When i lived in south africa about4 years ago, iwas on the100m national relay team, and had beensprinting since the age of 10, and these are my observations:
When i started running at ten, i first ran the 80m (thats what 10 year olds run in south africa). Andthe gold medal was usually, if not always won by a white boy.
At 12, i started running the 100m (ran it 13.14secs),, and needless to say, the gold was also won by a white kid.
At 13, i ran the 100 (nationals) in 12.45 secs, and this was also won by a white guy.
At the age of 14, this is where everythingtook a drastic change,and ALL the white boys that used todefeat me, on a primary level, started getting fat, and obviously slow. That year i ran the 100m in (nationals) in 11.55 secs, however i was beaten by2 other blacks, who both ran close to under 11 secs (11.02 to be exact)
At 15, i ran a 10.8secs at the nationals, and needless to say i was 9th that year, the fastest guy (mixed racekid) ran 10.53secs ....at 15 !!!
At 16, i ran at the nationals in 10.34, and took second place, the fisrt place wastaken by the same mixed kid who ran 10.29,......no white guys even qualified. that year (and white guys are pretty fast in south africa)...
So I'll have say that white guys start off as fast (if not faster) than black guys,...but this tendfs to change around the ages of 14-15-16......Ive seen this happen rightbefore my own eyes....White guys simply get slower. In fact i remember at the age of 13,thinking thatthey had to be the fastest guys in the world........but those same white guys couldnt even see me the next few years......
take care