Exercise and fertility: an update

The last several decades have resulted in a tremendous upsurge in physical activity among both men and women. This enhancement can be seen in the level of participa- tion in both casual and competitive sports endeavors. For example, the marathon was once considered the pinnacle of endurance athletic achievement, capable of being completed only by a select few. In 2007, however, there were 340 marathons run in the United States, with 403000 finishers (40% women). This represents an increase of roughly 35% in only 7 years! Additionally, sports league participation for softball, basketball, and even bowling are at all-time highs.