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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Childhood Obesity Overview National epidemic Affects both boys and girls across all socioeconomic strata Critical public health threat for 21 st century

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Terms Defined Obese –BMI equal to or greater than 95th percentile Overweight –BMI between 85th and 94th percentile

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Terms Defined Childhood –Period before development of secondary sex characteristics –Girls Age 11 –Boys Age 13

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Terms Defined Adolescence –Period between childhood and adulthood –Girls Ages 12 to 18 –Boys Ages 14 to 18 Youth and pediatric –Children and adolescents

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Prevalence of Youth Obesity 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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Prevalence of Youth Obesity 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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Prevalence of Youth Obesity 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

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Etiology of Pediatric Obesity Involves complex familial, psychological, sociocultural, economic, and environmental factors Genetic conditions –E.g., Prader-Willi syndrome

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

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Environmental Risk Factors Leading to Obesity Changes in availability of physical education Increased access to television, videos, and computer games

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Metabolic Syndrome Clustering of traits, including: –Hyperinsulinemia –Obesity –Hypertension –Hyperlipidemia Present in 30 percent of obese adolescents Negatively effects cardiovascular health

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Other Medical and Psychological Complications Asthma Sleep problems Gastrointestinal problems Orthopedic disorders Exacerbated polycystic ovary syndrome –In females

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Other Medical and Psychological Complications Depression Low self-esteem

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

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

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

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Design Considerations 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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Program Design Considerations Underestimate participants’ physical abilities to ensure compliance Obtain medical clearance for preexisting conditions

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Exercise Testing Considerations Perform 1 RM or 10 RM strength tests under qualified supervision Allow participant to practice proper exercise technique prior to testing

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

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

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

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

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

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

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

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

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

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Perceived Exertion for Children

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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Other Training Considerations 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

Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Other Training Considerations Use frequency of two to three times per week on nonconsecutive days Periodization may be increase compliance