Everyone knows that physical activity is good for your health. That's why it was embarrassing to have Men's Health magazine name Lexington as the nation's most sedentary city.
But doctors and scientists have a lot of questions about why exercise is so beneficial, how muscles work and the role muscle strength plays in overall health.
Answering those questions is the mission of the University of Kentucky Center for Muscle Biology, a unique collaboration of more than 100 faculty members, graduate students and postdoctoral fellows from nine UK colleges.
The center was created three years ago after UK researchers realized they were looking at many of the same questions from different perspectives. They thought they could get further faster by working together.
"Our overall umbrella is the concept of weakness," said Karyn Esser, the center's director. "We're trying to figure out what makes muscle tissue weak and how to make it stronger."
With outside grants of more than $12 million, center researchers are looking at everything from injury prevention in young athletes to rehabilitation for elderly stroke patients. Physical activity and muscle strength seem to contribute to everything from better memory to disease prevention.
For example, even moderate exercise can help Type 2 diabetes, which has become epidemic among overweight Kentuckians. Muscles store most of the body's insulin. "When you exercise and make muscles work, it creates a separate path for absorbing glucose," Esser said.
The center's researchers are working with UK's Barnstable Brown Kentucky Diabetes and Obesity Center and Markey Cancer Center to look at muscle strength's effects on disease and prevention.
"A lot of us believe that exercise is an anti-cancer approach," Esser said. That is because muscles send chemical and electrical signals to the brain and other organs that aren't fully understood.
Drs. Gerald Supinski and Leigh Ann Callahan are studying ways to improve the strength of diaphragm muscles to help patients get off ventilators. It is a huge problem: about 60,000 Americans are on ventilators at any given time, and it costs billions of dollars to care for them, Supinski said. Besides, the longer most people are on a ventilator, the more likely they are to die.
"Is the problem with their lungs or their breathing muscles?" Supinski asked, adding that muscle weakness is the main culprit in about 70 percent of ventilator patients. They are investigating drug t herapies that could be used to strengthen those muscles.
Muscle weakness is most often caused by inactivity or infection, Supinksi said. But other causes are not well understood. Why, for example, do some patients lose strength so rapidly after being hospitalized and others don't?
"My father died of cancer a few years ago, but he actually died of weakness," Supinski said. "I wish I had known then what I know now."
Tim Uhl and Patrick McKeon, who are certified athletic trainers, run a lab that uses high-tech gadgets to study muscle function and improve rehabilitation. They do a lot of work with stroke and breast cancer surgery patients.
They also use mobile labs to go out and screen high school athletes for risk factors that can lead to injuries. Preventing injuries is not only beneficial now; it can help those young athletes stay active as they age. Old injuries are a frequent reason people become less active later in life.
Massage and ice have long been known to play important roles in muscle repair and strength. The reasons aren't fully understood. Tim Butterfield has built a machine to standardize massage stimulation, and he uses it to study the effects of massage on mice, rats and rabbits to figure out how to optimize it for humans.
Similarly, researchers know that muscle-resistance training — lifting weights — can improve memory in elderly people. Why? Nobody is sure.
How can skeletal-muscular injuries caused by repetitive motion be avoided? It's not just "tennis elbow" anymore. Researchers now see cases of what they call "Xbox syndrome" and "Nintendonitis."
Esther Dupont- Versteegden studies inactivity — what Men's Health magazine says Lexingtonians are so good at — and the detrimental effects it has on overall health.
"We know that people feel better when they exercise regularly, but why is that?" she asked. "What is inactivity doing to people?"
Much of her work focuses on what she calls "frailty prevention" in old age.
"The elderly in particular are really sensitive to inactivity," she said. "It's probably an additional stress on their already physically stressed makeup, but we don't really know."
One area of investigation is what she called "pre habilitation." For example, can exercise before some kinds of surgery hasten recovery? When and how should it be done?
Dupont-Versteegden said there is promising research that indicates an individual's level of activity might even have benefits for others. Pregnant mice that exercise a lot tend to have healthier babies than those that do not. Is it also the case with humans?
"This is exciting stuff," she said. "You can imagine short-term intervention that could produce significant public health benefits."