Transcript Chapter 17

Chapter 17
Exercise for Special
Populations
EXERCISE PHYSIOLOGY
Theory and Application to Fitness and Performance,
6th edition
Scott K.Presentation
Powersrevised
& Edward
T.
Howley
and updated by
Brian B. Parr, Ph.D.
University of South Carolina Aiken
Diabetes
• Characterized by an absolute (type 1) or relative
(type 2) insulin deficiency that results in
hyperglycemia
• A major health problem and leading cause of death
in the United States
– More than 18.2 million have diabetes
– Only 11.1 million are diagnosed
• Warning signs:
– Frequent urination/unusual thirst
– Extreme hunger
– Rapid weight loss, weakness, and fatigue
– Irritability, nausea, and vomiting
Diabetes
• Type 1
– Lack of insulin
• Dependent on exogenous insulin
– Develops early in life
– Associated with viral infections
– 5–10% diabetic population
• Type 2
– Resistance to insulin
– Develops later in life
– Associated with upper-body obesity
– 90–95% diabetic population
Characteristics of Type 1 and Type 2
Diabetes
Table 17.1
Exercise and the Diabetic
• Control of blood glucose is important
• Adequate insulin is required
• Ketosis
– Metabolic acidosis from accumulation of ketone
bodies
– May result from a lack of insulin
Effect of Prolonged Exercise in
Diabetics
Figure 17.1
Exercise and Type 1 Diabetes
• Metabolic control before physical activity
– Avoid exercise if fasting glucose is >300 mg/dl (or
>250 mg/dl with ketosis)
– Ingest carbohydrates if glucose is <100 mg/dl
• Blood glucose monitoring before and after exercise
– Identify when changes in insulin or food intake is
needed
– Learn how blood glucose responds to different
types of exercise
• Food intake
– Consume carbohydrates to prevent hypoglycemia
– Carbohydrates should be readily available during
and after exercise
Effect of Plasma Insulin Levels in
Type 1 Diabetics During Exercise
Figure 17.2
Exercise Prescription for Type 1
Diabetes
• Exercise 20–60 min, 3–4 days per week, 50–85%
heart rate reserve
• May use non-weight bearing, low-impact activities
– If weight-bearing activities are contraindicated
• Use lighter weights (40–60% 1RM), 15–20 reps
– Avoid the Valsalva maneuver
– Heavier weights for athletes
• Drink extra fluids and have carbohydrates available
• Exercise with someone in case of emergency
Exercise and Type 2 Diabetes
• Exercise is a primary treatment
– Help treat obesity
– Help control blood glucose
• Combination of diet and exercise may eliminate
need for drug treatment
• Exercise prescription
– Dynamic aerobic activity at 50–90% HRmax
– 20–60 min, 4–7 times/week
– Strength training is also recommended
– Goal to expend a minimum of 1,000 kcal/week
• May need to reduce dosage of medications to
maintain blood glucose
American Diabetes Association Goals
for Nutrition Therapy
• Attain and maintain optimum metabolic
outcomes to reduce risk of complications
– Blood glucose in normal range
– Improved lipid and lipoprotein profile
– Lower blood pressure
• Prevent and treat chronic diabetes
complications
• Improve health through healthy food choices
and physical activity
• Address individual nutritional needs
Prevention or Delay of Type 2
Diabetes
• Impaired fasting glucose (IFG)
– Fasting BG 100–125 mg/dl
• Impaired glucose tolerance (IGT)
– Oral glucose tolerance test
– 2-hour blood glucose 140–199 mg/dl
• Prediabetes
– Having IFG or IGT
– Likely to develop type 2 diabetes
– 150 min/week of physical activity and
losing 5-10% of body weight reduces risk
• Better approach than using drugs
Asthma
• A respiratory problem characterized by a shortness
of breath accompanied by a wheezing sound
• Due to:
– Contraction of smooth muscle of airways
– Swelling of mucosal cells
– Hypersecretion of mucus
• 20 million are affected by asthma
– 1.9 million emergency room visits
– 4,000 deaths
– Direct and indirect costs of $16.1 billion
Asthma: Diagnosis and Causes
• Diagnosed using pulmonary-function testing
– Low maximal expiratory flow rate
• Triggers
– Dust, chemicals, antibodies, exercise
• Causes influx of Ca+2 into mast cells
– Release of chemical mediators that cause:
• Increased smooth muscle contraction leading to
bronchoconstriction
• Bronchoconstrictor reflex via vagus nerve
• Inflammatory response
Proposed Mechanism by Which an
Asthma Attack Is Initiated
Figure 17.3
Prevention and Relief of Asthma
• Prevention
– Avoidance of allergens
– Immunotherapy
• Medications
– Cromolyn sodium
– 2-agonists
– Theophylline
– Corticosteroids
– Leukotriene inhibitors
Exercise-Induced Asthma
• More common in asthmatics
• Does not necessarily impair performance if controlled
• Caused by drying of respiratory tract
– Increases osmolarity on surface of mast cell
– Triggers Ca+2 influx and airway narrowing
• Reducing the chance of an attack
– Warm-up
– Short-duration exercise
• Treatment
– -agonist in case of attack during exercise
– Other medications to prevent attack
Chronic Obstructive
Pulmonary Disease (COPD)
• Includes chronic bronchitis, emphysema,
and bronchial asthma
– Can create irreversible changes in the lung
– Can severely limit normal activities
• Testing for COPD
– FEV1
– Graded exercise test
• VO2max
• Maximal exercise ventilation
• Changes in arterial PO2 and PCO2
Treatment of COPD
• Goals:
– Reduced reliance on O2 and medications
– Improved ability to complete daily activities
• Treatments:
– Medications (including supplemental O2)
– Breathing exercises
– Dietary therapy
– Exercise
– Counseling
• Outcomes:
– Increased exercise tolerance without
Hypertension
• Classifications:
– Normal <120/<80 mmHg
– Prehypertension 120–139/80–89 mmHg
– Hypertension (stage I) 140–159/90–99 mmHg
• Recommendations
– Lose weight if overweight
– Limit alcohol intake
– Reduce sodium intake
– Maintain adequate dietary K+, Ca+2, Mg+2
– Stop smoking
– Reduce dietary fat, saturated fat, and cholesterol
intake
Exercise for Hypertension
• Exercise can be used as a non-drug treatment
• Recommendations:
– Moderate intensity exercise (40–60% HR reserve)
– 30 minutes on most, preferably all, days
– Goal of expending 700–2000 kcal/week
– ACSM recommendation for improving VO2max can also
be followed
• Precautions
– Blood pressure should be monitored for those on
medications
Cardiac Rehabilitation: Patient
Population
• Those who have or have had:
– Angina pectoris
• Chest pain due to ischemia
– Myocardial infarction (MI)
• Heart damage due to coronary artery occlusion
– Coronary artery bypass graft surgery (CABGS)
• Bypass one or more blocked coronary arteries
saphenous vein or internal mammary artery
– Angioplasty (PTCA)
• Balloon tipped catheter used to open occluded
arteries
• May insert a stent to keep artery open
Cardiac Rehabilitation:
Medications
 -blockers
– Reduce work of the heart
• Anti-arrhythmics
– Control dangerous heart rhythms
• Nitroglycerine
– Reduce angina symptoms
Cardiac Rehabilitation: Testing
• Graded exercise testing
– ECG monitoring (12-lead)
• Heart rate and rhythm
• Signs of ischemia (ST segment depression)
– Blood pressure
– Rating of perceived exertion (RPE)
– Signs or symptoms
• Chest pain
– May include radionuclide imaging
• Evaluate perfusion (201Thallium)
• Evaluate ventricular ejection (99Technetium)
Cardiac Rehabilitation: Exercise
Programs
• Exercise prescription
– Based on GXT results
• MET level, heart rate, signs/symptoms
– Whole body, dynamic exercise
– Intensity, duration, and frequency based on
severity of disease
• Effects
– Increased functional capacity (VO2max)
– Reduced signs/symptoms of ischemia
– Improved risk factor profile
Exercise For Older Adults
• VO2max declines ~1% per year
– Regular exercise may reduce rate of decline
• Benefits of participation
– Improved risk factor profile
– Increased strength and VO2max
– Increased bone mass
• Recommendations
– Similar to younger subjects
– Medical exam and risk factor screening is
essential
Exercise and Bone Health
• Osteoporosis results in reduced bone mineral density
and increased fracture risk
– More common in women over fifty due to lack of
estrogen
• Prevention and treatment
– Dietary calcium
• >1000 mg/day through food and supplements
– Hormone replacement therapy (HRT)
• Prevents bone loss and reduces fracture risk
• May increase risk of cardiovascular disease and
cancers
– Exercise
• Weight-bearing activities and resistance training
• 2–3 hours per week
Exercise During Pregnancy
• Regular endurance exercise poses no risk to the fetus and
is beneficial for the mother
• Recommendations
– Pregnant women should consult their physician prior to
beginning any exercise program
• Absolute and relative contraindications
– Follow ACSM/CDC recommendation
• 30 min/day of moderate-intensity activity on most,
preferably all, days
– Intensity determined by:
• Heart rate, Rating of perceived exertion, or “talk test”
– No supine exercise after first trimester