Thys was born in
Prieska,
Northern Cape. He represented South Africa in the marathon at four consecutive editions of the
World Championships in Athletics from 1999 to 2005. He has also competed at the
IAAF World Half Marathon Championships on three occasions, highlighted by top six finishes in 1997 and 1998. Thys is a two-time winner of the
Beppu-Ōita Marathon and his time of 2:08:30 set in 1996 was the course record until 2013. He was also a
cross country runner earlier on in his career and was the 1994 winner of the
Chiba International Cross Country. He also had success in East Asia at the
Seoul International Marathon, where he won three times between 2003 and 2006, as well as taking the runner-up spot in 2005. However, he was disqualified after his 2006 win because his
doping test at the race was positive for the banned steroid
norandrosterone. Thys contested the outcome and a protracted hearing following his competitive ban by
Athletics South Africa eventually resulted in his exoneration. Laboratory errors in processing his sample meant the
Court of Arbitration for Sport CAS found in his favour. In May 2010 the
Federal Supreme Court of Switzerland overruled this decision, declaring that the CAS has no jurisdiction over this case. Thys successfully argued to the court that the fact that the same technician had analysed both his positive samples (a breach of the anti-doping rules) had meant that the validity of the tests could not stand. His doping ban was overturned on this basis in 2012 and he was re-instated as the winner of the 2006 Seoul Marathon. His extensive running career, which began at the age of thirteen, has taken in around forty competitive marathons. He came close to victory at the 2010
Beijing Marathon, but he slowed in the final stages and was runner-up to
Siraj Gena. ==Achievements==