Growth and Maturation in Adolescence - Week 8

Adolescence: typical definition

Teenage years (13-18 years) when puberty occurs

Puberty: definition

The process of sexual maturation driven by hormones

Puberty: characteristics involved

Primary and secondary sexual characteristics

Peak height velocity (PHV): age in females

Around 12 years

Peak height velocity (PHV): age in males

Around 14 years

Adolescence: when are strength gains greatest?

~8 months after peak weight velocity and ~12 months after peak height velocity

Adolescence: what drives muscular development?

↑ anabolic hormones; depends on relative nervous system maturation

Adolescence: role of hypertrophy

Muscle growth through hypertrophy accounts for a considerable portion of weight gain during growth

Adolescence: what does muscle development and performance depend on?

Relative maturation of the nervous system

Puberty: why does growth occur?

↑ concentration of anabolic hormones during puberty

Puberty: when does it begin?

At critical levels of fat, body mass, stature and skeletal maturity

Late maturers: adult height

Tend to become slightly taller adults

Late maturers: why taller?

They have been growing over a longer period of time

Males: effect of advanced maturation

Greater gains in height and weight; superior performance in physical tasks

Females: effect of advanced maturation

Greater gains in height, weight and weight-for-height

Females: nature of weight gains

Predominantly ↑ fat rather than muscle mass

Body size and maturity status: what are they predictors of?

Athlete selection, performance and socialisation in several sports

Biological maturity status and leisure-time exercise behaviour

At most weakly associated (self-report measures, adolescent males and females)

Relative age: who performs better?

Children born at the beginning of the year (depending on cut-off)

Maturation timing: key factor

Timing of puberty is a key factor in how adolescents react to it

Early maturation in boys

Generally positive

Late maturation in boys

Difficult

Early maturation in girls

Often difficult

Late maturation in girls

The picture is complicated

Trainability in adolescence: how to assess maturity

Chronological vs biological age; use Tanner stages or peak height velocity

Trainability in adolescence: when do strength increases occur?

~1 year following peak weight velocity

Trainability in adolescence: training during PHV

Modify training to account for weakened bone and muscle imbalances

Training modifications during PHV: what to do

Emphasise flexibility and co-ordination; reduce volume and intensity

Trainability in adolescence: when are near-maximal lifts appropriate?

Once sexually mature and in early adulthood, with good technique

Attitudes to physical activity: effect on MVPA (moderate-to-vigorous PA)

More favourable attitudes → ~30-40% more MVPA at 5- and 10-year follow-up than less favourable attitudes

PA promotion interventions: added value

May come from improving PA-related attitudes

School PE: potential

All youth participate; tremendous potential to influence PA attitudes

Parents: how can they foster positive PA attitudes?

Via modelling

Participation trend: age

Trend toward earlier participation

Participation trend: what is driving it?

Rule changes (e.g. Junior Blasters Cricket, Auskick)

Most popular sports for males aged 5-14

Soccer 21.7%, swimming 16.5%, Australian football 14.9%

Most popular sports for females aged 5-14

Dancing 27.1%, swimming 18.9%, netball 16.2%

Participation trend: new activities

Children are getting involved in what used to be considered nontraditional sports (e.g. tennis, cycling, bowling, cross-country skiing)

Reasons for participation in youth sports

Fun, followed by fun, followed by fun

Primary motivations for youth sports: type of factor

Intrinsic factors

Youth sports fun: most important factors (intrinsic)

Improving skills; testing abilities; excitement of the game; personal accomplishment

Youth sports fun: moderately important factors

Social factors, like being in a team or with friends

Youth sports fun: least important factors (extrinsic)

Getting awards, winning and pleasing others

Youth sports: what should the emphasis be on?

Involvement, skill development and enjoyment of doing the skills

Youth sports: what is of secondary importance?

Winning and receiving rewards for playing

Competence Motivation Theory: core idea

Individuals are motivated by achievement; when success is achieved, they are motivated to continue participation

Competence Motivation Theory: what sustains participation?

A positive motivational climate

Competence Motivation Theory: who should provide support?

Coaches, teachers and parents: good social support and positive feedback, particularly for children <10 years

Competence Motivation Theory: what to do if failure occurs

Parent/coach helps the child see why the mistake occurred, so the child doesn't see themselves as lacking physical ability

Competence Motivation Theory: feedback for children under 10

Parents and coaches are crucial

Competence Motivation Theory: feedback for children over 10

Peer feedback becomes more important

Non-participation: who is more likely to disengage from sport?

Students who are female; from culturally diverse families; lack confidence and don't perceive family and friends as supportive

Individual barriers: coaching and support

Poor coaching or teaching; parent/guardian support

Individual barriers: money and time

Financial barriers; lack of time

Individual barriers: priorities

Value of sport vs academic/creative/economic endeavours

Individual barriers: gender

Females are less likely to be engaged in sport and have lower physical activity than males, particularly in adolescence

Individual barriers: loss of interest

E.g. socialising, academic and cultural pursuits

Individual barriers: other examples

Injury, confidence or lack of facilities