Looking at USADAs list of 26 USA athletes/coaches suspended over the last 5 years (04-08) for serious doping offenses (2 or more years), here is what I found.
Note, suspensions of 1 year or less were not included here because they nearly all involve supplement contamination, not having proper approval for a medication, or use of a non-performance enhancing drug like cannabis.
18 TRACK (11 males, 7 females)
15 sprinters (Marion Jones 07, LaTasha Jenkins 06, Justin Gatlin 06, John Capel 06, Tim Montgomery 05, Chryste Gaines 05, Larry Wade 05, Michelle Collins 04, Jerome Young 04, Calvin Harrison 04, Alvin Harrision04, Kelli White 04, Torri Edwards 04, Mickey Grimes 04, Antonio Pettigrew 08 for doping in 97-01)
2 sprint coaches (Trevor Graham 08, Remi Korchemny 07)
1 mid-distance runner (Regina Jacobs 04, coach was Tom Craig)
6 FIELD (4 males, 2 females) <--- 5 throws & 1 jumps
3 hammer (Scott Boothby 06, John McEwen 04, Melissa Price 04)
1 shot (Kevin Toth 04)
1 Javelin - Serene Ross 06)
1 LJ/TJ (Erick Walder 05)
2 ROAD RACES (1 male, 1 female)
2 Marathoners (Eddy Hellebuyck 04, Deeja Youngquist 05)
Sprinters & sprint coaches accounted for 65% of USADAs 26 2+year suspensions.
Of the 15 sprint dopers, 14 were coached by the big 3 sprint camps:
9 were coaches by Trevor Graham of Sprint Capital USA who got a lifetime ban in 08.
3 (Wade, Edwards, Grimes) were coached by John Smith of HS International.
2 (Gaines, White) were coached by Remi Korchemny of ZMA who got a lifetime ban in 07.
The remaining sprinter (John Capel) received a serious 2-year suspension only because his use of cannabis was his 2nd offense. Capels coach was Mike Holiday.
Since 2001, only Graham, Smith & Korchemny have coached more than one athlete receiving a serious 2+ year suspension. These three coaches alone are linked to all of the serious USA sprinter suspensions and 2/3rds of all USADAs 2+year suspensions over the last 5 years.
Two athletes currently being investigated for doping are:
Maurice Green coached by John Smith of HS Intl.
Julien Dunkley (JAM) formerly coached by Trevor Graham of Sprint Capital.
Even if Green is not suspended in the future, why isnt USADA trying to issue a lifetime suspension to Coach John Smith?
Im aware of only two big-name athletes coached by Trevor Graham after 2004 who have not been charged with a doping offense: Shawn Crawford and Lisa Barber. Anyone know of others? Note, Crawford is now coached by Bobby Kersee (who also coaches Allyson Felix), and Barber is now coached by Gail Devers.
With the demise of two of these big-3 sprint coaches and the 3rd being closely monitored, there is now hope that most US Track athletes are now clean. I'm aware some track fans believe that most US athletes running very good times today are doping. But that appears to be just speculation on their part, as they have not provided any serious evidence to support their claims.
On the international scene the doping outlook is much worse because of Russia. The majority of Russias elite T&F stars might be doping. Russia amazingly has 62 women T&F athletes ranked amongst the top-10 in the world this year: sprints 4, mid-D 15, distance 6, marathon 2, jumps 14, throws 8, heptathlon 4, and race walk 9. Russia is the only country in the last few years where a rash of athletes has been caught doping. Because Russia dominates womens T&F, the impact of widespread doping in that country is huge internationally.