# Tag Archives: Michael Johnson

## Athletic World Records vs. my times (speed vs. distance in log plot)

Two weeks ago I published a post where I showed a graphic of the different world records in athletics with the speeds and paces.

I received a comment from Uwe, a reader of the blog, suggesting to plot it using a logarithmic scale. At first, I wanted to show how the long distance runners could almost keep a speed (between 20.5 and 23.8 km/h) for distances from 5 kilometres to 42, a marathon. However, Uwe convinced me to make the plot and here it is:

Athletics World Records vs. my times (speed) – logarithmic scale for the distances.

In this view, what it is interesting is to appreciate the different slops of the lines connecting the different records. There you can see how:

• 100m and 200m races are fully anaerobic where Usain Bolt is capable of maintaining an average speed of above 37.5 km/h. You can see in the explanation in the Wikipedia how these two races (both lasting below ~30 seconds) use as energy source high energy phosphates.
• races from 400m to 1 km are still a high intensity activity, with some anaerobic component, though another energy source enters into play: anaerobic glycolisis. And as we have heard often in descriptions about 400m races, the consequence of rapid glucose breakdown is the formation of lactic acid.
• from then (1.5 or 2km) on (up to 42km) professional runners are able to keep a high speed out of aerobic metabolism (using adenosine triphosphate, ATP). Of course, speed decreases with distance, but from the 26.2 km/h of a 1,500m to the 20.5 km/h of a marathon the speed decrease is of -22% for a race 28 times longer!
• for ultramarathons (over 42k) speed starts decreasing at a higher pace, though Wikipedia only offered the 100k time. Probably more data can be found in the web to try to find with more accuracy up to which distance the long distance stable pace could be maintained.

Uwe, you were certainly right. This view offers another very interesting perspective to the game :-).

Filed under Sports

## Athletic World Records vs. my times (pace & speed)

I have many times commented with friends and acquaintances how impressive professional athletes are, what does it mean running a marathon in barely over 2 hours…

Many amateurs (not to mention sedentary people) would not keep up pace much longer than 100 metres. Each time I have made this comment to someone I had to verbally make some numbers for my interlocutor. I am sure these verbal calculations were not always well understood and digested. Following the adage “an image is worth more than a thousand words”:

Athletics World Records vs. my times

Red lines show speed (in km/h; decreasing as race distances get longer). Blue lines show pace (in mm:ss / km; increasing as race distances get longer). I have included a table so you can compare the numbers.

I took athletics world records from the Wikipedia. You can find my times in the page “Races” of this blog. I only added a tag to the records that most of you will recognise, as they were achieved by well-known super stars.

There are many catches in the graphic. Two impress me the most:

• I could have kept up the pace of Patrick Makau in his marathon world-record-beating performance for 100 metres… but not for 400m! (see black dotted lines).
• How once we enter into aerobic exercise, we’re able to almost keep up speed despite distance increases. The difference in speeds between Bekele’s 5k (23.77 km/h) and Makau’s marathon (20.48 km/h) is only 3.25 km/h!

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NOTE: I am not a particularly fast runner, thus don’t take the times and paces and interpret them as if no amateur runner could keep up pace for more than 100m… some will keep it up somewhat longer. I just wanted to share the idea.