Exercise for Optimum Fitness

“If people knew how hard I worked to get my mastery,  it wouldn’t seem so wonderful after all”   - Michelangelo

Boosting your physical activity can actually decrease your biological age by at least 8-10 years!  In fact, fitness cuts your risk of dying.  It doesn’t get much better than that.  Exercise can negate many of the adverse effects from other risk factors, such as smoking, high blood pressure, and high blood sugar.  The more frequent the exercise, the greater the benefit.  This overriding effect of fitness, and its apparent effect as a remedy for various chronic diseases, makes physical fitness among the most important things an aging person can do to remain healthy.  If you are at risk because of certain genetics or habits you cannot change, getting in good physical shape is a valuable step you can take to keep yourself alive longer.  A physically active life may allow you to approach your true biogenetic potential for longevity.  

Physical activity can make a major difference in the risk of many aging-related diseases, including:

1. Coronary heart disease

2. High blood pressure

3. Colon and rectal cancer

4. Breast cancer survival 

5. Diabetes and related problems

6. Arthritis

7. Osteoporosis

8. Falls and balance

Want to cut back on trips to the doctor and stay out of the hospital? You may want to start spending more time at the gym. A study reported in the December, 2004, issue of the journal Medicine & Science in Sports & Exercise shows that physically fit men visit their doctors less often and are less likely to require an overnight hospital stay.  "Fit men, as well as those who become fit, may reduce health care costs by more than 50%," says researcher Tedd L. Mitchell, MD, of the Cooper Clinic in Dallas. 

Another study published in the journal Circulation, March 2004, suggests that regular exercise might slow the progression of mild to moderate coronary heart disease and reduce coronary risk even better than angioplasty.  Moreover, the exercisers in the study experienced fewer cardiovascular events, including heart attack, stroke, and hospitalization for worsening angina.

For men, better physical fitness may mean better sex.  Harvard researchers concluded that frequent exercise can reduce the risk of erectile dysfunction in older men.  They found a 30 percent reduction in the risk of erectile dysfunction in those who exercised vigorously - the equivalent of running at least three hours a week - compared with those who exercise very little or not at all.

In addition to reducing the risk of death and improving strength, exercise improves mood and reduces the impact of other health risks.  Exercise can make your heart stronger, improve circulation, lower LDL and raise HDL cholesterol levels, reduce body fat, lower blood pressure, decrease the risk for cancer of the breast, colon, prostate and endometrium, help prevent adult onset diabetes and osteoporosis, plus exercise increases back strength and mobility.  Breast cancer survivors have a 20-54% lower risk of dying, depending on the amount of exercise they do.  However, keep this in mind: you have to use it, or risk losing it.  In order to reap the benefits of physical fitness, you not only need to get into shape - you must stay in shape.  Physical activity must be maintained for a lifetime.  The substantial protective effect of continued physical activity persists even to advanced old age.  Exercise keeps you young only as long as you keep doing it.

Exercising regularly ensures that the body is in a constant state of cellular regeneration.  This continual regeneration promotes the production and release of important hormones such as growth hormone and testosterone.  Exercise promotes balance in all hormones, improves cellular hormone communication and cellular sensitivity to hormones.   For example, diabetics see improvements in sensitivity to insulin with exercise.  Similarly, the effectiveness of all hormones improves with exercise.

The benefits of exercise appear to be cumulative.  It is possible, nevertheless, to overdo it.  Exercise increases respiration and energy production (of ATP) in the cells, resulting in free radical production.  The body can safely handle limited free radical production.  Excessive levels overwhelm the bodies’ ability to scavenge them, resulting in oxidative stress.  Oxidative stress, recall, is one of the primary causes of pathological aging.  Prolonged, intensive exercise can easily place the body in a state of oxidative stress.  Marathon runners, for instance, expose their body to an extended state of oxidative stress.  Additionally, extreme and prolonged exercise has been shown to suppress the immune system.  This is commonly called overtraining syndrome (OTS).  The body needs regular exercise for optimum efficiency, but not too much.

The trouble is that it isn’t easy to know whether you have reached a state of free radical overload.  On the other hand, monitoring the source of free radicals produced during exercise - energy expenditure - can provide an indirect measure of free radical levels.  Measuring caloric expenditure during exercise provides a gauge of respiration and energy utilization.  Any amount of exercise is better than no exercise.  However, studies suggest that the greatest preventive-aging benefits of exercise mentioned are realized after a minimum daily energy expenditure of at least 300 extra calories from exercise - or more than 2,000 calories a week.  A brisk walk burns about 300 calories an hour, and jogging burns about 400-500 calories an hour.  The following table provides estimates of caloric expenditure associated with many common forms of exercise.  If you have not been exercising regularly, it is best to begin slowly.  The long-term goal is to increase your exercise-induced calorie expenditure, slowly, to a maximum of 3,500 calories a week.  It is not essential that you do so with one continuous during your daily workout.  You can divide this up throughout the day.  The important thing is to exercise on a regular basis, 5-7 days a week.  Exercising to the point of expending much beyond 3,500 calories a week increases your risk that oxidative stress may outweigh the antiaging benefits of exercise and cause accelerated aging.  Limiting heavy intensity workouts to less than 90 minutes will minimize your risk of oxidative stress.

      How Many Kilocalories Each Activity Uses   

Activity                                                    Kcal Used Per Minute

Modified from Ainsworth, B.E., et al., “Compendium of Physical Activities: Classification of Energy Costs of Human Physical Activities.”  Medicine & Science in Sports and Medicine, 1993; 25: 71-80

It is never too late to exercise.  Unless we take some action to the contrary, the older we become, the less physically fit we become.  Significant loss of muscle strength and function is called sarcopenia.  Muscles weaken and shrink; we begin to lose our sense of balance; we often walk in a slow, shuffling, unbalanced fashion; it becomes harder to breathe.  Without regular exercise, the decline of physical fitness with aging begins in the thirties and progresses steadily thereafter.  Sarcopenia doesn’t occur suddenly and is not limited to the very old.  It is a gradual wasting away of the body over the course of decades.  Muscle atrophies at a rate of about 6.6 pounds per decade of age past 20 years old if not exercised.  The rate of loss accelerates after age 45.  From age 20 to 70, we lose nearly 30% of our total number of muscle cells.  By the age of 80 years old, there is an estimated 50% reduction in muscle mass.  Moreover, with age the muscle cells that remain start to atrophy.  However, sarcopenia is not a necessary component of aging.  The important thing to keep in mind is that severe physical decline does not have to happen to you.  Much of the loss of muscle as you age is preventable - and even reversible.  A fitness trainer put it this way: “It’s never too late to start.  But it is always too early to quit.”

Physical activity must be frequent, intense, and/or of long duration – preferably frequent and intense – in order to exert cardiorespiratory benefits on sedentary individuals.  In 2006, the American Heart Association and the American College of Cardiology recommended all adults engage in moderate-intensity aerobic exercise between 30 and

60 minutes a day, for a minimum of five days a week.  Moderate-intensity exercise is defined as any activity that raises heart rate to 45-55% of your maximum heart rate (see below for determination of your maximum heart rate).  Unfortunately, exercising at a moderate intensity only three or four times a week provides suboptimal, limited cardiorespiratory benefit.  High-intensity exercise requires achieving a heart rate of at least 65-85% of your maximum rate.  

Low-frequency exercise is physical activity occurring 3-4 times a week.  High frequency means exercising 5-7 times a week.  The duration is the length of time spent on an exercise.  The minimum is whatever you are able to tolerate - even if it is only 5-10 minutes.  Fortunately, multiple short intervals during a day provide a cumulative benefit; three 10-minute sessions can offer a substantial share of the benefit obtained from one 30-minute session.  In general, for resistance training and cardiovascular training, 30-90 minutes is a reasonable and necessary duration, depending on your level of fitness and your fitness goals.