Doping is the consumption of banned substances and performance-enhancing materials designed to improve sporting performance. In football, that will mean increased stamina or strength. A player who is doping might have the edge in extra time, or be able to increase his or her sprint speed for crucial matches. As per FIFA guidelines, all players are obliged to undergo doping controls that consist of urine samples and blood samples. If athletes are found guilty of taking performance-enhancing drugs, they are subject to a ban from the sport from as many as several months to a lifetime, based on the severity of the individual cases. If the consumption of the banned substances was not intentional, bans can last for up to two years. However, if the player knowingly participated in illegal doping, they will be banned for up to four years. The complex nature of anti-doping efforts requires a carefully crafted legal system to accomplish the dual goals of ensuring fair sport through effective anti-doping measures and assuring equity to individual athletes. Although procedural issues (e.g., the burden of proof and proportionality of punishments) often run together with substantive issues (e.g., the culpability of the accused athletes) in anti-doping jurisprudence.