Today at the bookshop I found a little book behind the counter, Principal Drugs and Their Uses, a 1934 Faber & Faber pocket guide for nurses by A.L. Morton (a tutor from the Royal College of Nursing, not the Marxist historian Arthur Leslie Morton.
There a quite a few surprises; the book reveals the 1930s to be an era when morphine and opium derivatives were still commonly prescribed as sedatives, diamorphine (i.e. heroin) for bronchitis and various coughs, and mercury compounds (under picturesque names like blue pill and grey powder) as laxatives. Probably the scariest example, though, is strychnine: "General tonic. Prescribed in various nervous disorders. It is among the most valuable and widely prescribed drugs".
The useful property was that strychnine, in small doses, is a stimulant. This, however, led to its misuse, before amphetamines came on the scene, as a performance-enhancing drug in athletes (this use was apparently known to the ancient Greeks, but lost until its rediscovery in the 1800s). The book Doping in Sports (page 233, Detlef Thieme & Peter Hemmersbach, Springer, 2010) mentions its use by 19th century cyclists, and its possible implication in the death of the Welsh champion cyclist Arthur Linton in 1896. It was also one of the drugs used in the now-defunct Victorian sport of pedestrianism.
Pedestrianism took various forms, sometimes cross-country, but its classic version was a gruelling track-based race called a Six-Day Go As You Please or a "Wobble". Competitors walked around a track for six days, the winner being the one who covered the greatest mileage. Entrants came from a broad social spectrum, from elite gentleman athletes to the lowest working classes (for instance, men who had developed superhuman stamina working as navvies), and the races attracted big money, both in prizes and the associated betting.
The record distance was set in 1888 by George Littlewood, who covered 623.75 miles (an average pace of 4.33 miles per hour) despite bad burns from a saboteur setting fire to his alcohol footbath. Littlewood's achievement was finally bettered by a modern ultramarathon runner, but even before that, the physiologist BB Lloyd wasn't far wrong in his 1966 description of this as "probably the maximum sustained output of which the human frame is capable". See Athletics: Littlewood's giant strides ("The Anniversary: 110 years ago an Englishman defied sabotage and fatigue to run 623 miles" - Simon Turnbull, The Independent, 29th November 1998).
Running Through the Ages by Edward S Sears has a detailed history, "The Struggle for the Astley Belt" (previewed at Google Books) surrounding the most famous promoter of these races, the sports enthusiast and politican Sir John Astley. This contemporary account by J. Ewing Ritchie, quoted at Lee Jackson's The Victorian Dictionary - Chapter VIII, Pedestrianism - gives something of the flavour of the races, as does this 1888 New York Times piece about an American race at Madison Square Gardens, Started by the Marquis.; the Go-As-You-Please pedestrians all hard at work.
As to the point: strychnine and pedestrianism form the backdrop to an excellent crime novel by Peter Lovesey, Wobble to Death. His debut novel, the first in his Sergeant Cribb series, it won the Panther/Macmillan First Crime Novel Competition and is a fine example of building a story around bizarre-but-authentic historical detail. I won't spoil the plot for you, except to say that it involves the mystery surrounding the sudden death of a competitor in mid-race, under circumstances where possession of strychnine doesn't necessarily prove murderous intent.
Update, February 7, 2013
Ptak Science Books has a piece - Strychnine for Weak Women, 1920 - mentioning a patent medicine called Nuxated Iron, which undoubtedly relied on the stimulant effect of strychnine.