Presentation revised and updated by

Brian B. Parr, Ph.D.University of South Carolina Aiken

Chapter 17Exercise for Special

Populations

EXERCISE PHYSIOLOGYTheory and Application to Fitness and Performance,

6th edition

Scott K. Powers & Edward T. Howley

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 dyspnea– Increased sense of well-being

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