It's a mix of various factors.
Firstly it's necessary to mention a little about muscle physiology. In crude terms, skeletal muscles have 2 basic types of fibres in them, fast twitch and slow twitch. Fast twitch fibres, as the name suggests, work faster than slow twitch so are best suited to activities that need sudden bursts of power. The downside is that they produce energy anaerobically so can only function for a limited period of time. Anaerobic respiration produces lactic acid so is not sustainable for any significant length of time. Slow twitch fibres work more slowly but produce energy aerobically and are therefore much more efficient and go on for much longer. On average, people have about a 50/50 split of slow/fast fibres.
West Africans have a genetic predisposition towards a higher percentage of fast twitch fibres and East Africans have a predisposition towards a higher percentage of slow twitch fibres. It's why most of the best sprinters in the world are of West African heritage and most of the best distance runners are of East African heritage. Of course, just because one group has a predisposition towards a certain feature doesn't mean all members of the group have that feature or that no member of another group does. So you'll get plenty of European and Asian people with more fast twitch fibres than a lot of West Africans.
Then you have to factor in the cultural aspect. Running is a big part of life in East Africa. Kids in Europe may grow up wanting to be a footballer, in East Africa they're more likely to want to be a runner. This means that there's a good chance that those who have a natural talent for distance running will be picked up by coaches and will have that raw talent honed to the level needed to compete at the highest level.
What everyone else said: combination of genetics, geography and culture.
The men's marathon domination is astonishing: 39 of the top 40 times ever have been produced by either Kenyans or Ethiopians. Can't verify this one, but I read somewhere a couple of days ago that the 20 fastest marathon runners this year are ALL Kenyan.
Personally I find it rather a shame that (in nearly all running events) elite athletes' preparation is now so uniformly excellent that the decisive factor becomes ethnigeocultural rather than, um, 'the will to win' or whatever.
Two reasons. First, a lot of kids run to get around. Without many cars or buses, the kids have to run to get to school. With an entire nation running in its formative years, it's easy to spot talented runners. From there, it's relatively easy to polish that talent into a world-class runner.
Second, Kenya and Ethiopia have deep traditions of long distance running. They take pride in long distance running and hail Olympic champions as national heroes. The result is talented young runners are drawn to the lure of running as a way to better their lives and the lives of their family.
They don't,
They dominate long distance running, and practice at high altitude, also it costs nothing to train and gets them out of grinding poverty, because when they visit abroad they don't have to bribe officials to receive their fees.
West Africans dominate short distance running, but again it is a way out of poverty, most of the Jamaicans originate in West Africa.
But actually it is down to numbers running, also I was interested in our young 17 year old Adam Gemili who took up running because he put in a fast time when training for football.
My Ex'es lad was a football fanatic who was capped 3 times for England in the Youth team, at age 16 he did a sub 11 seconds (10.8 seconds seems to stick in my mind) in an officially timed 100 metres, but the lure of the big money at Man United was too much, however injury put paid to his hopes.
How many runners would we have if there were not other options, and the lure of big money.
Maybe both and from what I heard they have slow twitch which make them better at distance running. Some enjoy running and can make a career out of running marthons
Many of the African heritage in western countries are from the west. They have better training equipment then people in west african countries. plus it does not have as much money in short distance races
They generally train at higher altitudes than other countries such as the UK, even though we go over to these places to train, we don't live their all of the time and haven't done for any period of time.
The lack of oxygen in these places means that the athletes have more red blood cells in their body which means when doing exercise they are able to produce more oxygen to provide their muscles with in order for them to maintain a speed or go quicker, it also means that they don't tire as quick as someone who doesn't have as many of these cells as that person would be working overtime to ensure all of their muscles and organs were getting substantial amounts of blood and oxygen!
There pelvis' are at a different angle to ours. It enables them to run more easily!
when i run for the bus i could beat the lot of them..
they are nothing special.....
countries like Kenya, Ethiopia, Somalia, Eritrea etc, is it genetic or environment or culture.
