FLM2009 The Flora London Marathon: A cautionary tale from last year’s runners Through our analysis of finish time from last year’s 34,500 Flora London marathon runners we have provided some interesting insights into the enormous range of age, sex and completion times of individuals who participate in endurance events such as this. Whilst these observations are interesting in isolation, we were also able to analyse the split times recorded for every single competitor at 5km intervals throughout the race. So having analysed these split times, examined running speeds and how they fluctuated during the marathon in 2008, we can now describe some of the insights we’ve gained and offer practical advice on how best to pace your Flora London marathon this year. The graph below shows the average 5km time for runners at different stages in the marathon, along with a dotted line depicting a theoretical ‘evenly-paced’ race* (*31 minutes and 33 seconds average 5km time) that finishes with the same overall time. It’s interesting to see firstly how the time taken to complete 5km progressively lengthened such that the second half of the marathon took almost 17 minutes longer than the first, but also how the 5km splits varied by more than 5 minutes between runners slowest and fastest points. Figure 1 Average runners 5km split lengths: for the distance of 0-40km
Taking this same data, but translating it into running speeds, enabled us to generate the following graph in which the dashed blue line shows the average runners speed at each 5km marker during the marathon, along with a flat red line to show our theoretical evenly paced marathon. As before, comparing the two shows that in contrast to the flat, even profile, the line we plotted for our actual data isn’t very straight and actually fluctuates by more than 15% between runners’ quickest and slowest splits- Suggesting that not many people managed to run an evenly paced marathon.
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Furthermore, our data also shows that the average running speed over the first 5km was higher than the average overall speed for more than 85% of last years marathon runners – So most runners didn’t maintain their initial speed for the duration of the marathon, and actually opted to set off at a seemingly unsustainable pace. Figure 2 Average runners variation in pace during the marathon
As our analysis shows that most runners in last years race set off much faster than if running at an even pace, and slowed down considerably throughout the marathon, we thought it would be useful to provide you with some practical information as to why and how you should go about evenly pacing your race.
Pacing your marathon; Be a tortoise not a hare! In contrast to elite runners – who are in a competitive race and have to run ‘tactically’ (for e.g. responding to changes in the masses are afforded the relative luxury of being able to plan exactly how we pace our marathon well in advance. This is good news because we know that the most economical and efficient way to complete the marathon is to run at a constant pace – evenly distributing your energy expenditure and effort throughout the race by identifying a pace you can sustain during your training and sticking to it on race day. Some elite runners even favour ‘negative’ pacing strategies – setting off at less than target speed in order to gradually wind up the pace as they go, finishing strongly and crossing the line with a well-timed sprint finish. What’s also clear is that starting fast and ‘hanging on’ until the end is an unattractive option, both psychologically and physiologically. For instance we know that setting off too fast, at a pace you can’t sustain will only serve to hasten fatigue, deplete the bodies crucial glycogen stores sooner, and leave you without the ‘fuel’ you need long before you reach the finishing line. This has the potentially of causing an impromptu encounter with the obstacle marathon runners fear most – the dreaded wall - a seemingly insurmountable barrier for runners who’ve all-but exhausted their bodies supply of carbohydrates and can only sustain light jogging or walking through to the finish line.
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By following some general tips and advice however, you can help avoid making the classic pacing mistakes of last years runners, and help to preserve carbohydrate energy stores for as long as possible, so that come race day you’re less likely to experience hitting the wall.
• Set realistic goals - If you know your target time, or have recently timed yourself running a shorter
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distance (such as a 10km), one useful and popular practice is wearing and using ‘pacing bands’. These give specific timings as to when you should be at different distances throughout the race and help you continually assess where you are relative to your target pace. They also help - providing you stick to them - to ensure that you don’t run too fast or slow. (– To create your own, visit www. lucozade.com/running or look out for them on race day at the Lucozade Sport Performance Zone on race day. Regularly consume carbohydrate – Most runners favour isotonic sports drinks containing carbohydrate during the marathon to help the body top up stored carbohydrate fuel (in the muscles and liver) and maintain hydration. With Lucozade Sport stations at 5, 10, 15, 19 and 23 miles, we have calculated that the average runner is never more than 40-50 minutes from their next drink anywhere on course. Run your own marathon – it’s easily said, but having the confidence to run your own race is essential if you’re to avoid being distracted by the sights and sounds of running the Flora London Marathon (spectators, landmarks, other runners etc.). It’s also vital in helping you resist temptations to capitalise on fresh legs or an adrenaline rush at the start – thus, ensuring you avoid chasing toohigh-a pace early on.
Summary Hopefully by highlighting some of the trends seen with last years marathon runners we’ve shown that running too fast at the beginning of the marathon is a common pitfall, that’s all too easy to fall into bearing in mind the unique and exciting nature of the Flora London marathon. Setting off too fast could also be a good reason why runners have to slow down so noticeably over the latter stages of the course, so following the simple advice above, and being aware of the perils of over enthusiasm at the start should help you to run across the finish line at the pace you started at, maybe even with a smile on your face.