Diabetes Forecast

Exercise Boosts Health From the Start

By Erika Gebel Berg, PhD , ,

One step in front of the other—that's all it takes to start getting fit. Even so, for people who don't exercise, that first step can seem like a giant leap. Only 1 out of 5 people in the United States exercises for the recommended 150 minutes per week, according to a recent report by the Centers for Disease Control and Prevention.

Looking for motivation? Try focusing on exercise's immediate benefits instead of taking the long view. Research shows that every time you exercise, your body gets a quick health boost. This goes double for people with diabetes because of extra blood glucose benefits. "We are realizing more and more how exercise is like a medicine," says Barry Braun, PhD, associate professor of kinesiology at the University of Massachusetts–Amherst. "You take it in a dose, it has an effect, and, over time, it wears off. Then you have to take it again."

Prescribing Sweat

Exercise is a particularly effective medication for people with diabetes, and here's the nice thing: Its benefits are the same whether you are a marathon runner or a couch potato. "It doesn't matter if you are trained or untrained," says Sheri Colberg-Ochs, PhD, professor of exercise science at Old Dominion University in Norfolk, Va. "The reason it's helpful for everyone … is that you have two mechanisms to get blood glucose out of your bloodstream." And exercise revs up them both.

The first route to lower blood glucose levels is via insulin, a hormone that ushers glucose from the blood into the body's cells, where it can be processed into energy. But people with type 2 diabetes are insulin resistant, meaning their cells are less responsive to insulin. Exercise temporarily lessens the cells' resistance. "If you exercise for 30 minutes, then you have improved insulin action from two to 72 hours after," says Colberg-Ochs.

Exercise also activates a completely insulin-independent route into the muscles. During exercise, a little door opens up to the muscles so that they directly absorb glucose from the blood.

Another exercise benefit for everyone regardless of fitness level, according to Colberg-Ochs, is that it creates space in the muscles to store glucose coming into the body from what you eat. Your muscles can spin glucose into a large molecule called glycogen, which stores the sugar until it's needed. But there's only room in each muscle cell for a fixed amount of glycogen. "If you think of the glycogen as your storage tank for carbs, when glucose comes in, it can go in the storage tank," says Colberg-Ochs. Yet that's only true if there is enough space in the muscle cells to store incoming glucose. "If you don't [exercise], the tank is always full." Full muscles force the body to send that homeless glucose to the liver, which turns it into fat for long-term storage. Too much fat in the liver is harmful.

Just Beat It

The benefits of exercise don't stop with blood glucose. The heart gets into the action right away, too, thanks to a boost in beats per minute. Blood pressure decreases after exercise because the heart pumps blood harder through the circulatory system. "Increased blood flow makes blood vessels more compliant and elastic, which allows them to handle more pressure," says Braun. "You want them to be as flexible as possible."

Exercise's mood enhancements can be felt immediately as well. "I don't know how to quantify this, but everyone is a nicer person after they exercise," says Braun. This lifting of mood may be an especially attractive incentive for people with diabetes, who are at increased risk of developing depression. "Exercise is an effective treatment," says Colberg-Ochs. "It releases brain hormones, such as dopamine, and the other 'feel good, be happy' kind of hormones that you will start feeling right away." These are the same pleasure hormones that are released when eating sugar, salt, and fat. So for people who are trying to eat healthfully, exercise "is a good way to replace the hormones," she says, because a walk can make you feel just as good as a bowl of ice cream can. The better mood can last for hours.

What about being stronger and slimmer? That takes time, and evidence suggests that exercise is better at helping people maintain weight than drop pounds. Even so, muscle improvements from strength training can happen surprisingly fast, says Braun: "People feel the difference very quickly. The first two, three, or four times you do it, you see a big change."



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