Martha's Minute: Navigating Your Grocery Store

How do you make healthy choices at the supermarket? Food journalist Michael Pollan helps us navigate the grocery store to find fresh, whole foods.

The Fitness Philosophy

Exercise is fun, it feels good and it helps fight disease: What more could you ask for?

Flabby flesh and unflattering bulges lead many people to start exercising, but the biggest benefits of exercise occur beneath the surface. Exercise boosts immunity, improves mood and helps stave off conditions such as heart disease, cancer, depression, osteoporosis and type 2 diabetes. It can also reverse some of the signs and symptoms of aging.

The heart is one of the biggest beneficiaries of regular exercise. It's a muscle and, like skeletal muscles, it needs exercise to stay healthy. Exercise makes the heart stronger and more efficient, so it has to beat less to pump blood throughout the body. It also lowers the amount of fat and "bad" cholesterol (low-density lipoprotein, or LDL) in the blood, clears out plaque that can accumulate in the arteries, helps reverse arteriosclerosis (artery hardening) and lessens your risk of having a heart attack or stroke.

More and more studies are also showing that people who exercise regularly have a decreased risk of developing cancer, particularly colon, prostate and breast cancer. Exercise helps prevent colon cancer by speeding the digestive process, which prevents food and toxins from sitting in the gut. It may also help prevent breast cancer by reducing fat deposits the body uses to create estrogen, which some tumors thrive on.

Because hard-working muscles use glucose for energy, exercise can also help prevent and control type 2 diabetes. Type 2 diabetes develops when the body stops responding to insulin, which normally facilitates the entry of glucose into cells. When glucose can't get into cells, it remains in the bloodstream, where it can cause damage. When people exercise, their muscles use glucose for energy, which helps reduce blood sugar levels. Exercise also helps people control their weight, which is important because overweight people are at a greater risk of developing type 2 diabetes.

There's also one condition everyone experiences that exercise helps to manage: aging. As you age, your body begins losing lean muscle mass, oxygen uptake ability and bone density. But this degeneration isn't inevitable. Muscles, bones and the cardiovascular system respond to the stress of exercise by getting stronger.

And don't worry if you're impatient, and think it will take too long to see these health benefits. Exercise has a mood-altering effect, relieving anxiety, raising energy levels and increasing sexual interest. It increases the body's levels of serotonin, a chemical that causes good feelings and decreases incidents of depression, and beta-endorphine, a chemical that's more potent than morphine. In fact, this release can occur just 12 minutes into a workout, which should keep you hooked long enough to reap the other rewards.