From Scientific American:
The general upward trend in performance is largely due to advances in our understanding of fitness, conditioning, diet and nutrition, says Mark Williams, a professor of sport, health and exercise science at Brunel University in London.
But this progress has not been steady, and many things have helped or hindered it. As an example, Geoffroy Berthelot of the National Institute of Sport and Physical Education—INSEP in Paris highlights the stagnation of most records during World War I and World War II. “When you have world wars you don’t focus on sport competition,” Berthelot says. But conversely, the cold war led to the Soviet Union and its satellites developing a rigorous scientific approach to athlete improvement—an aggressive illegal doping program notwithstanding. Some event records set during that time have never been beaten, such as the Men’s Hammer Throw world record, which was last broken by Soviet hammer thrower Yuri Sedykh in 1986 at the European Championships in Stuttgart, three years before the fall of the Berlin Wall and five years before the U.S.S.R. collapsed. “Today we have a lot of difficulty [with breaking the records] because athletes use less doping substances,” Berthelot says.
Social change can also drive performance, as it seems to have done in women’s marathon times. Women were excluded from performing in many such events, including the Boston Marathon, because it was commonly believed their constitutions could not handle long races. In 1966 Roberta Gibb hid in the bushes beside the starting line of the Marathon and became the first known woman to complete the course. The next year Kathrine Switzer entered the race under the name K. V. Switzer, and photos of the race organizers trying (unsuccessfully) to remove her forcefully mid-race made international headlines. These events coincided with Second-Wave feminism in the U.S., and a dedicated …