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It’s all about speed

That’s great: at the bottom of this page, you can enter your own time and distance!

While running, I’m often wondering: while orienteering, it’s “which way?”, on the road, it’s “how fast?”. Like: “I am now running at a pace of 4’01”, I’m halfway my 1 km interval, how much fasther should I run to get to an average of 3’59” by the end of this interval, and how much does that differ on half a marathon?”. That type of questions.
[Dutch version]

Some time ago, I discussed (and calculated!) that you shouldn’t be thinking while running, at least not when you already know whereto and how fast, but that is even more a motivation to do that beforehand. And, while running, dig the answers from your memory. That’s the reason for this article.

Let’s start simple: for once and for all -and that will be this year- I want to finish the Half Marathon within the one-and-a-half. So, that is 21.098 kilometer in 90 minutes. Dividing those figures results in a speed of 14.06 km/h (or 8.74 mph). With some experience I gained, I got a feeling for that speed. But still, it’s better to comprehend when express it as 234 meter per minute. And it sounds quite fast when I say 3.91 m/s (meter per second), which is about twice what I’m tall.

Since I take part in Orienteering races, the pace started to make sense to me (and because my GPS watch tells me). And now I know what it means to run 416”/km (4 minutes and 16 seconds per kilometer, or 652”/mile). The distance between two 'hectometerpaaltjes' (100 m signs)...I get a feeling for it. And, because I know that I have to keep that pace on the Half Marathon, it’s my reference for everything. 4’00” /km sounds already very quick, but recently, while training intervals with some colleagues, we incited each other easily to below 03’50” /km, and even with a sprint at the end, of 03’40” /km. Yet again, it’s easier to survey 100 meter than 1 km, especially when you want to estimate a distance on the road (the same as between the two ‘hectometerpaaltjes’). And, for my desired pace, I need to accomplish those 100 m within 25.60 seconds.

In my case, per 100 m, that is about double paces, representing 1.29 2pace/second, or 77 2pace per minute. In the past, I have looked into the relation between speed and heart-rate, (see my article Linschoten Loop on my blog), but I assume that that changes with time, with your training history, and with the terrain. And there is no space for that discussion here.

But what occupies me most, on my way, are the relative differences: how much faster should I run per 100 meter to finish one minute quicker? And, while running, I am typically not fit enough to realize that one minute contains about 60 seconds, so for each individual kilometer of the 21, that is let’s say 3. Or 0.3 seconds per 100 meter. That’s nothing! If that’s all for a finish time that’s one minute better, give me 10!

Below, a table, to observe the trends:

time speed pace difference
hh:mm km/h m/min m/s min/km s/hm % s/km s/hm pas/s pas/min
01:20 15.82 264 4.39 00:03:47.54 22.75 1.45 87.02
01:25 14.89 248 4.14 00:04:01.76 24.18 1.18 2.84 0.28 1.36 81.90
01:26 14.72 245 4.09 00:04:04.61 24.46 1.17 2.84 0.28 1.35 80.95
01:27 14.55 242 4.04 00:04:07.45 24.75 1.16 2.84 0.28 1.33 80.02
01:28 14.38 240 4.00 00:04:10.30 25.03 1.14 2.84 0.28 1.32 79.11
01:29 14.22 237 3.95 00:04:13.14 25.31 1.13 2.84 0.28 1.30 78.22
01:30 14.06 234 3.91 00:04:15.98 25.60 1.12 2.84 0.28 1.29 77.35
01:31 13.91 232 3.86 00:04:18.83 25.88 1.10 2.84 0.28 1.27 76.50
01:32 13.76 229 3.82 00:04:21.67 26.17 1.09 2.84 0.28 1.26 75.67
01:33 13.61 227 3.78 00:04:24.52 26.45 1.08 2.84 0.28 1.25 74.85
01:34 13.46 224 3.74 00:04:27.36 26.74 1.07 2.84 0.28 1.23 74.06
01:35 13.32 222 3.70 00:04:30.21 27.02 1.06 2.84 0.28 1.22 73.28

You may have noticed that for every minute you subtract from your projected finish time, the required increase in speed, per minute, becomes larger. Not only the speed itself –that’s obvious– but the speed difference too. Meanwhile, the difference in pace is always the same. The relative difference, in %, of the time per 100 m changes, but the absolute difference, in s per 100 m, stays the same. It’s all logical, but it may be practical to remember while you’re on the go: time over distance (pace) is linear as a function of the finish-time; speed, and relative changes in pace, are inversely proportional.

When you run the first half 1″ per km slower than the 416”/km you should run, you will have to catch up those 21.098/2 s during the second half. To do that, you will have exactly half of the total 21098 m available. So you have to run exactly 1″ faster per km, than the overall average. The net difference is 2″/km with respect to you pace in the first half. Sounds easy.

For 1:30:00, you will have to run precisely 4’15.98”/km. Your GPS is not that accurate, but fortunately it’s close to 4’16”/km. However, you will just miss your target time by 19 ms. That is 19 milliseconds –not much, but all your hairs grow about one atom in that time, still at total of about 1/100 of a mm altogether. You miss your target by 7.1 cm! But, if you would have run 4’15”/km (the difference is hardly visible on your GPS watch), that will gain you advantage of 21 s at the end. Just a matter of approximation. Again, this a figure that is easily remembered: for every 1 second you run faster than planned, on a distance of 21.098 km, you gain in the end as many seconds as there are kilometers. For every distance!

If your run a a bit slower, and have to cache up at the end, then it may be interesting to express that lag in meters. Just as if, at that moment, you pick another runner -who keeps running at a constant pace- that many meters in front of yourself, and strive to overtake him right at the finish. Suppose, you ran 1 second to slow per kilometer. Then, at the end, you have to catch up that 21.098 s lag, what, right at the end (which is in fact too late) boils down to 82 meter. This way, it sounds quite tough. And, when you find out 1 km before the finish, that all the time you aimed at a pace 01:31:00, one minute too slow, then you have to overtake, in that last km, someone who, at that moment, is 223 meter in front of you. No, you’re not going to make that.

There are a few things to remember: Suppose you’re in terrific shape, and it goes very smooth. You can keep a pace of 4’00” /km, then you will finish at 01:24:23 Fantastic! To get a feeling for those finish times, I have written them on a dial: thinking in time like an old-fashioned clock is -for me at least- still the most intuitive representation. On top of the dial it says 4’00”, and ever second/km more counts clockwise. Can you print this one on your retina?

The moral of the story? Just run just below the 4’16” /km, and you need not think about anything. That saves a lot of energy!

But the best about this page is maybe that you can change all the numbers to your own pace! Just enter here, km, the distance your are about to run, and here, , your planned finish time. And see what happens with all the figures on this page…

Routegadget : Boshoverheide/Sylvester 2011

The issue with the database has been resolved. You can now upload your GPS tracks, or draw your route on the map manually. If you have questions, send me an email: jg.2011 at

Pictures of the event can be found on

This page is in English, for all the foreign competitors. Sorry, but I don’t speak all the other languages that have subscribed for this event.


With Routegadget, you can view the actual routes on a map. The different courses are pre-loaded, and the results, the Splits, are pre-loaded. You can make the different runners actually run on the map, with there respective pace on each leg.

But even better, you can edit your own route. That is the main advantage. We get the most out of it when more and more people enter their route. You can show your brilliant path-finding to others, and learn from the route decissions of the best runners.

There are two ways to enter a route:

  • By oploading a GPS track (GPS watches are not always allowed, but non-interactive GPS-trackes without a screen can be used in general). This particular Routegadget map has been georeferenced which means that your GPS data will fall right on place. Very easy.
  • By entering it manually with you mouse. Draw a line by clicking on the points you passed, and that is it.

The routes are directly visible to others. I have even prepared a laptop to allow entering your breadcrumb-track during the event (after the last participant has started).

After 13:30, at December 29th 2011, the site will be enabled. THIS IS THE LINK TO THEM MAP .

Pay attention: Wait until the map has fully loaded until you click on anything, otherwise Java might crash. And starting RouteGadget or SplitsBrowser twice can cause problems as well.

To view the maps, you need Java. Quite often, this has been installed in your browser already, but otherwise you can download it here. Then, after you clicked the link to RouteGadget, the map will be loaded. You can select the desired language on the top-right of the screen.

  1. Wait until the map has become visible.
  2. Select one or more competitors.
    1. Therefore, click on the popup underneath Choose competitors.
    2. Select a course from the list. The controls of the course will be plotted on the map.
    3. The names of the competitors will be shown underneath the selected course. The order of the names may be random.
    4. Select competitors by clicking on them, one at a time. You can use the button Deselect all on the bottom of the screen to clear your selection.
  3. Then click, on the bottom of the screen, on View routes. Now, the routes of the runners are shown, when the selected competitors have entered them but GPS-upload or manual drawing.
  4. With the + and – buttons, you can zoom in and out of the map. (Smooth scaling indicates the method Java uses to render the zoomed map, sharper or less sharp.) With your right mouse button, you can drag the map.
  5. You can start an animation with the selected runners. First, select the course, then the competitors, like described above, then FIRST click View routes and THEN View animation. Then animations starts when you press Start (bottom right of the screen). You can stop it, and make it go faster or slower. Note that you have to drag the map to the start position to see the animation, when the first control is not yet visible on your screen.


Upload a GPS track by clicking on “GPS” in the top right of the screen. Then select the file format to upload. You must first have downloaded the data from your GPS. (If you have trouble getting the data from your GPS, send me an email, maybe I can help you.) The track you upload should only contain the race. That means that you will have to edit the track in your favourite software (e.g. Mapsource, TrainingCenter, Basecamp, etc) to cut off the points before and after the actual race.

Then select the file (use Browse to browse your local storage), and click OK. In principle, the map has been georeferenced, you your track should be fitting immediately. Otherwise, drag the three blue handles until your track matches the map.

Follow the instructions after the upload. Select course and competitor name. When done, click the link to return to the map. Now, your track should be visble, among the others.

Draw your route

If you don’t have a GPS track, you can manually draw your route. This works quite easy. Click on Draw your route, select your course and your name, and start drawing. The straight-line course is already shown in magenta.

  • Drag the map to the start location.
  • The first leg is highlighted in blue. Your track is in red, but now, it is still only a dot.
  • Point on the location you moved to after the start. Click on the map. Now, the actual track is shown in red, and a blue line indicates the direction to the next control.
  • Continue until you reach the first control. Now the next leg is highlighted in blue.
  • Just continue those steps. Remember to drag the map with the right mouse button.
  • If you made a mistake, you can take steps back, by clicking the Undo button on the top right of the screen, next to Draw your route.
  • When you have reached the finish, click on Save route, and follow the further instructions.

When done, click the link to return to the map. Now, your track should be visble, among the others.

That is it. Now enjoy the results, as more competitors draw their trails, and analyse the differences in speed, to learn for a next race.