Ms. Colberg is an exercise physiologist and associate professor of exercise science at Old Dominion University in Norfolk, Virginia.A diabetes researcher with almost four decades of practical experience as a type 1 diabetic exerciser, she is a Fellow of the American College of Sports Medicine, a professional member of the American Diabetes Association, and the author of three books on diabetes.

Editor's Note: It's no secret: The fountain of youth is exercise. If you do nothing else for yourself, MOVE. It's never too late to start. Sure, you may be tired right after exercising, but long-term, you will have more energy and be sharper mentally as well as physically. Oh yes, you will most likely feel better emotionally, too.

The following is an excerpt from a new book by The Doctor's Senior Living specialist, gerontologist, Dr. John Morley: The Science of Staying Young, 10 Simple Steps to Feeling Younger than You Are in 6 Months or Less, written with Sheri R. Colberg, Ph.D. (McGraw-Hill, 2008). Used by permission.

If exercise isn't the closest thing to an elixir of eternal youth, then we don't know what is. There remains no doubt that to feel, look, and act as young as possible — regardless of your current age — you must choose to become (or remain) physically active. In fact, being active throughout your lifetime is critical to being successful at aging well, although it's never too late to start if you're currently sedentary. Even a small effort in the direction of being more active will bring you great health and other benefits, including more energy, a renewed vigor, greater strength, a better outlook on life, and even a stronger sex drive.

Inactivity, not aging, is the real reason so many of us experience 'inevitable' declines in energy and health as time passes.

To gain all of the myriad health benefits of exercise, you will need to participate regularly in five types of physical activities: endurance, resistance, balance, posture, and flexibility exercises. This [article] gives you a plan incorporating each of these activities and discusses other things you need to know about being active.

How Physical Activity Improves Your Life
Simply expending energy through any physical activity, including leisure time activities, will make you feel younger, look better, and live longer. It will even make you lose some fat while gaining more muscle, leading you to look more physically toned and younger than other people your age. An even more pressing reason to become active, though, is to reduce your risk of not feeling good during your lifetime. Inactivity, not aging, is the real reason so many of us experience "inevitable" declines in energy and health as time passes. Studies on men and women between the ages of 35 and 60 years of age have shown that simply being more physically active during leisure time keeps heart disease and other life-shortening health problems at bay. Moreover, people who are active in their 40s through their 60s (the new "middle age") end up being more active and independent after they reach retirement age. Being regularly active even reduces your chances of getting colds and other viral illnesses by boosting the ability of your immune system to fight off disease. Thus, both of us believe that exercise is an eternal youth elixir when it comes to optimizing quality of life by keeping your body healthier and disease-free.

Becoming physically fit is more than worth it for numerous other reasons, many of which are listed [below]. For starters, it can greatly enhance your energy levels, reduce your risk of certain cancers (e.g., colon, prostate, and breast), help lower your blood pressure, prevent or reverse heart disease, reduce depression and anxiety, prevent thinning bones (osteoporosis), reverse prediabetes and new-onset type 2 diabetes, and dramatically lower your risk of developing diabetes, even if you have a strong family history of it. If you already have diabetes, being active can help you control your blood sugar and prevent diabetes-related health problems.

Health Benefits of Physical Activity
  • Brain/Emotions: enhanced feeling of well being, improved memory, prevention of dementia, decreased brain atrophy, reduced depression, and better sleep
  • Metabolism/Hormones: enhanced metabolic rate and energy levels, greater libido (sex drive), improved immune system function, more effective blood glucose use, and diabetes prevention
  • Heart: prevention and possible reversal of heart disease, lower blood pressure, and stronger heart muscle
  • Muscles: higher energy levels, better tone, more muscle mass (and prevention of loss over time), increased strength, endurance, flexibility, and balance, and heightened glucose storage
  • Bones: greater bone mineral density and prevention of thinning, reduced symptoms of arthritis, and less likelihood of bone fractures and falls
  • Cancer: reduced risk of colon, prostate, and breast cancer (and possibly others)
  • Longevity: increased length of life and better health

From a metabolic standpoint, it's always better to be fit, no matter what your body weight is. Exercise enhances your body's sensitivity to insulin, which usually results in better blood sugar control, but also a lower risk of heart disease and high blood pressure. Regular exercise can also alleviate severe arthritic symptoms that can make daily living painful. It even helps you sleep better, which is especially important since sleeping too little (e.g., only five hours a night) can increase your risk of gaining weight and getting diabetes.

Exercise More - Think Better
Exercise has payoffs for the mind, too, as it can improve feelings of overall well-being, along with reducing stress and depression. Many people who feel tired all the time are simply just out of shape. Exercising makes you feel tired while you're doing it, but its longer-lasting effect is the reverse: it enhances your overall energy levels. Likewise, movement lowers your mental stress. Just getting up from your desk and work when you're stressed out and going for a short walk can clear your mind, improve your mood, and enhance your productivity when you return to the task at hand. Studies have also shown that exercise is an effective remedy for mild to moderate depression, as well as possibly major depressive disorder as long as the activity is continued over time.

Exercising makes you feel tired while you're doing it, but its longer-lasting effect is the reverse: it enhances your overall energy levels.

What's more, it cut the risk of Alzheimer's and other forms of dementia that have recently begun appearing at earlier ages in many adults, even well before retirement age. For older individuals, exercise clearly improves brain function. By way of example, in a study of 1,740 adults over 65 years of age who were followed for over six years, individuals who exercised three times a week were a third less likely to develop dementia. However, even in younger individuals, regular exercise is associated with less brain atrophy (shrinkage), and even as little as six months of regular aerobic training can reduce your rate of brain loss.

Any activity increases blood flow and oxygen delivery to your brain and results in a reduced cell loss in the part of your brain called the hippocampus, which is the region associated with memory and spatial navigation. So, not only can exercise delay or prevent dementia, it may be able to restore some of what you've lost mentally. Thus, you need to exercise to keep from losing your brain, but also if you've already lost some of it.

It's Never Too Late to Start
It's never too late to regain a great deal of the physical fitness you have lost through inactivity. What's more, regular exercise can improve your coordination, balance, and posture and keep them optimal over time. If you have reached 40 years or more and haven't started exercising yet, now is definitely the time to begin. A recent study on exercise demonstrated that even for people who are already middle-aged, exercising more can add years to their lives, and you can be assured that those extra years are much more likely to be lived well. Frankly, remaining inactive is the most devastating thing you can do to your long-term health and longevity. Alternately, becoming more active at any age is a sure-fire way to stay younger (or at least to look and feel that way).

Find out more in The Science of Staying Young, 10 Simple Steps to Feeling Younger than You Are in 6 Months or Less Copyright ©2008 by John E. Morley and Sheri R. Colberg. Reprinted by permission of the authors.