Graded training of little benefit in novice runners

NEW YORK (Reuters Health) - In a study of inexperienced runners training for a recreational 4-mile road race, a graded 13-week training program did not reduce the number of running-related injuries compared with a standard 8-week training program.

Dr. Ida Buist from University Medical Center Groningen, the Netherlands, and colleagues hypothesized that if the human body has more time to adapt gradually to the external impact forces of running, the incidence of running-related injuries will decrease. This hypothesis not supported by the study findings and "should be rejected."

When preparing for a 4-mile run, "it does not matter how you get there (either fast or slow) -- the risk of sustaining a running-related injury is the same," conclude Buist and colleagues.

Although running has positive effects on health and fitness, the incidence of running-related injuries is high, affecting 20 to 50 percent of novice runners, they note.

The principle that the volume of exercise should be increased gradually over time is widely viewed as crucial to minimize overuse injuries. This general principle fueled the so-called "10-percent rule" for runners; that is, to minimize the risk of running-related injuries, an increase in training volume should not exceed 10-percent per week.

Buist's team evaluated the effects of a modified graded training program for novice runners, based on the 10-percent rule, on the risk of sustaining a running-related injury,

All 486 runners were instructed to walk for 5 minutes to warm-up and cool-down, and to run three times a week on a self-chosen course and surface at a comfortable pace at which they could talk without losing breath.

The 250 runners in the graded training group started their training 13 weeks before the Groningen 4-mile run, while the 236 runners in the comparison group started their training 8 weeks before the run.

Following the 10-percent rule, in week 1, participants assigned to the graded training group ran 30 minutes per week and walked for 30 minutes per week. In week 2, they ran for 34 minutes and walked 26 minutes. In week 3, they ran 36 minutes and walked 24 minutes. By week 12 they ran for 90 minutes.

The standard 8-week training group also ran for 30 minutes and walked for 30 minutes in week 1. In week 2, they bumped up their running time to 46 minutes and decreased their walking time to 22 minutes. In week 7, they ran for 95 minutes.

Both training groups ran for 30 minutes the week before the race.

The graded training program, with a more gradual increase in running, failed to have a significant impact on the number of running-related injuries, Buist and colleagues report in the American Journal of Sports Medicine.

Injuries occurred 20.8 percent of runners in the graded training group and 20.3 percent of those in the standard training group.

SOURCE: American Journal of Sports Medicine, January 2008.