ACSM Chapter 8

Questions to Evaluate Readiness to Exercise in a Hot Environment (10)

-Adults should ask the following questions to evaluate readiness to exercise in a hot environment. Corrective action should be taken if any question is answered "no.": 1.Have I developed a plan to avoid dehydration and hyperthermia? 2. Have I acclimatized by gradually increasing exercise duration and intensity for 10-14 d? 3. Do I limit intense exercise to the cooler hours of the day (early morning)? 4. Do I avoid lengthy warm-up periods on hot, humid days? 5. When training outdoors, do I know where fluids are available, or do I carry water bottles in a belt or a backpack? 6. Do I know my sweat rate and the amount of fluid that I should drink to replace body weight loss? 7. Was my body weight this morning within 1% of my average body weight? 8. Is my 24 h urine volume plentiful? 9. Is my urine color "pale yellow" or "straw colored"? 10. When heat and humidity are high, do I reduce my expectations, my exercise pace, the distance, and/or duration of my workout or race? 11. Do I wear loose-fitting, porous, lightweight clothing? 12. Do I know the signs and symptoms of heat exhaustion, exertional heatstroke, heat syncope, and heat cramps (see Table 8.4)? 13. Do I exercise with a partner and provide feedback about his/her physical appearance? 14. Do I consume adequate salt in my diet? 15. Do I avoid or reduce exercise in the heat if I experience sleep loss, infectious illness, fever, diarrhea, vomiting, carbohydrate depletion, some medications, alcohol, or drug abuse?

FITT for children and adolescents (Aerobic)

-Frequency: Daily. -Intensity: Most should be moderate-to-vigorous intensity aerobic exercise and should include vigorous intensity at least 3 d ∙ wk−1. Moderate intensity corresponds to noticeable increases in HR and breathing. Vigorous intensity corresponds to substantial increases in HR and breathing. -Time: ≥60 min ∙ d−1. -Type: Enjoyable and developmentally appropriate aerobic physical activities, including running, brisk walking, swimming, dancing, and bicycling.

FITT for Older Adults (Muscle Strengthening/Endurance)

-Frequency: ≥2 d ∙ wk−1. -Intensity: Moderate intensity (i.e., 60%-70% one repetition maximum [1-RM]). Light intensity (i.e., 40%-50% 1-RM) for older adults beginning a resistance training program. When 1-RM is not measured, intensity can be prescribed between moderate (5-6) and vigorous (7-8) intensity on a scale of 0-10 (82). -Type: Progressive weight-training program or weight-bearing calisthenics (8-10 exercises involving the major muscle groups; ≥1 set of 10-15 repetitions each), stair climbing, and other strengthening activities that use the major muscle groups.

FITT for Older Adults (Flexibility)

-Frequency: ≥2 d ∙ wk−1. Intensity: Stretch to the point of feeling tightness or slight discomfort. -Time: Hold stretch for 30-60 s. -Type: Any physical activities that maintain or increase flexibility using slow movements that terminate in sustained stretches for each major muscle group using static stretches rather than rapid ballistic movements

FITT for children and adolescents (Bone Strengthening)

-Frequency: ≥3 d ∙ wk−1. -Time: As part of 60 min ∙ d−1 or more of exercise. -Type: Bone strengthening activities include running, jumping rope, basketball, tennis, resistance training, and hopscotch.

FITT for children and adolescents (Muscle Strengthening)

-Frequency: ≥3 d ∙ wk−1. -Time: As part of their 60 min ∙ d−1 or more of exercise. -Type: Muscle strengthening physical activities can be unstructured (e.g., playing on playground equipment, climbing trees, tug-of-war) or structured (e.g., lifting weights, working with resistance bands).

Environmental Considerations: Exercise in High Altitude Environments (altitude acclimatization)

1. Altitude acclimatization: -Altitude acclimatization consists of physiologic adaptations that develop in a time-dependent manner during repeated or continuous exposures to moderate or high altitudes and decreases susceptibility to altitude sickness. -In addition to achieving acclimatization by residing continuously at a given target altitude, at least partial altitude acclimatization can develop by living at a moderate elevation, termed staging, before ascending to a higher target elevation.

Assessing individual altitude acclimatization status

1. Assessing individual altitude acclimatization status: -The best indices of altitude acclimatization over time at a given elevation is a decline (or absence) of altitude sickness, improved physical performance, decreased HR, and an increase in arterial oxygen saturation (SaO2). -The presence and severity of AMS may be evaluated by the extent of its symptoms. -The uncomplicated resolution of AMS or its absence in the first 3-4 d following ascent indicates a normal acclimatization response. -After about 1-2 wk of acclimatization, physical performance improves. -Assessing individual altitude acclimatization status -Measurement of SaO2 by noninvasive pulse oximetry is a very good indicator of acclimatization. -Pulse oximetry should be performed under quiet, resting conditions. From its nadir on the first day at a given altitude, SaO2 should progressively increase over the first 3-7 d before stabilizing

Children and Adolescents

1. Children and adolescents (defined as individuals 6-17 yr) are more physically active than their adult counterparts. 2. Only our youngest children are as physically active as recommended by experts, and most young individuals older than the age of 10 yr do not meet prevailing physical activity guidelines. 3. Children and adolescents are physiologically adaptive to endurance exercise training, resistance training, and bone loading exercise. 4. The benefits of exercise are much greater than the risks. 5. Physiologic responses to acute, graded exercise are qualitatively similar to those seen in adults. 6. Because prepubescent children have immature skeletons, younger children should not participate in excessive amounts of vigorous intensity exercise. 7. Exercise testing for clinical or health/fitness purposes is generally not indicated for children or adolescents unless there is a health concern. 8. The exercise testing protocol should be based on the reason the test is being performed and the functional capability of the child or adolescent. 9. Children and adolescents should be familiarized with the test protocol and procedure before testing to minimize stress and maximize the potential for a successful test. 10. Treadmill and cycle ergometers should be available for testing. Treadmills tend to elicit a higher peak oxygen uptake (VO2peak) and maximum HR (HRmax). Cycle ergometers provide less risk for injury but need to be correctly sized for the child or adolescent. 11. Compared to adults, children and adolescents are mentally and psychologically immature and may require extra motivation and support during the exercise test. 12. Health/fitness testing may be performed outside of the clinical setting. 13. The components of the Fitnessgram test battery include body composition (BMI or skinfold thicknesses), cardiorespiratory fitness (1-min walk/run, PACER), muscular fitness (curl-up test, pull-up/push-up tests), and flexibility (sit-and-reach test).

Special Considerations for children and adolescents

1. Children and adolescents may safely participate in strength training activities provided that they receive proper instruction and supervision. Generally, adult guidelines for resistance training may be applied (see Chapter 7). Eight to 15 submaximal repetitions of an exercise should be performed to the point of moderate fatigue with good mechanical form before the resistance is increased. 2. Because of immature thermoregulatory systems, youth should avoid exercise in hot humid environments and be properly hydrated. 3. Children and adolescents who are overweight or physically inactive may not be able to achieve 60 min ∙ d−1 of moderate-to-vigorous physical activity. These individuals should start out with moderate intensity, physical activity as tolerated and gradually increase the frequency and time of physical activity to achieve the 60 min · d−1 goal. Vigorous intensity, physical activity can then be gradually added at least 3 d ∙ wk−1. 4. Efforts should be made to decrease sedentary activities (i.e., television watching, surfing the Internet, and playing video games) and increase activities that promote lifelong activity and fitness (i.e., walking and cycling).

LBP Ex Rx

1. Clinical practice guidelines for the management of LBP consistently recommend staying physically active and avoiding bed rest. 2. Individuals with subacute and chronic LBP as well as recurrent LBP are encouraged to be physically active. 3. When recommendations are provided, they should follow very closely the recommendations for the general population (see Chapter 7) combining resistance, aerobic, and flexibility exercise. 4. In chronic LBP, exercise programs that incorporate individual tailoring, supervision, stretching, and strengthening are associated with the best outcomes. 5. A complete exercise program based on the exercise preferences of the individual and health/fitness, clinical exercise, and/or health care professional may be most appropriate. 6. Minimum levels for intensity and volume should be the same as for a healthy population (see Chapter 7).

LBP ET

1. Exercise and physical fitness testing is common in individuals with chronic LBP with little to no evidence of contraindication based on LBP alone. 2. If LBP is acute, guidelines generally recommend a gradual return to physical activity. 3. Exercise testing should be symptom limited in the first weeks following symptom onset. 4. Cardiorespiratory fitness -Compared to cycle and upper extremity ergometry, treadmill testing produces the highest VO2peak in individuals with LBP. Actual or anticipated pain may limit performance. -Actual or anticipated pain may limit submaximal testing as often as maximal testing. Therefore, the choice of maximal versus submaximal testing in individuals with LBP should be guided by the same considerations as for the general population. 5. Muscular strength and endurance -Reduced muscle strength and endurance in the trunk has been associated with LBP, as have changes in strength and endurance ratios (e.g., flexors vs. extensors). -There has also been the suggestion that neuromotor imbalances may exist between paired muscles such as the erector spinae in individuals with LBP. -Assessments using isokinetic dynamometers with back attachments, selectorized machines, and back hyperextension benches specifically test the trunk muscles in individuals with LBP. The reliability of these tests is questionable because of considerable learning effect in particular between the first and second sessions. -For individuals with LBP, performance is often limited by actual or anticipated fear of reinjury. 6. Flexibility -A range of studies have shown associations between measures of spine flexibility, hip flexibility, and LBP. Flexibility testing in individuals with LBP should be guided by the same considerations as for the general population (see Chapter 7). -It is essential, however, to identify whether the assessment is limited by stretch tolerance of the target structures or exacerbation of LBP symptoms

Environmental Considerations Exercise in High Altitude Environments: -Ex Rx -personalized plan -organizational planning

1. Exercise prescription: -During the first few days at high altitudes, individuals should minimize their exercise/physical activity to reduce susceptibility to altitude illness. -After this period, individuals whose Ex Rx specifies a THR should maintain the same exercise HR at higher altitudes. The personalized number of weekly training sessions and the duration of each session at altitude can remain similar to those used at sea level for a given individual. -This approach reduces the risk of altitude illness and excessive physiologic strain. 2. Developing a personalized plan: -Monitor the environment: High altitude regions usually are associated with more daily extremes of temperature, humidity, wind, and solar radiation. Follow appropriate guidelines for hot and cold environments. -Modify activity at high altitudes: Consider altitude acclimatization status, physical fitness, nutrition, sleep quality and quantity, age, exercise time and intensity, and availability of fluids. Provide longer and/or more rest breaks to facilitate rest and recovery and shorten activity times. Longer duration activities are affected more by high altitude than shorter duration activities. Developing a personalized plan -Develop an altitude acclimatization plan: Monitor progress. -Clothing: Individual clothing and equipment need to provide protection over a greater range of temperature and wind conditions. -Education: The training of participants, personal trainers, coaches, and community emergency response teams enhances the reduction, recognition, and treatment of altitude-related illnesses. 3. Organizational planning: -Screening and surveillance of at-risk participants. Using altitude acclimatization procedures to minimize the risk of altitude sickness and enhance physical performance. -Consideration of the hazards of mountainous terrain when designing exercise programs and activities. Organizational planning -Awareness of the signs and symptoms of altitude illness. -Develop organizational procedures for emergency medical care of altitude illnesses. -Team physicians should consider maintaining a supply of oxygen and pharmaceuticals for preventing and treating altitude sickness.

Hot environment Ex Rx

1. Exercise prescription: -Health/fitness and clinical exercise professionals may use standards established by the National Institute for Occupational Safety and Health (NIOSH) to define WBGT levels at which the risk of heat injury is increased, but exercise may be performed if preventive steps are taken. Exercise prescription -Individuals whose Ex Rx specifies a target heart rate (THR) will achieve this THR at a lower absolute workload when exercising in a warm/hot versus a cooler environment. -As heat acclimatization develops, a progressively higher exercise intensity will be required to elicit the THR. -The first exercise session in the heat may last as little as 5-10 min for safety reasons but can be increased gradually. 2. Developing a personalized plan: -Monitor the environment: Use the WBGT index to determine appropriate action. -Modify activity in extreme environments: Enable access to ample fluid, provide longer and/or more rest breaks to facilitate heat dissipation, and shorten or delay playing times. Perform exercise at times of the day when conditions will be cooler compared to midday (early morning, later evening). Children and older adults should modify activities in conditions of high ambient temperatures accompanied by high humidity (see Box 8.6). -Consider heat acclimatization status, physical fitness, nutrition, sleep deprivation, and age of participants; intensity, time/duration, and time of day for exercise; availability of fluids; and playing surface heat reflection (i.e., grass vs. asphalt). Allow at least 3 h, and preferably 6 h, of recovery and rehydration time between exercise sessions. --Heat acclimatization: -These adaptations include decreased rectal temperature, HR, and RPE; increased exercise tolerance time; increased sweating rate; and a reduction in sweat salt. -Acclimatization results in the following: (a) improved heat transfer from the body's core to the external environment; (b) improved cardiovascular function; (c) more effective sweating; and (d) improved exercise performance and heat tolerance. -Seasonal acclimatization will occur gradually during late spring and early summer months with sedentary exposure to the heat. However, this process can be facilitated with a structured program of moderate exercise in the heat across 10-14 d to stimulate adaptations to warmer ambient temperatures. -Clothing: Clothes that have a high wicking capacity may assist in evaporative heat loss. Athletes should remove as much clothing and equipment (especially headgear) as possible to permit heat loss and reduce the risks of hyperthermia, especially during the initial days of acclimatization. -Education: The training of participants, personal trainers, coaches, and community emergency response teams enhances the reduction, recognition (see Table 8.5), and treatment of heat-related illness. Such programs should emphasize the importance of recognizing signs/symptoms of heat intolerance, being hydrated, fed, rested, and acclimatized to heat. Educating individuals about dehydration, assessing hydration state, and using a fluid replacement program can help maintain hydration.

Environmental Considerations:Exercise in Cold Environments (Ex Rx)

1. Exercise prescription: -Shoveling snow raises the HR to 97% HRmax and systolic BP increases to 200 mm Hg. -Walking in snow that is either packed or soft significantly increases energy requirements and myocardial oxygen demands so that individuals with atherosclerotic CVD may have to slow their walking pace. -Swimming in water <25° C (77° F) may be a threat to individuals with CVD because they may not be able to recognize angina symptoms and therefore may place themselves at greater risk.

LBP special considerations

1. Exercises to promote spinal stabilization are often recommended based on the suggestion that intervertebral instability may be a cause of certain cases of LBP: -This approach provides no clear additional benefit over other approaches to the management of nonspecific LBP. -This approach may be beneficial when LBP is related to a mechanical instability; however, further research is required. -There does not appear to be any detrimental effect of including spinal stabilization exercises within a general exercise program for individuals with LBP based on the preference of the individual and the health/fitness, clinical exercise, and/or health care professional 2. Certain exercises or positions may aggravate symptoms of LBP: -Walking, especially walking downhill, may aggravate symptoms in individuals with spinal stenosis. -Certain individuals with LBP may experience a "peripheralization" of symptoms, that is, a distal spread of pain into the lower limb with certain sustained or repeated movements of the lumbar spine. In such a situation, exercise or activities that aggravate peripheralization should temporarily be avoided. 3. Exercises or movements that result in a "centralization" of symptoms (i.e., a reduction of pain in the lower limb from distal to proximal) should be encouraged. 4. Flexibility exercises are generally encouraged as part of an overall exercise program. -Hip and lower limb flexibility should be promoted, although no stretching intervention studies have shown efficacy in treating or preventing LBP. -It is generally not recommended to use trunk flexibility as a treatment goal in LBP.

Absolute Contraindications for Exercising during pregnancy

1. Hemodynamically significant heart disease 2. Restrictive lung disease 3. Incompetent cervix/cerclage 4. Multiple gestation at risk for premature labor 5. Persistent second or third trimester bleeding 6. Placenta previa after 26 wk of gestation 7. Premature labor during the current pregnancy 8. Ruptured membranes 9. Preeclampsia/pregnancy-induced hypertension

bottom line for cold environment

1. In general, cold temperatures are not a barrier to performing physical activity. However, exercise-related cold stress may increase the risk of morbidity and mortality in individuals with CVD and asthmatic conditions. The risk of frostbite is <5% when the ambient temperature is greater than −15° C (5° F). Frostbite can occur when the WCT is lower than −27° C (8° F). Dressing appropriately for the type of weather expected and understanding the risks most likely to be encountered during exercise will reduce the risk of cold injuries substantially.

Special considerations for older adults

1. Intensity and duration of physical activity should be light at the beginning in particular for older adults who are highly deconditioned, functionally limited, or have chronic conditions that affect their ability to perform physical tasks. 2. Progression of physical activities should be individualized and tailored to tolerance and preference; a conservative approach may be necessary for the most deconditioned and physically limited older adults. 3. Muscular strength decreases rapidly with age, especially for those >50 yr. Although resistance training is important across the lifespan, it becomes more rather than less important with increasing age. 4. For strength training involving use of weightlifting machines, initial training sessions should be supervised and monitored by personnel who are sensitive to the special needs of older adults (see Chapter 7). 5. In the early stages of an exercise program, muscle strengthening/endurance physical activities may need to precede aerobic training activities among very frail individuals. Individuals with sarcopenia, a marker of frailty, need to increase muscular strength before they are physiologically capable of engaging in aerobic training. 6. Older adults should gradually exceed the recommended minimum amounts of physical activity and attempt continued progression if they desire to improve and/or maintain their physical fitness. 7. If chronic conditions preclude activity at the recommended minimum amount, older adults should perform physical activities as tolerated to avoid being sedentary. 8. Older adults should consider exceeding the recommended minimum amounts of physical activity to improve management of chronic diseases and health conditions for which a higher level of physical activity is known to confer a therapeutic benefit. 9. Moderate intensity, physical activity should be encouraged for individuals with cognitive decline given the known benefits of physical activity on cognition. Individuals with significant cognitive impairment can engage in physical activity but may require individualized assistance. 10. Structured physical activity sessions should end with an appropriate cool-down, particularly among individuals with CVD. The cool-down should include a gradual reduction of effort and intensity and optimally, flexibility exercises. 11. Incorporation of behavioral strategies such as social support, self-efficacy, the ability to make healthy choices, and perceived safety all may enhance participation in a regular exercise program (see Chapter 11). 12. The health/fitness and clinical exercise professional should also provide regular feedback, positive reinforcement, and other behavioral/programmatic strategies to enhance adherence.

Low Back Pain (LBP)

1. Low back pain (LBP) is traditionally described as pain that is primarily localized to the lumbar and lumbosacral area that may or may not be associated with leg pain. 2. Best evidence clinical guidelines now recommend physical activity as a key component of management across the spectrum of the condition. 3. Most cases of LBP show rapid improvement in pain and symptoms within the first month of symptom occurrence. 4. Roughly one-half to three-quarters of individuals, however, will experience some level of persistent or recurrent symptoms, with the prevalence of LBP being twice as high for individuals with a prior history of LBP. 5. Recurrent episodes tend toward increased severity and duration and higher levels of disability including work disability and higher medical and indemnity costs. 6. Individuals with LBP can be subgrouped into one of three general categories: -LBP associated with a potentially serious pathology (e.g., cancer or fracture) -LBP with specific neurological signs and symptoms (e.g., radiculopathy or spinal stenosis) -Nonspecific LBP, the latter of which accounts for up to 90% of cases 7. LBP may be further subgrouped according to the duration of symptoms: -Acute (the initial 4-6 wk) -Subacute (<3 mo) -Chronic (≥3 mo) 8. When LBP is a symptom of another serious pathology (e.g., cancer), exercise testing and Ex Rx should be guided by considerations related to the primary condition. 9. For all other causes, and in the absence of a comorbid condition (e.g., CVD with its associated risk factors), recommendations for exercise testing and Ex Rx are similar as for healthy individuals (see Chapter 7).

Environmental Considerations:Exercise in Cold Environments

1. Many factors including the environment, clothing, body composition, health status, nutrition, age, and exercise intensity interact to determine if exercising in the cold elicits additional physiologic strain and injury risk beyond that associated with the same exercise done under temperate conditions. 2. In most cases, exercise in the cold does not increase cold injury risk 3. There are scenarios (i.e., immersion, rain, low ambient temperature with wind) where whole body or local thermal balance cannot be maintained during exercise-related cold stress that contributes to hypothermia, frostbite, and diminished exercise capability and performance. 4. Exercise-related cold stress may increase the risk of morbidity and mortality in at-risk populations such as those with CVD and asthmatic conditions. Inhalation of cold air may also exacerbate these conditions. 5. Hypothermia develops when heat loss exceeds heat production causing the body heat content to decrease. The environment, individual characteristics, and clothing all impact the development of hypothermia. 6. Some specific factors that increase the risk of developing hypothermia include immersion, rain, wet clothing, low body fat, older age (i.e., ≥60 yr), and hypoglycemia. 7. Medical considerations: cold injuries -Frostbite occurs when tissue temperatures fall lower than 0° C (32° F). -Frostbite is most common in exposed skin (i.e., nose, ears, cheeks, and exposed wrists) but also occurs in the hands and feet. -Contact frostbite may occur by touching cold objects with bare skin, particularly highly conductive metal or stone that causes rapid heat loss. Medical considerations: cold injuries -Important information about wind and the WCT incorporates the following considerations: -Wind does not cause an exposed object to become cooler than the ambient temperature. -Wind speeds obtained from weather reports do not take into account man-made wind (e.g., running, skiing). -The WCT presents the relative risk of frostbite and predicted times to freezing (see Figure 8.3) of exposed facial skin. Facial skin was chosen because this area of the body is typically not protected. Medical considerations: cold injuries -Important information about wind and the WCT incorporates the following considerations: -Frostbite cannot occur if the air temperature is >0° C (32° F). -Wet skin exposed to the wind cools faster. If the skin is wet and exposed to wind, the ambient temperature used for the WCT table should be 10° C lower than the actual ambient temperature. -The risk of frostbite is <5% when the ambient temperature is greater than −15° C (5° F), but increased safety surveillance of exercisers is warranted when the WCT falls lower than −27° C (−8° F). In those conditions, frostbite can occur in 30 min or less in exposed skin. 8. Clothing considerations -Adjust clothing insulation to minimize sweating. -Use clothing vents to reduce sweat accumulation. -Do not wear an outer layer unless rainy or very windy. -Reduce clothing insulation as exercise intensity increases. -Do not impose a single clothing standard on an entire group of exercisers. -Wear appropriate footwear to minimize the risks of slipping and falling in snowy or icy conditions.

Environmental Considerations: Exercise in High Altitude Environments (medical considerations)

1. Medical considerations: altitude illnesses: -Rapid ascent to high and very high altitude increases individual susceptibility to altitude illness. -The primary altitude illnesses are acute mountain sickness (AMS), high altitude cerebral edema (HACE), and high altitude pulmonary edema (HAPE). Medical considerations: altitude illnesses -AMS is the most common form of altitude sickness. -AMS symptoms include headache, nausea, fatigue, decreased appetite, and poor sleep and, in severe cases, poor balance and mild swelling in the hands, feet, or face. -AMS develops within the first 24 h of altitude exposure. Its incidence and severity increases in direct proportion to ascent rate and altitude. -If ascent is stopped and physical exertion is limited, recovery from AMS occurs over 24-48 h after symptoms have peaked. Medical considerations: altitude illnesses -HACE is a potentially fatal, although not common, illness that occurs in <2% of individuals ascending >12,000 ft (3,658 m). -HACE is an exacerbation of unresolved, severe AMS. -HACE most often occurs in individuals who have AMS symptoms and continue to ascend. Medical considerations: altitude illnesses -HAPE is a potentially fatal, although not common, illness that occurs in <10% of individuals ascending >12,000 ft (3,658 m). -Individuals making repeated ascents and descents >12,000 ft (3,658 m) and who exercise strenuously early in the exposure have an increased susceptibility to HAPE. -The presence of crackles and rales in the lungs may indicate increased susceptibility to developing HAPE.

Older Adult Neuromotor Exercise for Frequent Fallers or Those with Mobility Limitations

1. Neuromotor exercise training, which combines balance, agility, and proprioceptive training, is effective in reducing and preventing falls if performed 2-3 d ∙ wk 2. General recommendations include using the following: -Progressively difficult postures that gradually reduce the base of support (two-legged stand, semitandem stand, tandem stand, and one-legged stand) -Dynamic movements that perturb the center of gravity (tandem walk and circle turns) 3. General recommendations include using the following: -Stressing postural muscle groups (heel and toe stands) -Reducing sensory input (standing with eyes closed) -Tai chi **Supervision of these activities may be warranted

Environmental Considerations: Exercise in High Altitude Environments (prevention and treatment of altitude sickness)

1. Prevention and treatment of altitude sickness: -Altitude acclimatization is the best countermeasure to all altitude sickness. -Minimizing sustained exercise/physical activity and maintaining adequate hydration and food intake will reduce susceptibility to altitude sickness and facilitate recovery. -When moderate to severe symptoms and signs of an altitude-related sickness develop, the preferred treatment is to descend to a lower altitude. -Prevention and treatment of altitude sickness -AMS may be significantly diminished or prevented with prophylactic or therapeutic use of acetazolamide (i.e., Acetazolamide [Diamox]). -Headaches may be treated with aspirin, acetaminophen, ibuprofen, indomethacin, or naproxen (see Appendix A). -Oxygen or hyperbaric chamber therapy will usually relieve some symptoms such as headache, fatigue, and poor sleep. -Prevention and treatment of altitude sickness -Prochlorperazine (Compazine) may be used to help relieve nausea and vomiting. -Dexamethasone (Decadron, Hexadrol) may be used if other treatments are not available or effective. -Acetazolamide (Diamox) may be helpful. -Treatment of individuals diagnosed with HACE or HAPE includes descent, oxygen therapy, and/or hyperbaric bag therapy.

Relative Contraindications for Exercising during pregnancy

1. Severe anemia 2. Unevaluated maternal cardiac dysrhythmia 3. Chronic bronchitis 4. Poorly controlled Type 1 diabetes mellitus 5. Extreme morbid obesity 6. Extreme underweight 7. History of extremely sedentary lifestyle 8. Intrauterine growth restriction in current pregnancy 9. Poorly controlled hypertension 10. Orthopedic limitations 11. Poorly controlled seizure disorder 12. Poorly controlled hyperthyroidism 13. Heavy smoker

Older Adults Exercise Testing

1. The initial workload should be light (<3 metabolic equivalents [METs]) and workload increments should be small (i.e., 0.5-1.0 MET) for those with low work capacities. The Naughton treadmill protocol is a good example of such a protocol (see Figure 5.3). 2. A cycle ergometer may be preferable to a treadmill for those with poor balance, poor neuromotor coordination, impaired vision, impaired gait patterns, weight-bearing limitations, and/or foot problems. However, local muscle fatigue may be a factor for premature test termination when using a cycle ergometer. 3. Adding a treadmill handrail support may be required because of reduced balance, decreased muscular strength, poor neuromotor coordination, and fear. 4. However, handrail support for gait abnormalities will reduce the accuracy of estimating peak MET capacity based on the exercise duration or peak workload achieved. 5. Treadmill workload may need to be adapted according to walking ability by increasing grade rather than speed For those who have difficulty adjusting to the exercise protocol, the initial stage may need to be extended, the test restarted, or the test repeated. In these situations, also consider an intermittent protocol (see Chapter 5). 6. Exercise-induced dysrhythmias are more frequent in older adults than in individuals in other age groups. 7. Prescribed medications are common and may influence the electrocardiographic (ECG) and hemodynamic responses to exercise (see Appendix A). 8. The exercise ECG has higher sensitivity (i.e., ~84%) and lower specificity (i.e., ~70%) than in younger age groups (i.e., <50% sensitivity and >80% specificity). The higher rate of false-positive outcomes may be related to the greater frequency of left ventricular hypertrophy (LVH) and the presence of conduction disturbances among older rather than younger adults.

Exercise Testing for the Oldest Segment of the Population

1. The oldest segment of the population (≥75 yr and individuals with mobility limitations) most likely has one or more chronic medical conditions. 2. The likelihood of physical limitations also increases with age. 3. The approach described earlier is not applicable for the oldest segment of the population and for individuals with mobility limitations. 4. The following recommendations are made for the aging population: -In lieu of an exercise test, a thorough medical history and physical examination should serve to determine cardiac contraindications to exercise. -Individuals with cardiovascular disease symptoms or diagnosed disease can be risk classified and treated according to standard guidelines (see Chapter 2). -Individuals free from CVD symptoms and disease should be able to initiate a light intensity (<3 METs) exercise program without undue risk.

Environmental Considerations: Exercise in High Altitude Environments

1. The progressive decrease in atmospheric pressure associated with ascent to higher altitudes reduces the partial pressure of oxygen in the inspired air, resulting in decreased arterial oxygen levels. 2. In this section, low altitude refers to locations <3,950 ft (1,200 m), moderate altitude to locations between 3,950 and 7,900 ft (1,200-2,400 m), high altitude between 7,901 and 13,125 ft (2,400-4,000 m), and very high altitude >13,125 ft (4,000 m). 3. Physical performance decreases with increasing altitude >3,950 ft (1,200 m). 4. The physical performance decrement will be greater as elevation, physical activity duration, and muscle mass increases but is lessened with altitude acclimatization. 5. The most common altitude effect on physical task performance is an increased time for task completion or more frequent rest breaks.

Older Adults

1. The term older adult (defined as individuals ≥65 yr and individuals 50-64 yr with clinically significant conditions or physical limitations that affect movement, physical fitness, or physical activity) represents a diverse spectrum of ages and physiologic capabilities. 2. Health status is often a better indicator of ability to engage in physical activity than chronological age. Individuals with chronic disease should be in consultation with a health care provider who can guide them with their exercise program. 3. Overwhelming evidence exists that supports the benefits of physical activity in: -slowing physiologic changes of aging that impair exercise capacity, -optimizing age-related changes in body composition, -promoting psychological and cognitive well-being, -managing chronic diseases, -reducing the risks of physical disability, and -increasing longevity. 4. Older adults are the least physically active of all age groups. 5. Although recent trends indicate a slight improvement in reported physical activity, only about 22% of individuals aged ≥65 yr engage in regular physical activity. 6. The percentage of reported physical activity decreases with advancing age, with fewer than 11% of individuals aged >85 yr engaging in regular physical activity.

FITT for older adults (Aerobic)

1. To promote and maintain health, older adults should adhere to the following Ex Rx for aerobic (cardiorespiratory) physical activities. When older adults cannot do these recommended amounts of physical activity because of chronic conditions, they should be as physically active as their abilities and conditions allow. -Frequency: ≥5 d ∙ wk−1 for moderate intensity, physical activities or ≥3 d ∙ wk−1 for vigorous intensity, physical activities or some combination of moderate and vigorous intensity exercise 3-5 d ∙ wk−1. -Intensity: On a scale of 0-10 for level of physical exertion, 5-6 for moderate intensity and 7-8 for vigorous intensity (82). -Time: For moderate intensity, physical activities, accumulate at least 30 or up to 60 (for greater benefit) min ∙ d−1 in bouts of at least 10 min each to total 150-300 min · wk−1, or at least 20-30 min · d−1 of more vigorous intensity, physical activities to total 75-100 min ∙ wk−1 or an equivalent combination of moderate and vigorous intensity, physical activity. -Type: Any modality that does not impose excessive orthopedic stress — walking is the most common type of activity. Aquatic exercise and stationary cycle exercise may be advantageous for those with limited tolerance for weight-bearing activity.

Environmental Considerations:Exercise in Hot Environments

1. When the amount of metabolic heat exceeds heat loss, hyperthermia (i.e., elevated internal body temperature) may develop. Sweat that drips from the body or clothing provides no cooling benefit. 2. Sweat losses vary widely and depend on the amount and intensity of physical activity and environmental conditions. 3. Heat acclimatization results in higher and more sustained sweating rates, whereas aerobic exercise training has a modest effect on enhancing sweating rate responses. 4. Dehydration increases physiologic strain as measured by core temperature, HR, and perceived exertion responses during exercise-induced heat stress. 5. Dehydration can augment core temperature elevations during exercise in temperate as well as in hot environments. The typical reported core temperature augmentation with dehydration is an increase of 0.1° to 0.2° C (0.2° to 0.4° F) with each 1% of dehydration. 6. Decreased sweating rate (i.e., evaporative heat loss) and decreased cutaneous blood flow (i.e., dry heat loss) are responsible for greater heat storage observed during exercise when hypohydrated. 7. Counteracting dehydration: -Dehydration (i.e., 3%-5% body mass loss) likely does not degrade muscular strength or anaerobic performance. -Dehydration >2% of body mass decreases aerobic exercise performance in temperate, warm, and hot environments; and as the level of dehydration increases, aerobic exercise performance is reduced proportionally. -The critical water deficit (i.e., >2% body mass for most individuals) and magnitude of performance decrement are likely related to environmental temperature, exercise task, and the individuals' unique biological characteristics (e.g., tolerance to dehydration). -Acute dehydration impairs endurance performance regardless of whole body hyperthermia or environmental temperature; and endurance capacity (i.e., time to exhaustion) is reduced more in a hot environment than in a temperate or cold one. -Overdrinking hypotonic fluid is the mechanism that leads to exercise-associated hyponatremia, a state of lower than normal blood sodium concentration (typically <135 mEq · L−1) accompanied by altered cognitive status. -Hyponatremia tends to be more common in long duration physical activities and is precipitated by consumption of hypotonic fluid (water) alone in excess of sweat losses (typified by body mass gains). -The syndrome can be prevented by not drinking in excess of sweat rate and by consuming salt-containing fluids or foods when participating in exercise events that result in many hours of continuous or near continuous sweating.

Special Considerations for Ex Rx during pregnancy

1. Women who are pregnant and sedentary or have a medical condition should gradually increase physical activity levels to meet the recommended levels earlier as per preparticipation completion of the PARmed-X for Pregnancy (see Figure 8.1). 2. Women who are pregnant and severely obese and/or have gestational diabetes mellitus or hypertension should consult their physician before beginning an exercise program and have their Ex Rx adjusted to their medical condition, symptoms, and physical fitness level 3. Women who are pregnant should avoid contact sports and sports/activities that may cause loss of balance or trauma to the mother or fetus. Examples of sports/activities to avoid include soccer, basketball, ice hockey, roller blading, horseback riding, skiing/snow boarding, scuba diving, and vigorous intensity racquet sports. 4. Exercise should be terminated immediately with medical follow-up should any of these signs or symptoms occur: vaginal bleeding, dyspnea before exertion, dizziness, headache, chest pain, muscle weakness, calf pain or swelling, preterm labor, decreased fetal movement (once detected), and amniotic fluid leakage. In the case of calf pain and swelling, thrombophlebitis should be ruled out. 5. Women who are pregnant should avoid exercising in the supine position after 16 wk of pregnancy to ensure that venous obstruction does not occur. Women who are pregnant should avoid performing the Valsalva maneuver during exercise. 6. Women who are pregnant should avoid exercising in a hot humid environment, be well hydrated, and dressed appropriately to avoid heat stress. See this chapter and the ACSM position stands on exercising in the heat and fluid replacement for additional information. 7. During pregnancy, the metabolic demand increases by less than ~300 kcal ∙ d−1. Women should increase caloric intake to meet the caloric costs of pregnancy and exercise. To avoid excessive weight gain during pregnancy, consult appropriate weight gain guidelines based on prepregnancy BMI available from the Institute of Medicine and the National Research Council. 8. Women who are pregnant may participate in a strength training program that incorporates all major muscle groups with a resistance that permits multiple submaximal repetitions (12-15 repetitions) to be performed to a point of moderate fatigue. Isometric muscle actions and the Valsalva maneuver should be avoided as should the supine position after 16 wk of pregnancy. Kegel exercises and those that strengthen the pelvic floor are recommended to decrease the risk of incontinence 9. Generally, gradual exercise in the postpartum period may begin ~4-6 wk after a normal vaginal delivery or about 8-10 wk (with medical clearance) after a cesarean section delivery. Deconditioning typically occurs during the initial postpartum period so women should gradually increase physical activity levels until prepregnancy physical fitness levels are achieved. Light-to-moderate intensity exercise does not interfere with breastfeeding.

Environmental Considerations: Exercise in High Altitude Environments (rapid ascent)

1.Rapid ascent: -Beginning within hours after rapid ascent to a given altitude up to about 14,000 ft (4,300 m), and lasting for the first couple of days, AMS may be present and physical and cognitive performances will be at their nadir for these individuals. -Voluntary physical activity should not be excessive, whereas endurance exercise training should be stopped or its intensity greatly reduced to minimize the possibility that AMS will be exacerbated. -When AMS subsides because of partial altitude acclimatization, individuals may resume all normal activities and exercise training, if desired. Rapid ascent -Monitoring exercise HR provides a safe, easy, and objective means to quantify exercise intensity at altitude, as it does at sea level. -Using an age-predicted maximal HR equation such as "220 − age" and multiplying the result by the same percentage intensity desired at altitude as at sea level provides a similar training stimulus as long as the weekly number and durations of the training sessions are also maintained. -For the same perceived effort, jogging or running pace will be reduced at altitude relative to sea level, independent of altitude acclimatization status

Bottom Line for Older Adults

All older adults should be guided in the development of a personalized Ex Rx or physical activity plan that meets their needs and personal preferences. The Ex Rx should include aerobic, muscle strengthening and endurance, flexibility, and neuromotor exercises, and focus on maintaining and improving functional ability. In addition to standard physical fitness assessments, physical performance tests can be used. These tests identify functional limitations associated with poorer heath status that can be targeted for exercise intervention.

Ex. Test & Rx Guidelines for Pregnancy

Ex. Testing: -not necessary, unless medical -sub-max if any health problem Ex. Prescription: -3-4x/week -Intensity: -Moderate for BMI <25 -Light for BMI >25 -HR unreliable -Talk test or RPE (12-14) 15 min, build to 30 min Rhythmic exercise Resistance exercise = 12-15 reps to moderate fatigue

LBP Bottom Line

LBP is a complex multidimensional phenomenon. Recommendations for exercise testing and Ex Rx are similar to those for healthy individuals when LBP is not associated with another serious pathology (e.g., cancer). It may be best to avoid exercise in the very immediate aftermath of an acute and severe episode of LBP so as not to exacerbate symptoms. However, individuals with subacute and chronic LBP as well as recurrent LBP should participate in physical activity. Performance is often limited by actual or anticipated fear of reinjury and/or pain.

Hot Environment Bottom Line

Metabolic heat produced by muscular contractions increases body temperature during exercise. Heat illness ranges from muscle cramps to life-threatening hyperthermia. In addition, dehydration has been associated with an increased risk for heat exhaustion and is a risk factor for heatstroke. Sweat losses vary widely among individuals and depend on exercise intensity and environmental conditions. Thus, fluid needs will be highly variable among individuals. The risk of dehydration and hyperthermia can be minimized by monitoring the environment; modifying activities in hot, humid environments; wearing appropriate clothing; and knowing the signs and symptoms of heat illness.

Bottom Line for children and adolescents

Most children >10 yr do not meet the recommended physical activity guidelines. Children and adolescents should participate in a variety of age-appropriate physical activities to develop CRF and muscular and bone strength. Exercise supervisors and leaders should be mindful of the external temperature and hydration levels of children who exercise because of their immature thermoregulatory systems.

Environmental Considerations: Exercise in Hot Environments (Organizational Planning)

Organizational planning Screening and surveillance of at-risk participants Environmental assessment (i.e., WBGT index) and criteria for modifying or canceling exercise Heat acclimatization procedures Easy access to fluids and bathroom facilities Organizational planning Optimized but not maximized fluid intake that (a) matches the volume of fluid consumed to the volume of sweat lost and (b) limits body weight change to <2% of body weight Awareness of the signs and symptoms of heatstroke, heat exhaustion, heat cramps, and heat syncope (see Table 8.5) Implementation of specific emergency procedures

Bottom line for Altitude

Physical performance decreases with increasing altitude >3,950 ft (1,200 m), with greater decrements associated with higher elevation, longer activity duration, and larger muscle mass. During the first few days at high altitudes, individuals should minimize their physical activity to reduce susceptibility to altitude illness. After this period, individuals whose Ex Rx specifies a THR should maintain the same exercise HR at higher altitudes.

Environmental Considerations: Exercise in High Altitude Environments (staging guideline)

The general staging guideline is as follows: For every day spent >3,950 ft (1,200 m), an individual is prepared for a subsequent rapid ascent to a higher altitude equal to the number of days at that altitude times 1,000 ft (305 m). For example, if an individual stages at 6,000 ft (1,829 m) for 6 d, physical performance will be improved and altitude sickness will be reduced at altitudes to 12,000 ft (3,637 m). This guideline applies to altitudes up to 14,000 ft (4,267 m).

The Bottom Line for Ex Rx during pregnancy

Women who are pregnant and healthy are encouraged to exercise throughout pregnancy with the Ex Rx modified according to symptoms, discomforts, and abilities. Women who are pregnant should exercise 3-4 d ∙ wk−1 for ≥15 min ∙ d−1 gradually increasing to a maximum of 30 min ∙ d−1 for each exercise session, accumulating a total of 150 min ∙ wk−1 of physical activity that includes the warm up and cool down. Moderate intensity exercise is recommended for women with a prepregnancy BMI <25 kg ∙ m2. Light intensity exercise is recommended for women with a prepregnancy BMI of ≥25 kg ∙ m2.