1 Chapter 12 Physical Development of Children © Gallahue, D.L., & Ozmun, J.C.. Understanding Motor Development. McGraw-Hill

2 Key Concept The Physical Fitness of Children Has Been Assessed Through a Variety of Laboratory and Field-based Measures, and May Be Improved Through the Application of Appropriate Training Techniques

3 “Fitness” Defined Physical Fitness Is a Positive State of Well-being Influenced by Regular Physical Activity, Genetic Make-up, and Nutritional Adequacy

4 Are Children Fit? No (> obesity, < fitness scores, sedentary lifestyles, conventional wisdom) Yes (children are naturally active, lack of “gold standard”, apples & oranges, lack of criterion measures) Perhaps (what do you think?)

5 Components of Health- related Fitness (Table 12.2) Aerobic endurance Muscular strength Muscular endurance Joint flexibility Body composition

6 Aerobic Endurance Max VO 2 (45-55ml.Kg) Heart rate responses (Children around age 6 at rest ~80bpm, around age 10 ~70 bpm) Measures of physical activity (activity recall, heart rate monitors, doubly labeled water, direct observation, accelerometers) Aerobic trainability (“trigger” hypothesis)

7 Muscular Strength and Endurance (Table 12.1) Isotonic/isometric/isokinetic The Strength – Endurance continuum Measures of Strength (Lab: dynamometers & tensiometers, Field: internal validity?)

8 Muscular Strength and Endurance (cont.) Muscular endurance (lab: ecological validity?, field: sit-ups, push-ups, pull-ups) Minimal sex differences Trainability (resistance training vs. weight lifting) Training results (positive: neuromuscular adaptation, muscle hypertrophy, negative: growth plate injuries, overuse injuries)

9 Joint Flexibility Static/Dynamic flexibility (static vs. ballistic stretching) Joint specific Girls outperform boys Preadolescent growth spurt (bone growth precedes muscle & tendon growth) Trainability (“use it or loose it”)

10 Body Composition Proportion of lean body mass to fat body mass Measures (Lab: hydrostatic weighing, electrical impedance, Field: skin-fold calipers, BMI) Sedentary lifestyles and obesity Trainability (team approach, physical activity/nutrition education)

11 Components of Motor Fitness (Table 12.3) Movement control factors: -balance (static & dynamic) -coordination (gross motor & eye-hand) Force production factors: -movement speed -agility/quickness -power

12 Coordination Sensory-motor integration process Boys more proficient than girls from age 6> Measures (cable jump, hoping, skipping, ball dribble with hands or feet) Changes (linear throughout childhood)

13 Balance Vestibular apparatus (semicircular canals, otolith, macula) Girls more proficient up to age 7-8 Measures (Static: one foot balances, Dynamic: walking board) Changes (linear improvements from 2-12)

14 Movement Speed Reaction time & movement time No sex differences to age 6-7, boys faster at all later ages Measures (dashes to meters) Changes (linear throughout childhood)

15 Agility/Quickness Speed with directional changes Minimal sex differences during early childhood Measures (shuttle runs, side straddle) Changes (linear for both boys and girls, but girls level at age 13 while boys continue to improve through adolescence)

16 Power Explosive strength (strength x speed) Boys outperform girls at all ages Measures (vertical jump, long jump, distance throw, velocity throw) Changes (linear changes - early childhood through adolescence in boys, to in girls)

17 Concluding Concept Although the Components of Childhood Fitness Can Be Modified Through Training, We Need To Find Ways to Help Children Sustain Increased Physical Activity That Are Both Purposeful and Meaningful