The 22,000 runners gathering before dawn for the Twin Cities Marathon and 10-mile runs won't be able to stretch out and stay warm inside U.S. Bank Stadium on Sunday morning.

The noon game for the Minnesota Vikings against the Houston Texans requires a security lockdown of the building Saturday night, team officials said. After that point, only employees, ticketed and credentialed visitors are allowed inside. At 9:30 a.m., the gates open for 66,000 fans attending the game.

The lockout has caused a ripple of runner consternation as evidenced by an online petition that calls on the stadium doors to open for the runners. Before the Metrodome was demolished in January 2014, runners were allowed inside to keep warm and use the restrooms before the start of their races.

The Vikings have regularly accommodated the marathoners with away games and bye weeks on the day of the event. Only once since 2001, when security was tightened because of 9/11, have the Vikings played at home on marathon Sunday. The exception was 2012 when the team hosted the Tennessee Titans. That game was pushed from noon to 3:15 p.m. so runners could get into the building that morning.

Since then, security at NFL and other major sporting events has increased significantly because of the Boston Marathon bombings in April 2013. At that marquee marathon, two brothers dropped backpacks loaded with explosives on the ground near the finish line, killing three people and injuring 264. Beginning with the 2013 season, the NFL restricted what fans could bring to the game, allowing only wallets and clear plastic bags of a certain size.

The good news for runners, though, is that the Vikings, Twin Cities in Motion (TCM) and the Minnesota Sports Facilities Administration agree they want to try to get the building open in coming years.

"We're looking forward to the future and hope that the People's Stadium can in fact be that," TCM president Mike Logan said, using the name Gov. Mark Dayton has used for the publicly funded facility.

Provided the schedule works, MSFA Chair Michele Kelm-Helgen said the runners would be welcome indoors in 2017.

Logan said he's been speaking with the Vikings about accommodating the marathon since spring — before the NFL season schedule was set for 2016. A convergence of big events made scheduling difficult this year.

The Vikings opened their new building on Sept. 18 playing the Green Bay Packers. Eight days later, Ryder Cup golf events started at Hazeltine National Golf Club in Chaska, drawing some 250,000 fans. The marathon, generally held on the first Sunday in October, was pushed back a week to avoid a conflict with the golf event.

But the NFL sets the schedules for the 32 teams. Vikings spokesman Jeff Anderson said the team requested not to have a home game that coincided with the end of the Ryder Cup Sunday afternoon. The NFL scheduled the Vikings on Monday night against the New York Giants.

The team made a similar request for the upcoming weekend, to not play a home game on marathon Sunday, but the back-to-back requests were apparently too much for the NFL to juggle.

Since 9/11, the NFL has intensified security substantially because of concerns related to having 66,000 fans in a stadium at the same time. That necessitates the prior-evening shutdown, officials said.

The 10-mile runners start first at 7 a.m. Some 10,900 runners will head from the streets near the stadium to the Capitol.

The marathoners, who cover 26.2 miles, start at 7:55 a.m. The marathon field is 11,500. (Note: Logan said about 50 spots remain for last-minute athletes.)

To compensate for the lack of a heated building and bathrooms, Logan said TCM will set up 285 portable toilets in the starting area. Runners will be able to convene on the grassy commons park and the plaza in front of the new $1.1 billion building. Logan said it will be a great communal experience for the runners to gather and stretch.

For the past two seasons, when the Metrodome had been demolished and the new stadium was under construction, runners essentially started next to a hole in the ground.

The marathon will use two of the Vikings' giant video boards to direct runners to corrals. Ten-milers will use the A, B and C corrals. Marathoners will head to corrals 1, 2 and 3.

Runners may not be happy with being shut out, but they can be thankful that the weather appears to be a perfect 40 to 50 degrees at start time.

Rochelle Olson • 612-673-1747

Twitter: @rochelleolson