Fuel Training Studio is hosting the Fuel River Run, a half-marathon and relay on Sunday, with a portion of the proceeds to benefit One Fund Boston Inc. to help victims affected by the Boston Marathon bombing. The event, scheduled to begin at 9 a.m., starts at the Newburyport Towle Building, 260 Merrimack St. After the race there will be a party with live music and food. Participants must be at least 12 years old to run the relay and 16 or older to run the half-marathon. Prizes will be awarded to the top teams and male and female runners. Registration fees are $75 for the half-marathon and $120 for the three-person relay.