Sunday, August 26, 2012

Prescription for healthier humans: More time at the park

“Parks are a part of our healthcare system,” said Daphne Miller, a professor of family and community medicine at the University of California, San Francisco. These green spaces are crucial to solving hypertension, anxiety, depression, diabetes — “the diseases of indoor living.”

But parks officials and the medical profession still need more data to take aim at the many “naysayers on the other side” who don’t believe in what landscape architects (and many urban residents) value, Miller said....

Miller was speaking at a recent conference in New York City called Greater & Greener: Reimagining Parks for 21st Century Cities. In a separate panel [(Powerpoint available at] ... Deborah Cohen, senior natural scientist at RAND, and Sarah Messiah, a research professor at the University of Miami, presented some exciting results.

... Cohen has used “systematic observations” measuring “play in communities” to determine if and how people burn calories in parks (see downloadable app). Her team of researchers visited parks and counted people in target areas every hour, three or four days a week. Cohen was particularly interested in “vigorous” physical activity such as brisk walking, jogging, or running....

She said some 50 percent of all vigorous activity occurs in parks. Unfortunately, that doesn’t say much, because “hardly anyone engages in vigorous activity anymore.” For boys, the average is two minutes a day, and for girls, just one minute a day.

To measure the impact of new parks on activity levels, Cohen did a before and after study. She watched residents in low-income, high-crime areas in Los Angeles before and then after three pocket parks were installed. These are tiny parks (less than half an acre), mainly playgrounds, which aren’t staffed. She found that for two of them, “the parks were better used than the larger parks serving larger areas.”...

Then, Cohen evaluated 12 “fitness zones”  — places in L.A. parks where the Trust for Public Land has installed outdoor exercise equipment. Of the 23,500 people who used the parks during her study, some 2,500 were in the fitness zones — two to four people each hour on average. She said these fitness zones led to “increases in moderate, vigorous activity” and were “relatively cost-effective”: At $45,000 a piece, with a 15-year lifespan, these systems offer 11 cents per metabolic equivalent of task (MET), referring to the metric for measuring the energy use of physical activities. “Anything under 50 cents per MET is worth it,” she said.

Benefits did not necessarily increase with the amount invested. When Cohen looked at the MET value of new facilities costing upwards of $1 million, she found that in one park, after the major improvements, the use actually fell from 2,000 to 1,500 people a day. The culprits? Reduced hours, cut programs, less maintenance, and a shorter baseball season....

In ... another experiment, some parks were given $4,000 to spend on signage, courses, activities, and other programming, while a “control group” didn’t receive any money. The “control” parks saw user levels fall, while the intervention parks saw increased users.
By Jared Green

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