Cardiovascular Exercise Questions:
Q: Does an aerobic workout cause an individual's resting metabolic rate to stay elevated for a long time after a workout (the so-called ''after burn'' effect)?
Q: I sweat profusely (literally dripping wet) during my aerobic workout. Is this an indication that I'm out of shape?
Q: What is cross training and does it offer any significant benefits?
Can you offer some basic guidelines for avoiding overuse injuries associated with running?
Generally speaking, the vast majority of overuse injuries associated with running can be avoided by utilizing commonsense and not exposing your body to sudden, high levels of orthopedic stress. Here are some basic guidelines for sidestepping runningrelated overuse injuries:
- Stretch before and after exercising. Proper stretching can mean the difference between pain and enjoyment, and can provide several potential benefits, including improving joint flexibility, enhancing performance and reducing injury potential. As a general rule, always precede stretching exercises with at least five minutes of low-intensity physical activity.
- Increase your mileage sensibly. Avoid doing too much exercise too soon. A general guideline is to limit any increase in weekly distance to 10 percent or less of the previous week’s total mileage. Contrary to what some people believe, more is not always better. Instead, limit your total weekly mileage to a reasonable level according to your fitness level, body size and training experience. Exercising too much substantially increases your chances of sustaining an overuse injury. Remember: Exercise quality is usually more important than quantity.
- Don’t subject your body to consecutive days of very intense exercise. Always follow a relatively “hard” day of exercising with an easier day. If you run considerably faster and farther than usual on a particular day, take the next day off or decrease the duration and/or intensity of your next workout.
- Incorporate an occasional “easy” week into your exercise regimen. Keep in mind that you don’t need to increase your mileage every week to continue to benefit from your training efforts. Some level of physical and/or psychological fatigue is natural following a steady diet of hard workouts. Fatigue may increase the likelihood of injury because it can diminish the precision of motor control and inhibit voluntary muscle-stabilizing activity.
- Don’t ignore sudden pain or discomfort. Pain is the body’s way of telling you that if you persist in what you’re doing, you will either injure yourself or exacerbate a relatively minor injury that has already occurred. You must learn to listen to your body and respond appropriately. The acronym “RICE” (rest, ice, compression and elevation) should serve as the basis of treatment for most minor injuries such as pulled or strained muscles and shin splits). If your acute pain does not respond to self-treatment within a reasonable period of time, see a physician, preferably a sports medicine specialist.
- Don’t try to “run through” pain. If you alter your normal running mechanics in an effort to accommodate pain or discomfort, you may place excessive stress on your joints, muscles and connective tissues (ligaments and tendons). Refrain from exercising until the pain subsides and no longer interferes with your natural running pattern.
- Periodically replace your running shoes. Proper footwear can have a significant impact on minimizing your chances of being injured. Record your mileage daily and replace your running shoes once the cumulative total exceeds 500 miles.
- Vary your workout options. Give your joints and muscles an occasional break from the “same old grind.” Engage in other forms of low-impact, joint-friendly exercises such as elliptical cross-training, cycling or swimming, in addition to running. Exercise variety can be both physically and mentally refreshing.
Q: Will I lose body fat more efficiently by performing my aerobic workouts at a low, rather than a high, intensity?
A: Many aerobic exercise programs and videos feature low-intensity workouts which purport to maximize fat burning. The argument behind such an alleged theory is that low-intensity aerobic training will allow your body to use more fat as an energy source, thereby accelerating the loss of body fat.
While it is true that a higher proportion of calories burned during low-intensity exercise come from fat (about 60 percent as opposed to approximately 35 percent from high-intensity programs), high-intensity exercise still burns more calories from fat in the final analysis.
For example, if you perform 30 minutes of low-intensity aerobic exercise (i.e., at a level of 50 percent of maximal exercise capacity), you'll burn approximately 200 calories - about 120 of those come from fat (i.e., 60 percent).
However, exercising for the same amount of time at a high intensity (i.e., 75 percent of your maximal exercise capacity) will burn approximately 400 calories. Using a 35 percent fat utilization yardstick, 140 of the calories you've burned will have come from stored fat.
Although the more vigorous exercise burns both more total and more fat calories, the less intense form of exercise has its benefits as well. For example, because many overweight people tend to find that lower-intensity exercise is more comfortable, they may, therefore, be willing to engage in such workouts.
The point to remember is that low-intensity workouts do, in fact, promote weight and fat loss. You just have to do them for a longer period of time.
Low-intensity aerobic exercise, however, is not a better or more effective way to lose weight than more intense physical activity - the idea of a "fat-burning zone" is simply a myth.
Keep in mind that you lose weight and body fat when you expend more calories than you consume, not because you burn fat (or anything else) when you exercise.
Q: What causes the pain in my side that occurs suddenly while I am running and how can I prevent it?
A: The pain that you've described is referred to as a "side stitch".
No clear-cut explanation has ever been offered regarding this painful burning sensation that can occur near the upper portion of the abdominal wall where it meets the rib cage.
It has been hypothesized that side stitch pain is caused by the jarring and pulling on the ligaments that attach the stomach to the diaphragm.
Anyone who has experienced a side stitch has probably tried several methods to relieve the pain. While each individual is different, the following methods have been observed to be effective in relieving the pain of a side stitch:
While you can't totally prevent a side stitch from occurring, you can reduce your likelihood of experiencing one by exercising at an intensity level that matches your fitness level and by gradually increasing how hard you work out as your fitness level improves.
Q: Why is an elevated heart rate alone not always a valid indicator of an effective aerobic-training stimulus?
A: During aerobic exercise, an individual's heart rate is a reliable indicator of how hard that individual is working. As the energy demands of the exercise increase, heart rate increases proportionately. Because the exercising muscles need more oxygen and fuel, an individual's heart rate and stroke volume (i.e., the amount of blood pumped per beat) must increase to deliver more blood to the tissues to meet the increased metabolic needs of the active muscles. It is this increased metabolic demand that overloads the cardiorespiratory system and provides the necessary stimulus to improve aerobic exercise capacity.
With resistance training, heart rate is disproportionately elevated relative to oxygen uptake. At any given level of oxygen uptake, heart rates are much higher for resistance training than for aerobic conditioning. The disproportionate rise in heart rate during resistance training is due to a phenomenon known as the pressor response, which is governed by the autonomic nervous system and occurs reflexively from the contraction of the skeletal muscles. It causes an increase in heart rate with a corresponding reduction in stroke volume. As a result, even though heart rates are increased during resistance training, the oxygen uptake is not increased to the same degree as it is during aerobic conditioning. This factor minimizes the metabolic overload to the muscles and, therefore, limits the aerobic training benefit that can occur as the result of resistance training. The pressor response helps to explain, from a physiological standpoint, why the heart rate is disproportionately elevated, relative to oxygen uptake, during resistance training.
The misperception that resistance training can increase aerobic exercise capacity is not new. In fact, it was popularized in late 1970s and early 1980s in a form of exercise known as circuit weight training (CWT), which involves performing 10 to 15 repetitions of eight to 12 exercises, using 40 percent to 60 percent of one-repetition-maximum. During CWT, individuals rapidly move from machine to machine, with very brief (less than 30 seconds) rest periods between exercises. A review of studies involving CWT indicates that such training programs are effective at increasing muscular fitness, but only modestly improve aerobic capacity (i.e., approximately 5 percent to 7 percent). Conventional aerobic exercise training programs (e.g., running, cycling, swimming) conducted over a similar period of time, on the other hand, typically result in greater improvements in aerobic exercise training (i.e., 15 percent to 25 percent).
Despite marketing claims to the contrary, exercise products and programs that focus predominantly on resistance training do not provide a sufficient stimulus to produce meaningful aerobic training benefits even though exercisers' hear rates are elevated during such training. It is important to understand that although a regular, sustained increase in heart rate is widely recognized as critical to achieving increased aerobic fitness, the heart rate merely serves as a monitor for the real training stimulus (i.e., increased energy expenditure or oxygen uptake). The best training approach for optimally improving both aerobic and muscular fitness is to separately participate in aerobic- and resistance-type activities. Circuit weight training can, however, serve as a time-efficient and relatively effective way for beginners and deconditioned individuals to achieve modest-to-moderate increases in both aerobic and muscular fitness.
Q: Does regular participation in aerobic exercise lower an individual's risk of developing cancer?
A: While it has not been shown that a given level of physical activity per se can reduce overall cancer risk, research suggests that exercise often modifies some of the risk factors associated with certain kinds of cancer. Obesity, for example, has been linked to cancer of the breast and the female reproductive system.
In turn, regular exercise has been shown to help promote weight loss. Several studies have also found that men who worked at sedentary jobs for most of their lives had a greater incidence of colon cancer than those in more active jobs. A longitudinal study of Harvard alumni found that highly active or even moderately active individuals had a substantially lower risk of developing both colon and lung cancer than alumni who were less active or sedentary.
On the other hand, exercise will not offset the effects of a high-fat diet or smoking. Still, it can contribute, even indirectly, to a reduced risk of cancer. As such, exercising regularly is recommended by the American Cancer Society as an integral part of its cancer prevention program.
General Exercise Questions:
Should I exercise when I have aches and pains?
A: Muscle soreness or discomfort that occurs 24 to 48 hours after exercise is normal, particularly if the exercise involved a high amount of eccentric work (e.g., downhill running, resistance training, landing after jumping) or activities you are unaccustomed to performing. The proper response to this type of pain is rest followed by continued moderate exercise and stretching. There are, however, occasions when the pain or discomfort is more troublesome and indicative of a real problem. The following guidelines or basic warnings signals can help you determine if the pain you are experiencing warrants cessation of exercise and/or medical attention:
- Joint pain or discomfort. Joint pain of any degree of severity or type should not be dismissed or ignored. Pain in the ankle, knee, elbow or wrist joints is especially concerning because these joints are not covered by muscles and, therefore, the pain is rarely muscle-related.
- Localized pain or discomfort. If the pain occurs at a specific location, it is likely an early indicator of some type of injury. If the pain does not occur in the same location on the opposite side of the body, consult a doctor.
- Persistent pain or discomfort. If the pain persists for longer than two weeks or gets worse, see a healthcare professional-especially if the pain doesn't respond to standard treatment methods (e.g., rest, ice, over-the-counter pain medications)
- Swelling in or around the area of pain. Swelling is a classic sign of an injury and should never be ignored. It is not uncommon for swelling in or around a joint to cause pain and stiffness.
- Disturbs normal routine. Pain that disrupts your sleep patterns or interferes with work or activities of daily living is also a strong indicator of a more serious problem.
The bottom line is that you should generally avoid trying to push or work through pain. The "no pain, no gain" mantra is outdated and inaccurate. Pain is the body's way of communicating to us that a problem exists and a potential injury may be on the horizon.
Q: Should I train my abdominal muscles every day? Also, how many repetitions of crunches should I optimally perform?
A: You should treat your abdominal muscles like any other muscle group, which means you shouldn't train them every day. Your abdominals, like all of your other muscle groups, need recovery time between workouts.
As with any resistance training exercise, you ideally want the last few repetitions to be difficult to complete.
Performed correctly, 10 to 25 repetitions for one to three sets of abdominal exercises provide a more than adequate training stimulus. If you can perform more than 25 repetitions of an abdominal exercise, you are most likely performing the repetitions too rapidly or with improper form.
You can increase the challenge and intensity of abdominal exercises by using added resistance, moving more slowly or performing the exercises on a slant board or exercise ball so that your head is at a lower elevation than your legs.
Q: What are the benefits of cross training and how can I incorporate it into my training routine?
A: Incorporating several different forms of exercise in a training program can be an excellent way to develop the various components of fitness. Here are some of the numerous documented benefits of cross training:
- Reduced risk of injury. By spreading the cumulative level of orthopedic stress over additional muscles and joints, individuals are able to exercise more frequently and for longer durations without excessively overloading particularly vulnerable areas of the body (e.g., knees, hips, back, shoulders, elbows and feet). People who are particularly prone to lower-leg problems from running long distances should consider incorporating low-impact activities such as elliptical training, cycling and swimming into their regimens. It should be noted, however, that competitive cross-trainers can experience certain overuse injuries due to inadequate muscle rest, an unbalanced workout schedule, or both.
- Enhanced weight loss. Individuals who want to lose weight and body fat should engage in an exercise program that enables them to safely burn a significant number of calories. Research has shown that such a goal, in most instances, is best accomplished when individuals exercise for relatively long durations (i.e., more than 30 minutes) at a moderate level of intensity (i.e., 60 percent to 85 percent of maximal heart rate). Overweight individuals can effectively achieve a reduction in body weight and fat stores by combining two or more physical activities in a cross-training regimen. They can, for example, exercise on an elliptical trainer for 20 to 30 minutes and then cycle for an additional 20 to 30 minutes.
- Improved total fitness. Cross training can include activities that develop muscular fitness, as well as aerobic conditioning. While an individual's muscular fitness gains will typically be less than if he or she participated only in strength training, the added benefits of improving muscular strength and endurance can pay substantial dividends. For example, research has shown that resistance training can help individuals prevent injury, control body weight and improve functional capacity.
- Enhanced exercise adherence. Research on exercise adherence indicates that many individuals drop out of exercise programs because they become bored or injured. Cross training is a safe and relatively easy way to add variety to an exercise program. In the process, it can play a positive role in promoting longterm exercise adherence by reducing the incidence of injury and eliminating or diminishing the potential for boredom.
The essential fundamentals of cross training are the same whether you are exercising for improved health and fitness or for competition. Try varying your exercise program from workout to workout by engaging in different types of activities, or simply add a new form of exercise (e.g., resistance training, Pilates, a boot-camp class) to your existing workout routine.
One of the easiest ways to incorporate cross training is to alternate between activities (e.g., run one day, stair climb the next, cycle the next). You can also alternate activities within a single workout (e.g., walk on a treadmill for 10 minutes, exercise on an elliptical trainer for 10 minutes and cycle for 10 minutes, for a total of 30 minutes of exercise). Cross training can offer you a refreshing physical and mental challenge.
Q: I’ve heard that exercise can help control hypertension. How much and what type of exercise is recommended for individuals with hypertension?
A: While drug therapy is traditionally considered to be the most effective form of treating high blood pressure, exercising on a regular basis has been found to be a valuable and safe adjunct therapy for many people with hypertension. In fact, a sound exercise program may serve as an effective non-drug alternative for some people.
Research shows that low-intensity (40 percent to 70 percent of VoO2 max) aerobic exercise can lower systolic blood pressure by approximately 11 mmHg and diastolic blood pressure by approximately 9 mmHg in people with mild-to moderate hypertension. It is theorized that exercise lowers resting blood pressure by decreasing sympathetic nervous system activity. A reduction in sympathetic nerve activity could lower one or both of the two principal determinants of blood pressure, since mean arterial blood pressure equals the product of cardiac output and total peripheral resistance.
Over the past 15 years, substantial information has emerged concerning what constitutes an appropriate exercise prescription for individuals with hypertension. When choosing an exercise program, individuals with hypertension should:
- Avoid exercise if resting systolic blood pressure exceeds 200 mmHg and/or diastolic blood pressure exceeds 115 mmHg.
- Emphasize non-weightbearing activities (e.g., aquatic activities, stationary cycling) or low impact aerobic activities (walking, elliptical cross-training, cycling) if you have lower-body orthopedic problems.
- Keep the intensity level at the low end of the intensity range (40 percent to 70 percent of O2 max or 50 percent to 75 percent of maximum heart rate [MHR]). Evidence suggests that higher-intensity exercise (greater than 70 percent of VoO2 max or 80 percent of MHR) produces no greater reductions in blood pressure
- Use the ratings of perceived exertion (RPE) scale to monitor exercise intensity if taking antihypertensive medications (e.g., betablockers) that influence heart-rate response. The recommended RPE range is 2 to 4 (weak to moderate).
- Exercise for 20 to 30 minutes per session and progress to 30 to 60 minutes.
- Exercise at least four times per week (although exercising on a daily basis is preferable). A single bout of aerobic exercise may temporarily reduce blood pressure for several hours.
- Warm up longer than five minutes to ensure that the cardiovascular system is prepared for the upcoming physical activity. This will reduce the chance of experiencing an abrupt, sudden rise in blood pressure.
- Perform more than five minutes of cooldown exercises so that a gradual transition can be made from the conditioning activity to the resting state. Cooling down helps to prevent dizziness, lightheadedness or fainting, which are frequently associated with an abrupt cessation of exercise, especially for those who are taking certain medications such as vasodilating agents.
- Avoid isometric or high-tension, dynamicresistance strength-training exercises. All strength-training exercises should be performed at a low-to-moderate intensity (i.e., able to perform 12 to 20 repetitions per set).
- Maintain normal breathing patterns while exercising (particularly while engaged in strength training), since holding your breath can cause an excessive, transient rise in blood pressure.
- Start with a prolonged warm-up, especially before high-intensity, start-stop bursts of activity (e.g., racquetball, tennis, basketball, handball).
Finally, make a firm commitment to exercise, because even a small amount of regular activity (and the subsequent reduction in blood pressure) can help diminish the long-term consequences of high blood pressure. For example, lowering systolic blood pressure by a mere 2 millimeters of mercury has been shown to reduce deaths from stroke by 6 percent, heart disease by 4 percent and all causes by 3 percent.
The widespread tendency to treat hypertension pharmacologically has markedly reduced stroke mortality, but has not significantly reduced the mortality from coronary heart disease (CHD). Proper use of a non-drug therapy, such as exercise, in conjunction with drug therapy can offer hypertensive patients added protection against CHD. Exercise has also been shown to favorably modify other CHD risk factors (e.g., obesity, lipidlipoprotein profiles and glucose tolerance). In short, a sound exercise program is an excellent strategy for helping to treat and prevent high blood pressure.
Q: What steps can an individual take to avoid heat injury when exercising in a hot environment?
A: A potential health hazard of exercising in warm weather exercise is heat injury.
A key point to remember is that anyone who exercises in a hot environment is susceptible to heat injury. In the excessively warm and often humid conditions that frequently occur in the summer and early fall, heat stress can be a real threat for individuals who engage in aerobic-type exercise activities - either outdoors or indoors in facilities without air conditioning.
Individuals exercising in a warm, humid environment should adhere to five relatively basic guidelines to avoid heat injury.
First, make sure that they are adequately hydrated. This can be accomplished by consuming copious amounts of fluid (just short of feeling fully bloated) thirty minutes before exercise, drinking at least six ounces of fluid after approximately every 20 minutes of exercise, and drinking beyond thirst cessation during the recovery period.
Water is generally considered the best hydration fluid unless the duration of the exercise bout exceeds 60 minutes. If an individual exercises for longer than an hour, a sports drink (e.g., Gatorade or PowerAde) may be the more beneficial.
Second, an individual should become acclimatized to the environment. Acclimatization, the body's gradual adaptation to changes in environment (it usually takes 10-14 days of heat exposure combined with exercise), can greatly reduce an individual's risk for heat injury.
Following acclimatization, individuals will sweat sooner, produce more sweat, and lose fewer electrolytes in their sweat. The net effects of acclimatization are a lower body core temperature, a decreased heart rate response to exercise, and a diminished potential for dehydration and electrolyte depletion.
Third, individuals should lower the intensity level of their exercise bout (especially during the acclimatization period) because this step will decrease the heat load and reduce the strain on their thermoregulatory mechanisms.
Fourth, individuals should never wear clothing that is impermeable to water (e.g., rubberized sweat suits), since such clothing prevents the evaporation of sweat from the skin and thereby increase the risk of heat injury.
Fifth, every individual should respect the existing environmental conditions since temperature and relative humidity can greatly influence both the degree of heat stress and the body's ability to effectively respond to the heat stress.
As a general rule of thumb, an individual should consider curtailing exercise when the ambient temperature is above 90 degrees Fahrenheit and, concurrently, the relative humidity is above 60 percent.
In summation, warm weather exercisers should adhere to the following motto: "Drink up, slow down, and have fun exercising."
Q: What is overtraining? Are there any easy-to-recognize signs or symptoms of overtraining?
A: Overtraining is a term that is used to express a situation when an imbalance occurs between training and recovery. The symptoms of overtraining can vary from one individual to another.
Overtraining, however, frequently involves one or more of the following common signs or symptoms:
- Impaired physical performance
- Reduced enthusiasm and desire for training
- Increased resting heart rate (i.e., your heart rate taken first thing in the morning before getting out of bed)
- Increased resting blood pressure
- Chronic muscle or joint soreness
- Increased incidence of musculoskeletal injuries
- Increased incidence of colds and infections
- Impaired recovery from exercise (e.g., heart rate remains elevated well after the completion of a bout of exercise)
- Increased perceived exertion during your normal workouts
- Reduced appetite
- Dramatic weight loss
- Disturbed sleep patterns
- Increased depression, irritability, or anxiety
Q: When is the best time to exercise? I have heard that if you are overweight you should exercise after you eat, and if you are at the weight you want, you should exercise before you eat. Does it matter? And, if it does, why and how?
Q: Is it possible to selectively train your lower abdominal muscles?
Q: What are the benefits of varying your workout routine?
There are several ways you can spice up your current workout routine, including boosting the intensity of your workouts. For instance, if you jog or run, try incorporating some intervals of sprinting (e.g., sprint to a given landmark, then jog to the next one) or adding more hill work to your run. You can also cross train and perform different activities to provide your body with a new challenge. A nice alternative for resistance-training exercises involves changing the sequence in which you perform the training exercises. By fatiguing the muscles in a new order or pattern, you are requiring them to adapt to a new training stimulus. Another option for adding variety to strength-training workouts is to replace some or all of the exercises in your workout routine (e.g., substitute a dumbbell pectoral fly exercise on a stability ball for your typical barbell bench press exercise).
Keep in mind that doing the exact same workout, day after day is not necessarily a bad thing. Some people enjoy a predictable, consistent routine. They don't mind the possibility of experiencing a training plateau and are content to maintain their health and fitness levels with a comfortable exercise habit. However, many individuals need to push themselves to new levels and try different activities to stay enthusiastic and excited about their workouts. By varying their exercise routines, individuals can not only stay physically challenged, but mentally stimulated as well.
Q: What is the Pilates Method of exercising?
Weight Questions:
Q: Why is the concept of spot reduction
considered a myth?
A: Unfounded programs and devices that purport to achieve spot reducing have become a multi-million dollar industry in a country where the health and aesthetic disadvantages of obesity are well recognized. Numerous scientific studies, however, cast doubt on the validity of spot reduction—the process of selectively taking inches off the waist, thighs or buttocks.
In one study, for example, the circumferences and fat deposits in the arms of high-level tennis players were compared. The investigators proposed that if spot reduction worked, the playing arm of a tennis player should have considerably less fat than the inactive arm. This prediction, however, was not the case. Despite the fact that circumference measures in the playing arms of the athletes were greater due to more muscular development, skinfold thickness measures revealed no difference in fat deposition between the two arms.
Arguably the most compelling evidence refuting the myth of spot reduction comes from a study conducted at the University of Massachusetts in the mid-1980s. In this investigation, 13 male subjects participated in a vigorous abdominal exercise training program for 27 days. Each participant in the study was required to perform a total of 5,000 sit-ups over the course of the research project. Fat biopsies were obtained from the subjects' abdomens, buttocks and upper backs before and after the exercise program. Contrary to what spot-reducing proponents would have you believe, the results of the study revealed that fat decreased similarly at all three sites—not just in the abdominal region. These findings may help explain one reason why spot reducing sometimes appears to work. If the caloric expenditure is sufficient enough, it will cause fat from the entire body to be reduced, including a particular target area. Although fat is lost or gained throughout the entire body, it appears that the last areas to become lean tend to be those areas where an individual tends to gain fat first. In most men (and some women), the abdominal region is the most difficult area to trim, while the hips, buttocks and thighs tend to be the trouble spots for most women (and some men).
Q: What is the best method for determining an
individual's ideal body weight?
A: To determine ideal body weight, individuals should not rely solely on a bathroom scale, height-weight tables, or percent body-fat measurements.
Sound nutrition and exercise science principles, along with common sense, mandate that individuals should avoid setting ''hard and fast'' body-weight goals. Rather, they should strive for achieving a level of body weight that is compatible with a healthy lifestyle (e.g., sensible eating, regular exercise, etc.).
All factors considered, the body weight that results from adopting such a lifestyle should ultimately be considered as the ideal union between an individual's wellness level, genetic potential, and a state of reality.
What represents a safe, realistic, and, perhaps more importantly, attainable body weight for an individual will depend (to a large extent) on the following factors:
- Medical history
An individual's current medical history, to include a thoughtful review of personal health-risk factors, should be taken into account when attempting to define ideal body weight. For example, if an individual's blood pressure is elevated, a modest weight reduction (as little as 10 lbs.) has been shown to be quite beneficial.
Extra body mass means that the heart must work harder to pump blood through miles of extra capillaries that feed that extra tissue. Type 2 diabetes and blood lipid-lipoprotein profiles are further examples of medical conditions that can be positively affected by weight loss.
- Family history
Body weight, like most other physical characteristics, is strongly influenced by genetic factors. If an individual's parents and siblings are extremely overweight, it is highly unlikely that such an individual will ever be ''model-thin.'' As unfair as such a judgment might first appear, such a limitation should be kept in mind when establishing realistic body-weight goals. - Body composition
Leaner bodies are more effective calorie burners. The more muscle or lean body mass individuals have, the more calories they burn.
Men naturally have more muscle mass than women, and, as a result, have higher metabolic rates. Furthermore, individuals who exercise on a regular basis tend to have more muscle mass and higher metabolic rates compared to their sedentary counterparts.
Accordingly, although individuals who have a relatively high amount of muscle may weigh substantially more than others of similar heights, their body-weight levels may be entirely appropriate given their lean muscle mass.
- Body-fat distribution
Body fat located in the upper-body region is very risky in terms of health profiles. If individuals possess a high amount of upper-body or abdominal fat, they should consider losing weight (specifically body fat) through a combined program of sensible eating and exercise.
One commonly accepted method of determining whether individuals have excessive amounts of upper-body fat is to look at their waist-to-hip ratios. The waist-to-hip ratio (WHR) is a simple, yet accurate, method for determining body-fat distribution patterns.
WHR is determined by dividing the waist circumference by the hip circumference. Waist circumference is defined as the smallest circumference between the rib cage and belly button. Hip circumference is defined as the largest circumference of the hip-buttocks region.
Men with WHR values exceeding 0.95 are considered to have an excessive amount of upper-body fat, while those with less than 0.95 are deemed to have an acceptable level of upper-body fat. Women with WHR values above 0.86 are considered to have an unhealthy amount of upper-body fat, while those with scores less than 0.86 are designated as having a reasonable level of accumulated adipose tissue on their upper bodies.
- BMI (Quetelet’s Index) assesses weight relative to height. It is derived from body mass and stature to evaluate normalcy of one’s weight. While ideal for ranking and determining patterns of distribution, it is not valid for children, senior populations or hypertrophied populations groups (athletes)
BMI Table
BMI = Wt (kg) ÷ Ht(m) 2.
BMI = Wt (kg) ÷ Ht(m) 2.
BMI = Wt (lb) x 703 ÷ Ht (inches) ÷ Ht (inches)
| BMI (kg/m2) | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 35 | 40 |
| Height (in.) | Weight (lb.) | |||||||||||||
| 58 | 91 | 96 | 100 | 105 | 110 | 115 | 119 | 124 | 129 | 134 | 138 | 143 | 167 | 191 |
| 59 | 94 | 99 | 104 | 109 | 114 | 119 | 124 | 128 | 133 | 138 | 143 | 148 | 173 | 198 |
| 60 | 97 | 102 | 107 | 112 | 118 | 123 | 128 | 133 | 138 | 143 | 148 | 153 | 179 | 204 |
| 61 | 100 | 106 | 111 | 116 | 122 | 127 | 132 | 137 | 143 | 148 | 153 | 158 | 185 | 211 |
| 62 | 104 | 109 | 115 | 120 | 126 | 131 | 136 | 142 | 147 | 153 | 158 | 164 | 191 | 218 |
| 63 | 107 | 113 | 118 | 124 | 130 | 135 | 141 | 146 | 152 | 158 | 163 | 169 | 197 | 225 |
| 64 | 110 | 116 | 122 | 128 | 134 | 140 | 145 | 151 | 157 | 163 | 169 | 174 | 204 | 232 |
| 65 | 114 | 120 | 126 | 132 | 138 | 144 | 150 | 156 | 162 | 168 | 174 | 180 | 210 | 240 |
| 66 | 118 | 124 | 130 | 136 | 142 | 148 | 155 | 161 | 167 | 173 | 179 | 186 | 216 | 247 |
| 67 | 121 | 127 | 134 | 140 | 146 | 153 | 159 | 166 | 172 | 178 | 185 | 191 | 223 | 255 |
| 68 | 125 | 131 | 138 | 144 | 151 | 158 | 164 | 171 | 177 | 184 | 190 | 197 | 230 | 262 |
| 69 | 128 | 135 | 142 | 149 | 155 | 162 | 169 | 176 | 182 | 189 | 196 | 203 | 236 | 270 |
| 70 | 132 | 139 | 146 | 153 | 160 | 167 | 174 | 181 | 188 | 195 | 202 | 207 | 243 | 278 |
| 71 | 136 | 143 | 150 | 157 | 165 | 172 | 179 | 186 | 193 | 200 | 208 | 215 | 250 | 286 |
| 72 | 140 | 147 | 154 | 162 | 169 | 177 | 184 | 191 | 199 | 206 | 213 | 221 | 258 | 294 |
| 73 | 144 | 151 | 159 | 166 | 174 | 182 | 189 | 197 | 204 | 212 | 219 | 227 | 265 | 302 |
| 74 | 148 | 155 | 163 | 171 | 179 | 186 | 194 | 202 | 210 | 218 | 225 | 233 | 272 | 311 |
| 75 | 152 | 160 | 168 | 176 | 184 | 192 | 200 | 208 | 216 | 224 | 232 | 240 | 279 | 319 |
| 76 | 156 | 164 | 172 | 180 | 189 | 197 | 205 | 213 | 221 | 230 | 238 | 246 | 287 | 328 |
Body weight in pounds according to height and body mass index.
Adapted from Bray, G.A., Gray, D.S., Obesity, Part I, Pathogenesis, West J. Med. 1988: 149: 429-41
| Body Mass Index | ||
| Classification | BMI Score (kg/m2) | |
| Underweight |
< 18.5
| |
| Normal | 18.5 – 24.9 | |
| Overweight | 25.0 – 29.9 | |
| Obese | 30.0 – 39.9 | |
| Extreme Obesity | > 40.0 | |
| Reference: ACSM Guidelines for Exercise Prescription (2006) | ||
- Functional ability
If the ability to effectively and efficiently perform activities of daily living and to comfortably engage in a variety of recreational pursuits is inhibited, an individual should strive to attain a level of body weight that will support a healthy, functional lifestyle.
