The second chart that we propose our readers is that of 20km women.
We summarize data selection standard.
- We have first of all chosen the best ten performances in the world as they appear from the official lists of the IAAF
- We have limited our choice to the last five years, starting from 2014 up to and including 2018
- The average speed of these ten best performances in the world is the reference mark for every single year
- We then analyzed the ten best performances for each Area, obtaining the relative average speed for each Area. The difference in terms of km/hr between that obtained by analyzing the data of the first ten athletes in the world and those of the top ten athletes in each area is what we have called "negative spread".
Some considerations
- The graph curves of the average speed measured at world level and those of the graphs of the same speed detected at the level of Europe and at the Asia level are very similar over the years.
- The only exception is represented by the average European speed that in 2017 has a decrease compared to that of 2016, while the world average remains the same and that of Asia shows growth.
- The average speed recorded at world level and the one recorded at European level are both affected by the performances of Russian athletes in each of the years taken into consideration. It is true that from 2015 the exclusion from international competitions has decreased their presence in the World and European rankings, but it is also true that the performances obtained in their "Winter and/or Summer Championships" (in Sochi and/or Cheboksary ) have always been of a high standard.
The following tables show us the relative "negative spreads"
| 20km women - average speed | 2014 | 2015 | 2016 | 2017 | 2018 |
| | | | | | |
| World average speed | 13,75 | 14,00 | 13,88 | 13,88 | 13,83 |
| Europe average speed | 13,72 | 13,91 | 13,78 | 13,69 | 13,77 |
| Negative Spread: Europe-World | -0,03 | -0,09 | -0,10 | -0,19 | -0,06 |
| 20km women - average speed | 2014 | 2015 | 2016 | 2017 | 2018 |
| | | | | | |
| World average speed | 13,75 | 14,00 | 13,88 | 13,88 | 13,83 |
| Asia average speed | 13,27 | 13,62 | 13,53 | 13,65 | 13,50 |
| Negative Spread: Asia-World | -0,48 | -0,38 | -0,35 | -0,23 | -0,33 |
from which we note that the only year in which the average speeds were very similar was the 2017 in which the negative spreads compared to the world average were 0.19 (the one between Europe and World) and 0.23 (the one between Asia and World).
That year in Sochi the three athletes of Russia who were still the first ten places in the world and European rankings had obtained more human performance than the exceptional ones we were used to (Yelena Lashmanova: 1:25:18, Yekaterina Medvedeva: 1:25:22 and Sofiya Brodatskaya: 1:26:27). On the other hand, China's selection for the World Championships in London 2017 held in Huangshan had three similar results (Lu Xiuzhi: 1:26:28, Wang Na: 1:26:29 and Yang Jiayu: 1:26:35 then improved in London where gold wins in 1:26:18).
Another moment of reflection is given by the examination of the curves of the average speeds of the NACAC (North America and the Caribbean) and the CONSUDATLE (South America).
Between 2014 and 2016, their trend is almost overlapping, while in 2017 South America gets better performances, although the NACAC is very positively influenced by the results of Mari Guadalupe Gonzalez (MEX).
The following tables show us the relative "negative spreads"
| 20km women - average speed | 2014 | 2015 | 2016 | 2017 | 2018 |
| | | | | | |
| World average speed | 13,75 | 14,00 | 13,88 | 13,88 | 13,83 |
| NACAC average speed | 12,97 | 12,87 | 13,15 | 12,99 | 12,84 |
| Negative Spread: NACAC-World | -0,78 | -1,13 | -0,73 | -0,89 | -0,99 |
| 20km women - average speed | 2014 | 2015 | 2016 | 2017 | 2018 |
| | | | | | |
| World average speed | 13,75 | 14,00 | 13,88 | 13,88 | 13,83 |
| CONSUDATLE average speed | 12,92 | 12,91 | 13,13 | 13,29 | 13,06 |
| Negative Spread: CONSUDATLE-World | -0,83 | -1,09 | -0,75 | -0,59 | -0,77 |
We leave our readers in the following link the consulation of the chart and the complete table of average speeds in the five-year period and the considerations they would like to make.