Des Moines, Iowa (CNN) -- Rick Perry's best asset in the race for the White House these days might just be a pair of Brooks running shoes.
After recovering from a painful summer back surgery that left him weary and unable to exercise, the Texas governor, an avid runner, has returned to old form.
Perry's frequent jogs, along Iowa roadways and in hotel fitness centers, have become both an energy booster and a welcome break from his marathon bus tour of 42 Iowa cities, a late push that campaign advisers hope will vault him to a top three finish in the January 3 caucuses.
His aides are now carving out time for the governor to jog at least four times a week, usually at distances between three and four miles at a time.
Perry is always accompanied on the runs by a member of his security detail, and often by his 26-year-old traveling aide, Clint Harp.
"I get anywhere between 13 and 16 or 17 miles a week, which is enough," the Republican candidate told reporters during a recent visit to the eastern Iowa hamlet of De Witt.
"It's good to get back running," he said, even inviting a reporter to accompany him on one of his outings.
Perry, 61, belonged to a student military organization at Texas A&M University and later served in the Air Force, but he did not become a devoted runner until much later, when he was a state legislator in Austin.
In 1989, at the urging of local fitness expert Paul Carrozza, Perry began to run regularly, often taking a scenic route along Austin's Lady Bird Lake.
His jogging habit became famous in early 2010, when Perry said he shot and killed a menacing coyote with his laser-sighted .380 Ruger pistol during a run in rural Texas.
But Perry had to hang up his running shoes in July, when, after a special legislative session concluded in Austin, he underwent spinal surgery to fix a nagging back ailment.
Perry did not attempt to jog again until 10 weeks after the surgery, in mid-September, just after he announced his presidential bid, and right before a crucial gauntlet of Republican debates that came to define his candidacy.
He started out again by walking and slowly "eased back into it," Perry's press secretary Mark Miner recalled.
Perry described the surgery as an "awesome success," but he also blamed the recovery process for an onset of fatigue that induced several lethargic and absent-minded debate performances. His once-soaring poll numbers cratered soon after.
But in the two most recent Republican debates, Perry displayed the energy that appeared to be lacking throughout the fall campaign season.
It may be too late for a comeback: Recent polls show him mired in fourth place behind Ron Paul, Mitt Romney and Newt Gingrich in Iowa, where he needs a strong showing to survive.
Perry, though, seems to have a noticeable bounce in his step as he forges his way across the state glad-handing with caucus-goers and hoping for a late surge.
That renewed vigor, Perry aides say, can be linked directly to his running routine.
During a recent bus tour stop in Manchester, Perry spoke inside a Pizza Ranch restaurant and delivered a series of familiar broadsides against the Obama administration's regulatory policies.
Then, after sitting down to tape an interview with ABC's "Nightline," he shed his black suit and put on a cap and cold-weather running pants for a brisk three-mile jog in the middle of the day.
"We had a little a break in the schedule, so I just threw on my gear and ran downtown and ran to the courthouse," Perry said.
His campaign later tweeted a picture of the midday workout, and Perry campaigned well into that evening.
Like any veteran runner, Perry said he prefers to exercise outdoors.
Treadmills are "boring," he said.
The governor has braved temperatures as low as 20 degrees to run outside during his Iowa tour, said longtime adviser Ray Sullivan, but the Midwestern cold can sometimes be prohibitive.
Perry awoke before dawn one morning last week at a Dubuque area Holiday Inn Express and headed out into the early morning chill with a state trooper, but with the temperature still hovering below freezing, he retreated back into the hotel.
A few minutes later, he hopped onto one of two treadmills in the hotel fitness center and turned the television to ESPN, which was showing highlights from the previous night's NBA preseason and NFL action.
Perry ran three and a half miles at a slight incline, at about an eight and half minute per mile pace.
A reporter in the same room complimented Perry on his impressive regimen. "I got some catching up to do," he responded.