It’s a Boston Marathon museum, a free locker room for runners, and a retail store with gear from Adidas, all in one.
An unusual project involving the Boston Athletic Association, the local retailer Marathon Sports, and the global athletic supplier Adidas is scheduled to open a few blocks from the finish line on April 16 — just four days before this year’s race.
Dubbed Boston Marathon RunBase, the 2,000- square-foot store at 855 Boylston St. will feature Adidas products, offer free access to showers and changing rooms, and provide historical information about the 118-year-old race.
The groups expect the facility to serve as a gathering place for runners, who can store their belongings, change, and clean up after a quick lunch-break run.
For the BAA, the new storefront will be a showcase for Marathon history, said executive director Tom Grilk. Artifacts that have been housed at BAA headquarters on Dartmouth Street — out of public view — will now have a prominent display area.
“We’ve never had a front door to the world,” Grilk said. “We had talked about a museum and wondered, could we merge that idea with the BAA’s mission to promote health and fitness?’”
The last facility the BAA opened was its original clubhouse, a members-only gym with a weight room, swimming pool, and lavish amenities such as a Turkish bath and cigar and wine rooms, that was shuttered when the organization went bankrupt during the Great Depression, said Tom Derderian, a Boston Marathon historian and coach of the Greater Boston Track Club.
The new RunBase location will feature space for five or six exhibits that are expected to change every three months.
Historic relics on display will include the shoes and shirt worn by two-time champion Johnny Miles during the 1929 race and the second-place medal from the first Boston Marathon, in 1897.
The first-place medallion is missing.
There will be four individual showers, split up for men and women, as well as changing rooms. The facilities will be available to any runner who signs a liability waiver. Runners will receive a wristband with a key to a locker to leave their belongings as they head out for a run.
An interactive treadmill will feature a visual tour of the course and settings that replicate certain sections. If a runner selects Heartbreak Hill, for example, he or she can expect the machine to adjust to a steep incline, said Chris Brewer, the US director of running at Adidas.
The retail section will feature only Adidas shoes, clothing and other products, as well as exclusive running products not available elsewhere.
“It’s going to be an interactive hub for those that love the Boston Marathon,” Brewer said. “It will be a retail experience like no other.”
Adidas financed construction of the store, which previously housed a Bank of America branch, and Marathon Sports will be responsible for the retail operation.
In an unusual twist for Marathon Sports, its workers are expected to be marathon history buffs as well as shoe specialists. The BAA has held history lessons of sorts for the workers to prepare for the opening, said Colin Peddie, the owner of Marathon Sports.
“The store itself is a little different from what we’ve done in that its really about the experience that we’re trying to give to the customers,” Peddie said.
The BAA will supply the marathon history and artifacts and receive royalties on official marathon-licensed gear. All three parties will contribute to the rent.
Grilk said the extra revenue might not even cover the BAA’s portion of the Boylston Street lease — a sum he declined to quote. In 2013, the most recent year for which BAA tax filings are publicly available, the organization collected $762,683 in royalties, mostly in payments by Adidas for selling marathon-licensed gear.
Royalties comprise just 6 percent of BAA revenue, and the nonprofit has few commercial ventures besides the Adidas deal. Race entry fees make up 51 percent of revenue, and donations account for 43 percent.
The store is the first RunBase for Adidas in the United States and the sixth worldwide. The Boston store is unique because of the partnership with the BAA and the museum element.
Micah Risk, a nutritionist and first-time Boston Marathon runner, said she will test out the facility to fit a run into her bike commute from home in Roxbury to her daughter’s school in Jamaica Plain and work in Kendall Square. She said free facilities similar to the RunBase are hard to find in Boston, and some runners buy expensive gym memberships just for access to the showers.
“There’s so many runners in this city, and the more resources, the better,” Risk said. “I’ve definitely skipped runs because I didn’t have somewhere to put my stuff or shower.