Wednesday, September 17, 2014

Keep on Truckin'

Like political polls, study results can be misleading, hard to believe, depressing, or downright silly. Gretchen Reynolds, who writes a running column for the New York Times, often quotes study results. Some offer something to ponder, confirm what you already know, and sometimes even share new and useful information. Recent studies say:
Marathons rarely kill. An article in the May 2012 American Journal of Sports Medicine revealed that between 1999 and 2009 the number of marathon finishers in a year rose from 299,000 to 472,000 but the death rate remained the same—less than one per 100,000 participants.  Twenty-eight people died during or in the 24 hours after a marathon, mostly men with heart problems. A few died from low blood sodium caused by drinking too many liquids.

The January 2012 New England Journal of Medicine confirms what cardiologist Dr. Paul Thompson, already believed: “You are at slightly higher risk of suffering a heart attack during a marathon than if you were sitting or walking during those same hours. But overall, running decreases the risk of heart disease. Genetics, viruses, and bad habits from the past can cause development of plaque in the heart arteries and enlargement of the heart muscle which running cannot prevent.

The doctor, who was forced to quit running because of a bad hip says: “I ran marathons because I loved them, not because I expected them to help me live forever. I don’t know if it’s the healthiest way to spend years of your life. But it was enjoyable. I miss running very, very much.”

A recent study at the University of South Carolina Arnold School of Public Health offers good news for the slow and steady. Researchers found that running in moderation provided the most benefits. People who logged up to 20 miles a week at about 10 or 11 minutes per mile pace reduced their risk of dying compared to people who did not run and compared to those who ran more than 20 miles a week, as well as to those who ran faster than 7 miles an hour.

Less running appears to provide the best protection from mortality risk. “More is not better, and can be worse,” says Dr. Carl J. Lavie. “Run more if you like, but only if you don’t experience extreme fatigue or frequent injuries.”

Researchers at the University of Arizona wondered why our ancestors continued to run over time rather than developing other strategies for survival.  Blood samples from humans and dogs after they had run for 30 minutes, showed increased levels of a naturally occurring cannabis-like chemical that alters and lightens mood. After 30 minutes of walking, no such increase occurred. When ferrets were encouraged to run (with difficulty), their blood samples showed no change in endocannabinoid levels.  Conclusion: Humans are hard-wired to run, ferrets are not.

 A  study of Western adults reported that every hour of television viewing after age 25 lowers life expectancy by 21.8 minutes.

Our physical activity can affect how long, and more importantly, how well we live.  All the studies tell us so. No exercise prevents aging, according to Reynolds. “Only death can do that.” 

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