When Gov. Mark Sanford called for South Carolinians to exercise more in his State of the State speech, he also challenged himself.

A lifelong runner, Sanford started running for exercise less often when he started running for governor in 2002. After his election, a back ailment sidelined him for a while. He abandoned his routine of running three times a week and doing some other aerobic exercise two other days. And he hated himself for it.

“It’s not just about longevity and health statistics,” Sanford said of routine exercise. “It’s about how we feel and how we function. (The body is) like a saw. It cuts fine at first, but then it dulls. You need to sharpen it.”

Sanford will lead the first stage of his three-stage bike ride across the state Saturday, starting at 9 a.m. at Croft State Natural Area near Spartanburg. The 65-mile trip ends at Reunion Park in Little Mountain.

Exercise serves as a catharsis for Sanford, and the leader of a state as oft-conflicted as South Carolina can use some mental relaxation.

“I’ve worked out consistently since junior high school,” said Sanford, who ran on the cross country team in high school but doesn’t boast of his record times like former Gov. David Beasley once did. “(Running) always has been therapy for me — my way of clearing my head, clearing my stress.”

In challenging the state’s residents to exercise to improve their health, Sanford invited everyone to ride along with him on the cross-state bike tour. That also gave him extra incentive to put aside matters of state every once in awhile and take a long, mind-clearing run.

Lately, he has squeezed in about two running sessions a week, five to six miles. He prefers to run by himself, and often slips away in the late afternoon or early evening to popular jogging locations near his office.

Clare Morris, spokeswoman for the Commerce Department and an avid runner, ran with Sanford during a trade mission to China last year. She said he’s definitely a runner, not a jogger.

“The pace was really, really fast,” said Morris, who has run a half-marathon. “He had to cut me some slack.”

Sanford and his 9-year-old son Landon recently ran in the Cooper River Bridge Run, both completing the 6.2-mile race in just less than an hour.

What’s more impressive is the governor did it on an aching knee. He made a classic mistake when he started training for the cross-state bike ride. Thinking he needed to kick it up a notch because he had only a few weeks to train, he put his old, beat-up bike in the highest gear possible to give his legs a power workout.

He strained his knee.

After that, Sanford relented and got some expert advice. He agreed to replace his old bike, the one with the seat held together by duct tape. Bike manufacturer Trek offered to loan him a new bike fitted to his lanky frame. (The bike will be auctioned after the cross-state ride, with proceeds going to charity.)

Sanford, who said he’s never pedaled longer than an hour on a bike, took his first test ride on the new bike less than three weeks ago. He felt like a dude-ranch horseback novice on a Kentucky Derby contender. He hoped he could get used to the high-tech marvel quickly.

Brian Curran, who helped fit the Trek 5200 for the governor, said Sanford has a smooth pedal stroke and could be a strong distance rider if he worked at it.

“But it’s not like the governor can get out on a Sunday and ride five hours like I do,” said Curran said, who owns the Outspokin’ bicycle shop in Columbia.

Curran got the impression Sanford wished he could fit more cycling into his busy schedule. “He’s seems genuinely excited about the ride,” Curran said, “not like ‘Oh my gosh. What have I gotten myself into?’ ”

Sanford recognizes that in admonishing the state’s residents for their lack of exercise, he has set himself up for potshots if he can’t complete the 60-mile ride Saturday or the two nearly 50-mile trips on May 15-16.

Three years ago, before he started campaigning for governor, he would have been much more confident of his endurance. Now, he offers a pained smile when asked what will happen if he doesn’t finish the first-day route.

“Now that I’ve thrown down the gauntlet, I can’t look like a total loser and not finish,” Sanford said. “By hook or crook, I have to finish.”

Reach Holleman at (803) 771-8366 or jholleman@thestate.com.