Exercise is a key component to looking and feeling your best, but, especially for women over 40, shaping up and losing weight requires some real "sweat equity".

However, that sweat is well spent because exercise not only burns the "gristle" but it also improves your mood and fights disease.

Exercise: Your Secret Weapon

A brisk walk, hike or stretching and toning session will release endorphins into your system and give your mood an immediate boost. (If you can't get any exercise in and your mood is spiraling down you may be suffering from low blood sugar, so grab a healthy snack to get your body back to normal. You can also practice breathing exercises to relieve stress).

Studies show that in addition to being an important part of your weight loss program, exercise can help you to fend off serious diseases, including some forms of cancer.

Any amount of moderate physical activity will improve your health, but when you extend your workouts to 60 minutes you will experience the following benefits...

First of all, exercising at your maximum heart rate will enable you to lose fat. Besides being ugly, fat also produces hormones that speed up the growth of abnormal or unhealthy cells. With weight loss, you actually reduce the opportunity for unhealthy cells to survive.

With less body fat, we experience a loss in estrogen. Don't panic, because that can actually mean your body won't produce estrogen receptor positive breast cancer cells. You could actually reduce your risk of breast cancer by up to 20 percent by exercising and losing weight. And, you can also reduce the risk for endometrial cancer, or uterine cancer, by 30 to 40 percent with regular exercise.

During exercise your body's insulin level drops which reduces the risk of tumor growth. You can reduce your risk of pancreatic cancer by half if you walk or hike for a total of four hours or more each week. (Yet another benefit of walking!) If you walk for a total of six hours or more each week you can lower your risk of colon cancer drastically.

Regular exercise helps to reduce inflammation in your body. Chronic inflammation can trick your body into stimulating tumor growth. If you can believe it, one study determined that in 20 percent of cancers, inflammation played a major role and made cells more susceptible for malignancy. Along those lines, in more than 20 percent of ovarian cancer cases, chronic inflammation is attributed as a cause.

It's no secret that smoking wrecks havoc on your body including your skin, hair, and internal organs. The good news is that female smokers (reformed and practicing) who get at least moderate exercise each week, reduce their likelihood of contracting lung cancer by 21 percent.

Not only does exercise play an important part of a successful weight loss plan, it's an investment in your long term health. So get out there and start moving!