Ultramarathoners -- men and women who run distances longer than 26.2 miles at a time -- are physically healthier than the general population, according to a survey conducted by doctors affiliated with Stanford University and the University of California-Davis.
There were 63,530 finishers of ultra-length races in 2012, quadrupling from 15,500 in 1998, according to Ultrarunning Magazine. The survey results reported this month were based on more than 1,200 responses to a Web-based questionnaire.
Ultramarathoners reported missing just two days of work or school because of illness or injury during the previous year, half the rate for the general population.
Sixty-four percent of ultramarathoners said their visits to a health care professional were prompted by an exercise-related injury.
Most of the injuries reported were to the knees and other parts of the legs and feet. But only 3.7 percent were stress fractures, which other studies indicate account for 5 to 16 percent of all injuries in runners.
Ultramarathoners were more likely to suffer from asthma and allergies than the population as a whole. In the survey 11 percent reported asthma, 25 percent reported allergies. Only 7 to 8 percent of Americans suffer from these conditions.
This may be because ultramarathoners spend more time outdoors being exposed to pollen and pollutants, said Eswar Krishnan, an assistant professor of medicine at Stanford.
Not enough exercise
Only 25 percent of children 12 to 15 get enough exercise each day to meet federal guidelines, according to a survey by the National Center for Health Statistics.
Federal guidelines recommend youth get at least 60 minutes of moderate to physical activity each day, but only 27 percent of boys and 22.5 percent of girls reported doing so.
More than half (60.2 percent of boys, 49.4 percent of girls) said they got an hour or more of exercise five or more days a week, according to the National Youth Fitness Survey for 2012, which was released this month.
Only 6.4 percent of boys and 8.7 percent of girls reported failing to get 60 minutes or more of moderate to vigorous exercise on any day during the week.
The children surveyed were asked if during the past week they took part in any physical activity other than physical education classes at school; then if the total amount of physical activity they got -- including PE classes -- added up to 60 minutes a day or more.
Moderate to vigorous physical activity was defined as "any kind of physical activity that increased your heart rate and made you breathe hard some of the time."
Outside of physical education classes in school, boys were most likely to get their exercise by playing basketball (48 percent). For girls, running was the form of exercise most commonly reported (34.9 percent).
After basketball, the top activities reported for boys were running (33.5 percent), football (27.4 percent), bike riding (24 percent), and walking (23.6 percent).
After running, the top activities reported by girls were walking (27.6 percent), basketball (21.4 percent), dancing (20.8 percent) and bike riding (18.4 percent).
Among boys, those of normal weight were far more likely to get 60 minutes or more of exercise every day (29.5 percent) than were boys who were obese (18 percent).
Girls of normal weight were more likely to meet the exercise guidelines (24.1 percent), than were girls who were obese (20.4 percent), but the difference wasn't considered statistically significant.
Jack Kelly: email@example.com or 412-263-1476.