Precise calorie measurement

The most precise way to measure how many calories we burn is to measure the oxygen we consume and the carbon dioxide we breathe out. As we know the chemical reactions for fat and carbohydrate metabolism, in both cases we can work out the ratio of oxygen going in to carbon dioxide going out. From this, we can calculate how much of our energy is being derived from fat and how much from carbohydrates and, finally, knowing the total volume of oxygen consumed, we can then accurately determine how many calories we are burning at a given heart rate. The only real approximation here is to ignore the very small amount of energy we derive from protein (and alcohol!) metabolism. This test is usually performed with a respirometer as part of a VO2max test, whose principal aim is to determine your maximum oxygen uptake. The test can also be used to measure your anaerobic threshold, beyond which you are no longer to metabolize fats as the reactions are too slow for the rate of energy required, as well as your aerobic threshold, below which the calories you burn are mostly from fat.

The latest Garmin Forerunner models (305, 405, 405CX, 410, 310XT and 610) are able to upload a special file created by doing a New Leaf fitness test which is then used to calculate accurate calorie burns in function of heart rate. DC Rainmaker, in his excellent blog that I read every day, has not only just done one of these tests but he has explained in a post how one can "hack" an XML file in such a way that you can upload the results from any VO2 max test. This is good news for me because there is no New Leaf center where I live so I will definitely try this out next time I do one. I'm interested to know whether it is possible to upload a different profile for running and for cycling as the fat / carbohydrate ratio for a given heart rate will be different in each case. This is because you use a different muscle mass in each sport and there will be a different mix of type I (oxidative) and type II (fast twitch) muscle fibers and a correspondingly different VO2max.

Another thing altogether is being able to precisely measure how many calories we take on, short of burning an identical plate of food to the one we are about to eat. Knowing only one side of the calorie balance equation with precision is of limited use... But it can be a good way to equate the training load of running at low intensity with cycling at high intensity, for example (the idea behind TRIMPS or TRaining IMPusles).

Heart Rate Monitor blues

If you have been following my blog then you'll know that I was having a lot of problems with the so-called soft Heart Rate Monitor strap that comes as standard with the Garmin 310XT. Once I swapped it for the "classic" HRM that came with my now defunct Forerunner 305, the problems seemed to go away. It started playing up again last week so I decided to replace the batteries (although, to be honest, they shouldn't have worn out already). I couldn't find any shops stocking the little CR2023 battery that it was running on. It was only when one of the attendants gave me the sort of look that I expect she would have reserved for somebody looking for a Sega Megadrive that I thought I should do some further research on the internet. Well, I found out a couple of interesting things. First off, according to Garmin, you should wait for one minute after taking out the old battery and before putting in the new one, to give the HRM time to reset (in particularly its battery level). The other thing I learned is that the 2023 in the name of the battery actually means something: the 20 refers to a diameter of 2 centimeters while the 23 means that the thickness is 2.3 millimeters. In fact, there is no difference other than thickness (and corresponding battery life) between the CR2023, the CR2025 and the CR2032. What is more is that Garmin actually recommend the ubiquitous CR2032 as a replacement battery!

In the meantime I have been running quite a bit faster than I usually do. I suspect that it is because my heart rate was also correspondingly higher although I'm secretly hoping that having lost a few kilos since the Ironman is helping me run faster... We will see on the 18th, when I have a Half Marathon in Valladolid. I'm still recovering from the cold that knocked me out last week so I doubt that a PR is on the cards but I'm hoping to have a good solid race in preparation for the Marathon.

Holy Maffetone!

If you've been following this blog for a while then you'll know all about Dr Phil Maffetone. He was cited by 6 times World Ironman Champion, Mark Allen, as someone who transformed his way of training in this article, which is well worth reading. I've been preaching to anyone who'll listen for a while now, the benefits of "maximal aerobic training" which involves doing virtually all your training at an intensity at which you derive most of your energy from (aerobic) metabolism of fats. It is very hard to accept because we all have ingrained in us the "no pain no gain" dictum. As I have said before, Dr Maffetone is a holistic practitioner, which means taking everything into account but it also often ends up meaning "all-or-nothing". I've adopted what resonates with me and taken the rest with a pinch of salt.

My version of the MAF test (Maximum Aerobic Function, nothing to do with MAFfetone) is to run for an hour (he suggests 5 miles which would be a little over half an hour) at just under my Aerobic Threshold (AT) according to the tests Jonathan did to measure my O2 / CO2 exchange. Today I ran with my compression (calves and thighs) and on a flat, circular(ish) running track with moderate gusts of wind (11kph) and a cool 17 degrees. I managed to run exactly 14km without going over my AT, that's to say at an average heart rate of 150bpm! That's definitely a record for me. I think it is a good predictor of how fast I can run anything from 10k to a Marathon and it is useful to know for the future, if I am to compare myself with how I am now. Anyway, I am well pleased with this result.

Sudden Cardiac Death (SCD)

Three people I know have died, suddenly, of a heart attack. They were all young and in reasonable health - one was even extremely fit and died during a training session with the Oxford rowing team back in 1991. When a fit, young person is struck down in the prime of their life it is just as much of a tragedy as any potentially preventable death but it has an even bigger impact because we tend to think that heart problems are the territory of obese heavy smokers. When Andrés Iniesta scored the World Cup winning goal for Spain, he took of his shirt to reveal his vest below, on which was written "Dani Jarque, siempre con nosotros" (Dani Jarque, always with us)

Dani Jarque was a professional footballer who died of a heart attack in 2009, aged just 26. Even I had heard of this tragic death when it happened and I have a positive disinterest in football. I have also read the case of a Spanish Marathon runner - whose name escapes me - who had run 13 Marathons in less than 3 hours; the 14th was literally the death of him.

It is getting to the point that people are starting to think that running Marathons or Ironmans is something bad for you or even lethal. According to one article I found on the internet, the mortality rate over the last 20 years of the London Marathon is 1 in 67,414. On the other hand, according to another (random) article I found, the incidence of Sudden Cardiac Death in the general population is about 582 / 249,146 or roughly 1 in 428! I know that I am not being very scientific here but that is just because I don't really have time to do a proper study. Nevertheless the point is that we are much more sensitive to cases of SCD amongst athletes because of the media, our preconceptions of the "typical" heart attack sufferer and the fact that - and this is the clincher, I think - they often die in the middle of a race or competition rather than quietly at home. Who can forget when Tommy Cooper died on stage and made it look like it was part of his act? I particularly remember it because it was the first (and last) time I ever saw him on TV.

Many people can have a dormant heart condition that only becomes significant when they are subjected to a particular stress, be it running a Marathon or getting upset with their boss. One good thing about running Marathons is that you are more likely to have had a ECG or Electro Cardiogram done while running to exhaustion on a treadmill. I last did this 3 and a half years ago when I abruptly stopped smoking and started running again. On Wednesday I will do another ECG as well as an Eco Cardiogram (where they can actually see your heart beating and check for deformities, some of which can escape an ECG). I'm lucky that I can do these tests at work for free - my workplace has a joint venture with Valentín Fuster, who is a famous Spanish heart surgeon, which gives us employees access to state-of-the-art tests and gives him access to thousands of willing guinea pigs. Even if the tests were not free, I would be prepared to pay to do them - its difficult to put a price on hopefully preventing something both utterly devastating and very improbable - but certainly I value it more highly than my ticket to run the Ironman in Brazil. I have not even thought how I might feel or what I might do if they discovered something - I'll cross that bridge when, and if, I ever get to it.

If I manage to achieve anything with this blog and the money I am trying to raise for the British Heart Foundation, it would be to break down this bipolar perception we have of Sudden Cardiac Death - of overeaters and overexercisers - when, in fact, this is a very serious issue that could effect each and every one of us. Sponsoring research can have very tangible results such as improving detection rates, prevention, surgical intervention. So please, if you have found this blog at all interesting or entertaining or even if you would like to pay me to shut up, please click on the Just Giving logo at the top right of this page. And also think about getting your own heart checked up even if you feel fit as a fiddle. The fact is we probably have less doubts about taking our car in for an MOT checkup than we do for getting our motor - the heart - a certificate of good health.

POSTDATA: I did the electro and eco cardiograms yesterday and got the results back - I am officially OK to do the Ironman. Now my chest is all itchy where they shaved me pie bald so that the electrodes could have a good connection. I did my five hours training just beforehand, so I got to exhaustion on the treadmill quite quickly. Its wonderful all this science and technology to measure all kinds of clever things to do with the heart but, what surprises me is, they only test you up to 85% of your "maximum heart rate" as given by the very unsophisticated formula of 220 less your age. In my case, I have the maximum heart rate of a 29 year old, hahaha. No, really, the formula is a load of crap and it means that we only did a cardiogram up to a pulse rate lower than I will be clocking at in the Marathon at the end of the Ironmaneco as I have a friend whose heart problem went undetected by the ECG but was spotted in an eco. This potentially saved his life (and he was still able to become an Ironman).

Results of bike test

Please allow me to gloat just this once. I may never win anything again worth winning or beat any records worth beating but I think I have a right to feel chuffed about the results of my bike test. You get a mark out of 10 for each of the various categories, your VO2max, how close to your VO2max your anaerobic threshold is, your effeciency in terms of oxygen use, how many watts you can crank out etc. The mark "10" usually corresponds to an elite athlete (for example, Paula Radcliffe, unsurprisingly, gets 10 out of 10 for running efficiency and VO2max, a combination of which makes her a World Record Marathon runner). Ordinary mortals may get very high marks for some aspects but not for others, resulting in a good performance but not a World beating one. Well, I didn't get 10 in some of the criteria, I got #N/A! which means literally "off the scale" (more than 10, not less than zero - very funny!). My VO2max came out lower than in the running test I did at the end of last year (53 versus 61) which I suppose reflects the comments I made here on the day of the test.

I shall enjoy my little victory but now the trick is to convert it into something meaningful, or at least, something that is recognized (by me, if not by others).

Haha, I managed to crash the spreadsheet with pure leg power

Bike test

I did the VO2max test on the bike today. You can't really argue with that very straight line showing an almost perfect linear relationship between my pulse rate and the number of watts I was cranking out, which were being steadily increased by Diego, my friendly "torturer". It got to the point where I couldn't go any further just because the weight of my legs was not enough to move the pedals any more; I would have had to get up out of the seat which is probably more like running than cycling (certainly it has little to do with cycling in an Ironman).

I found it very useful to do the test (again) even though my thresholds look as though they will still be where they have been for the past year. This time there was a point in the test when I noticed my breathing pattern change; I glanced at my watch and - lo and behold - it showed 125bpm which is exactly where my aerobic threshold is. The same thing happened at my anaerobic threshold. So this gives me confidence in the thresholds, something that is vitally important, as I have stressed several times already, if I am going to stick to the training and racing plans. What also helps me to accept the 30bpm difference between my cycling and running aerobic thresholds is the fact that I was only able to get to 178bpm while seated; in running (and in general, for that matter) my maximum heart rate is 191. I had previously estimated my maximum heart rate while cycling to be 185bpm, which I registered during a duathlon last year. However, this was going up a b*astard hill standing up on the pedals and cursing loudly.

I still have some doubts over how much the cooling of a 30kp/h wind on the position of the aerobic and anaerobic thresholds. It's clear to me that you can eek out more wattage at a given pulse rate cycling outdoors compared to being on a stifling static bike but this doesn't necessarily mean that the thresholds obtained in the lab are wrong; the question becomes whether you should go by power, by heart rate or by "feel". One thing I do notice, is that when you are out on the road, you are much more distracted and the conditions are constantly changing, such that it becomes very difficult to judge your aerobic zone by feel. By contrast, when I am running, I can usually predict my heart rate to within a beat. I guess this is why so many people by those extraordinarily expensive power meters. I'll stick to my trusty heart rate monitor.

Maffetone

Over Christmas I have been reading a book by Dr Philip Maffetone, "The Big Book of Endurance Training and Racing".

Maffetone takes a holistic approach, that is to say, he never loses sight of the big picture. It does mean the book is a bit repetitive because, he cannot explain one bit in detail without showing how it fits into the overall context. In spite of this, the book is thankfully devoid of that self deprecating style that is all too common and wastes no words on trying too make the subject matter more interesting, instead assuming that, having bought the book, it is quite likely that you'll want to read it.

The first surprising thing about the book is that it has to be the only book on training that has no training schedules nor exercises which is just as well because I already have all that ten times over. The second surprising thing is that it a lot of the conclusions to which I had been coming are all in this book. Well, that is not so surprising as I wouldn't have bought the book otherwise but it is surprising in the sense that Maffetone has been touting these ideas since the eighties when he helped Mark Allen to his winning streak of six times Ironman World Champion.

I am normally suspicious of the word "holistic" as it is often offered as a justification when no scientific reason exists. That says nothing for my prejudices against Chiropractors of which Dr Maffetone is one. Nevertheless, as with most things, there are some sound principles behind Chiropractice and Maffetone's book gives scientific reasons for all of its claims, which is just as well, because some of them are pretty radical. Where the science falls down is that many justifications are anecdotal and not based on controlled studies. But he is only one man and has seen more than his fair share of professional athletes (which he refers to as patients rather than clients) in his thirty years of practice. I can relate to the holistic principle - whenever I have been injured I have consulted different experts but, in most cases, each one has only been able to advise me based on their narrow view leading to conflicting information and for me to ultimately decide what is best. The classic example is the doctor who, when told your knee hurts when running, recommends you not to run. Often complete rest is not the best way to recover.

The other thing about the book that would normally make me very suspicious is - I know this is going to sound silly - the photo of the author. He has a shock of white hair but a completely lineless face. He looks like he has made a pact with the Devil. Either he is taking a very unholistic and unwholesome approach, or what he preaches really works for him. I suppose it makes me suspicious because the photo says to me "you too can look as good as Phil just by following his simple plan". It is just a photo, he can't help it if he looks about thirty years younger than he really is. (POSTDATA: I was amused to see that one of the searches someone did to get to this article was "how trustable is Maffetone?". Seems like I'm not the only one!)

There are two things that I especially admire about Maffetone. The first is that he questions everything and researches the answers tirelessly. The second is that he doesn't just limit himself to digging deeper and deeper in the same hole; every so often he suddenly decide to start digging elsewhere. Now he is making music and has already released a couple of CDs. He is one of these very rare people with depth and breadth.

Something that he mentions in the book that makes a lot of sense and comes from the world of Chiropractice is the idea of muscle balance. All muscles have counterbalancing muscles (protagonists and antagonists) and are part of an overall kinetic chain. I have certainly experienced both of these imbalances. When I started to run again, I would find that the weakest link would be in pain - first I had problems with my knees, then my hips, then my calfs, the Achilles and finally my feet. Also, after an injury I would notice the imbalance between my atrophied muscle and its opposing muscle.

I think I will try a couple of the "experiments" in the book but not this side of the Ironman. I'd already been coming round to the persuasive idea behind the Paleo diet - namely that we should eat the foods that our organism has evolved to digest - but I don't feel ready just yet to cut out all refined carbohydrates from my diet. Maffetone claims that these interfere with the aerobic functioning of the body. He suggests abstaining from taking refined carbs for two weeks and comparing your aerobic performance before and after.

His more radical "experiment" is really the premise of his whole book: that you should do all of your training at the Maximum Aerobic heart rate given by his formula. I'm sure he has had a lot of experience with many athletes but without having seen the statistics I just can't buy into the formula. It puts my aerobic running threshold at 147bpm, almost 10 beats below that established in a lab test especially for me and, what is potentially more disturbing, is that it puts my aerobic cycling threshold (also at 147bpm) at more than 20 beats higher than the lab established value - this is likely to be the intensity at which I complete the bike leg of the Ironman (in fact, Maffetone would say that the bike leg should be 100% aerobic). The question I can't avoid asking is how much he actually supervised Mark Allen's day to day training and how religiously Mark Allen followed Maffetone's principles. No doubt about it, Maffetone definitely on to something but I wonder if he has to polarize his findings somewhat to give them more impact, as if he is already taking into account that you will inevitably cut some corners. Or, put another way, when he first had these ideas they were far ahead of their time - now Sports Science has caught up on many fronts and perhaps it is hard for him to acknowledge these advances without discrediting his own work. The testimonials in the book are pretty striking and more or less follow the same pattern: they describe starting off having to jog or even walk so as no as not to exceed the maximum heart rate but then how, over a period of months and years, they return to their original training pace or faster but at tens of beats per minute less. What I found particularly intriguing is that many of them go on to say that they even start to find it very difficult to maintain a pace that takes them over their Maximum Aerobic heart rate! Maffetone even suggests that you could consider doing aerobic series - that is to say, run for 5 minutes at a pulse rate of 145bpm, say, and then 5 minutes at 120bm. Phew!

Today I did at 2 hour run a la Maffetone. I ran the whole way at an average pulse rate of 137bpm - that's 10 beats below the prescribed rate. It felt ridiculously easy but what was great was that, even so, I managed to cover over 23km so my aerobic base can't be so bad. It shouldn't be too traumatic to try Maffetone's experiment - at least in cold weather and over relatively flat terrain -  maybe I will try it out next year.

Whatever your conclusions you can't afford to ignore this book...

Hmmm, slightly disappointing...

I got the results back from the "lab" today. As I predicted, my VO2max has gone up a little bit as a result of losing some weight but. contrary to my expectations, my running economy has got worse (that is to say, it is a higher number). Still, the optimistic way to look at it is to say that I did a good Marathon with a less than optimal running economy so there is some room for some improvement if I concentrate on running instead of this triathlon business. What's probably more likely is that there is a lot of error in the measurement - the most important thing for me is to go by the pulse rates in training rather than by the paces in the table (which tend to be much slower when I run on the treadmill). What is good news is that my thresholds have gone up by about 5 beats per minute so that means I can push the envelope a little more in my training runs. Anyway, so that you see what kind of feedback I get, here is the report - sorry that it is in Spanish:

CORRECTION:  In the end, I asked Diego to double check the results because it was strange that my thresholds should have increased by so much, when they have been around the same levels for years now. This is the revised report:

The VO2 Max Challenge

Now I know what a lab rat feels like...

I did a VO2max test today because Jonathan said that it would be a good idea to have a point of reference for the Marathon when it comes to the Ironman: I may find that all the cycling and swimming has a slightly detrimental effect on my running economy and we will be able to measure that and make the necessary adjustments.

The test itself is quite simple on paper but quite hard in practice. It consists of running on a treadmill while your pulse rate, oxygen consumption and carbon dioxide emissions are measured. Ah, and the speed is gradually increased until you can't keep up with the belt and are finally forced to stop. I always finish thinking I could probably have continued just a little longer but then, looking at the results, I usually see that I have hit my maximum heart rate and so that the debate I was having with myself in my head was eventually won by the right "me". In any case, it doesn't make sense to go crazy - I'd only end up getting injured.

Apart from measuring where my aerobic and anaerobic thresholds are (see previous post) and, of course, where my VO2max is, it is very interesting to see whether my running economy is improving. The VO2max is basically a measure of the maximum volume of oxygen I can burn (literally) per minute divided by my mass. The only improvements there seem to come from me losing weight. My running economy, however, has been improving in leaps and bounds. The running economy is defined by how much oxygen consumption (again, divided by mass) is required per velocity at each of the two thresholds - the lower the number, the better. As you can see, my running economy at both thresholds has been getting steadily better. It will be interesting to see the results from the test: I'll post them here once I get them.

In January I'll do the corresponding test on the bike. As you use less muscle mass when you are cycling, the thresholds for the bike are at much lower heart rates than for running. In my case, they are some 30 beats lower which I have trouble accepting. It means that I have to go really easy on the bike in training and it is impossible to go up even the slightest hill without breaching the limit. What makes it particularly hard to accept is that, in running, I notice my breathing pattern changes at each of the two thresholds and I don't really need a pulsemeter to know I am in the right zone; on the bike it feels like I don't get to the lower (aerobic) threshold unless I am competing. I have to decide whether to "have faith" like I did, finally, for my running training. The risk is that I will not advance enough on the bike in training and that I will get frustrated in the race and throw all caution to the wind. Phil Maffetone, the coach of Mark Allen (6 times Ironman World Champion), claims that the thresholds are independent of the sport and can be accurately predicted with a formula. My coach says that he absolutely does not agree with him and, I have to say, I am naturally sceptical of anyone claiming to have a magic formula. But this is just the sort of thing that might pop into my head half way through the bike leg of the Ironman if I am below my desired pace... I have the answer to that one already: thou shalt not worship false idols!

Master class



The other day I attended a talk by Jonathan based on his own research and the results of the athletes he coached through the Klagenfurt Ironman (Austria) this year. What was surprising, given the small sample (7) of those who could actually be bothered to fill in all the information on how many minutes they spent training in each sport and at each intensity, was how faithfully the results confirmed his hypotheses.

I've talked before about the concept of "polarized training", which means that you perform the majority of your training (approximately 80%) at below your aerobic threshold and the rest (20%) at above your anaerobic threshold. This was basically the premise of his talk but it was very interesting to understand where this idea comes from.

One of the papers he cited, by Fikerstrand and Seiler, was a study of Norwegian Rowers from 1970 up until 2001. The paper showed that one of the main changes in training which could account for the increase in performance in these rowers was a polarization of their training intensities. It is interesting to bear in mind that the event they were training for lasts approximately 6 minutes, a world apart from an Ironman event which can take anything from 8 hours to 17 hours (the cut off which, incidentally, is the time that the creator of the event took to complete it in 1978).

Another interesting nugget is that, if you look at the training patterns of elite Marathon runners, they spend only 4% of their total training time running at Marathon pace (and even this is probably in tune up half Marathon races)! This reminds me a little of the rowing training I did in the 90s, where we would either do underdistance (sprints) or overdistance (steady state) but, of course, no-one trains overdistance for the Marathon. What is hard to accept, as I have said many times before, is that you are doing some good by training underdistance and below pace.

Jonathan did various regressions of the performance (time) of each of the athletes who competed in the Klagenfurt Ironman (by the way, everyone he coached completed the event) against different parameters. There was clearly a correlation between overall training time and performance but, what was significant, was that there was no notable correlation between performance and "TRIMPS" - an objective measure of training intensity and volume. In particular, there was a high correlation between time spent training in zone I (below aerobic threshold) and performance, a very low correlation between time spent in zone III (above anaerobic threshold) and performance and a significant anti-correlation between time spent in zone II (between the two) and performance.

Why should this be? Surely, there should be more performance benefit from training in zone III? And how is it possible that training in zone II is bad? The argument goes something like this. Let's suppose that we have a limited amount of time in which we can train (this is always the case in practice but, for non-professional athletes it is a much more obvious limitant). How should you divide up those X hours a week between the different zones? The so called "high quality" training (a euphemism for "high pain" if ever I heard one) is very beneficial to speed but it is also very stressful for the body. The body needs time to adapt to the stresses placed upon it (recovery or "supercompensation") before it can be re-stressed; otherwise injury results. Not only can you be doing low intensity, zone I, work in the meantime, it appears that the zone I work helps the body adapt to the stresses of zone III training, as well as developing the aerobic fat burning engine.

I have to admit I work in a bank so I'll give you an analogy from an investment point of view. If you had a fixed amount of money to invest, you might choose to invest a proportion of it in high risk investments and the rest in low risk investments. It would be foolish to put all your money at risk - although you might be lucky of course - and, it would be suboptimal to put all your money in a low yielding, conservative fund. The same idea applies here - you should invest only a proportion of your training time in the high risk zone III and the rest in the safe but boring zone I. The reason that there is no sense in investing time in zone II is that it doesn't appear to promote specific adaptations in the body as effectively as the other zones and it has the added disadvantage of tiring you out more for your next zone III workout. (In the finance analogy, imagine that you get a free Playstation by placing money in the low risk fund...)

I suppose that the optimal proportion of time in zone I to zone III could vary from one individual to another (just as risk preferences do) but, for now, we will accept that one should spend 4 hours in zone I for every hour in zone III. In practice, we tend to do our series at a little bit less that zone I if we are tired - another reason to not overdo the amount of zone I training - and it is sometimes difficult to do all zone III training in the zone because there are hills, gusts of wind, or we just get bored and want to get home sooner. Furthermore, some proportion of races of distance more than 5k will be run in zone II, so it is inevitable that a percentage of training time will end up in this category. In the case of our Klagenfurt athletes, 75% of training time was spent in zone I, 21% in zone II and 4% in zone III; in the competition itself, the numbers were remarkably similar except that, of course, zone I and zone II were switched around.

(By the way, we haven't even mentioned the most obvious things to try to correlate: performance and physiology or talent - be it  measured in VO2max or whatever. This is what struck me most looking at the graphs in the presentation, that performance seemed to be dictated by hours of work alone - this would mean hope for the less blessed but determined amongst us! Perhaps an explanation for this is that the number of hours one can tolerate in training is linked to one's physiology and, similarly, the more competitive the athlete, the more of a priority training will be for them.)

The conclusion was basically that, if you want to do an Ironman:

- you have to put in the hours (10-15 hours weekly as a minimum);

- you should save yourself for the hard training days and not be tempted to push it just because you feel good

- and you should stick to your training plan!

A last point that Jonathan brought up was the importance of strength training. When you run, forces of several times your body weight ripple through your muscles, tendons, ligaments and bones a thousand times per kilometer. Anecdotally, he has been able to spot those athletes who are about to get injured as those who struggle to squat (lift with legs in standing position) 1.4 times their body weight (+1 for the weight of their own body, of course).

Post Marathon analysis

You can see from the first graph the difference between the two Marathons I have run. What is striking is that the line representing the Amsterdam Matathon from 2008 is very similar to the line representing San Sebastian, just shifted left by about 15 kilometers! It looks like I was using my anaerobic engine from the start of Amsterdam - probably a combination of starting too hard and not having done enough aerobic training prior to the race.

In the second graph, you can see the very clear trend that I was running faster and faster throughout the whole race - I wasn't even aware of this until after the 35km mark, when I decided that I felt strong enough to push on to the finish line. I think I could have started off a bit faster but, who's to say that I wouldn't have blown up. Something to try next time now that I finally have a Marathon I can be proud of under my belt... Certainly I was trying too hard to be below Jonathan's prescribed heart rate: as there is always some "noise" due to slight inclines, wind, etc., perhaps I should have allowed it to go a bit over the limit knowing that there would be other stretches that would compensate.

What is really interesting (well, to me, anyway) is the third graph. I had thought that the calorie counter in my watch would have a fairly simple algorithm that would correlate calorie expenditure to heart rate but I was surprised to see that I was burning as many calories per kilometer at the beginning of the race as at the end. This is partly due to the fact that, at the beginning, my heart rate was low but I was taking more time to cover the ground; at the end, my heart rate was much higher but I was running faster. Even correcting for this, it turns out that my watch has something a lot more sophisticated under the hood. The third graph compares the number of calories I was supposedly burning per kilometer with the number of heart beats I was above or below Jonathan's prescription. There definitely appears to be a relation between the two - maybe something for Jonathan to look into? It would certainly be a lot easier to maintain my calorie burn at 63kcal/km, say, rather than having to scribble the particular heart rates for each kilometer on the back of my hand / watch.

As for how I feel today, I really don't feel bad at all. My weight is back to normal (although I did break the 8% body fat barrier!). My legs are a bit stiff, mainly in the muscles that I didn't concentrate on in my weight training, interestingly enough, like the groin, glutes and hip flexors. Now I have a little holiday from serious training, to allow my body to rebuild itself after its little ordeal. Its definitely a good moment to get back in the swimming pool and see if I can get some halfway decent technique...

It ain't half hot...

I hate running in the heat but I suppose it's a price I'm willing to pay for the otherwise great lifestyle in Madrid. How can I be complaining about the heat in November? Thing is, I decided to run indoors in the work gym today. The air conditioning is set at about the right temperature for sitting around in a t-shirt and shorts, but as soon as you start actually doing anything you - at least I - start sweating buckets. (To give you some idea, if I spend more than an hour on the elliptic machine, the puddle of sweat goes as far as causing a short circuit which puts all the machines out of action - seriously!)

Today was worse than usual because I was running late and hit the lunchtime rush hour. When there are lots of other hot and sweaty bodies working out, it gets even more stifling. On the running machine, you don't have the cooling benefit of the air rushing past you so it's inevitable that your performance is going to be affected but that I should have to run 35% slower to achieve the same heart rate (intensity) as I would have running outdoors is just ridiculous! I suppose it is good to train heat tolerance now and again but it's got to the point where I can't do a proper workout indoors. It may also explain why I spent too much time running at too high an intensity the last couple of years - its only since I started biking that I found good outdoor trails and so, previously, I did almost all of my training on the running machine.

In the Zone

This year I decided to heed my coach's advice. Apart from being able to run a Marathon in less than 2h40, he's also an academic researcher in Sports Science at the Universidad de Europa (which is conveniently near where I work). It's one thing to follow advice when your heart rate is at less than 100bpm, but it is another thing altogether when most of your blood is anywhere in your body but in your brain. Bizarrely enough, the advice I have found most difficult to adhere to has been not to run too hard. I guess it is ingrained in me from my brief rowing career in the late 80's to early 90's, that you cannot be seen to be slacking off.

A lot of people run with a pulse monitor but I'm not sure that everyone is necessarily using it correctly: I certainly wasn't. For me it served as a compensation if a competition or a training session hadn't gone as well as I had planned: at least I had hard evidence that I had tried my best. I'm not sure exactly how I got past this masochistic phase but I think that getting into triathlon has helped. The great thing about triathlon is that every race course is different (sometimes the transition zone alone can add kilometers to the distance) and even the same course from one year to the next can be a very different kettle of fish (current, wind conditions, etc). So, in the same year that I have changed my goals from beating my best time - which no longer makes sense - I have also done just that, and had personal bests in 10k and the half-Marathon... "Go figure" as our American friends would say.

A simplified view is that the human body is powered by 3 main energy systems and, when they run out, it has a 4th "backup" energy system which isn't nearly as effective but is practically unlimited: this is fat oxidation (literally "fat burning") and is what you rely on almost exclusively when you hit the wall (or "bonk" in cycling parlance) and run out of carbohydrate stores in the Marathon. The first system is the catchily-named ATP-PC system or Adenosine Tri >PO3 Creatine Phosphate system if you want to sound impressive. It is able to deliver tremendous power but only for periods of about 10 seconds and is very slow to regenerate. The second system is the Anaerobic system which, as its name suggests, doesn't use oxygen to generate energy; the third system is the Aerobic system which does use oxygen. Both of these systems operate in parallel and use glucose (sugar or carbohydrates) stored as glycogen in the muscles. However, the Anaerobic system generates lactic acid as a by-product and the build up of acidity causes fatigue in the muscles. If you do an activity and increase the intensity with which you do it, there comes a point when you are mainly relying on your Anaerobic system. Everybody has a different tolerance to lactate acid build up but it gets us all in the end. Sports physicians like to measure the point (usually in terms of heart rate) where your body starts to rely primarily on the Anaerobic system (AT or Anaerobic Threshold). There is a lower threshold - the Aerobic threshold (AeT) - below which your body is relying almost entirely on the Aerobic system. Somewhere above this, is a point called the MLSS (Maximal Lactate Steady State) threshold above which lactate acid accumulates in the blood, which is really useful for Marathon runners: it is theoretically the intensity at which you sh/could run a Marathon, supposing that you are efficient enough not to use up all your glycogen before you get to the finish line. The only bugger is that nobody has yet devised a way to measure it that doesn't involve running round a track and pricking your finger to measure the lactate level.

That was the simplified view, haha. To be honest, I have found so many conflicting definitions, especially concerning lactate thresholds and their relationship to the Aerobic and Anaerobic Thresholds, that I just content myself to be know that there are two main thresholds - an upper and a lower, both of which are highly individual and movable with the right training.

If you are still reading, then this is the good bit. Once you have established these thresholds, the theory is that you should do the vast bulk of your training for a long distance event at less than the AeT - which is kind of good news because, in my case, its a pretty easy pace. The idea is that, by consistently training at below the AeT, you are working your Aerobic system and it will adapt more effectively to the demands you put upon it. In particular, it will encourage the body to derive more energy from fat oxidation and help save those precious glycogen stores for later. The bad news is that almost all the rest of the training should be at above the AT, which is damn hard. This training is supposed to increase your AT (what good is that, I hear you ask, it just means I'll have to train even harder!) and increase your lactate tolerance. This is typically the goal of the dreaded "series" where you run very fast for a few minutes say, have a break of 30 seconds or so, and then do it again... and again... The interesting thing is that very little, if any, training is recommended in between the two intensities. Anyway, those are the training sessions I most hate because they are neither light enough to be able to tolerate for a long time, nor are they short enough to be able to put up with easily. However, that is the intensity that you typically run anything from a half-Marathon to a Marathon.

By the way, if you are serious about training, it really is worth getting your thresholds measured properly with a VO2 Max or Lactate Threshold test. There are loads of short cuts around to estimate these thresholds but I think that most of them are quite dubious. The famous formula for your maximum heart rate as a function of age is a good example: it might work on average, but two identically aged people could easily have maximum heart rates differing by 30bpm. Also, the whole point is that training can move the thresholds so you should get them measured regularly.

In trying to keep my heart rate below my AeT I have found it hard to factor in the fact that your heart rate drifts slowly upwards as you run. This is due to the energetic cost of evacuating the heat from your muscles: the drift is very sensitive to the ambient temperature. This means that you should be going ever slower as you run which seems to contradict the perceived wisdom of doing a run where you finish faster than you started. Some people say that you should set the thresholds at a certain pace rather than a particular heart rate; nevertheless, the energetic cost of the heat evacuation is a real cost whether you like it or not. Its taken me a while to accept, but I am really feeling the benefits, in particular I seem to be able to run faster and longer at my AeT. I hope that I notice the difference in the Marathon!