With the closing ceremony of the 2012 Olympics tonight in London, I decided it was time to present the Olympics-related stories I had been sitting on for the past three weeks. Here are the stories about Americans' lack of exercise and the negative health outcomes of their inactivity that I included in Overnight News Digest: Science Saturday (Two space anniversaries edition), Overnight News Digest: Science Saturday (Opening of London Olympics edition), and Overnight News Digest: Science Saturday (PECASE, President's Birthday, and Curiosity edition) on Daily Kos.
First, how the Olympics showcase the role of exercise in human evolution, and how the lack of exercise is causing more problems than people realize.
Olympics: Run for your life
Humans evolved to run. This helps to explain our athletic capacity and our susceptibility to modern diseases, argue Timothy Noakes and Michael Spedding.
July 19, 2012
The forthcoming Olympics in London will celebrate the performance capacity of humans and our remarkable ability to prepare our bodies and minds for specific tasks. But, at the same time as we are pushing our bodies to new limits in athleticism, we are experiencing unprecedented levels of relatively modern diseases such as obesity, diabetes and psychiatric and neurodegenerative disorders.That lack of exercise is contributing to mental health problems is a new one to me, but I shouldn't be surprised. I've known for decades that I think better when I'm walking than when I'm standing still. To a healthy mind in a healthy body!
Over millions of years, humans evolved from tree-dwelling apes to become Homo sapiens, capable of elite athleticism. Simply put, we evolved to run. While early hominins were undergoing intense skeletal and metabolic changes, major changes also occurred in their brains. We propose that these changes have rendered us dependent on mental and physical exercise to maintain brain health. Exercise doesn't just help muscles — it activates our brains, particularly through one pathway that helps to increase the number of neuronal connections.
Most humans today do not live in an environment where they must exercise regularly to chase down meat. For many, exercise is no longer an integral part of daily life, leading to a host of modern ailments.
In short, we think that exercise is not just important for general health — it is essential to the molecular memory of who we are. Without it, we are at risk of being obese and diabetic, and of developing diseases linked to brain function, such as psychiatric disorders, dementia and even violent behaviour.
Given the above information, the following pair of stories should be disturbing.
University of North Carolina, Chapel Hill: Get off the couch!
July 16, 2012
The average American may expend as little energy as a person who sleeps 24 hours a day by the year 2020, following a worldwide trend of decreasing activity.University of Washington: Americans gaining more weight than they say
That's one prediction from UNC-Chapel Hill researchers whose study found a global decline in activity levels. They foresee a continuing decrease in activity worldwide. When viewed in the context of physical activity levels throughout human evolution, the global decline in the past few decades is particularly abrupt.
Faculty members Barry Popkin and Shu Wen Ng conducted the study. They used extensive data from the 1960s onward to determine how people around the world spend their time and how they move in their daily lives. The resulting publication, “Time use and physical activity: a shift away from movement across the globe,” will be published in the August issue of Obesity Reviews.
By William Heisel
August 3, 2012
Despite the increasing awareness of the problem of obesity in the United States, most Americans don’t know whether they are gaining or losing weight, according to new research from the Institute for Health Metrics and Evaluation, also known at IHME, at the University of Washington.So, not only are we not exercising, but we're not even aware of how much weight we're gaining. Lovely. Denial may be a normal psychological defense mechanism, but too much of it can unhealthy, especially if what people are in denial about is something dangerous to their health. That's not sweet.
Obesity increased in the U.S. between 2008 and 2009, but in response to the questions about year-to-year changes in weight that were included in the most widespread public health survey in the country, on average, people said that they lost weight. Men did a worse job estimating their own weight changes than women. And older adults were less attuned to their weight changes than young adults. The findings are being published in the article “In denial: misperceptions of weight change among adults in the United States” in the August edition of Preventive Medicine.
“If people aren’t in touch with their weight and changes in their weight over time, they might not be motivated to lose weight,” said lead author Catherine Wetmore. “Misreporting of weight gains and losses also has policy implications. If we had relied on the reported data about weight change between 2008 and 2009, we would have undercounted approximately 4.4 million obese adults in the US.”
I should go for a walk now, but instead, I'm going to compose an entry speculating on the future of the Olympics. Hey, what do you expect for a blog with a science fiction slant?