DEVELOPMENT AND TRAINING FROM CHILD TO ADULT James Veale B.App.Sci. HONS PhD Research Student Exercise Physiology AIS/AFL Academy U17 Strength & Conditioning Coach james.veale@live.vu.edu.au 1
INTRODUCTION Today we will cover two questions: 1. What is the growth and development of kids? 2. How do we start physically training kids in Junior Programs? 2
TERMINOLOGY Chronological age date of birth Skeletal age age of bone growth, and Stage of sexual maturation rate of sexual development. Growth an increase in the size of the body or its parts Development the functional changes that occur with growth Maturation process of taking on an adult form and becoming fully functional 3
BIOLOGY vs. CHRONOLOGY Biological age and chronological age are not necessarily the same thing!! Biggest challenges in junior sport 4
PHYSICAL ACTIVITY Does physical activity influence height? Malina, Bouchard & Bar-Or (2004) Growth, Maturation & Physical Activity. Human Kinetics, 2Ed 5
INFLUENCES IN STRENGTH GAINS Prepubescent strength Coordination MU activation Neurological activation Adolescent Neural adaptation Muscle size (FFM) Hormonal 6
GROWTH DEVELOPMENT Girls mature physiologically about 2 years earlier than boys do. Bones are formed through the process of ossification, which is usually complete by one s early 20s. 7
GROWTH PLATES Epiphyseal plate maturation 18-20 years Injuries may impede growth 8
ADJUSTING PHYSIOLOGICAL VARIABLES FOR BODY SIZE Many processes that determine fitness or performance are associated with structures whose sizes relate to total body dimensions. i.e. lung capacity ventilation heart size cardiac output skeletal muscle mass muscle strength 9
CARDIOVASCULAR CHANGES Heart rate Basal HR in newborns ~140bpm (SD 20). 1yr ~ 100bpm 6yrs ~ 80bpm 10yrs ~ 70bpm Late adolescence Boys ~ 57-60bpm Girls ~ 62-63bpm 10
CARDIOVASCULAR CHANGES Resting stroke volume 3-4 ml at birth 40ml prior to adolescence 60ml young adult male 11
CARDIOVASCULAR CHANGES Resting cardiac output 0.5 L/min at birth 5L/min in young adult male 12
RESPIRATORY FUNCTION Respiratory rate (breaths/min) Birth ~ 40 breaths/min 1yr ~ 30 breaths/min 5-6 yrs ~ 22 breaths/min Stabilizes at ~16-17 breaths/min No consistent sex differences 13
SHORT-BURST ACTIVITIES AND ANAEROBIC PERFORMANCE Average duration of intense exercise in 6-10 yr olds over a 12 hr period = 3sec (Bailey et al. 1995). No single periods of over 10 consecutive minutes. 95% of all intense activity < 15secs. Average duration of all activities, was 6 sec. Rowland (2004) Children s Exercise Physiology. 2 nd Ed. Human Kinetics. 14
THERMOREGULATION Body surface area to body mass ratio. Having a greater BSA/BM ratio means that smaller children are better able to lose heat via dry heat loss (radiation, convection, conduction) than larger children or adults in temperate or slightly warm environments. However, due to the larger BSA/BM ratio, a child s body in a hot environment absorbs heat from the surroundings which may not be able to be compensated for by evaporation. In cold environments, the child s body dissipates heat to the surroundings which may not be able to be compensated for by heat production. 15
PHYSICAL ACTIVITY vs. TRAINING Training programs need to be monitored: Quality of coaching, Coach-athlete relationships, Dietary control and manipulation, Parental involvement, and related Psychosocial factors. 16
GROWTH DEVELOPMENT Strength increases Blood volume, heart size, and blood pressure increase Heart rate decreases Aerobic and anaerobic capacities and running economy increase Lung volume and peak flow increase 17
TRAINING RECOMMENDATIONS Let them play!!! Teach them basic principles involved in training: Warm-up Stretching Cool-down Children will often enjoy these activities as it makes them feel like they are training like their hero s. Ultimately, Junior football should be about having FUN! 18