Another good reason to keep training hard: A new study from researchers at the University of Michigan says that white muscle, or fast twitch muscle, may not be bad for diabetics, as was long thought. Instead, they found that it could have the opposite impact by assisting in regulating blood sugar levels.
Slow twitch muscles, which are more prevalent in long distance runners, are red while fast twitch muscles, which are more prevalent in sprinters and weightlifters, are white. Slow twitch muscles use a steady stream of energy from fat. This means they end up burning fat while fast twitch muscles deplete glycogen stores in muscles in order to perform fast, explosive movements and burn sugar.
“Most people are in the middle and have a mix of red and white,” said Jiandie Lin, who was on the research team. “We wanted to figure out the relationship between muscle types and body metabolism, how the muscles were made, and also what kind of influence they have on diseases like type 2 diabetes.
“For a long time, the red-to-white shift was thought to make muscle less responsive to insulin, a hormone that lowers blood sugar,” continued Lin. “But this idea is far from proven. You lose red muscle when you age or develop diabetes, but is that really the culprit?”
Lin and her colleagues identified a protein called BAF60c and, after testing with mice, found that the cells that had more of this protein were less red than others. The team carried out an experiment by engineering mice with more BAF60c protein. They put these mice on a diet that made them obese and then carried out some running tests. Though the mice were obese and tired quickly, their blood sugar levels were more regulated than normal mice.
“The results are a bit of a surprise to many people,” commented Lin. “It really points to the complexity in thinking about muscle metabolism and diabetes.”
So keep lifting heavy and rest assured you’re getting even more benefits than a killer body.
