In wake of the April 15 bombings at the Boston Marathon, both the New York City Marathon and Marine Corps Marathon have banned hydration vests. The list of banned items at the New York City Marathon includes strollers, vests with pockets, and “costumes covering the face or any nonformfitting, bulky outfits extending beyond the perimeter of the body.” Runners can continue to use fuel belts and hand-held water bottles.

According to Runners World, New York Road Runners instituted the ban at all its events in April but sent a security update with a link to banned items via email to marathon registrants prompted Facebook discussion.

Organizers of the Marine Corps Marathon said on its official website, “For marathoners, 10K participants and spectators, the following items are prohibited from entering any MCM event location: hydration vests and backpacks like CamelBaks; glass containers; masks; and flammable liquids.”