Scientists haven't yet discovered how many children, upon hearing of time travel, dream of heading back a few decades to visit their parents as kids. Stripped of height and authority, would parents be any fun? Maybe they would just be bossy, brutish, and short. Would they know how to play tag?
If today's kids could wangle such a playdate, however, they might find themselves left in the sandbox dust, according to new research presented at Tuesday's annual meeting of the American Heart Association.
Exercise physiologists at the University of South Australia who analyzed research on 25 million children around the world determined that today's kids, on average, take a minute and a half longer to run a mile than did kids in 1975. The studies measured how far children of different ages could run in 5 to 15 minutes, and how quickly they could run distances up to two miles.
But do fleet feet really matter now that most of our predators, as well as our prey, are stored behind bars? Isn't texting speed more relevant to modern survival?
Apparently running still matters. According to these researchers and many others, several factors make running fitness a key measure of heart health.
The Associated Press reported details on the findings, which were fairly constant across gender and age groups:
"The decline in fitness seems to be leveling off in Europe, Australia and New Zealand, and perhaps in the last few years in North America. However, it continues to fall in China, and Japan never had much falloff – fitness has remained fairly consistent there. About 20 million of the 25 million children in the studies were from Asia."
The study's lead scientist, Grant Tomkinson, said that increased bodyweights and TV/video game consumption, along with unsafe and decentralized neighborhoods, and school curricula stripped of physical education, may all make it hard for children to get the 60 minutes of daily exercise recommended by government health experts.
"We are currently facing the most sedentary generation of children in our history," said Sam Kass, a White House chef and head of first lady Michelle Obama's Let's Move program, in a speech to the conference.
According to Tomkinson, it's important that parents limit their children's sedentary time – spent curled over a tablet, computer, or smartphone – to less than two hours per day.
What kids really need, he said, is good old-fashioned sweaty, exhausting exercise. Roller skates, anyone?
"You want exercise to be fun," said Tomkinson, "but there needs to be some huff and puff there as well."