Every athlete has their own unique pattern of stride length and frequency. Striking the perfect balance between the two is one of the Holy Grails in sprinting because you cannot increase one without decreasing the other or vice-versa.
An equation for running speed is then:
(strides / second) * (meters / stride) = meters / second
When I saw Wayde van Niekerk run a new world record of 43.03 in the 400m, I immediately noticed that his running style was vastly different to that of the previous record holder, Michael Johnson. The latter was well known for his distinct upright stance and a short, choppy stride. Wayde, on the other hand, seems to be extremely springy and I wanted to know more about his stride length and frequency.
And so I did some research. I already had the split times from writing my previous blog about the record-breaking run and now I also counted all the strides for van Niekerk, Kirani James, LaShawn Merritt (all from their run in this year’s Olympic final) and Michael Johnson (from his record-breaking run of 43.18 from 1999 in Seville).
My main goal was to compare the new and the old world record holders (van Niekerk and Johnson), but I also decided to include Merritt and James to get a better sense of where van Niekerk differs from his main rivals.
The comparison tables below include data for each of the four athletes, but the charts only show van Niekerk and Johnson for the sake of better readability.
As I said in my previous blog, all three athletes from the 2016 Olympic final were ahead of Johnson’s world record pace at 300m because they started out incredibly fast. Johnson, however, ran a much more controlled race and he was able to cover the last 100m in 11.52; much faster than others. James and Merritt struggled and they didn’t even go under 12.5 seconds whereas van Niekerk had enough in the tank to hold on for the world record.
Van Niekerk’s time without reaction time is 42.85 which is even faster than Michael Johnson’s fastest-ever 4x400m relay split of 42.94* from the 1993 World Championships in Stuttgart.
*This time is taken from photo-finish pictures taken at the start and finish of Johnson’s leg supplied by Seiko. Using different methods, the DLV Biomechanics Report from Stuttgart variously shows times of 42.91 and 42.92.
Note: The splits from the 2016 Olympic Final aren’t official and should be rounded to tenths instead of two-hundredths of a second like I did. I used my own methods to estimate the splits using a 50 fps video of the race, but it’s impossible to get conclusive and 100% correct splits.
2) Stride Frequency (steps per second)
Stride frequency is always at its highest in the first 100m as athletes have to accelerate out of the blocks and get up to speed. Frequency then tends to drop because the rest of the race is all about maintaining a specific rhythm. Every one of our studied athletes follows this pattern, but it’s interesting to note that Johnson has a relatively substantial increase in the third 100m section of the race. This is in accordance with his famous race strategy of four P’s.
P1: Push hard for the first 100m and get up to speed as soon as possible.
P2: Pace yourself in the second 200m, meaning that you just sort of let your legs float without too much effort.
P3: Position. Make sure that you’re well positioned in the race and aren’t lagging behind others (that’s why it’s generally undesirable to run in the outer lanes where you can’t see your main rivals). You can never increase your speed at this point, but it’s where you usually have to increase your effort due to fatigue.
P4: Pray that your legs take you to the finish line as fast as possible.
Wayde threw the rule book and its old strategies out the window and (in his own words from Twitter and interviews) just went for it from the gun. He was running on the outside in lane 8, so he just focused on his own race and didn’t adjust his rhythm based on how others ran. This is reflected in his splits and stride frequency. Both got progressively worse over each sector, but he still maintained a great rhythm throughout the race.
Wayde is a religious man and I’d say that his race strategy isn’t four P’s, but rather just one. A ‘P’ that stands for Pray from gun to tape.
3) Number of Strides
As we’ll see later, Wayde is the shortest of our four athletes, but he covers the 400m in virtually the same number of steps as the tallest one, Kirani James.
4) Stride Length
You’ll notice that this chart is just an inverse of the previous one with different numbers. Before we were talking about strides per second and now it’s meters per stride.
In any case, it firmly confirms my suspicion that van Niekerk has an extremely long stride. 2.63 m is a stride length that very few of the world’s best 100m sprinters can achieve while running at top speed (!), let alone in a 400m race where distribution of energy is essential to a good run. [Usain Bolt’s longest recorded stride length is 2.85 m from the last 20m of his 100m WR run.]
And while the much taller Kirani James has the longest recorded avg. stride (second sector), van Niekerk has a much longer avg. stride (and frequency) in the last 100m where it really counts and where James and Merritt were gradually starting to lose ground on the South African.
Up next is a direct comparison of height and average stride length.
Van Niekerk has the longest stride relative to his height. His average stride length in the race was 2.45 m, which is 1.34 times larger than his height of 1.83 m. Johnson has the lowest ratio as his avg. stride length of 2.22 m from his run was only 1.20 times his height of 1.85 m. James and Merritt are somewhere in between. Kirani James has the longest stride, but if he’d want to emulate van Niekerk’s ratio, he’d have to have an avg. stride length of 2.56 m!
- Michael Johnson has the highest frequency of the four, but the shortest stride length.
- Van Niekerk has an unusually long stride length relative to his height and a very good frequency.
So does stride length prove to be more important?
Not quite. Johnson just relied too much on frequency and while Wayde does rely more on stride length, he still manages to maintain a great frequency. It’s a killer combination and it’s similar to how Usain Bolt manages to dominate by having the same frequency as other (shorter) athletes, but a much longer stride.
Let’s use our equation from the opening paragraph to determine Johnson’s and van Niekerk’s average speeds based on their average stride length & frequency. Of course we can very easily calculate avg. speed by dividing total distance over total time, but here I’m just using our equation as proof of concept. The results differ slightly from the actual speed due to standard rounding errors and errors in determining the decimals of the stride length. The latter is never going to be entirely precise because it was extrapolated from the number of strides, which was in turn only estimated by eye from video. But the similarity of the two results confirms that my methodology was pretty good.
(4.18 strides / s) * (2.22 m / stride) = 9.278 m/s
Actual speed: 400 m / 43.18 s = 9.264 m/s
Wayde van Niekerk:
(3.79 strides / s) * (2.45 m / stride) = 9.286 m/s
Actual speed: 400 m / 43.03 s = 9.296 m/s
Wayde van Niekerk simply has the best combination of stride length & stride frequency we have ever seen from a 400m runner. This would be true of any world record holder, but what is interesting about van Niekerk is that he is much more reliant on stride length.
Žiga P. Škraba