We all know that slouching in chairs and sitting in cars all day is no good for our bodies. But can even a little laziness—a few days off from the gym, a weekend of lounging—cause problems? It appears so: A new study suggests healthy people will develop higher blood sugar after only three days of a sedentary lifestyle.
Most studies that just compare sedentary people with active ones don’t tell us much about whether sedentary living actually causes the problems—diabetes, high blood pressure, and so on—associated with it. The inactive people with health problems might have genetic or other reasons for them, and it could be that their illnesses are causing their lack of exercise, rather than the other way around. But this study is pretty clever: it compares people against themselves before and after forced laziness, so differences can be pinned to reduced activity.
What’s the News: If you’ve ever been told been that a massage is good for “releasing toxins”—or to sound more scientific, “lactic acid”—from your muscles, then you’ve been told wrong. Turns out muscle cells do like a good massage, but it has nothing to do with lactic acid.
In the first study on the cellular effects of massage post-exercise, researchers found that massage bolsters chemical signals reducing inflammation and promoting repair of muscle cells.
When we rip open a 100-calorie snack pack, few of us have an idea of how much energy that really is–or how much walking, biking, or schlepping groceries it will take to burn it off. But what if nutrition labels included descriptions of how much exercise you’d need to burn off that candy bar?
One recent study explored that possibility by testing the effects of signs describing in one of three different ways the energy contained in a sugary drink. Researchers found that a sign that said “Did you know that working off a bottle of soda or fruit juice takes about 50 minutes of running?” halved the number of drinks purchased from a drink cooler by African American teenagers, while signs that mentioned calorie count or percentage of total recommended calorie intake did not have a significant effect. Though the study was pretty small, and thus should be verified with larger studies, the effect seems plausible, given that exercise is a much more concrete measure of energy value than calories. Some health campaigns have in fact already taken up this tactic: if you’re a New Yorker, you may have noticed subway ads using exactly this strategy, linking the calories in a 20-oz soda with the three-mile walk between Yankee Stadium and Central Park. Read More
That’s the conclusion of a study by University of Pittsburgh scientists published this week in the Journal of the American Medical Association. The work reviewed the results of nine other studies over the years that included more than 34,000 people aged 65 or older. When they tallied the total results, the numbers jumped off the page:
Only 19 percent of the slowest walking 75-year-old men lived for 10 more years compared to 87 percent of the fastest walking ones. Only 35 percent of the slowest walking 75-year-old women made it to their 85th birthday compared to 91 percent of the fastest walkers. [Boston Globe]
The results aren’t a huge surprise (“duh” comes to mind). The researchers note that walking is controlled falling, involving fine muscle control and the synchronicity of several systems:
“Walking requires energy, movement control, and support and places demands on multiple organ systems, including the heart, lungs, circulatory, nervous, and musculoskeletal systems,” the authors wrote. “Slowing gait may reflect both damaged systems and a high energy cost of walking.” [Los Angeles Times]
Breaking free of the the Earth’s gravity and floating in zero-G: It’s certainly a thrill for those who get to experience it, either through traveling to space or simulating the journey. All good things, though, must come in moderation. Too much time free from the grip of gravity and we turn into weak-muscled wimps, which is a huge hurdle for hopes to travel to Mars or deep into space.
Robert Fitts wanted to know just how quickly the lack of resistance on one’s muscles makes them out-of-shape and atrophied. So his team tested nine astronauts before and then just after their six-months stays aboard the International Space Station. The study appears this week in the Journal of Physiology.
In recent years, antioxidants have been touted as a secret to healthy living: The molecules bind to reactive oxygen compounds called “free radicals” that are known to damage the body’s tissues. The amount of oxidative damage increases with age, and according to one theory of aging it is a major cause of the body’s decline [The New York Times]. But a new study examined the effects of the antioxidant vitamins C and E when combined with an exercise regimen, and found a considerably more complicated story. The researchers found that free radicals may be beneficial in small doses, and may even help protect against diabetes. And mopping them up with antioxidants may do more harm than good [BBC News].
During a workout, the muscles metabolize glucose to create energy, but in the process some free radicals are released. The body has a natural defense mechanism to combat these free radicals, but many researchers had theorized that the body can’t catch all of the harmful compounds, which makes antioxidant supplements sound like a logical solution.
Astronauts who live aboard the International Space Station for months are losing more muscle mass and strength than researchers thought, and NASA thinks there’s only one cure: a better workout. A new study that used MRI scans and biopsies to test astronauts’ muscles before and after a stay at the space station found that the volume of their calf muscles decreased by an average of 13 percent during six months in space…. [Lead researcher Scott] Trappe says that the magnitude of loss in muscle mass is akin to the difference between a 25-year-old and an 80-year-old [Scientific American]. Leg muscles are the most vulnerable to atrophy, researchers say, because on Earth they receive constant exercise just by supporting a person’s weight.
Space station residents currently exercise at least two hours each day to prevent their muscles and bones from wasting away in the weightless microgravity environment. The recent study showed a range of astronaut exercise regimens, including five hours per week spent on aerobics, and anywhere from three to six days per week spent on resistance training [SPACE.com]. However, the treadmill and exercise bike that astronauts use are mostly intended to maintain cardiovascular health, and are little help for muscle strength.
A drug that mimics the effects of a compound found in red wine has been shown to prevent obesity and diabetes in mice that were fed a high-calorie diet and prevented from exercising, taking another step towards the target of a anti-obesity pill. The natural compound found in grapes and red wine, called resveratrol, is believed to have numerous health benefits related to longevity, heart health, and metabolism. But tests in mice suggested gallons of wine would be necessary for humans to stand a chance of getting the same benefits. The scientists turned their attention to creating a more potent drug [BBC News].
The new experimental drug, called SRT1720, was developed by the pharmaceutical company GlaxoSmithKline. Researchers explain that mice fed a high-fat diet were tricked into switching their metabolisms to a fat-burning mode that normally takes over when energy levels are low…. “We are activating the same enzymes that are activated when people go to the gym,” said Peter Elliott, a vice president at Sirtris Pharmaceuticals, the Glaxo unit that developed the drug. “That is why we believe the profile for this drug is very safe” [Reuters].
Researchers have developed two drugs that mimic some of the effects of exercise in mice, leading to rampant speculation that people may soon be able to take a dose of “exercise in a pill.” The dramatic study showed that the drugs built fat-burning muscles in mice and increased their endurance on an exercise wheel. Four years ago researchers bred genetically engineered mice that could run much further than normal, but this is the first test to prove that drugs can have the same effect [Telegraph].
“It’s tricking the muscle into ‘believing’ it’s been exercised daily,” said the study’s lead researcher, Ronald Evans…. “It’s basically the couch potato experiment, and it proves you can have a pharmacologic equivalent to exercise” [Wired News]. One drug proved effective for mice that were already exercising regularly, increasing their running time by 68 percent and distance by 70 percent. The other drug worked on mice that hadn’t been trained to exercise; that compound increased their running time by 23 percent and distance by 44 percent.