• Highlights
• Introduction
• Recommended Exercise Methods
• Exercise's Effects on the Heart
• Exercise's Effects on Diabetes
• Exercise's Effects on Bones and Muscles
• Exercise's Effects on the Lungs
• Exercise's Effects on Weight
• Exercise's Effects on Other Conditions
• Complications
• Motivation
• Resources
• References

Exercise

Description

An in-depth report on the benefits and types of exercise.

Recommended Exercise Methods

A few simple rules are helpful as you develop your own routine.

• Don't eat for 2 hours before vigorous exercise.
• Drink plenty of fluids before, during, and after a workout.
• Adjust activity according to the weather and reduce it when fatigued or ill.
• When exercising, listen to the body's warning symptoms, and consult a doctor if exercise causes chest pain, irregular heartbeat, undue fatigue, nausea, unexpected breathlessness, or light-headedness.

Heart Rate Goal

Heart rate is the standard guide for determining aerobic exercise intensity. It can be determined by counting one's own pulse or with the use of a heart rate monitor. To feel your own pulse, press the first two fingers of one hand gently down on the inside of the wrist or under the jaw on the right or left side of the front of the neck. You should feel a faint pounding as blood passes through the artery. Each pounding is a beat.

There are different types of heart rates.

Resting heart rate . The average resting heart rate for a person at rest is 60–80 beats per minute. It is usually lower for people who are physically fit, and often rises as you get older. You can determine your resting heart rate by counting how many times your heart beats in one minute. The best time to do this is in the morning after a good night’s sleep before you get out of bed.

Maximum heart rate . To determine your own maximum heart rate per minute subtract your age from 220. For example, if you are 45, you would calculate your maximum heart rate as follows: 220-45= 175.

Target heart rate . Your target rate is 50 to 75% of your maximum heart rate. You should measure your pulse off and on while your exercise to make sure you stay within this range. After about 6 months of regular exercise, you may be able to increase your target heart rate to 85% (but only if you can comfortably do so).

Certain heart medications may lower your maximum and target heart rates. Always check with your doctor before starting an exercise program.

Note: Swimmers should use a heart rate target of 75% of the maximum and then subtract 12 beats per minute. The reason for this is that swimming will not raise the heart rate quite as much as other sports because of the so-called "diving reflex," which causes the heart to slow down automatically when the body is immersed in water.

TARGET HEART RATES FOR A ONE-MINUTE PULSE COUNT
Age	Low	High
	(50% max.)	(75% max.)
20	100	150
30	95	142
40	90	1135
50	85	127
60	80	120
Source:American Heart Association

VO2 Max. Serious exercisers may use a VO2 max calculation, which measures the amount of oxygen consumed during intensive, all-out exercise. The most accurate testing method uses computers, but anyone can estimate V02 without instrumentation (with an accuracy of about 95%):

• After running at top pace for 15 minutes, round off the distance run to the nearest 25 meters.
• Divide that number by 15.
• Subtract 133.
• Multiply the total by 0.172, then add 33.3.

Olympic and professional athletes train for VO2 max levels above 80. But for the average person interested in fitness, a VO2 max equaling between 50 and 80 is considered an excellent score for overall fitness.

Warm-Up and Cool-Down

Warming up and cooling down are important parts of every exercise routine. They help the body make the transition from rest to activity and back again, and can help prevent soreness or injury, especially in older people.

• Warm-up exercises should be practiced for 5 to 10 minutes at the beginning of an exercise session. Older people need a longer period to warm up their muscles. Low-level aerobic exercise such as brisk walking, swinging the arms, or jogging in place, is the best approach.
• To cool down, you should walk slowly until the heart rate is 10 to 15 beats above your resting heart rate. Stopping too suddenly can sharply reduce blood pressure, and is a danger for older people. It may also cause muscle cramping.

• Stretching may be appropriate for the cooling down period, but it must be done carefully for warming up because it can injure cold muscles. (There is no clear evidence, however, that stretching reduces muscle injuries.)

For most people, exercise may be divided into three general categories:

• Aerobic or endurance
• Strength or resistance
• Flexibility

A balanced program should include all three. (Speed training is also a major category, but is generally practiced only by competitive athletes.)

Aerobic (Endurance) Training

Benefits of Aerobic Exercise. Regular aerobic exercise provides the following benefits:

• Builds endurance
• Keeps the heart pumping at a steady and elevated rate for an extended period
• Boosts HDL ( "good") cholesterol levels
• Helps control blood pressure
• Strengthens the bones in the spine
• Helps maintain normal weight
• Improves one's sense of well being

Types of Aerobic Exercise. Aerobic exercise is usually categorized as high or low impact. Examples of each include the following:

• Low- to moderate-impact exercises: Walking, swimming, stair climbing, step classes, rowing, and cross-country skiing. Nearly anyone in reasonable health can engage in some low- to moderate-impact exercise. Brisk walking burns as many calories as jogging for the same distance and poses less risk for injury to muscle and bone.
• High-impact exercises: Running, dance exercise, tennis, racquetball, squash. High-impact exercises should be performed no more than every other day and less for those who are overweight, elderly, out of condition, or have an injury or other medical problem that would preclude high-impact.

Aerobic Regimens. As little as one hour a week of aerobic exercises is helpful, but 3 to 4 hours per week are best. Some research indicates that simply walking briskly for 3 or more hours a week reduces the risk for coronary heart disease by 65%. In general, the following guidelines are useful for most individuals:

• For most healthy young adults, the best approach is a mix of low- and higher - impact exercise. Two weekly workouts will maintain fitness, but three to five sessions a week are better.
• People who are out of shape or elderly should start aerobic training gradually. For example, they may start with five to 10 minutes of low-impact aerobic activity every other day and build toward a goal of 30 minutes per day, three to seven times a week. (For heart protection, frequency of exercises may be more important than duration.)
• Swimming is an ideal exercise for many elderly and certain people with physical limitations, including pregnant women, individuals with muscle, joint, or bone problems, and those who suffer from exercise-induced asthma.
• People who seek to lose weight should aim for six to seven low-impact workouts a week.

One way of gauging the optimal intensity of exercise is to aim for a "talking pace," which is enough to work up a sweat and still be able to converse with a friend without gasping for breath. As fitness increases, the "talking pace" will become faster and faster.

Shoes. All that's really necessary for a workout is a good pair of shoes that are made well and fit well. They should be broken in, but not worn down. They should support the ankle and provide cushioning for impact sports such as running or aerobic dancing. Airing out the shoes and feet after exercising reduces chances for skin conditions such as athlete's foot.

Clothing . Comfort and safety are the key words for workout clothing. For outdoor nighttime exercise, a reflective vest and light-colored clothing must be worn. Bikers, roller bladers, and equestrians should always wear safety devices such as helmets, wrist guards, and knee and elbow pads. Goggles are mandatory for indoor racquet sports. For vigorous athletic activities such as football, ankle braces may be more effective in preventing ankle injuries than tape.

Aerobic-Exercise Equipment. Home aerobic exercise machines can be adapted to any fitness level and can be used day or night. Before investing in and bringing home any exercise machine, however, it is wise to first test it at a gym. In addition, initial supervised training when using these machines can reduce the risk of injury that might occur with self instruction.

Very inexpensive exercise machines tend to be flimsy and hard to adjust, but many sturdy machines are available at moderate prices. The higher-end models may utilize computers to record calories burned, speed, and mileage. While their readouts may provide motivation and gauge the intensity of a workout, however, they are not always accurate.

The following are a few observations on specific equipment:

• A good floor mat is important to provide cushioning for all home exercises.
• A simple jump rope improves aerobic endurance for people who are able to perform high-impact exercise. Jumping rope should be done on a floor mat plus a surface that has some give to avoid joint injury.
• For burning calories, the treadmill has been ranked best, followed by stair climbers, the rowing machine, cross-country ski machine, and stationary bicycle. (Elliptical trainers, however, may be even better than treadmills for increasing heart rate, calorie expenditure, and oxygen consumption.)
• Stationary bikes condition leg muscles and are fairly economical and easy to use safely. The pedals should turn smoothly, the seat height should adjust easily, and the bike's computer should be able to adjust intensity.
• Stair machines also condition leg muscles. They offer very intense, low-impact workouts and may be as effective as running with less chance of injury.
• Rowing and cross-country ski machines exercise both the upper and lower body.

Shoes for Sports
Aerobic dancing	Sufficient cushioning to absorb shock and pressure that is many times greater than ordinary walking. Arches that maintain side-to-side stability. Thick upper leather support. Toe-box. Orthotics may be required for people with ankles that over-turn inward or outward. Soles should allow for twisting and turning.
Cycling	Rigid support across the arch to prevent collapse during pedaling. Heel lift. Cross-training or combo hiking/cycling shoes may be sufficient for casual bikers. Toe clips or specially designed shoe cleats for serious cyclers. In some cases, orthotics may be needed to control arch and heel and balance forefoot.
Running	Sufficient cushioning to absorb shock and pressure. Fully bendable at the ball of the foot. Sufficient traction on sole to prevent slipping. Consider insole or orthotic with arch support for problem feet.
Tennis	Allows side-to-side sliding. Low-traction sole. Snug fitting heel with cushioning. Padded toe box with adequate depth. Soft-support arch.
Walking	Lightweight. Breathable upper material (leather or mesh). Wide enough to accommodate ball of the foot. Firm padded heel counter that does not bite into heel or touch ankle bone. Low heel close to ground for stability. Good arch support. Front provides support and flexibility.

Strength or Resistance Training

Benefits of Strength Exercise. While aerobic exercise increases endurance and helps the heart, it does not build upper body strength or tone muscles. Strength-training exercises provide the following benefits:

• Build muscle strength while burning fat
• Help maintain bone density
• Improve digestion

It is also associated with a lower risk for heart disease, possibly because it lowers LDL (the so-called "bad") cholesterol levels.

Strength exercise is beneficial for everyone, even people in their 90s. It is the only form of exercise that can slow and even reverse the decline in muscle mass, bone density, and strength that occurs with aging. Please note: People at risk for cardiovascular disease should not perform strength exercises without checking with a doctor.

Types of Muscle Contractions. There are three types of muscle contractions involved in strength training:

• Isometric contractions do not change the length of the muscle. An example is pushing against a wall.
• Concentric contractions shorten muscles. An example is the "up" phase of a bicep curl.
• Eccentric contractions lengthen muscles. An example is the "down" phase as weights are lowered.

Strength-Training Regimens. Strength training involves intense and short-duration activities. For beginners, adding 10 to 20 minutes of modest strength training two to three times a week may be appropriate. The following are some guidelines for starting a strength regimen:

• The sequence of a strength training session should begin with training large muscles and multiple joints at higher intensity and end with small muscle and single joint exercises at lower intensities.
• Both concentric (shortening) and eccentric (lengthening) muscle actions should be performed. Emphasizing eccentric contractions (the movements that lengthen muscles) is of increasing interest. This approach involves slowing and increasing the duration of these "down" movements. It appears to significantly increase blood flow, and some evidence suggests it may achieve stronger muscles more quickly and improve cardiovascular function compared to a standard movements. It may be particularly beneficial for older people and some people with chronic health problems. Eccentric training increases the risk for muscle soreness and injury, however, and this approach is still controversial.
• Strength training involves moving specific muscles in the same pattern against a resisting force (such as a weight) for a preset number of times. This is called a repetition. Students should first choose a weight that is about half of what would require a maximum effort in one repetition. In other words, if it would take maximum effort to do a single repetition with a 10-pound dumbbell, than the person would start with a five-pound dumbbell. In the beginning, most people can start with one set of 8 to 15 repetitions per muscle group with low weights. As individuals are able to perform one or two repetitions over their routine, weights can be increased by 2 - 10%.
• Breathe slowly and rhythmically. Exhale as the movement begins. Inhale when returning to the starting point.
• The first half of each repetition typically lasts 2 to 3 seconds. The return to the original position lasts 4 seconds.
• An alternative technique called "super slow" training stretches out one repetition to a 14-second count. This method places far more stress on the muscle group, so fewer repetitions are needed. A full week of recovery is required before repeating this workout. The goal is to initiate changes in the muscles so that the body continues to burn calories after the exercise. Some people report dramatic results from this approach, but scientific verification of these anecdotes is not available. It is very tedious, in any case, and people have a hard time sticking with it. People with high blood pressure should not use this approach.
• Joints should be moved rhythmically through their full range of motion during a repetition and not locked up.
• For maximum benefit, one should allow 48 hours between workouts for full muscle recovery.

Strength-Training Equipment. Unlike aerobic exercise, strength training almost always requires some equipment. Strength-training equipment does not, however, have to cost anything.

• Any heavy object that can be held in the hand, such as a plastic bottle filled with sand or water, can serve as a weight.
• Dumbbells (1 to 10 pounds) and resistance bands are inexpensive, portable, and effective.
• Wearable weights help strengthen and tone the upper body.
• Ankle weights strengthen and tone muscles in the lower body. Wearable ankle weights should not be worn during high-impact aerobics or jumping.
• Handgrips strengthen arms and are good for relieving tension.
• A pull-up bar can be mounted in a doorway for chin-ups and pull-ups.

More elaborate and expensive home equipment for working body muscles is also available, costing from $100 to over $1,000. No one should purchase or use strength-training equipment without instruction from a professional.

Flexibility Training (Stretching)

Benefits of Flexibility Training. Flexibility training uses stretching exercises. Many stretching exercises are particularly beneficial for the back. In general, flexibility training provides the following benefits:

• Prevents cramps, stiffness, and injuries
• Improves joint and muscle movement (range of motion)

Certain flexibility practices such as yoga and tai chi, also involve meditation and breathing techniques that reduce stress. Such practices appear to have many health and mental benefits and may be very suitable and highly beneficial for many older people and patients with certain chronic diseases.

Flexibility Training Regiments.  Doctors recommend performing stretching exercises for 10 to 12 minutes at least three times a week. The following are some general guidelines:

• When stretching, exhale and extend the muscles to the point of tension, not pain, and hold for 20 to 60 seconds. (Beginners may need to start with a 5- to 10-second stretch.)
• Breath evenly and constantly while holding the stretch.
• Inhale when returning to a relaxed position. (Holding your breath defeats the purpose; it causes muscle contraction and raises blood pressure.)
• It is important when doing stretches that involve the back to relax the spine, to keep the lower back flush with the mat, and to work only the muscles required for changing position, often only the abdomen.

Specific Exercise Tips for Older People Studies continue to show that it is never too late to start exercising. A report published in the February 2006 Journal of Aging and Health found that older and elderly adults who exercised twice a week for four months significantly increased their body strength, flexibility, balance, and agility. The exercise program included walking and lifting weights. The average age of the study participants was 83.5. The study adds further evidence that even small improvements in physical fitness and activity can prolong life and independent living. Still, about half of Americans over 60 describe themselves as sedentary. According to a 2004 report by the Centers for Disease Control and Prevention, approximately 12% of people aged 65 to 75 years and 10% of people aged 75 years or older meet current recommendations for strength training. The following tips for exercising may be helpful: Any older person should have a complete physical and medical examination as well as professional instruction before starting an exercise program. Start low and go slow. For sedentary, older people one or more of the following programs may be helpful and safe: Low-impact aerobics, gait training, balance exercises, tai chi, self-paced walking, and lower extremity resistance training using elastic tubing or ankle weights. (Even in the nursing home, programs aimed at improving strength, balance, gait, and flexibility have significant benefits.) Strength training assumes even more importance as one ages, because after age 30 everyone undergoes a slow process of muscular erosion. The effect can be reduced or even reversed by adding resistance training to an exercise program. As little as one day a week of resistance training improves overall strength and agility. Strength training also improves heart and blood vessel health. Power training, which aims for the fastest rate at which a muscle or muscle group can perform work, may be particularly helpful for older women in strengthening muscles and preventing falls. Flexibility exercises promote healthy muscle growth and help reduce the stiffness and loss of balance that accompanies aging. Chair exercises may be performed by people who are unable to walk. Older women are at risk for incontinence accidents during exercise. This can be reduced or prevented by performing Kegel exercises, limiting fluids (without risking dehydration), going to the bathroom frequently, and using leakage prevention pads or insertable devices.

• Review Date: 3/6/2006
• Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital

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