The most well-known doping medication for sprinters is testosterone, an anabolic steroid that increases muscle protein synthesis and can give a runner with improved strength and speed. But while testosterone enhances performance in athletes of all types, it's not generally used by runners because of the risk associated with taking a drug like this without proper supervision from a physician. However, there are other drugs that can be used for doping. For example, progesterone has been shown to increase running speed and fatigue resistance. This hormone is naturally produced by women during pregnancy and after birth, but it can also be given to female athletes in special cycles designed by doctors to enhance performance. There are many different medications that can be used for doping. Here are some others: epoetin - which increases blood production- may be used by cancer patients undergoing chemotherapy or radiation therapy Epinephrine - which increases heart rate- may be used during exercise to help control symptoms of low oxygen levels in people who suffer from asthma Caffeine - which increases energy level- is found in many foods and drinks- includes coffee, tea, chocolate, soda, etc.- and is used by everyone to stay awake during long periods of time The list goes on and on.