Aug. 9, 2012. An Appalachian State University professor has been selected to participate on an expert panel being convened by NASA to help address problems of muscle and bone density loss on long space missions.
Dr. N. Travis Triplett, director of the exercise science program in the College of Health Sciences’ Department of Health, Leisure and Exercise Science at Appalachian, will help review research related to currently available exercise equipment that is being used for earth-based studies of micro-gravity.
This is the second NASA panel Triplett has served on. The first panel helped engineers develop a weight-training machine that is now aboard the International Space Station.
The panel will convene in mid-September at Johnson Space Center in Houston. “This panel will review the findings from researchers who have been involved in using exercise equipment related to NASA’s goal of preserving musculoskeletal strength, conditioning and rehabilitation in astronauts subjected to long-duration spaceflight,” she said.
Earth-based studies mimic the effects of microgravity by confining volunteers to bed for as long as 90 days or more. The test subjects then engage in a variety of upper and lower body exercises to minimize loss of muscle mass and bone density.
“NASA wants to pull together all the research that is available and create a summary of the equipment available and how effective it is in minimizing or reversing muscle and bone loss,” Triplett said.
“Space travel is like accelerated aging with a lot of muscle and bone loss. Even a 30-year-old person ends up with the muscles and bones of a much older person following prolonged space exposure,” she said.
Peak bone density occurs around 30-35 years of age, and while the average age of astronauts is 34, NASA has no age restriction for the program. When he was 62, Story Musgrove flew the last of his six shuttle missions on the 1996 flight of the Space Shuttle Columbia. At age 77, John Glenn was the oldest astronaut to fly in space during a 1998 flight.
Muscle atrophy following space flight is short term and can be replaced within a few months with weight training, Triplett said. The body constantly replaces old bone with new bone cells, but it’s a much longer process. “You are looking at probably a year or two before getting most of the lost bone back,” Triplett said.
“And the older a person gets, more bone loss than bone rebuilding is also occurring,” Triplett said. “If I’m age 55 and I go up in space and lose a lot of bone, I’m probably not going to get that back and will be more prone to osteoporosis at an earlier age.” That bone loss can result in complications, including bone fractures.
The exercise regimens on the early shuttle missions focused on cardiovascular exercise through treadmills, rowing machines and stationery bikes, Triplett said. “While your heart is a muscle too, they found the cardiovascular changes with space exposure weren’t as bad as the changes occurring to the major muscle groups and in bone density. NASA realized they need to address that more.”
Since it takes weight-bearing exercise, such as resistance training, to build bone, NASA developed the aRED (advanced Resistive Exercise Device) for use on the International Space Station in 2008, based on reports from the first NASA panel Triplett served on. The aRED is similar to a strength-training machine found in gyms used to exercise the major muscles in the upper and lower body.
“NASA certainly wants astronauts to be able to return to earth and not be at higher risk of fractures,” Triplett said.