The National Recreation and Park Association recommends that adults spend time outdoors daily, but a survey it commissioned found three in 10 U.S. adults spend no time outdoors daily.

When adults do venture outside, 47 percent spend less than half an hour there. And the figures are worse for adults ages 35 or lower, with 56 percent spending less than 30 minutes in fresh air.

More than a third of survey participants said work gets in the way of the great outdoors. One in five said the same of technology such as tablets and smartphones, and nearly as many blamed television.

"Time outdoors is good for our health, happiness and overall well-being, yet these findings indicate adults are putting their priorities elsewhere," said Barbara Tulipane, president and CEO of the NRPA. "Community parks and recreation are leaders in getting more people outdoors and active. They are the perfect place for people to reset their priorities and make outdoor time a regular part of their daily routine."

More than half of the outdoorsy adults surveyed exercise or play sports outside, and as many spend time with family outside. Almost as many go outside to enjoy nature.

This month, the NRPA has launched its "OUT is IN" challenge, and it is asking adults to photograph their daily outside activities and tweet those photos or post them on Instagram with the hashtag #JulyOUTisIN. NRPA will award a daily prize at random to a Twitter or Instagram poster.

The NRPA is a national nonprofit with 40,000 recreation and park professionals and citizens. The survey was conducted by Ipsos Public Affairs, a nonpartisan survey-based research practice. The survey was conducted over May 2-5 with 1,005 adults.