With six weeks left before the Honolulu Marathon, distance runners of all ages, sizes and abilities are gearing up for the last seriously long runs of their training cycle.

At Jack Scaff's Honolulu Marathon Clinic, a free training program that offers expert instruction and group training runs every Sunday, volunteer coaches are preaching the need for sustained but controlled effort.

Over the years, the clinic has safely shepherded thousands of beginning runners to the marathon finish line via a training program of incremental increases in mileage that build strength and endurance and strategic plateaus that allow athletes to safely acclimate to the rigors of distance running.

The clinic organizes its training runs around advanced, intermediate and beginners groups, with each group splintering into smaller groups to allow for different levels of ability. For the beginning groups especially, the patience and restraint they exhibit over the next several weeks will be critical to their marathon success.

The clinic started up again in March with runners walking or running just a few miles (or less) at a time. Over the course of the next seven months, each group slowly increased both the weekly mileage and the distance of their Sunday "long" runs. Many intermediate and advanced runners, those who already have a solid running base that they've maintained, started their training later — some just recently.

At this point in the training arc, however, there is nothing more for the runners to do but stay on track. Adding more mileage, adopting new training techniques, or changing their diet at this late stage comes with more risks than benefits.

And yet, with confidence blooming and the big day quickly approaching, many runners feel the need to do more, either to make up for inconsistent training or to prepare even better for what may be the pinnacle of their athletic endeavors so far.

And that, says clinic coaches, is a recipe for disaster.

"The most dangerous time is when you feel good," says longtime clinic coach Norman Uyeda. "We see the most injuries during the September-to-October time frame because people feel strong and they want to push it."

While experienced runners understand and accept the clinic's conservative approach to training — a long incremental building of muscular and cardiovascular capacity followed by a tapering period to recover and build energy for the race — many beginning runners worry that they won't be prepared for the race if they don't come close to running the marathon distance in practice.

Rosemary Kyte's beginners group is nearing the tail end of its "Big 8" training cycle. Rather than increasing their weekly mileage, they've purposely plateaued at 30 miles a week with maximum long runs of 14 miles on Sunday.

"It's been the experience of the clinic that that level of training is adequate preparation for the marathon," Kyte said. "You don't need to do more and more and more.

"Runners typically feel better as they repeat the same regimen week after week. But with that comes a dangerous sense of guilt," Kyte says.

"For the first time in your training your body starts to catch up and you feel good, but there is still an underlying level — your body is still pretty pounded from all the previous training. They feel like they want to do more, but they don't realize how close they are to injury."

Blair Hoashi's intermediate group has been adding two miles each month to their Sunday long runs. This weekend, they'll take a bus out to Makapu'u and run 15 miles back to Kapi'olani Park. They'll max out their mileage at 18 to 20 miles next week before hitting the tapering stage.

"A big thing at this point is ego," Hoashi said. "Everybody wants to run faster and longer, but they already have a lot of training under their belts. They just need to stay healthy."

Hoashi said runners who continue to push their weekly training risk knee problems and other overtraining injuries. Fatigue, which can lower a runner's resistance to illness, is also a concern, especially for those who don't schedule adequate rest and recovery.

For clinic runners to meet the shared goals of the clinic — finish the race, meet your personal goals, and have fun — the challenge now is to trust in their training and stick to the game plan.

Reach Michael Tsai at mtsai@honoluluadvertiser.com.