If an athlete refuses to provide a sample or avoids testers, the are treated as if they had returned a positive sample and can be penalised accordingly. Many common medicines such as flu medications, headache tablets and asthma treatments can also contain banned substances, and athletes must be very careful to check with a doctor, coach or ASDA before they take anything. The second half of the twentieth century has seen the evolution of sport from a largely amateur affair into big business with millions of dollars worth of sponsorship and endorsements up for grabs to a select few champions. Sport has also developed into a significant social institution, and to succeed in sport has become highly valued. This has placed pressure on athletes to become not only successful, but the best, and this has contributed to the escalation in the incidence of drug taking within the sporting community in recent years.
Elite athletes are extremely disciplined, motivated individuals, and often perfectionists.
The accolades and rewards available to champions in sports such as basketball, football, athletics and road cycling are enormous, and athletes usually have only a limited amount of time to reach the top of their sport. Athletes suffering injury problems can also be tempted to take substances that will aid the recovery process, enabling them to train hard. Coaches can be another source of pressure. A successful athlete is often associated with a successful coach, and their wins can result in rewards for the coach in the forms of publicity, new athletes wanting to train under them, and even endorsements. Many athletes claim they resorted to drug use because they believed their competitors were using drugs and that they would never be able to compete with any chance of success unless they too took drugs.