DORAL, Fla. — Winning multiple PGA Tour titles is hard, even if Tiger Woods made it look ridiculously easy as recently as last year, when he collected five titles in 16 starts to raise his career total to 79. Australian Jason Day, a two-time tour winner, suggested that Woods, in his drive to become golf’s career leader in tour wins and major championships, developed an automatic pilot that few athletes could access.

“When you have a goal like that and you’ve been trying to achieve that, you’ll do anything you can to win the event,” Day said, adding: “That’s why he made it look so easy and that’s why he made everything in the clutch; he put the work in and his goals were motivating him to achieve that.”

That will to win, Woods said Wednesday, “hasn’t changed.” His goals are the same, but since his last tour win, at the World Golf Championship event in Ohio last August, Woods has identified an enemy impervious to his resolve.

It is age, and it is a bear of a different color from Jack Nicklaus, whose 18 major titles Woods has spent the past 19 years chasing. Injuries have forced Woods, 38 and long considered the best-conditioned athlete on the tour, to retire during a round four times in the past five years.

On the eve of his title defense at the World Golf Championship event at Doral’s Blue Monster, Woods explained how playing on a broken leg, as he did while winning the 2008 U.S. Open, was manageable next to trying to finish his final round Sunday at the Honda Classic with a balky back.

“A bad back is something that is no joke,” Woods said.

With a leg that is broken, or a knee that is unstable, he explained, the pain “was always after impact.”

He said: “So I can do my job and deliver the club and deliver the final moment to the ball and hit the shot I want to hit. It’s just going to hurt like hell afterwards. I played that way for years.”

Trying to hit shots between back spasms, Woods said, “is a totally different deal. There are certain moments, certain movements, you just can’t do.”

Woods’ physical struggles, and those of other top golfers in recent years as the technology has become more unforgiving and players’ schedules more unrelenting, have spawned a cottage industry of pit crews employed to work on golfers’ bodies to keep them purring.

At 20, Jordan Spieth is at the age when he could get away with rolling out of bed and proceeding directly to the first tee. And yet, he has a chiropractor in his traveling entourage.

“I don’t experience any injuries and I don’t expect to going forward because I feel like I have the right program,” Spieth said.

Part of Adam Scott’s program is a pre-round routine that starts three hours before his tee time and includes stretching and riding a stationary bike.

“I feel like I loosen up and I’m in a good position to tee off on the first hole,” said Scott, the reigning Masters champion. “Your body is constantly changing as you get older and you have to try to make the best adjustments to your routine to suit that.”

Day’s program includes active recovery, which sounds like an oxymoron but, in fact, is part of his post-round routine. After experiencing tightness in his back early in last month’s match-play championship outside Tucson, Ariz., Day made sure to go to the gym after the rest of his matches to loosen and strengthen key muscles.

“Golf is not a contact sport, so you really don’t think that there’s so many injuries,” he said, “but there’s a lot of twisting and turning and torque that you put in the golf swing. We swing a million times in one direction and we don’t swing it the other direction to balance out the muscles that are in balance. So it’s very easy for people to get injured.”

In pursuit of birdies, some golfers have embraced the pigeon pose and other yoga movements. Since 1999, Katherine Roberts, a yoga instructor and avid golfer, has been creating programs for golfers that fuse biomechanics with mind and body conditioning.

“When I started yoga for golf, there were definitely people who looked at me like I might be a little crazy,” Roberts said in a telephone interview. “But now athletes across the board are doing yoga as part of their conditioning programs.”

Woods said his maintenance work includes yoga.

“I’m not real good with the patience part of it,” he said with a smile, “but, yes, it does help.”