Strychnine, around 1889
In the early 20th century, strychnine was taken in very small amounts by long-distance runners to increase endurance. For example, Thomas Hicks won the 1904 Olympics marathon after ingesting two doses of strychnine diluted in brandy. He collapsed shortly after crossing the finish line, where it took hours to revive him. In larger doses, strychnine can be fatal. If Hicks had taken another dose, it could have killed him. Had the race been run under current rules, Hicks could have been disqualified, but strychnine use was considered an acceptable practice at the time.

Iron supplement, 1906-08
Iron Bitters, a patent medicine used for a variety of ailments, was commonly taken by long-distance runners in the early 20th century. It was believed to build muscle and boost energy.

PowerGel, 2003
PowerGel was invented by the makers of PowerBar to provide electrolytes and carbohydrates in a dense, semiliquid emulsion. The product is appealing to runners who don’t like sports drinks or find it difficult to digest solid energy bars. This package of PowerGel also contains caffeine, reflecting how runners have recently returned to the use of stimulants to maintain endurance.