Sunday, July 3, 2011

How Fast Should I Run? A guide for multi-day ultra runs.

If you've ever completed any type of ultra run, generally people will ask you the same questions on your return. The questions are normally along the lines of 'What position did you finish?', 'How fast did you run it?', 'How fast did the winner run it?'. The correct answers to these questions are:

'I completed it'
'As fast as I could'
'Faster than me'

Then there are questions like 'Was it hard, was it tough, did you have to train for it?'

The correct answer to this is 'As you can see I'm wearing flip-flops, not out of choice, but because my feet are swollen and due to some other injuries I can't wear shoes of any description; at one point I think I went into hypothermic shock after running at night in the forest and had to get into my sleeping bag fully clothed; so yes, I would say it was tough. Yes, I thought training would be a good idea on this occasion, as doing a couple of 5k fun runs didn't seem enough, though from my conditioning currently you may doubt my assertion that I did indeed train for this event.'

When you tell people the average speed you're running at, they always look somewhat disappointed. Even more so if they are a runner of any description, because they may have an idea of how fast they can run a 10k or a marathon.Then you explain that the MDS (Marathon De Sables) was won this year with an average speed of 11.99kph, and that if you ran an average of 10kph you would be pretty much in the top 10, and even if your average speed was just under 9kph, you would still be top 30 in the MDS (click here to see the results for 2011).

Another inevitable question is 'Did you run it all, or did you walk?', the answer is 'well, I tried to run as much as I could, but some hills are so steep that there is no point running them, and because of fatigue and the terrain and the heat, you will be running as fast as you can, and then you will look down at your GPS, and it says you are only running at something like 7.9kph, and you think, how can that be, I'm going as fast as I can?!'

(I'm aware that some events are so long and the terrain so hard that they are almost impossible to run. In this case, calling it an ultra run is a misnomer, it should be called an 'ultra walk' or 'ultra stroll'. Of course, these don't sound as cool as ultra running, so it wont happen.)

I should also say I have no experience of 24 hour events, where your don't have to carry any food or water, as there are aid stations, so I couldn't tell you how fast you can expect to run. And if you are in one of those events where you run a circuit over and over again for 24 hours, I would say boredom and insanity are your biggest barriers.

Your marathon time is irrelevant.

How fast you can run a flat city marathon like London or Berlin in ideal conditions carrying no weight has very little bearing on an event where the terrain is all trail, your are carrying a rucksack, its hot and you're four days in. For example, on the Trans Aq, day 5 is approximately 28k, and you can expect to run this in the same time you normally do a marathon in. That's right, you will run 28k in the same time you normally run 42k in. Whats more the terrain on this day is not particularly difficult, there isn't much sand, but having just run a night stage, and with 4 days of accumulated fatigue, lack of sleep etc this is what you can expect. This doesn't take into account injury, you can then expect to run slower.

There is no comparison between road running standard distances like 10k and 42k and the multi day events. Yes, if you are general fast at these, you should be fast at longer distances but not always ( see the advice at the bottom of this post about running slow). It's like comparing playing darts in the pub and traditional archery in Bhutan, and then when your mate returns from Bhutan, asking him how many double tops he got. (Yes, this is a rubbish analogy, but I can't think of anything better at the moment). Apples and oranges my friend.

This doesn't mean running 10k isn't hard, as Scott Jurek as alluded to, running 10k as fast as you can is very hard, the fatigue and mindset is just different from running much longer distances.

The map is not the ground.

I can't begin to tell you how hard running on sand is. I practiced running on sand once, I don't know if it helps or not, definitely practice running on trails, but running constantly on sand may make your achilles more prone to injury possibly.

However, if you intend doing all your training on the road without a rucksack and you live in a temperate climate you might want to re-think your strategy. If this works for you then good luck and well done. If however, the event you're entering is trail/ sand based and involves carrying some weight for several days, don't say I didn't warn you when your achilles starts screaming in a way you never thought possible.

Getting to the point.

All of the above was really a long winded introduction to this section. The advice below is taken directly from the Trans Aq website ( ), and I take no credit for it. It explains the effects of terrain, fatigue, heat and backpack on your average speed much better than I could. I can also say from experience that it is accurate as well. I have re-formatted and re-worded some parts so it makes more sense in English and highlighted important parts:


For those who have never taken part in the Trans Aq’ or run in Africa, it’s important for you to understand what awaits you… Backpack + more or less sandy tracks + relief + heat = -20% to -30% of moving speed. Yes, if you usually run a marathon in 4 hours, then it will take you 6 hours or even more to run a stage of 42 km

This theory has been verified even for the best runners, because the Trans Aq’ is won at a speed of 10 to 11km/h (depending on the year) by runners capable of running these distances at 14 to 15km/h without a backpack, no sand, etc… 

Training advice

1. Quality – run quickly. This is why it’s important to include quality (speed-work) in your training sessions, to increase your speed and average speed, so you’ll not be forced to walk 90% of the Trans Aq’.

E.g. if you run a marathon in 4h10m, your speed is an average 10km/h. With a backpack weighing 5kg (day 1), you lose about 2km/h at the same level of effort[note: there's a good chance your backpack will weight more than this, don't forget you'll be carrying water as well]

With temperatures at 27°C to 30°C you’ll lose at least another km/h in comparison to 20°C still at the same level of effort. And the average state of the ground on the Trans Aq’ will make you lose another 1 to 2km/h. So, the first day, if it’s hot, in order to not overdo it, you’ll have to run at 7km/h in the morning (when it’s cool) then 6km/h if the heat remains until the end of the stage, always at the same level of effort for a 4h10m marathon… This is only an average. 

To resume, if the backpack is heavier, if the weather is hotter and in sandy passages, you’ll be at a maximum 5km/h, if you don’t want to put yourselves into the “red zone”. It’s essential to understand this if you want your Trans Aq’ to be a success. A 4h10m marathon runner will, therefore, walk often. At each sandy passage, at each uphill passage. A 3h marathon runner, if he knows how to manage his effort, will probably never have to walk because his average speed will be between 9 to 10km/h. So, this is why it’s useful to do some quality training sessions, otherwise you’ll be forced to walk often. 

2. Specific – slow running. On the contrary, I know many runners where the Trans Aq’ has “completely passed them by” because they didn’t take the time to learn how to run slowly. 

When you’re used to training at 11 to 13km/h, it’s very difficult muscularly to run at 8 or 9km/h. But it will very often be necessary so as not to “explode” and have to finish a stage by walking. It is, therefore, necessary during training sessions to run for at least 2 hours using these specific speeds. Thigh muscles will become accustomed to work under compression and you’ll avoid pain and injury when you’ll be forced to run at these speeds over many hours (the long stage). The same goes for the slower runners; they’ll have to walk often (as shown above) and so it’s useful to train yourself to walk because the tendons and muscles don’t work in the same way. 

Blisters: Many runners suffer from blisters when usually they never have them… If it’s not owing to shoe size or even new shoes, it’s often because you’ll provoke unusual rubbing/friction. By walking, you may suffer from blisters on the heels if you usually don’t walk, whereas when running you never get blisters, except on the toes. 

To sum up, teach yourself to run slowly, or do speed training, running at your marathon speed is unnecessary for preparing for the Trans Aq’. This is only my opinion, it’s not advice carved in stone."

Don't under-estimate the sleep deprivation effect of three guys sharing a two man tent and listening to snoring all night! Buy some ear-plugs and an inflatable pillow and everything should be fine.

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