Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chapter 9 Resistance-Training Strategies for Youth Obesity

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED.

Chapter 9

Resistance-Training Strategies for Youth Obesity


Childhood Obesity Overview

• National epidemic

• Affects both boys and girls across all socioeconomic strata

• Critical public health threat for 21st century


Terms Defined

• Obese– BMI equal to or greater than 95th percentile

• Overweight– BMI between 85th and 94th percentile


Terms Defined

• Childhood– Period before development of secondary sex

characteristics

– Girls• Age 11

– Boys• Age 13


Terms Defined

• Adolescence– Period between childhood and adulthood

– Girls• Ages 12 to 18

– Boys• Ages 14 to 18

• Youth and pediatric– Children and adolescents


Prevalence of Youth Obesity

• During last 30 years, rates have doubled for adolescents and tripled for children

• 31.9 percent overweight

• 16.3 percent obese

• Approximately 9 million American children over age 6 considered obese



• 20 percent of overweight 4-year-olds and 80 percent of overweight adolescents may become obese adults

• Of children ages 2 to 5, 24.4 percent considered overweight– 12.4 percent obese



• Overall adult life expectancy decreases due to comorbidities– E.g., type 2 diabetes, cardiovascular disease, cancer

• Of new military recruits who exceed weight-for-height standards, 80 percent leave service before completing first term



• Of children ages 9 to 13, 61 percent do not participate in organized physical activity during non-school hours– 23 percent do not participate in any free time physical

activity


Economic Impact of Youth Obesity

• Obesity-associated hospital costs for youth more than tripled over last 20 years

• $117 billion spent annually in health care costs attributed to obesity/obesity-related complications

• Consumes 6 percent of national health care dollars


Etiology of Pediatric Obesity

• Involves complex familial, psychological, sociocultural, economic, and environmental factors

• Genetic conditions– E.g., Prader-Willi syndrome


Etiology of Pediatric Obesity

• Very small increases in energy intake over time can lead to weight gain

• Reduction in total daily energy expenditure more prevalent in children


Environmental Risk Factors Leading to Obesity

• Family dynamics– E.g., food choices, parental adiposity

• Lack of safe places for physical activity

• Lack of access to healthful food

• Increased consumption of energy-dense fried foods and carbonated beverages


Environmental Risk Factors Leading to Obesity

• Changes in availability of physical education

• Increased access to television, videos, and computer games


Type 2 Diabetes

• Lifetime risk of being diagnosed with diabetes estimated at 30 percent for boys and 40 percent for girls

• Related conditions occur earlier in life– E.g., kidney failure, amputation, blindness

• 45 percent of new cases occur in (obese) children and adolescents


Metabolic Syndrome

• Clustering of traits, including:– Hyperinsulinemia

– Obesity

– Hypertension

– Hyperlipidemia

• Present in 30 percent of obese adolescents

• Negatively effects cardiovascular health


Other Medical and Psychological Complications

• Asthma

• Sleep problems

• Gastrointestinal problems

• Orthopedic disorders

• Exacerbated polycystic ovary syndrome– In females


Other Medical and Psychological Complications

• Depression

• Low self-esteem


Benefits of Resistance Training

• Increases muscle strength and power

• Increases local muscular endurance

• Increases bone mineral density

• Increases cardiorespiratory fitness

• Improves blood lipid profile

• Improves body composition


Benefits of Resistance Training

• Improves motor performance skills

• Enhances sports performance

• Increases resistance to injury

• Enhances mental health and well-being

• Stimulates more positive attitude toward lifetime physical activity


Research Supports Resistance Training

• Studies show improvements in health and body composition of both normal-weight and obese youth

• Refer to Table 19.2 for summary of results


Program Design Considerations

• Must be carefully prescribed and supervised to avoid injury

• Risk for overuse soft tissue injuries greatest concern

• No minimum age for participation

• Children should understand potential risks and benefits



• Trainers must be qualified exercise professionals with additional awareness of issues unique to childhood/adolescence

• Special considerations include:– Close supervision

– Age-appropriate instruction

– Safe exercise environment



• Underestimate participants’ physical abilities to ensure compliance

• Obtain medical clearance for preexisting conditions


Exercise Testing Considerations

• Perform 1 RM or 10 RM strength tests under qualified supervision

• Allow participant to practice proper exercise technique prior to testing


Exercise Testing Considerations

• Gradually increasing weight and adding testing sets may improve accuracy of strength testing

• Perform dynamic activities during warm-up

• Perform static stretching during cooldown


Program Components

• Develop rapport with each child

• Make exercise area non-threatening

• Use positive encouragement

• Treat performance as “challenge”– Instead of pass/fail test

• Provide qualified instruction and supervision


Program Components

• Ensure safe, hazard-free exercise environment

• Teach youth benefits and concerns associated with resistance training

• Begin each session with five- to 10-minute warm-up period


Program Components

• Start with 1 or 2 sets of 10 to 15 repetitions with light load on variety of exercises

• Progress to 2 or 3 sets of 6 to 15 repetitions depending on needs and goals

• Increase resistance gradually as strength improves


Program Components

• Focus on correct exercise technique– Instead of amount lifted

• Strength train two to three times per week on nonconsecutive days

• Use individualized workout logs to monitor progress

• Review sample 24-Week Program


Exercise Selection

• Must be appropriate for obese child’s body size, fitness level, and experience

• Should promote muscle balance across joints and between opposing muscle groups


Benefits of Weight Machines

• Fixed, stabilized movement easier to perform

• Seated position means excess body weight cannot hinder performance

• May be more motivational– At least in the beginning


Sequence of Exercises

• Perform larger muscle group exercises before smaller muscle group exercises

• Perform multiple-joint exercises before single-joint exercises– Allowing heavier weights to be used first


Training Intensity

• Start with 1 set of 10 to 15 repetitions on variety of exercises

• Systematically perform additional sets

• Vary intensity to avoid training plateaus and optimize training adaptations


Training Intensity

• Understand relationship between percent of 1 RM and number of repetitions that can be performed

• Establish repetition range– Then adjust training load to maintain desired intensity

• Use tools to help gauge intensity– E.g., perceived exertion for children scale


Perceived Exertion for Children


Other Training Considerations

• Effective to have 1-, 2- or 3-set protocols for both normal-weight and obese youth during first few months

• Multiple-set training protocol likely more effective at maximizing training adaptations and maintaining adherence over long-term



• Periodically vary sets, repetitions, and number of exercises

• Include rest period of one to two minutes between sets

• Use moderate velocity in the beginning– Vary with experience



• Use frequency of two to three times per week on nonconsecutive days

• Periodization may be increase compliance

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Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Chapter 9 Resistance-Training Strategies for Youth Obesity