When a really great idea comes along, you do your best to run with it.

The Poor Clares of Perpetual Adoration of Our Lady of Solitude Monastery (the “Desert Nuns”) near Phoenix have taken this axiom literally: Their second-annual “Nun Run” will take place March 12.

Last March, more than 1,000 people turned out to run (or walk) in order to help the good sisters raise money for a chapel in the Arizona desert.

The Nun Run, with “shadow participants” from many states joining in for “companion” runs (amazingly, 200 people signed up to run or walk in 29 states from California to New Jersey, Missouri to Minnesota, plus Canada and Puerto Rico), was so successful last year that the beautiful new Chapel of Our Lady of Solitude is nearing completion. It stands with medieval-inspired grace on land donated to them in Tonopah, just west of Phoenix. This is the first Poor Clares of Perpetual Adoration monastery in the West and the first contemplative community of nuns in the Phoenix Diocese.

This year’s goal for the donations and pledges for the runners will be for the second building phase: the monastery itself, which will house 28 nuns.

Right now, the six Poor Clares who live in temporary quarters are joyfully preparing for this year’s spectacular Nun Run.

No doubt there will be a few parents pushing baby strollers, like they did last year. Everyone can find their niche, since this year’s categories of competition have been expanded to three: a 10K run, 5K run/walk and 1K walk.

Shadow runners don’t even have to clock their miles on the same day; they can set their own time or can be Nun Run fundraisers by obtaining sponsorships (the nuns will even mail an official T-shirt).

The six sisters, who came to Arizona in 2005 from Hanceville, Ala., aren’t going to remain on the sidelines. They’ll lace up their running or walking shoes at Kiwanis Park in Tempe, Ariz. This year, three sisters will run, and three will walk, so participants and spectators shouldn’t be surprised to see nuns with brown habits and white veils flying in the wind in either the 10K or 5K divisions of the race. Last year, Sister Augustine Marie finished sixth in her female age division, and Sister Esther Marie placed 15th in her division.

The video capturing last year’s event had its own kind of Chariots of Fire moment.

As one of the sisters in last year’s video said enthusiastically, it wasn’t just about winning the race: “You’re running not for a crown that withers or fades, but for a crown for eternal life.”

This year’s goal is to sign up participants in all 50 states — and beyond. A few runners have registered from Rome and Israel.

The largest team outside of Arizona gets an award. Last year, the largest outside group — 28 strong — put in their kilometers in the Orlando, Fla., area.

At the end of February, the number of all registered participants was already twice what it was in 2010 at the same time.

It just might be the right time to join the Nun Run to help build this monastery. After all, as the motto for this year’s race says: “It’s a Good Habit!”

Register staff writer Joseph Pronechen is based in Trumbull, Connecticut.