They also had faulty notions about electrolytes. Almost a third incorrectly believed they needed extra salt while running, and 57 percent said they drank sports drinks to prevent low blood sodium.
"Many athletes hold unscientific views regarding the benefits of different hydration practices," the researchers wrote in the June issue of the British Journal of Sports Medicine.
Drinking too much while running can actually do harm by over-diluting blood sodium, causing the potentially fatal condition exercise-associated hyponatremia. In recent years, 12 runners have died of it, according to the researchers, who say that sports drink ads promoted overdrinking during the 1980s and 1990s. - Marie McCullough
Volunteering must be altruistic, not selfish, to foster longevity
Volunteering might lead to a longer life, but only if you do it for the right reasons, a new study shows.
In work published last week in the American Psychological Association's journal Health Psychology, researchers found that people who volunteered primarily because they were thinking of others lived longer than those who volunteered because they thought it would help themselves. People who volunteered for other personal reasons had the same death rates as people who didn't volunteer at all.
The researchers from Rochester and Stony Brook University medical centers and the University of Michigan used data from 10,317 Wisconsin students who graduated in 1957. They looked at who in that group was volunteering in 2004 and why, and who was still alive in 2008, when the average age of the group was 69.
The death rate for non-volunteers and people who had volunteered to feel better about themselves or to escape their own troubles was about 4 percent. It was 1.6 percent for people who said volunteering was important to help others or people they cared about. - Stacey Burling
Study finds many elderly have undiagnosed brain blockages
If PopPop is walking slower and his hands are shaking, it might not be just aging at work.
Researchers from Rush University Medical Center in Chicago have found evidence that some of the common signs of aging may actually be caused by tiny blocked blood vessels in the brain.
The microscopic lesions cannot be detected by current technology. But when they examined brains during autopsies of older people - 418 nuns and priests, average age 88, who had donated their brains for examination after death - the researchers found that 30 percent of those with no diagnosed brain disease or stroke nevertheless had the lesions. However, all had motor skills evaluations that rated balance, ability to maintain posture, walking speed, and other factors.
The study was published in Stroke, Journal of the American Heart Association.
Because of how many remained undiagnosed, "the public health implications are significant," said Aron S. Buchman, lead author of the study and associate professor of neurological science at Rush. "We need additional tools in order to identify this population," he said. - Sandy Bauers
Asthmatics are more prone to tooth decay, study affirms
Asthma is not fun. Neither are cavities. A new study suggests that having the first appears to predispose you to the second.
Cavities in baby teeth were twice as common in children with asthma as in other kids, according to the analysis of 11 previous studies of a link. An analysis of another 14 studies found an even greater correlation in adults.
Various researchers have examined the issue, mostly in small studies. Findings were inconclusive, according to the Finnish authors of a report in the American Journal of Epidemiology. Their analysis, using a statistical technique for synthesizing data from multiple unrelated studies, identified a clear connection.
The reasons for such a link are unknown. The authors suggest the most likely mechanism is that asthma medicines significantly decrease salivary secretion. The decrease is known to predispose people to tooth decay.
They recommend that asthmatics use fluoride toothpaste and that they "be especially attentive to oral hygiene after using asthma medication."
- Don Sapatkin