Growth and Development Chapter 18
Learning Objectives: • Identify the stages of growth & development • Describe factors affecting growth & development • Understand the necessity of physical activity for optimal growth & development • Recognize and understand gender and individual differences in growth & development
Terminology • Human growth- proceeds by the release of chemicals (hormones) from glands. The hormones and their levels vary throughout your life. Growth can be physical (height, weight, strength), mental (cognitive) or emotional. • Motor Learning- physical or motor skills can be learned through repetition and practice. Involves physical development and nervous control
Terminology • Sport psychology- psychology is the study of thought processes and behaviour in relation to the environment. The goal here is to enhance performance by improving mental aspects of sport. • Coaching- a coach supports the development of an athlete or team. They design training schedules, strategize, resolve conflict and determine philosophy
Areas of Human Development • Physical: bones, muscles, energy systems, nervous system • Cognitive: interpret and process information. Also emotional development and self-awareness/self-concept • Motor or skills development: physical and cognitive to learn how to do repetitive tasks • Social development: relationships with peers, friends, relatives, adults and others.
Age and Physical Development • Measures of age can be chronological, skeletal or developmental. • Skeletal age is defined based on the ossification of bones and fusion of growth plates. Nutrition, diet, disease and injuries can all delay skeletal development. • In general mesomorphs mature earlier and develop broad muscular bodies. Ectomorphs tend to mature late and tend to have narrow hips and shoulders with long limbs. Endomorphs tend to lay down more fatty tissues and be thicker of limb. • Most people belong to more than one category!
Age and Physical Development • Developmental age is related to the motor and cognitive abilities of the person: • General bench marks include potty training, walking, tying shoes. • Some people mature in these respects faster than others and may be developmentally delayed or enhanced.
Adolescence • The variability of body types (somatotypes) become more evident • Ectomorph • Mesomorph • Endomorph • Usually individuals are a combination of these body types
Ectomorph • Linear shape • Delicate bone structure • Little fat • Long limbs relative to the body
Mesomorph • Well-muscled • Little body fat • Broad shoulders • Narrow waist
Endomorph • Rounded appearance • Heavy bone structure • Little bone and muscle definition
Stages of Growth & Development • Infancy • Childhood • Adolescence • Adulthood
Infancy • BIRTH TWO/THREE YEARS • Period of rapid growth • Males are usually heavier and taller than females at birth
Childhood • ONE YEAR (1) TENYEARS (10) • Consists of: • Early childhood • Mid-Childhood • Late Childhood
Early Childhood • One year to six years of age • Gradual loss of “baby fat” • Girls lose less fat than boys • Rapid growth but not as rapid as infancy • Quite flexible • Muscle development while at play
Mid-Childhood • Six to ten years of age • Slower, more constant growth • Improved coordination and motor functioning
Late Childhood • Ten to sixteen years of age • Increased rate of growth • Fat deposition just prior to adolescent growth spurt • 9-10 years of age in girls • 11-12 years of age in boys • Individual differences in maturation
Late Childhood • Development of the reproductive system • Appearance of secondary sex characteristics • Breasts • Pubic Hair • Redistribution of body weight • Boys - muscle tissue, body fat • Girls - slight body fat
The adolescent growth spurt occurs approximately two years earlier in girls than in boys. TRUE True or False?
There is a significant difference between female and male physique prior to puberty. FALSE True or False?
Within each of the life stages, there is individuality and variability in growth and development among people TRUE True or False?
Late Childhood • Earlier onset of maturation in females may account for their ability to achieve world-class status across many sports • For example, Tara Lipinski, is the youngest US ladies’ figure skating champion (15 y.o.a)
Adolescence • Fourteen to twenty years of age • Following puberty • Ends with onset of adulthood • Obvious differences in physical growth cease with the end of adolescence
Adolescence • External social pressures for the “ideal” body type • Combined with many physical, hormonal, and psychological changes that occur at this time
Different Rates of Growth for Body Parts • From birth arms and legs grow 4x their length, while head only doubles • Cephalocaudal sequence • Growth is fastest in the head, followed by trunk and then extremities • Proximodistal sequence • Body movements that originate closer to the centre of body develop faster. i.e/ running develops earlier than precise finger movements to play piano
Factors Affecting Growth & Development • Large variation among individuals • A number of factors affect growth and development, including: • Hormonal activity • Heredity • Nutrition • Socioeconomic status • Exercise
Hormonal Activity • Pituitary gland secretes hGH – causes widespread growth • Pituitary gland secretes hormones that activate testosterone production in males and estrogen production in females at puberty • Thyroid gland secretes thryroxine, which is important for regulating metabolism
Hormonal disorders • Androgen insensitivity • No secondary sex characteristics • Hypo/hyperthyroidism • Weight gain/loss • Cold/hot • Gigantism/acromegaly • Excessive hGH production
Acromegaly - Andre The Giant 7’4” Gigantism – World’s tallest man 8’11”
Heredity • Genetic information that is passed on from generation to generation • These genes are also affected by environmental factors • For example, malnutrition may prevent an individual from growing to their maximum potential height
Nutrition • Adequate nutrients are essential for growth & development • Proteins contribute to the growth and repair of body tissues, including muscle
Nutrition • Undernourishment or malnutrition can delay growth • Undernourishment exists even in countries with abundant food supplies • Overeating is also a problem in these countries and can lead to obesity when combined with a sedentary lifestyle
Socioeconomic Status • Body size is positively related to socioeconomic status and may be related to nutrition • That is, socioeconomic status affects • Income (money to spend on food) • Education (knowledge about healthy food) • Time (food selection and preparation time) • Availability (access to stores with healthy food choices)
Socioeconomic Status • Other factors may contribute to the differences observed in growth & development among individuals, such as • Lower levels of stress; • Better sleeping patterns • Regular exercise • These factors are easier to ensure when the basic necessities are met
Exercise & Body Composition • Active children and teenagers show: • An increase in lean body mass • A decrease in percent body fat • Muscle hypertrophy with exercise