(To those of you that are a little bit short of time I have copied the link to the useful webpage that this blogpost is explaining immediately below. The remainder of this blogpost helps to explain some rationale behind the webpage slowdown formula, but one can go straight to the webapage, and hopefully the data it provides will be reasonably clear. If not come back to this blog post.)
How fast should I run at the start of the marathon? This is where the following webpage is really useful. http://rsusmf2.appspot.com/ Please note that this slowdown formula has been updated form the version one which I introduced on UltraStu April last year within the post A Helpful Marathon Pacing Calculator The two improvements are that version two of the slowdown formula takes into account the gender of the runner, as this seems to have a significant effect on the percentage slowdown for the same finishing time. I have also removed those runners that in simple terms 'blow up', and therefore have a very high percentage slowdown. Further description on the formula are detailed below.
Back in May 2013 I wrote two blog posts on the fallacy of the negative split for road marathon running, which created 'a bit of a stir'. Which was further 'stirred up' with two other posts during April last year: A Helpful Marathon Pacing Calculator and Road Marathon Pacing - The Positive Split Pacing Strategy - My Final Comment At the time I stated that those posts would be my final comment on the topic, however, with marathon season 'kicking off' with the Brighton and Worcester marathons this weekend, and then Manchester, London and others during the following two weeks, I felt that one final blogpost on the topic could be so beneficial to the thousands of runners who will be running a road marathon during the next few weeks.
By now with the bulk of the physical training completed, the focus of the preparation should be on the non-physical training. By that I mean predominantly goal setting and visualisations. In terms of goal setting many runners will have a target marathon finish time that they would like to achieve, so this can form one of your goals, i.e. a destination goal. This is useful as having this target finish time goal can help you in providing a counter argument to the many messages you will get during the later stages of the marathon, strongly encouraging you to slow down. In addition to a destination goal, it is also useful to establish some journey goals for you to evaluate along the way, just to check that you are on track, and running well. These journey goals may be related to your emotions during the run. Are you enjoying the experience, are you 'staying within the present moment', are your race focused. are you running at the ideal intensity, right on that threshold? Yes, it is useful to establish some journey goals, and then include what you want to be achieving whilst running the event within your visualisations leading up to race day. Anyway, enough about goal setting, lets get back to marathon pacing.
As mentioned above, many runners will have a target finish time that they would like to achieve. The issue is, what pacing strategy is best to increase the likelihood of achieving ones target finish time. Now as ideal as the even paced marathon pacing strategy sounds, and with the argument typically being that most of the World records are set with an even paced, or a negative split paced strategy, in reality around 93 - 95 percent of all marathon runners who finish the marathon quicker than four and a half hours run a positive split. That is that they slow down during the second half of the marathon, so their second half marathon time from 13 - 26 miles, is slower than their first half marathon time from 0 - 13 miles.
Now, this post isn't going to repeat my discussions on why I think this positive paced strategy is the ideal strategy. You can go to my two posts from May 2013 if you want to read my rationale for my stand: The Negative Split - The Realisation that An Accepted Running Concept is Actually Flawed! and The Negative Split Fallacy - Part 2 - The Explanation! No this post is amount the reality of actually running the marathon, not opinions, theories and speculation!
So, the situation is that around 93 - 95 percent of marathon runners finishing a road marathon quicker than four and a half hours slow down during the second half of the marathon. At last year's London Marathon within the non-elite field. I think it is best to disregard what the elite marathon runners do, as their characteristics are quite different to the non-elite, 2:30 - 4:30 marathon runner. Interestingly though, at last year's London Marathon only two elite men (2/18 = 11.1%) and two elite women (2/14 = 14.3%) achieved a negative split, so not that dissimilar to the 10.0 and 16.0 percent of non-elite runners in the quickest time band (see below for time band explanation). Mo Farah also achieved a positive split of 3.30%, which is also not that dissimilar from the 3.88% for the quickest non-elite mens time band.)
Sorry, I got distracted there! So, the situation is that around 93 - 95 percent of marathon runners finishing a road marathon quicker than four and a half hours slow down during the second half of the marathon. As I was going to say, at last years London Marathon 93.3% of finishers quicker than 4:18 ran a positive split. The overall number of women runners from the first 4000 women finishers (4:18:15) that negative or even split their half marathon times totalled 292, which corresponds to a percentage of 7.3%. The overall number of men runners from the first 12000 men finishers (4:18:10) that negative or even split their half marathon times totalled 782, which corresponds to a percentage of 6.5%, which is a slightly lower percentage than for women.
So for 93 - 95 percent of marathon runners the big question is "How much time should I expect to slow down during the second half of the marathon"? The vast majority of marathon runners aiming for a target finish time need to have an idea of the amount of slowing down that is most likely to occur, as they need to take this amount of slowing down into consideration, so even with this slowing down, which I consider IS A REALITY, NOT, I WILL REPEAT NOT AN INDICATION OF POOR RUNNING OR POOR PACING, so that they will still achieve their target finish time.
Now I am NOT advocating for road marathons to start as fast as you can, to gain as much time as possible ahead of the even paced schedule. No, this would be unwise. This would be as foolish as trying to run at a constant pace for 26 miles. No, what I am suggesting is to look at the statistics on how much slowing down occurs within the marathon, and I have used the data from 4000 women runners, and 12000 men runners from the 2014 London Marathon as the database. And to base the calculation of how much slowdown one can expect to occur, on the AVERAGE of what happened for these sixteen thousand runners. So quite a good sample size!
In order for the resulting percentage slowdown formula to not be influenced by those runners that absolutely 'blew up', I removed the ‘mega slowdown’ runner, those that slowed down more than two standard deviations from the mean slowdown percentage.
Those of you that are particularly observant may have noticed for the quicker runners the percentage of runners that even split or negative split the marathon was greater the quicker the finish time, with the quickest time bands being 10.0% (men) and 16.0% (women). Yes, there does appear to be a gender difference. The percentage slowing down, (which is calculated as the time one slows during the second half marathon, divided by the first half marathon time, multiplied by 100), is therefore slightly less for the quicker finishers. therefore to accommodate theses characteristics of the 16000 finishers, different slowdown percentage were established for different finish time bands and for men and women runners. The following table displays the AVERAGE percentage slowdown values for each time band, for men and women runners.
Now having these percentages in a table is interesting, but what does it actually mean for the runner. How fast should I run at the start of the marathon? This is where the following webpage is really useful. http://rsusmf2.appspot.com/ Please note that this slowdown formula has been updated form the version one which I introduced on UltraStu April last year within the post A Helpful Marathon Pacing Calculator As stated above the two improvements are that version two of the slowdown formula takes into account the gender of the runner, as this seems to have a significant effect on the percentage slowdown for the same finishing time. I have also removed those runners that in simple terms 'blow up', and therefore have a very high percentage slowdown. Further description on the formula follows. Opps, I also forgot the third improvement for version 2, in that the slowing down now doesn't start until the 16th mile, rather than the 14th mile. I think this is more likely to be representative of what actually occurs. As long as the runners have a realistic target finish time, maintaining a constant pace for 15 miles should be a problem. It is during the last 11 miles when the effects of the previous miles run on the roads starts to have an impact and make the maintaining of the same constant pace a lot more difficult, hence the slowing down.
As an aside, if I recall at the time last year there was some confusion expressed regarding my perhaps wrong assumption that the accepted view at the time was that an even paced strategy pace was the standard approach, which would result in most runners not achieving their target finish time if adopting this approach. Now I think that probably more people realise that the even paced pacing strategy doesn't work, so hopefully this year there will be less confusion.
Unfortunately the webpage calculations aren't exactly correct, due to either some mystery formatting error or simply the effect of rounding error, which we now think is the likely cause of the error. We, actually, in reality it is good friend Tim, who is the brains behind the webpage, who has been working hard on looking to solve the problem. Anyway it is nearly working perfect.
Just to quickly summarise. The way the webpage ReSUltS - The Reality Slowdown UltraStu Marathon Formula works is that you select male or female, then enter your target finish time, then click calculate. I mentioned above that the webpage isn't working exactly right, but If you look at the minute mile pace the formula produces, the half way and 5mile, 10 mile and 15mile split times are all correct. But when the percentage slowdown linear increase occurs at mile 16, there is a big slowdown for mile 17 and then back to a linear increase in minute mile pace until the finish. It appears that this big slowdown at mile 17 is where the slight error occurs. In terms of the summary table on the right the pace column is for the last mile of that 5 mile split, NOT the average pace for the last 5 miles.
However, although the webpage isn’t exactly working, the key information, e.g. the percentage slowing down, which allows you to calculate your half marathon split time is correct. Also the idea that one should be able to run at a consistent pace for every mile up to 15 miles is also correct. The last 11 miles around 93 - 95% of marathon runners slow down, how they slowdown will be quite varied, but a gradual linear increase every mile from 16 miles onwards seems a reasonable guess, which the slowdown formula adopts. Remember slowing down after 15 miles doesn’t mean that you are running poorly, or that you did the first 15 miles too fast. Slowing down is reality. The webpage does produce a different minute mile pace for each mile from 16 miles through to the finish, however, I would recommend that you simply use the minute mile pace generated for the first 15 miles, which takes into account the average slowdown for that time band, and then from mile 16 onwards, simply run by feel. If feeling great then reduce the rate at which you slow down. If not feeling so great, then allow a slightly greater rate of slowing down and hope that the 'difficult patch' will pass, and that you may be able to get back 'on track' a few miles later.
Hopefully the above explanation of this ReSUltS - The Reality Slowdown UltraStu Marathon Formula webpage makes some sense, and for those of you are able to take on the fact that 93 - 95% of marathon runners slow down during the second half of a road marathon, I hope that you find this webpage useful. To those of you that aren't aiming for a target finish time, or are aiming for an even paced strategy, well then this webpage probably isn't relevant for you, so apologies if you have read this blogpost down to here!
To all of you running a road marathon during the next few weeks, I wish you all the best.
I will sign off with a few relevant quotes which may help during those 'challenging' moments between 16 and 26 miles.
"The way we perform is the result of the way we see ourselves. To alter our performance we need to alter or change ourselves and it is that changing that's difficult." Gary Elliot, New Zealand Coach to awesome NZ marathon runner Alison Roe (1983)
“A large amount of what we achieve is governed by our mental state and how we see ourselves. (It is) a lot about opening the mind to what might be possible when we throw away the self imposed limitations of our mind.” Tom Williams from MarathonTalk (2011)
“Remaining positive really is one of the most precious faculties for any athlete. That, and an ability to stay focused and disciplined. Develop a mind bank of positive images and thoughts – family, friends, previous successes, favourite places, a big plate of chips. You need to build it up as you would any collection, but soon you will have a range of thoughts to flick through when next your body and soul are screaming out for relief”.Chrissie Wellington, Four times World Ironman champion, from her book titled "A Life Without Limits".
Enjoy the journey,