Athletes are at times under pressure during competitions, especially when representing their countries on the biggest athletic stages, the Olympics. Some of these athlete’s crack under pressure and rely on performance enhancing substances to ensure they win and succeed on the world stage. These athletes are almost always caught through drug and doping tests.
Ali Saidi-Sief

Ali Saidi-Sief of Algeria crosse the finish line to win the 1500m race at the Lausanne Grand Prix athletics meeting in Lausanne July 4, 2001. Sief won the race in a time of three minutes 29.51 seconds. (Reuters)
Karam Gaber

Egypt's Karam Gaber Ebrahim reacts after defeating Poland's Damian Janikowski on the semifinals of the Men's 84120 Kg Greco-Roman wrestling at the ExCel venue during the London 2012 Olympic Games August 6, 2012. (Reuters)
Oussama Mellouli

Tunisia's Oussama Mellouli poses with his gold medal after the men's 10km marathon swimming at Hyde Park during the London Olympic Games August 10, 2012. (Reuters)
Yousef Ahmed Masrahi

Yousef Ahmed Masrahi of Saudi Arabia competes in the men's 400m event during the 15th IAAF World Championships at the National Stadium in Beijing, China August 24, 2015. REUTERS
Brahim Boulami

Morocco's Boulami celebrates winning men's 3000 metres steeplechase at the XV Mediterranean Games Almeria 2005 in Almeria. Morocco's Brahim Boulami celebrates winning men's 3000 metres steeplechase final at the XV Mediterranean Games Almeria 2005, southern Spain, July 1, 2005. Boulami won the gold medal with Spain's Antonio Jimenez taking the silver and France's Gael Pencreach bronze. (Reuters)
Ridouane Harroufi
Moroccan marathon runner Ridouane Harroufi (www.primerahora.com)
Asmae Leghzaoui

Asmae Leghzaoui is a middle-distance Olympian Moroccan runner who won gold at the 2001 Mediterranean Games during the 10,000m run.(middle-east-online)
Rashid Ramzi

Rashid Ramzi of Bahrain holds the national flag after winning the men's 800 metres final at the world athletics championships in Helsinki August 14, 2005. (Reuters)