1. Chapter 9 Resistance-Training Strategies for Youth Obesity

2. Childhood Obesity Overview • National epidemic • Affects both boys and girls across all socioeconomic strata • Critical public health threat for 21st century

3. Terms Defined • Obese • BMI equal to or greater than 95th percentile • Overweight • BMI between 85th and 94th percentile

4. Terms Defined • Childhood • Period before development of secondary sex characteristics • Girls • Age 11 • Boys • Age 13

5. Terms Defined • Adolescence • Period between childhood and adulthood • Girls • Ages 12 to 18 • Boys • Ages 14 to 18 • Youth and pediatric • Children and adolescents

6. 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

7. 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

8. 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

9. 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

10. 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

11. Etiology of Pediatric Obesity • Involves complex familial, psychological, sociocultural, economic, and environmental factors • Genetic conditions • E.g., Prader-Willi syndrome

12. 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

13. 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

14. Environmental Risk Factors Leading to Obesity • Changes in availability of physical education • Increased access to television, videos, and computer games

15. 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

16. Metabolic Syndrome • Clustering of traits, including: • Hyperinsulinemia • Obesity • Hypertension • Hyperlipidemia • Present in 30 percent of obese adolescents • Negatively effects cardiovascular health

17. Other Medical and Psychological Complications • Asthma • Sleep problems • Gastrointestinal problems • Orthopedic disorders • Exacerbated polycystic ovary syndrome • In females

18. Other Medical and Psychological Complications • Depression • Low self-esteem

19. 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

20. 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

21. 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

22. 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

23. 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

24. Program Design Considerations • Underestimate participants’ physical abilities to ensure compliance • Obtain medical clearance for preexisting conditions

25. Exercise Testing Considerations • Perform 1 RM or 10 RM strength tests under qualified supervision • Allow participant to practice proper exercise technique prior to testing

26. 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

27. 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

28. 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

29. 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

30. 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

31. 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

32. 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

33. 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

34. 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

35. 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

36. Perceived Exertion for Children

37. 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

38. 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

39. Other Training Considerations • Use frequency of two to three times per week on nonconsecutive days • Periodization may be increase compliance