Chapter 5 Considerations Regarding Physical Activity for Children and Youth Chapter 5 Chapter 5 2007 Data on Children • Obesity rates among children have risen from 5% in early 1970’s to more than 18% today. Over the past decade obesity prevalence has doubled in ages 2-5 and tripled in ages 6-11. Most Recent Data • Rates of asthma have doubled from 1980’s • Rates of type II diabetes may be as high as 43%. • Thus, there has been a dramatic rise in the number of children who are now coping with a chronic health condition Chapter 5 Physical Activity and Youth •Effects of Health Status and Physical Activity on Growth and Development • Growth Status is used as an overall health marker for children • Typically growth status is determined by comparing the height and weight of the child against normative data. •Growth may be retarded due to malnutrition or disease. Chapter 5 Physical Activity and Youth •Otherwise healthy children may experience impaired skeletal, muscular, functional development, and obesity if they are not physically active. Chapter 5 Physical Activity and Youth •Aerobic Activity –Typically measured on Treadmill or Cycle Ergometer –Maximal Aerobic considered the best indicator, but peak VO2 is most suited for this population (many will have difficulty achieving a true plateau in VO2 ) –There should be little difference in absolute VO2 (L/min) between the sexes. (male values are approximately 20% greater by late teens) Chapter 5 Physical Activity and Youth •Normal Responses to Aerobic Activity –Children have greater maximal and submaximal heart rate at given exercise intensities compared to adults. •Children under the age of 10 yrs frequently have maximal heart rates exceeding 210 beats per minute, whereas the average 20 year old has a maximal heart rate of approx 195 beats per minute. Chapter 5 Physical Activity and Youth •Normal Responses to Aerobic Activity –Children and adults differ in regard to resting respiratory rates •Resting breathing rates decreases ( volume increases ) progressively during childhood resulting in lower relative minute ventilation as children age. •Absolute minute ventilation increases, and maximum breathing frequency (ventilations per minute) declines as children age. Chapter 5 Physical Activity and Youth •Thermoregulatory Responses to Aerobic Activity –Children have decrease sweating rates –Slower to acclimatize to exercising in the heat –Experience a greater rise in core temperature –Thus, children are more susceptible to heat related illness compared to adults, and have a decreased ability to exercise efficiently in the heat Chapter 5 Physical Activity and Youth •Thermoregulatory Guidelines –Children must be acclimatized slowly to warmer climates –Children should have supervised hydration (every 15-20 minutes) and forced “rest” intervals in hot environments Chapter 5 Physical Activity and Youth •BP Responses to Aerobic Activity –Exercise SBP responses are similar but of less magnitude in children compared to adults ( 23mmHg vs. 6-8 mmHg SBP / MET) –Regulation of intensity is difficult with THR, better with RPE, if child is > 8yrs. The “talk test” is a good method of guiding exercise intensity in children Chapter 5 Physical Activity and Youth •Aerobic Exercise Testing in Children –Children can achieve steady state work faster than adults, so treadmill protocols using 2-3 minute stages are appropriate. –Test Protocols should be designed to last between 8-12 minutes (Peak Vo2) –Children rate RPE values lower for submaximal exercise than adults Chapter 5 Physical Activity and Youth •Guidelines on Exercise Testing in Children –(see article highlights) – See also ACSM's Guidelines for Exercise Testing and Prescription •Benefits of Exercise Testing in Children –Documenting any impairment in cardiac or pulmonary function. –Detecting and managing exercise induced asthma –Detecting myocardial ischemia –Assessing Physical Work Capacity –Assessing the results of rehabilitation programs Chapter 5 Physical Activity and Youth •Benefits of Exercise Testing in Children (cont.) –Documenting functional changes during the course of a progressive disease. –Providing indications for surgery, therapy or additional tests –Assessing cardiac rate, rhythm, and blood pressure response –Assessing exercise-related symptoms –Evaluating the effects of therapy –Increasing the “exercise confidence” of child and parents Chapter 5 Exercise Management Principles Anaerobic Exercise – Anaerobic Power: • 1) Capacity is lower than adults, both absolute and relative measures. • 2) Capacity increases throughout childhood and adolescence and peaks in early adulthood. Chapter 5 Exercise Management Principles Neuromuscular Function – Strength may be improved in both sexes prior to puberty due to neuromuscular adaptations – Significant changes in strength and muscle size in males can occur during the time of peak height velocity (puberty). Chapter 5 Exercise Management Principles Psychological – Social Function – Physical activity has a positive impact on: • • • • 1) Self-concept 2) Self-Efficacy 3) Self-Esteem 4) Depression Chapter 5 Exercise Management Principles Selected Diseases and Disorders of Children and Youth. This is FYI, at this point. We will discuss each pathology later in the semester and the exercise prescription models (precautions and modifications) are similar for adults and children. END. Chapter 5