After bombs ripped apart the Boston Marathon in April, thousands and thousands of people had the same idea: Next year, I’m running it for charity. However, so many aspiring runners have applied to the 2014 race’s 138 official charities that winning a bib may be harder than running the race. The heightened interest has prompted many charities to ask runners to raise more than the $4,000 and $5,000 fund-raising minimums set by the Boston Athletic Association and sponsor John Hancock , respectively.