Name: Rita Jeptoo

Country: Kenya

Stats: Jeptoo came in second, just behind Atsede Baysa, at last year's Chicago Marathon with a time of 2:22:04. She has won the Boston Marathon twice, in 2006 and 2013, the second of which she finished with a time of 2:26:25. She entered international competition in 2000 and won her first marathon in Stockholm in 2004.

Details: Jeptoo barely missed the Chicago Marathon win last year, competing neck-and-neck with Baysa near the end of the race. She returns to the competition hoping to solidify her win.