day after the Fling so I run/walked it as sweeper finishing in around 1:30 so this year I had a time to beat, and guessed might even be able to half that time.  In theory one doesn't prepare for a 10km race by running a mountain the day before, and in theory one doesn't run races one week prior to a big ultra.  However, things have gone so badly injury/training wise I've given up doing things right and went into the race thinking that if the race exacerbated my foot injury then I'd have a good warning to pull out of the Fling, if somehow I survived intact then perhaps I might still have a chance of pulling off the Fling as well.  Do or Die!

Stiff from the mountain run the day before I lined up at the start line in Dreadnought car park with 135 others.

We had time to exchange a few words with familiar faces then we were off.  The route goes straight up on the lower crags path climbing for the first 1km.  I started a few rows back from the front, but still far up enough to get caught up with pace and excitement of the faster runners.  I know to take the hills easier but still found my ego overriding common sense as other runners jostled around me all seemingly breathing much harder than myself - if they were putting in the effort then so should I, I knew it was too fast too early though for my present level of fitness. 

The second and third km takes you back down into streets Callander, thanks to gravity assist I put them away at 6min/mile pace and caught and overtook a few runners.  As the course flattened out the level of effort required to maintain pace became an effort, with my quads aching from the previous days run and my HR up in the high 170's, I knew that it would be too fast to maintain for the final 7km so relaxed a bit on try catching runners ahead.  There was piper in front of the St. Kellogs and a good crowd cheering which made tearing through the town center a delight.

The route crosses the river Teith, the 5km runners then headed right back to finish at the Meadows, while the 10km runners head out of the south of town past the Primary School and up the Creep to Cohallian Wood and with it another 1km of climbing up to the half way point where a lone piper spurred us on.  I check my watch I go through the half way point in 22 minutes as the half way point was at the top of the second hill, and only one more hill left figured that I should be able to get under my target time of 45 minutes.

The next 1km was a fast one descending down to Cohallian wood car park, then next two km's are initial flat then rising as one skirts underneath Samson's stone.  A short undulating descent then takes you down to Bochastle carpark and across the road to join the cycle path for that takes you back to Callander and the finish.   The mile along the cycle path is flat with a slightly overall descent so is fast, despite my attempts to muster an increase in tempo in the last mile I can't catch the runners ahead. My last mile was completed in 6:20 so I wasn't sloughing.

Once you cross the river Teith it's only 100m's to go but you can't see the finish through the trees, instead you turn right and pop out into the Meadows with just 20m last to the line.  My wife and girls cheer me on and greet me at the finish, while I stagger a bit incoherently and rather out of breath.  My final time was 42:13, 16th overall and 7th male vet.

The time was way faster than I expected to do on such a hilly route (580ft according to my gps phone app), with fatigued legs from the day before and very little running in the previous 6 weeks let alone anything resembling like race specific preparation.   My calf and quad injuries were not at all evident, but the problem in my left forefoot was still evident, not enough to slow me down but not a confidence builder given the the imminence of the Fling.  Overall a great run, on flatter course I would likely have gone under 40 minutes - not far off my PB so despite my dreadful last 6 weeks training wise it does look like I still have maintained a descent level of aerobic fitness.

Following the 10km a 1km fun run was held within the confines of the Callander Meadows park.

I and rest of the parents were rather taken a back by the sheer pace of the children that tore off at 6min/mile pace - the winner, a P4, maintained the pace this pace all the way to the end. 

My wife and follow helpers took Herbert the Hungry Caterpillar for a walk while my two eldest girls run together finishing well ahead of Herbert.

Thanks to the floods over previous two days the route was a bit damp in places but this seemed to just cause more hilarity as everyone splashed through the remaining puddles. 

The atmosphere was excellent, and while the wind was a little cold the rain stayed off and the sun even tried it best to squeeze through occasionally.  The BBQ at the finish was welcome addition to the prize giving, where. No surprises with the winners, last year's winner Prasad Presad retained his title in 34:14 while Elke Presad won the ladies race in 40:42.

Skidaddle have posted the race results up their facebook page, but it mixed in the 5km and 10km results making it a bit awkward to see the individual race placing, so I did a sort on the race category, attached is the resulting race result spreadsheet (in Open Document spreadsheet format.)

Epilogue: Reflection on prospects for Fling

Two hard runs in less 24 hours left me pretty stiff and fatigued and as there was a visiting sports message therapist in town I took the opportunity for a message.  While my calves coped well with the deep massage the manipulation of my quads was excruciating.  Two days on and my quads and hamstrings are still tender, more Continued Muscle Soreness Syndrome rather than the usual DOMS.  I'm pretty sure the level of discomfort is far more down to the massage than the back to back hard runs, but it all feels like it's all going to settle down nicely as the week progresses.

Today I went to my Physio to get her opinion on the lingering injury to my left forefoot and how fool hardly it would be to run on the injury.  The diagnosis was a bone bruise to lower/front of my metatarsal heads.  I believe the injury was caused back in March by running too my miles in my worm out Trailroc 245's.  After 800 miles the mid-sole had become compressed and eventually creased underneath the forefoot causing a very local hot spot of pressure on the front on my metatarsal heads.

I had done the right thing my cross training and getting new shoes but looks like adding in hill walking with running descents probably enough stress to hold back full healing.  Had I stopped all weight bearing training perhaps I might have been well on the road to recovery now.  However, without the hills I'm pretty sure the rest of my running capability will have suffered so it's rather been a case of be between a rock and hard place with training.

The big topic for today's session with the Physio was how likely was I to cause more serious damage to my foot my running the Fling in 5 days time.  Looks like the risk is there, but the nature of the injury looks like a stress fracture isn't imminent.  Most likely will be that I will set back my recovery but if I'm sensible and pull out if discomfort increases too much then it should be able to manage the risk.  My Physio recommend getting some Full Strike Sorbothane insoles for the race and carry my original soles with me as backup, and to not run this week.

I have an old pair of Sorbathan insoles that are a half size too small for the Trailroc's but might experiment with these to see if they are comfortable.  Without running this week it's kinda hard to know how well they might work though...

So where does this leave me?  We'll I'm still torn about the risks of running a 53mile ultra with little mileage in my legs over the preceding 7 weeks.  My longest runs this year were a series of hilly 15 milers back in February and early March - these went really well.  However, my planned marathon and 30+ mile training runs were pencilled in for late March early April but instead the furthest I've run has been 10miles.

Part of my thinks I'm crazy to consider running the Fling, but also other parts of me just loved the race last year and want to be back, and another part of me - the mad scientist just wants to know what happens to my body when doing a long race with such sub par training.  Given my lack of long runs finishing under my 10:46 time of last year is out of the window, simply finishing in one piece will be a great challenge.

To run or not to run, that is the question? I welcome opinions :-)

Friday, 19 April 2013

Callander X 10k, 5k and 1k fun run this Saturday!

This Saturday (20th April 2013) Skidaddle are running three events, the Callander X 10km, and new 5km and 1km fun runs.

The Callander X 10km and 5km races follow along the same hilly mixed trail/road course as last years 10km with the 5km completing just the first half before heading to the Callander Meadows.  Both races start at the 11am at Dreadnought Car Park, heading up onto the lower Callander Crags path before winding back through to the center of Callander. From the town centre the 5km route heads back towards the Meadows while the 10km route heads south towards and up Cohallian woods path.  The 10km route then returns home via the trail underneath Samson's putting stone and back along the cycle path to the meadows.  The last mile is flat and fast trail and without a doubt will be a lung buster!

The 1km fun run starts at 12:30pm, fancy dress will be very welcome :-)  The fun will take part within the Callander Meadows so no road or trail crossings.

Entrance on the day is available, just go along to registration that is based in Callander Meadows and open between 9:30 and 10:30am.  You can park at the Meadows or the Dreadnought Car Park.

Further information is provided here.

Tuesday, 16 April 2013

The effect of Pacing on Carbohyrdrate requirements for an Ultra

For Pacing an Ultramarathon Negative Split, Even split or Positive split best? Rather than cover all aspects of pacing on race outcomes, for this post I'll focus just on answering this question from the perspective of how much each pacing strategy will have on your Carbohydrate requirements - which strategy will conserve the most Carbohydrates and minimize the risk of accumulating muscle fatigue and hitting the wall?

In my previous post "The effect of Fat burning on Carbohydrate requirements for an Ultra" I explored the effect that being an efficient fat burning can have on sparing Carbohydrates during an Ultramarathon using the data from Scottish Ultrarunner Caroline McKay and with the paper "Maximal Fat Oxidation During Exercise in Trained Men" (MFO) as a reference.  Caroline has adopted a low carb Paleo style diet in the last six months and the results demonstrated outstanding fat utilization throughout her speed range.  For this post I'll use this same data and techniques used to analyse Carbohydrate utilization, extending them to allow me to study the effect of uneven pacing on Carbohydrate utilization.

Analysing Fitness data

The first step in the analysis is to establish the relationship between HR, pace, total Calories used, fat and carbohydrates used per hour.  Caroline's January fitness test provided the following graph:

For a representation comparison I think scaled the fat/carb utilization data provided in the MFO to fit with Caroline's HR range and total Calorie consumption, resulting in the following graph:


Analysing Carbohydrate utilization

For the purposes of analysing Carbohydrate usage during an Ultramarathon the key part of this data is the how much Carbohydrate is used per mile, using Caroline's HR to pace data I then combine Caroline's carbohydrate data with that provided by the MFO study, vertical axis in Calories, horizontal axis in mph:
Two key observation from this graph:
  1. Caroline is using far less Carbohydrate per mile than the athletes in the MFO study, suggesting that Caroline's training and low carb diet are extremely effective at sparing Carbohydrates.
  2. For both Caroline and the MFO athletes the Carbohydrate increases rapidly with pace and the relationship is not linear, so a 10% increase in pace requires much more than a 10% increase in Carbohydrate utilization.
The second observation about the non-linearity of Carbohydrate utilization suggests that an even pacing will result in the minimum Carbohydrate utilization for a given pace.  As a simple check of this consider a runner who keeps to a steady 6mph and note the carb utilization, then compare to a runner who runs at 5mph for half the time and 7mph for other half the time and we find the average cost goes up as the the cost of going 1mph faster is higher than the saving of going at 5mph.

If we re-draw the graph against HR rather than Speed then we also observe a very similar relationship, and for the same reasons can expect that an even intensity - at a consistent HR will lead to least Carbohydrate utilization for a given pace.  

This applies when we are going up and down hills so we'll want to aim for a consistent HR when going up hill and down hill and let the pace drop and increase to maintain the consistent level of effort.  For ultra paces this will mean walking up-hills for all but the top elite runners.

The above discussion doesn't introduce the issue of HR drift during a race, as this is something that varies from individual to individual and race day to race day it's not possible to accurately account for this factor, in this analysis.  HR drift over a long period won't effect the validity that consistency in HR over any particular stage in the race is likely best.  I would recommend pacing short periods like going up a hill and down the other side by aiming for a consistent HR, but expect the HR to drift upwards through the day for the same pace.  If you don't have a HR monitor then use your breathing intensity as guide - if you find yourself puffing up hill then you are very likely to be pushing too hard and should ease off.

Analysing the effects of overall pacing strategies

The observation that even pacing/intensity is likely best for minimizing carbohydrate utilization doesn't just apply to one particular instant in the race, it also applies to the whole race.  However, running even splits is next to impossible in an ultra for whole range of reasons, it's inevitable that we'll either go out too fast, too slow, do one or more stages too quick or hit a low point.  That's even without considering the effect of changes of the terrain, weather conditions, fatigue etc. through the race.  So we all will spend some time going too fast and some time going too slow during, with the ideal being constant intensity and average speed.  This leads me on to the next question - which the analysis can help answer - just how much of an effect does inconsistent pacing have?

To look at this I simplified the task by considering an evenly distributed terrain and a runner than spends half their time at a higher speed, and half the time at a lower speed and comparing their total Carbohydrate utilization to that of runner than run at same average speed across the whole race.  The maths behind the Carbohydrate utilization isn't effected by how the fast and slow running is distributed - so they could run a negative or positive split, or run fast and slow for alternating minutes and we'll still end up with the same result - all of these pacing strategies will all have the same consequences w.r.t overall Carbohydrate utilization, the only crucial factor is how much faster or slow that an even pace your at.

To illustrate the effect on the uneven pacing I plotted the number of calories required for a range of deviations away from even pacing, from even pacing to high speed/low speed ratio of just over 2.  The following graph illustrates the results for Caroline's excellent fat burning data, normalized so that all split combinations result in Highland Fling 10 hour finishing time:

As highlighted in my previous post, Caroline's should be able complete the Highland Fling with only around 1,000 Calories from carbs if she was able to run perfectly even splits.  If the splits were 2:1 then the requirements goes up by just under 1100 calories to just over 2090 Calories still amazingly low for two marathons but a doubling of Carb cost.  A more modest 1.25 to 1 pace split however costs an extra 106 Calories, which in practice would like like spending half the time at around 5.1mph while the other half at 6.43mph.  While a 1.5 to 1 pace split costs an extra 346 Calories and be equivalent to averaging 4.6mph and half at 6.9mph.
The following graph illustrate the results for the MFO study data, again normalized so that all split combination result in Highland Fling 10 hour finishing time:

The least amount of Carbohydrates required with an even split at just over 3,500 Calories, while a 2:1 pace split requires a further 1100 Calories.  A more modest split of 1.5 to 1 only requires 355 Calories.  While a 1.25 to 1 pace split just requires just over 108 calories more than the minimum.

The surprising thing about these two datasets is while the baseline Carb consumption is massively different 3500 Calories for the MFO data vs 1020 for Calorline's, the additional Carb costs due to sub-optimal pacing is almost the same. However, my expectation is that it would be easier for a fat burner like Caroline to be able to cope with needing an extra couple hundred Calories of Carbs than someone who already has exhausted their glycogen stores and is now relying on consumed Carbohydrates to fuel them through the second half of the race.  So while it's important that both Fat burning and Carb burners use their Carb stores efficiently by pacing evenly, it's the Carb burning that need to take the most care.

The effect of race intensity on sensitivity to uneven pacing

By setting a fixed pace split of 1.25 to 1 but varying the finishing time we can look at whether you become more sensitive to pacing errors as you increase or decrease you average running pace.  The following graph plots a range of finishing times for a fat burning athlete with an assumed 1.25 to 1 pacing split:

What is very apparent is that when running near your limit rather than taking things easy it becomes far more critical to get pacing right.  This means going out too fast or too slow compared to your eventually average finishing speed could significantly increase the overall Carbohydrate requirements and with it risks of missing your targets.  While taking it easier you should fine mistakes in pacing far less critical.

Looking at the MFO data we see a very similar picture, with the additional carbs being almost identical to that of those more efficient at burning fat:

Again we see that for those running faster the cost of uneven pacing is greater, and as total Carb usage is so much greater for the MFO data I believe the issue of pacing is even more critical to Carb burners as they'll be treading so much close to the line of Glycogen depletion.

The relationship between Muscle Fatigue and Carb usage

In sport science literature/studies muscle fatigue has been linked to production of Reactive Oxygen Species (ROS) that are believed to cause damage, especially muscle cell membranes.  ROS are particularly created during high intensity exercise, but also during pre-longed lower intensity exercise.  In the book "The Art and Science of Low Carb Performance" the authors go as far as suggesting it's metabolism of Carbohydrates that creates the most damaging levels of ROS and that this may explain why low Carb athletes report quicker recovery times times after training and races.

If this is indeed the case then it's not difficult to conclude that not only does even pacing reducing Carbohydrate needs in training and racing, but also reduces the ROS production and associated muscle damage.  As both muscle fatigue and glycogen depletion are amongst the biggest contributors to struggling to maintain pace towards the ends of races it suggests that even pacing and minimizing additional Carb costs is double important.

The goal of minimizing the accumulation of muscle fatigue looks to largely consistent with the goal of minimizing Carb usage, I would be inclined to go further and suggest that adopting a more conservative splits in the first half of race will result in less muscle damage so that you can continue the second half running in more comfort and with it more strongly and efficiently.

Applying these findings to race pacing

Looking at splits of Ultramarathon it's clear that it's very rare indeed for any athlete to run a negative split i.e. run faster in the second half than the second.  Analysis of race results show a broad correlation between faster athletes running more even splits but still even the elites do positive splits. However, even within the elites there is huge variation between individuals. Does this mean all the above analysis is somehow wrong?

From the point of view of carb sparing and reducing muscle fatigue the ideal is an even split, with a increasing cost of diverging from this.  It is however extremely difficult to run a perfectly paced race, so I wouldn't worry if you don't achieve it, no one does.  When deciding of race pace I'd advise you look at splits of previous races and adopt splits ratios of the runners that achieve the most even splits and finish strongest.  Even if you are middle or back of the pack runner adopting splits that get nearer to the ideal of even splits will spare Carbohydrates and reduce the accumulation of muscle fatigue.  It's also crucial that you are realistic about your finishing time, as great splits on paper can be terrible splits for a runner who can't keep the the pace up. 

To summarize all this analysis into one sentence:

Start easy, run with even intensity, finish strong, recovery quickly.

Sunday, 14 April 2013

The effect of Fat burning on Carbohydrate requirements for an Ultra

I've just completed some preliminary analysis of the effect of Fat burning on Carbohydrate requirements for the Highland Fling, comparing fat burning measurements of Scottish Ultra runner Caroline McKay and the figures published in the paper "Maximal Fat Oxidation During Exercise in Trained Men" (MFO).  The results are startling, demonstrating the low carb diet recently adopted by Caroline and the training she does has had a massive effect on fat and carbohydrate utilization, far eclipsing the reference data for typical trained athletes.

The analysis required Heart Rate (HR) data against speed, total Calorie consumption and amount of fat/carbohydrate matabolized.  I've been hunting such data and in particular was looking for local ultra athlete to give it relevance to Scottish ultra scene, and last week Caroline McKay posted "Quest to become a metabolically efficient fat burning machine!" entry on here blog.  Very kindly Caroline passed on the Metabolic Testing Report for her January session at Napier Uni's.  This report provided HR, speed, calorie and Respiratory Exchange Ratio (RER) values that allowed me to compute the fat/carb values, and as there is only a 6 data points provided I've had to fill in the gaps by fitting a mathematical functions to various elements of the data.

For reference I also mapped the data provided by the published MFO article normalizing to match Caroline's HR and total calorie usage so I could do a representative comparison.

The maths behind this analysis is something I've put together this weekend so isn't in any published article or book, and while I could attempt to explain it all I'll not attempt it in this blog entry, it's really not something I'd expect 99% of reader to ever want to get their heads around, ask me if you want to know more.  As I'm not trying to write an academic paper rather dwell on the details I'll just cut to the chase and show you the base graphs of the various key parameters, so you'll know where the final analysis is drawn from.

First up we have the relationship between HR and speed that Caroline's fitness test found - I've fitted the original test data to the straight line as this matched really well and allows me to extrapolate them to lower ultra-marathon relevant paces.

Next I turned to fitting a curve to the total calorie and fat usage for Caroline's report, and did the same for the MFO data whilst recalibrating the values to match Caroline's HR range and total calorie consumption.  The key was making the comparison of the data representative.  In the HR to Calorie/Fat chart below red data is Caroline's data, and yellow is the MFO reference, while blue is the total Calorie usage rate (Calories per hour).

While these are idealized curves, they are fitted to real data, take your time to digest just what the results are - Caroline is burning fat almost right up to here maximum HR, while the "Trained Men" reference began using carbs exclusively from a HR of 151 upwards - an intensity that Caroline is still getting almost half here energy from fats.  I find this quite simply extraordinary. Awesome job Caroline!

While the graph above is staggering, what does this mean in practice when running an ultra?  Like many in the Scottish Ultra scene the next big race for us is the 53.1 mile Highland Fling that runs along the southern half of the West Highland Way.  Using an estimate of 5,772ft of ascent for the route that John Kynaston kindly provided, and some of my own mathematical models for cost of elevation/descent on running efficiency I estimated a 9% time and energy cost for all those hills.  Then using the HR to speed and HR to energy usage graphs above I then extrapolated how many Calories of Carbohydrates would be required for different finishing times:

There is no way Caroline will be able to sustain her maximum HR for the whole route, but I thought it would be useful to see the effect on carbohydrate needs on the extremes both at maximum speed and at slow enough to just squeeze in before the 15 hour cut off.  Several amazing things drop out of this graph:
  • Normally trained runner requires at minimum 3000 calories of carbs to complete the race, this means consuming at least 1000 calories of carbs as well as burning all their 2000 Calories of stored glycogen.
  • If Caroline was happy to do a slow trot she could get by with just burning 500 calories of carbs.
  • Caroline's 2011 PB of 10:34 would now require less than 1000 calories of carbs.
  • While a normally trained runner would require nearly 3500 calories of carbs for the same PB pace.
  • A course record of 7 hours would require just under 4000 calories of carbs for a fat burner like Caroline, this would entail eating about 285 calories of carbs per hour to make up the extra 2000 calories required over glycogen stores.
  • While a normally training runner to run a course record would require over 6000 calories, and a staggering 571 Caloris/hour
  • I believe these figures suggest that for a 7 hour course record we'll need athletes that are even more fat adapted than Caroline, as well as having the extraordinary speed over distance that we've always expected.
I'm pretty blown away with all these stats.  But we do need to take a step back and remember this is just a quick analysis that makes several assumptions that compromise the accuracy to actual requirements on the day.  Lets run though these:
  • Assumed the fat/carb consumption doesn't change through out the race, I couldn't factor this in without any concrete data so rather than guess I've just left this as an assumption.  The assumption will mean that the above figures are likely an over estimate of actual carb requirements.
  • The hills and rough terrain may well be cost more than 9%, so this might push up/pull down the data a bit.
  • Weather effects fat/carb consumption, again this is large unknown so not possible to factor in so for the analysis I'm assuming that the temperature is the same as for Caroline's test.
  • Consumption of fluids and nutrition will have an effect on fat/carb consumption, again as I can't quantify this I've assumed it's net effect is zero.
  • Pacing is consistent through the race - I'm planning to specifically look at this issue in a follow up article (although as spoiler I can say from a carb sparing perspective the most efficient split is an even split - negative and positive splits will required more carbs overall.)
I'm sure I've made further sweeping assumptions, but I believe the general findings are useful:
  • Food Mix -> Fuel Mix : The low carb, high fat diet that Caroline has been following this year clearly is very effective at supporting high fat utilization across all running paces and especially at ultra race paces. 
  • Typical trained runners with high carb western diets metabolize carbs over fats, even at slow paces and will require large amounts of carbohydrates to finish the Fling, consuming at least 100 calories of carbs per hour will be required.
Further thoughts on what this means when it comes to race day:
  • For capable fat burners like Caroline it should not be necessary to consume large amounts of carbohydrates.  
  • Reducing the amount of carbohydrates consumed reduces the risk of stomach problems
  • Consuming carbs at too fast a rate is likely to induce a insulin response which switches off fat metabolism, so if you don't need them desperately then limiting consumption is likely to be lower risk
  • Might the new wave of engineered starches like SuperStarch help avoid the insulin response? Is anyone selling them in the UK yet?
There is lots more to think about besides, personally I think the results are jaw dropping.  An ultra runner diet looks to be one of most important aspects that we should be working on to improve our performance and enjoyment of races.


Poscript:  Just adding a small note: since writing this blog entry Caroline has run the Highland Fling 53 ultramarathon, setting a new personal best of 9:36 for the race, which an hour faster than her previous best.  Caroline in her blog entry, A Fling with Friends, reports that she felt strong throughout the race despite eating less than in previous years.  This performance provides good evidence that she has achieved her goal of becoming efficient at metabolising fats and as consequence has achieved a very impressive improvement to her ultramarathon race performance.

Wednesday, 10 April 2013

New Shoes : Trailroc 255

Yesterday my new shoes, Trailroc 255's arrived in the post, like an excited puppy I took them to for a spin up Ben Ledi. 6 miles and 2500 of ascent and descent later I'm one happy customer - I believe I found my shoe for Highland Fling. In this post I'll try and provide a quick review for those curious about the shoe.

The weather was stunning, but a bit a too windy right at the summit to take photo's so I head off the summit along ridge towards the north. Ben More and Ben Lawes stand out clearly on the horizon, visibility on Tuesday was stunning.

Just before heading down into Stank Glen the view I turned back towards the summit to take a quick photo.

I picked the Trailroc 255's as extra protection around the sides of the shoe compared to the lighter 235 and 245's is really needed when handling running in snow, ice and tough heather out on the open hill.  Taking my old trusty Trailroc 245's in similar conditions just wrecked the upper.

In combination with Inov-8 debri gaters the Trailroc 255's handled the crusty snow and ice really well - plenty of grip and protection.

I went for a half size larger than my old Trailroc 245's as I plan to use them for hill walking and running, and when walking will wearing thicker socks. The extra half size up should help when running ultra's when the feet start to swell  The downside of moving up a half size is on the more technical parts of the run my feet where shifting a little both laterally and my toes slide to the end of the toe box during really steep descents.  Normally I really dislike my toes touching the ends of shoes but the toe box shaped felt great, just lightly pushing against the front of my toes, with no pressure on my toe nails.

The extra heel drop of 6mm and extra width made for a less stable feeling compared to my Trailroc 245's with 3mm drop - which I feel complete glued to the ground.  The feel is half way between my Roclite 295's and the Trailroc 245's. The 245's are more fun to run in, they bring out the playful side to running, while my 295's have been relegated to a walking shoe.  The 255's will now replace my Roclite 295's as a walking shoe, but also been the workhorse I fall back on for long runs through tough terrain that would otherwise tear up the upper of the 245's.

The extra protected down the sides of the Trailroc 255's work very well for protecting the foot and the upper material from scraps and knocks, it looks to me like it'll really help with the life of the shoe.  I wouldn't be surprised if it helps the upper outlast my old Roclite 315's, and would consider the Trailroc 255's as a worthy replacement for the Roclite 295's and 315's - the shoes have a better last so are more comfortable, they have lower heel drop and keep your lower to the ground, the upper is more robust and they are a couple of ounces lighter as well.  What not to love :-)

There is a downside to extra side and toe protection - for small puddles the side walls helps prevent water getting in, but once you step in puddle/bog that takes the water over the side walls the water gets in largely stays in place. All the drainage routes for any water that makes it in are blocked, the only route out for any water that gets in is being squished out the top of the upper and evaporation.  In practice it means that your foot is going to damp for longer.  By contrast the lighter weight upper of the Trailroc 245's let in water easily but the bulk of it gets squished out within a few strides.

  • Lightweight for such a well protected shoe (~230g for my size 7's).
  • Upper is much more robust than most trail shoes on the market.
  • Excellent grip, handles road, trail, snow and open hill.
  • Good underfoot protection from roots and stones but still provides reasonable ground feel.
  • Anatomical last that accommodates even my wide hobbit feet.
  • Modest 6mm heel drop that does interfere too much with stride - you can forefoot/midfoot strike or heel strike comfortable.
  • Great replacement for Roclite 295 and 315, lighter and more comfortable!
  • As a mid-foot striker, I still would prefer the shoe to be zero drop, the more cushioned heel is a waste of weight and stability for a runner like me.
  • The extra protection on the side walls makes the shoes poor at draining any water that gets in
  • The extra protection also makes the shoes less airing than the lighter weight uppers of Trailroc 235's and 345.  This is good for a cold day, but might make then less comfortable on hot days - if we ever get any any!
The cons are really not that big of an issue, and all down to the compromises made for protection and robustness.  I really like the shoe and am eager to get out in them on the trails, and as long as my currently injury niggles subside in time will be my shoes that take me over the 53 miles of the Highland Fling.

My heart still belongs to the Trailroc 245's though, it just a little more nimble and fun to play in, while the Trailroc 255's are a rock solid and dependable.  Both are awesome shoes in their own right, and will fulfill different but overlapping roles for me. The 245's for general training and racing while the 255's will be my go to shoe when the conditions and routes get really tough and when I go out hill walking.

Friday, 5 April 2013

Making the most of Cross Training

My training plans for the Highland Fling came unstuck in March, a calf injury early in the month was followed by illness mid March followed by a foot injury, nothing was going my way so I've been forced to put my efforts into Cross Training to get in shape for the Fling.

Two years ago when preparing to run the Kielder Marathon I was forced to cross train due to a achilles injury spending 6 weeks training on my bike.  Three weeks before the race I got back into running but found it really tough, my legs just weren't able to cope with the eccentric loading during the first half of stance.  The lack of running training meant that my quads and hip flexores were totally fried in the last 8 miles of the race.

Clearly just cycling for cross training isn't going to cut it when preparing to run 53 miles of hilly trails with many thousand of feet of ascent and descent that the Fling entails.  My approach this time is to mix cycling with hill walking, specifically cycle to hill, quick march to the top then run down, then cycle back home.  The quick march up has been getting my HR up to where it is when doing a marathon paced run or even tempo run when up really steep slopes.  The descents while a bit tough on my injury forefoot and really stressing my quads ability to handle the eccentric loading.  The hill walking/running also provides a workout for a good range of muscles and ranges of motions that the bike just can't provide.  While the bike riding provides an good aerobic workout.

Fingers crossed this combination will allow my foot to heal whilst keeping myself fit for running long distances.  With just over three weeks to go it's rather nerve racking though, my longest training run of 30 miles with 5000ft ascent/descent was planned for this coming weekend.  Instead I'll be cycling, walking and a best tackling a short run if my foot feels OK.

One up side of the new Cross Training approach is that it's getting me up some great hills and mountains in the Trossachs:

Monday I cycled 19 miles and went up Ben A'an overlooking Loch Katrin
Monday a short cycle then brisk Ben Ledi, the approach to the Summit quite appropriate for Easter!
At the summit two the wind was 40mph+ yet two thrill seeking crows battled it out, my camera phone was blown from my hands several times.
Just before my un-gloved hands froze I got this last photo looking west towards Ben Lomond
Tuesday I cycled 14 miles and walked/ran the trail above Brig O'Turk
The trail at Brig O'Turk takes you briefly above the loch at Glen Fingless.
Wednesday I took it easy and just walked from the house up the Callander Crags
Thursday I cycled 21 miles and went up Ben Shean above Strathyre

Today (Friday) I did a 27mile tour of Trossachcs on the bike, at 7:30am I heading out with the temperature at 0 degrees, but beautiful sunshine.  The route took me from Callander to Lake of Mentieth, to Aberfoyle, up the Dukes pass, down past Loch Achray, to Brig O'turk then home to Callander past Loch Venacher.  It's hilly route but views were ample reward.  The sunshine didn't compensate for the low temperature early in the morning though, despite two sets of socks my toes were frozen for the whole 2 and half hour cycle.  As I was keen to get back to see our family guests I didn't hang around and take photo's today.

After putting in more than two hours of cycling/hill walking/running per day this week my legs are feeling quite fatigued.  I usually just manage a hour a day on average when running so it's quite a big jump up.  Fingers crossed it'll give my fitness the kick up the butt that it needs to compensate for all the lost running that I had planned for March.