No pain, no gain. Right? Wrong. That 1970s approach to exercise has been traded in for the new millennium’s favored philosophies: “no pain, much gain” and “train, don’t strain.”¹ The take-home message is that physical activity should be part of daily life, and it doesn’t have to be high intensity or inconvenient.

Surveying the hurdles

The promise of thinner versions of themselves may motivate most people to start exercising, but that’s not all that physical activity has to offer. Regular physical activity and/or exercise decreases mortality, improves cardiovascular and respiratory function, reduces coronary heart disease risk factors, lowers the risk of colon cancer, improves immune function, and enhances a sense of well-being.^2,3,4 After giving up smoking, becoming more physically active may be the best thing you can do for your health.

But despite common knowledge that exercise is healthful, more than 60% of the adults in this country do not engage in regular exercise, and some 25% are not active at all.³ Inactivity increases with age and is more common among women than men. It is more prevalent among those with lower income and less education.³ Physical inactivity is also more common among African-Americans and Hispanic adults than whites.³

Although many people enthusiastically begin exercise programs at one time or another, only 50% sustain their participation for more than six months.^5,6 It’s no wonder why individuals have trouble sticking to an exercise routine. Our high-tech society makes it convenient to remain sedentary, but difficult to start and maintain physical activity. Figuring out how to get Americans out of their seats and away from their TVs and computers poses a real challenge. However, by spreading the word that public health officials have been preaching, which is a kinder, gentler, philosophy of getting in shape, nurses can help drive a shift toward a more active lifestyle. In fact, government guidelines actually encourage nurses, like other health care professionals, to routinely talk to patients about incorporating physical activity into their daily lives.^1,6-8 In literal terms, nurses may assess physical activity habits, suggest basic lifestyle changes, and monitor their response to these changes.^4,5,9

Several health agencies have released guidelines to promote more participation in physical activity and encourage long-term adherence.^2-5,7,9-11 Current recommendations have evolved from a structured program of vigorous exercise for cardiovascular fitness to more moderate levels of physical activity for health benefits (disease prevention, longevity, and quality of life).

But before delving into the recommendations, we need to get the terms straight. Physical activity is any bodily movement produced by the contraction of the skeletal muscles that increases energy expenditure above a baseline level.¹² Exercise — a subcategory of physical activity — is planned, structured, and repetitive bodily movement done to maintain or improve one or more components of physical fitness.^3,4,7,10 Health-related aspects of physical fitness include cardio-respiratory endurance, muscular strength and endurance, flexibility, and body composition or percentage of body fat.^3,4,7,11 In 1992, the American Heart Association (AHA) officially named physical inactivity — not lack of exercise — as a major independent risk factor for heart disease. This term was used since a broad array of health benefits accrue from regular intermittent physical activity as well as from regular continuous exercise.^4,9

Taking the leap

Knowing how much you should exercise depends on your current health status, initial level of fitness, available time, personal goals, equipment, and facilities. Individual goals, such as enhancing vigor in daily life, improving cardio-respiratory fitness, or lowering blood pressure, also affect the required amount of exercise. Exercise guidelines and prescriptions are based on the FITT Formula and take into account the frequency (how often), intensity (how hard), time (how long), and type (mode) of exercise. Amount or volume of exercise is a function of these four variables and should be tailored to individual needs.^1,4,7,8,13

Men and women of all ages benefit from a moderate amount of physical activity. The Surgeon General has recommended that all Americans over the age of two years accumulate at least 30 minutes of physical activity, of at least moderate intensity, on most, preferably all, days of the week.^4,7 This can be accomplished by walking two miles in 30 to 40 minutes daily. Raking leaves for 30 minutes, running for 15 minutes, or playing volleyball for 45 minutes daily also produces a moderate amount of activity.^1,4,8,13

A dose-response relationship exists between physical activity and health/fitness.^4,7,14 Additional benefit can be achieved by adding more time in moderate-intensity activity (a longer walk), substituting more vigorous activity (30 minutes of running), or stepping up the frequency of physical activity (using the stairs more frequently). For those whose goals extend beyond health benefits and include higher levels of cardio-respiratory fitness, the more familiar classic recommendation still applies. Namely, the minimum level of FITT factors recommended is 20 minutes to 60 minutes of continuous aerobic exercise of moderate to vigorous intensity three to five days/week.^4,15

Total energy expended in exercise is usually expressed in kilocalories (kcal), and the minimum calorie expenditure for health is 150 kcal/day or 1,000 kcal/week.^7,16 If you are shooting for maximum health benefit, you are looking at five to six hours a week of physical activity and a caloric expenditure of 2,000 kcal/week above basal metabolic rate.¹⁴ For even higher levels of fitness, the upper end of the range is an expenditure of 300 kcal/day to 400 kcal/day in activity.^11,16 Even though this is the template for caloric expenditure, age, gender, and health status can influence the totals.

Considering the gains

The term aerobic means “with oxygen” and includes activities that require the body to use oxygen to produce the energy needed to perform an activity. Also referred to as dynamic or endurance exercise, aerobic exercise consists of continuous rhythmic movements of large muscle groups that can be sustained for a period of time.¹⁷ Walking, jogging, cycling, stair climbing, rowing, and swimming all fall into this category. Aerobic activities improve cardio-respiratory fitness by increasing the heart and breathing rates and training the heart, lungs, and skeletal muscles to use oxygen more efficiently, thereby increasing energy and capacity for work.

To help understand this concept, you need to think of your circulatory system as water flowing through pipes in a house. For instance, if you have one faucet on in your house the water moves fast, but if all the water outlets are turned on, the pressure will decrease and slow the water from that one source. In your body this is called your VO2max, which refers to the maximal amount of oxygen your body can obtain and use during cardiovascular training sessions. As you work out, your body can only pump a certain amount of blood throughout your body. To help keep your blood pressure down, the heart will distribute blood to different parts of the body and not concentrate the flow to one area. The higher VO2max, the more oxygen you can use and disperse to the needed muscles. To improve your VO2max, which measures your cardio-respiratory fitness, you just need to program your body, through cardiovascular exercise, to effectively use the oxygen available in the circulatory system.¹⁸

Improved exercise capacity offers cardiovascular, respiratory, hemodynamic, hormonal, metabolic, neurological, and immunological benefits.^1,5,7,8,11 The risk factors for heart disease and stroke go down. Regular aerobic activity increases high-density lipoprotein (good cholesterol) and decreases triglycerides. It lowers blood sugar and lessens the cell’s resistance to insulin. Because aerobic activity requires burning calories, it helps with weight loss and in maintaining weight loss, and it decreases intra-abdominal fat.¹¹ By lowering both systolic and diastolic blood pressures by 8 mm Hg to 10 mm Hg, aerobic exercise fights atherosclerosis by reducing stress on arteries and preventing the vascular injury that allows low-density lipoprotein (bad cholesterol) to begin forming fatty plaques.¹

Endurance exercise also decreases risk of heart attack by preventing the blood-clotting mechanism from forming clots while decreasing the stickiness of platelets.⁵ Dynamic exercise improves cardiovascular function by strengthening the heart muscle, so it can pump more blood with each beat.¹¹ A fit heart slows down and can still meet all the body’s needs for blood and oxygen. In addition to physical benefits, aerobic exercise relieves symptoms of depression and anxiety and improves self-esteem and self-confidence, in most cases.^1,5,7,11

Intensity — how hard?

Moderate-intensity aerobic activity raises your heart rate and gets the blood pumping without leaving you out of breath, exhausted, and ready to collapse. While the rate and depth of breathing rise during exercise, you should never feel so breathless that you are unable to carry on a normal conversation.^3,19 This simple measure is referred to as the “talk test” and is used to avoid overexertion. Use this only as a test and not as a continuous act, because carrying on a conversation during exercise will decrease your cardiovascular performance and inhibit your progress towards cardio-respiratory fitness.

Target heart rate (THR) and the Borg Perceived Rate of Exertion (RPE) scale also gauge exercise intensity. THR is a heart rate range that is considered to be safe for exercise and is affected by age, medication use, and fitness level. Using heart rate to estimate how hard you are working during exercise requires taking your pulse periodically and staying within 60% to 80% of your maximum heart rate.^4,8,13,20 An easier and more accurate way to monitor your THR is to buy a heart rate monitor or to use the built-in HR monitor found in most cardio equipment. The lower end of this range varies depending on baseline fitness level and is the minimum intensity needed to receive the benefits of physical activity. To find your target heart rate (THR), for your proper cardiovascular training zone, use the Karvonen Formula as a general rule of thumb. First, you need to determine your age-predicted maximum heart rate (HR max), by subtracting your age from 220. Once you have determined your max HR, you then need to calculate your resting heart rate (RHR) by monitoring your pulse for one full minute. After calculating your max HR and RHR, subtract the RHR from the max HR and then multiply the resulting number by .60 and .80. Finally, you must add your RHR to both numbers to find your THR range.²⁰

Example: 26-year-old man named Steve

Step 1: 220-26 = 194 (Age-predicted max HR)

Step 2: 194-65 = 129 (Max HR minus RHR)

Step 3: a. 129 x .60 = 77.4
 b. 129 x .80 = 103.2

Step 4: a. 77.4 + 65 = 142.4
 b. 103.2 + 65 = 168.2

THR RANGE FOR STEVE: 142.4 to 168.2

(For an abbreviated THR calculation, just use this formula: 220 minus age, multiplied by 60% and 80%.)

KARVONEN

Step 1: 220- your age = __________________

Step 2: Your Resting Heart Rate = _________________

Step 3:  ___ (max HR)  -  ___ (RHR) = ___ (HRH)

Step 4:  ___ (HRH) x .60 = ___ + (RHR)  = ___ (Low Range THR) 
             ___ (HRH) x.80 =  ___ + (RHR) = ___ (High Range THR)

SHORTHAND

220-your age = _____  x .60 = _____  (Low Range THR)  x .80 = _____ (High Range THR)

Personal trainers more commonly use this shorthand formula in a gym. Even though the shorthand is not as accurate, it should be the formula used by the average or unfit person. The Karvonen formula should be used for athletes who have a higher VO2max capacity, who can handle the higher HR.

While target heart rate is a helpful guide, this one-size-fits-all approach isn’t right for everyone due to a standard deviation of plus or minus 10 beats to 12 beats per minute.^4,8,15 Due to individual variation, the RPE Scale is also used when monitoring the intensity of exercise. This tool is a subjective measure of exercise intensity that requires listening to your body.²¹ It measures how hard you feel you are working during physical activity; simply put, light exercise feels light, and strenuous exercise feels strenuous. The RPE scale is most helpful for people who take medication that slows heart rate or who have irregular heart rates and/or difficulty taking their pulse. Breathlessness, sensory input from muscles and joints, and overall fatigue are taken into account when choosing the number that best describes your perception of how hard you are working. A rating of 6 is equivalent to doing nothing at all. A rating of 20 is maximal effort. During exercise, an RPE of “somewhat hard” or 12 to 13 on the Borg scale is considered moderate intensity, and an RPE of “hard” or 14 to 16 is vigorous.¹⁴

Taking Another Approach

For those who dislike traditional exercise, can’t find the time, are embarrassed at taking part, or are unable to exercise vigorously, another option can supplement or replace formal exercise. An alternative is to focus on lifestyle activities to increase energy expenditure.^2-7,9,22 This approach offers sedentary people a non-threatening starting point and encourages them to be more active throughout the day.

Housecleaning activities, walking breaks at work, using stairs, gardening, active recreational pursuits such as dancing and golf, and playing with toddlers provide health benefits when performed daily at a moderate intensity. A brisk walk to the store or office and/or housework, such as floor scrubbing, may be all that is necessary to meet the goals of some people. A level of physical activity necessary to achieve the majority of health benefits is less than that needed to attain a high level of cardio-respiratory fitness.^1,4,13,15 If finding time is a problem, shorter sessions of physical activity can be accumulated over the course of the day.¹⁴ Three 10-minute or two 15-minute bouts of exercise yield cardio-respiratory fitness gains comparable to those from one continuous 30-minute session of equal intensity.^1,4,7,11 Intermittent physical activity allows for more flexibility and is also associated with greater adherence to a regular exercise program.^1,4,14 This technique is for people with little or no available time, who are not in good cardiovascular shape, or who have health problems that limit their ability. The most efficient and effective way is 30 minutes of continuous cardiovascular exercise.

Strong for life

Strength training is an essential adjunct to a comprehensive fitness program. This exercise refers to performance of muscle contractions against a resistance that is greater than that to which the muscle is accustomed. Older persons, women, and even cardiac patients can enjoy the same benefits of resistance training as younger persons.⁷

Unique benefits include improved balance and decreased susceptibility to falls.⁷ Weight training empowers older people and enables them to remain independent by boosting their ability to perform activities of daily life, such as getting up out of a chair and getting in and out of a car. Because it strengthens bones, strength training is especially useful to women by decreasing the risk of osteoporosis.⁷

Recently, the AHA officially recognized resistance training as a means to improve cardiovascular function and health.^1,4,8,9,23 Weight training benefits the heart by favorably modifying several risk factors, including lipids and cholesterol levels, blood pressure, and glucose metabolism. It also helps in weight management because the more lean muscle or lean body mass you have, the more calories you burn, even at rest. With more muscle mass, activities of daily living, such as taking out the trash or carrying grocery bags, have less effect on the heart rate and blood pressure, resulting in the ability to do more work with less strain.

Strength training is performed two to three days a week on nonconsecutive days. Eight to ten exercises using one set of eight to 12 repetitions will provide benefit.^4,7,13,23 Pushing muscles to volitional fatigue (the muscles being worked tire to the point that you can’t complete any more repetitions using correct form) will elicit the best training effect. For frail persons or those 50 years or older, one set of 10 to 15 repetitions using lighter weights may be more appropriate.¹⁴

Movements during strength training should be slow and controlled with good posture and technique. Breathing correctly involves exhaling during exertion and inhaling during the “relaxed” motion. Most experts recommend two seconds up and four seconds down.²³ Weight machines, hand weights, and elastic bands or tubes are used. Exercises should include the major and minor muscle groups — major muscles of the legs, back, chest, and shoulders, and minor muscles of the biceps, triceps, and the abdomen (in order from largest to smallest).^4,23 Working only major muscle groups will still indirectly work out the minor or secondary muscle groups, if you’re in a hurry.

The stretch

Stretching is a major part of fitness, as is cardiovascular exercise and strength training for overall health. The American College of Sports Medicine and the AHA recommend stretching at least twice a week as part of a regular exercise program.^11,14 Stretching can reduce muscle soreness and prevent injury. By maximizing joint range of motion, stretching makes it easier to perform activities of daily living. Reaching for a jar on the top shelf, dashing across the street, even getting out of bed in the morning all require a limber body.

Stretching can be included in the warm-up phase of exercise as long as it is preceded by a simple, general, low-intensity activity, such as easy walking and/or rhythmic range-of-motion exercises for the whole body. If you stretch too intensely before a weight-training session, it can reduce muscle performance. Practicing a “cold stretch” when the muscles aren’t sufficiently warmed increases the chance of injury. According to the American College of Sports Medicine, warming up and cooling down should be performed at approximately 50% of normal cardiovascular intensity for about 5 to 15 minutes depending on health, age, and fitness level.²⁴ If you are weight training, only a moderate stretch should follow the warm-up and a heavier stretch should be included in the cool-down.

The best time to stretch to increase flexibility is after a workout, during the cool-down when muscles are warm and pliable. Aim for a slight feeling of tension in tight muscles, but never stretch to the point of pain. Breathe normally without holding your breath. Rather than bouncing, ease into a stretch. Stretches during the warm-up and the cool-down are held for 10 to 30 seconds. At least four repetitions per major muscle group should be completed at a minimum of two to three days per week.¹⁴

Words of caution

Adults with chronic health problems, such as heart disease, diabetes, or obesity or those who are at risk for these conditions should first consult a physician before beginning a new program of physical activity.^3,4,7 Men over age 40 and women over age 50 who plan to begin a new program of vigorous activity should consult their health care provider to be sure that they do not have heart disease or other health problems. It’s always a good idea to get a physical exam before starting an exercise routine, regardless of your age, gender, or previous health fitness.^3,4,7

Some sedentary people may worry about having a heart attack if they exercise. They need to know that although unusual exertion increases the risk of a cardiovascular event, getting regular, moderate exercise is safer than inactivity.⁷ In fact, sudden death is less likely in those who exercise regularly and follow basic exercise safety guidelines.^6,7,14

Musculoskeletal injuries are the most common health problems associated with physical activity and occur with excessive amounts of activity or when an activity is performed for which the body is not conditioned.^4,6,11 To avoid injury, physical activity should start with short 5- to 10-minute sessions and gradually build up to the desired amount. Remember to warm up and cool down before and after exercise. Just to reiterate, begin exercise with 5 to 15 minutes of light calisthenics or a less intense version of whatever you will be doing. To cool down, drop the intensity of exercise to prevent blood from pooling in the legs and minimize the risk of fainting and dizziness. Stretch thoroughly during the cool-down. To avoid unnecessary strain on the heart, avoid exercising within one hour after a meal, and don’t smoke or drink caffeine or alcohol for one to two hours before exercising. It is also sensible to avoid extreme weather conditions.^3,19

Signs of overexertion include nausea or vomiting after exercise, prolonged breathlessness, or excessive fatigue or insomnia. Stop exercising immediately and seek medical attention if irregular pulse, chest pain, dizziness, cold sweat, or a feeling of confusion occurs during exercise.^3,19 Also, consult a health care professional if exercise capacity decreases over time rather than increases.^3,19

There are still questions and controversy about what combination of FITT factors offers the best outcomes in terms of disease prevention and health promotion, but the real challenge may lie in how to get people to make exercise a priority and apply what we already know. In addition to sharing information about physical activity guidelines, nurses also need to teach behavior modification skills. Nurses can help patients to choose activities, formulate goals, and encourage them to make exercise fun. By counseling on goal setting, self-monitoring of progress, self-reinforcement, and the value of social support, nurses can help patients adopt this healthful habit and achieve long-term success.