Lecture 17 Flashcards
Lecture 17:
Define Growth
The increase in size of body or part of body
Lecture 17:
What are 2 ways development occurs?
1.) differentiation - tissues becoming more specialized in their functions as we age/mature
2.) functional changes
Lecture 17:
What is Maturation & 3 key ways it occurs?
The process of the body taking adult form (occurs @ different rates for everyone)
1.) chronological age
2.) skeletal age
3.) stage of sexual maturation (larger spikes in sex hormones)
Lecture 17:
When does development and maturation occur for infancy?
The full first year of life
Lecture 17:
What is the childhood development range?
First birthday to puberty
Lecture 17:
When discussing development/maturation, what is puberty?
Development of secondary sex characteristics
Lecture 17:
What is the adolescence development range?
From puberty to growth completion
Lecture 17:
Discuss the rate of change in heath and weight for the following age groups:
- 0-2years, 2years to before puberty, puberty onset, & mid puberty - late teens
1.) 0-2 years = fast growth in height/weight
2.) 2 - before puberty = slow
3.) puberty onset = fast
4.) mid puberty - late teens = slow
Lecture 17:
Do height and weight changes occur at the same time?
No, height & weight change is not synchronized
Lecture 17:
At what age is height change fastest in girls? In boys?
Height change is fastest in 12y girls & 14y boys
Lecture 17:
At what age is weight change fastest in girls? In boys?
Weight change fastest in 12.5y girls & 14.5y boys
Lecture 17:
When discussing bone ossification from fetus to adulthood; what happens to the growth plate?
Cartilage lines bone to bone & once growth plate is closed than ossification is complete
Lecture 17:
What is growth plate closure stimulated by?
- what age is ossification completed at in girls vs boys
Growth plate closure stimulated by estrogen
- girls have full bone maturity in mid teens vs boys who have full bone maturity in late teens or early 20’s
Lecture 17:
What is the importance of Calcium for growth & development?
Calcium is essential for bone health
- increase in bone mineral density occurs with increased consumption of calcium
- decrease chances of osteoporosis in later life when consuming adequate calcium
Lecture 17:
Muscle mass steadily increases with weight; what % of body weight is muscle mass @ birth?
25% of body weight is muscle mass at birth
Lecture 17:
What % of body weight is muscle mass in young women?
30-35% of body weight = muscle mass in young women (due to estrogen)
Lecture 17:
What % of body weight is muscle mass in young men?
40-45% body weight = muscle mass in young men (due to testosterone levels)
Lecture 17:
AT what age do girls and boys reach their peak % muscle mass?
1.) Girls reach peak muscle mass % @ 16-20 years
2.) Boys reach peak muscle mass % @ 18-25 years
Lecture 17:
What does fibre hypertrophy lead to?
Increased muscle mass
Lecture 17:
What are 3 factors affecting amount of fat deposits?
1.) Diet - changeable
2.) Exercise Habits - changeable
3.) Heredity - not changeable
Lecture 17:
When discussing changes in % body fat with age; what % @ birth? What % when physical;;y mature (women vs men)?
- Birth = 10-12% body fat
- Physically Mature Women = 25%
- Physically Mature Men = 15%
Lecture 17:
What happens during neurological development in childhood?
1.) balance, agility, & coordination improve
2.) ongoing myelination of nerves & brain helps increase strength which helps improve the above 3 things
Lecture 17:
What age does strength & muscle increase in women? In men?
Strength increases as muscle mass increases with age
- women peaks at ~20yrs
- men peak at 20-30yrs
Lecture 17:
What does strength, power, & skill require?
All 3 require myelination
Lecture 17:
What does peak performance in youth require?
- what age for boys vs girls
Peak performance requires neural maturity
- boys experienced marked change at ~12 years
- girls experienced more gradual, linear changes
Lecture 17:
What are resting & submaximal blood pressures like in youth?
Resting and submaximal blood pressure in youth is lower than in adults (related to body size) as they have smaller hearts & lower peripheral resistance during exercise
Lecture 17:
What is the resting and submaximal stroke volume & heart rate in children compared to adults?
Youth have lower SV due to smaller heart & lower blood volume and have higher HR to compensate for low SV
- slightly lower cardiac output than an adult
- O2 difference increases to compensate further
Lecture 17:
Compare Max HR & SV in children to adults? Is it higher or lower?
Max HR in children is higher than in adults but max stroke volume is lower in children than in adults
Lecture 17:
What is the difference in max cardiac output in children compared to adults?
Max cardiac output is lower in children which limits performance due to lowered O2 delivery
- not a serious limitation for relative workloads
Lecture 17:
Why are Cardiorespiratory changes important for children doing acute exercise?
Cardiorespiratory changes during exercise accommodate muscles’ need for O2
Lecture 17:
What are some key Cardiorespiratory changes that occur with age?
VO2max L/min increased with age (boys & girls)
- VO2max in ml/kg/min is steady with age in boys but decreases with age in girls
- L/min more appropriate representation during growth year
Lecture 17:
How can you scale VO2max data/measurements for size?
Since VO2max differs from absolute values we can reduce the effect of body size on data by using body surface area or weight to the 0.75 power
Lecture 17:
Compare children’s economy of effort to that of an adult
Children’s economy of effort is worse than an adults
- O2 consumption per kg in children is greater than adults
- with age, skills will improve & strides will lengthen
Lecture 17:
What happens to endurance running pace with age & why?
Endurance running pace increases with age purely resulting from economy of effort
- increases regardless of VO2 max changes & training status
Lecture 17:
Why is the glycolytic capacity lower in a child than an adult?
Lower glycolytic capacity in muscles due to… less muscle glycogen, less glycolytic enzyme activity, lower blood lactate levels, & increase in mean/peak power with age
Lecture 17:
What are 3 key endocrine responses that children experience during acute exercise?
1.) surge in exercising growth hormone & insulin-like growth factor increases more than in adults
2.) children are hypoglycemia at exercise onset
3.) children have immature liver glycogenolytic systems
Lecture 17:
What are the different substrates children rely more on compared to adults, during acute exercise?
Children are more reliant on fat oxidation and have higher exogenous glucose use compared to adults
Lecture 17:
What are 4 key reasons why children’s training needs differ from adults?
1.) body composition
2.) strength
3.) maximal oxygen consumption
4.) anaerobic capacity
Lecture 17:
When discussing physiological adaptations to exercise training, how do children’s body weights & compositions change with exercise?
Children’s response to physical training is similar to adult responses
- training in children leads to decreased body weight & fat mass and increased FFM
- significant bone growth occurs in children
Lecture 17:
Is weight lifting safe & beneficial for children?
- explain how
Weightlifting is safe & beneficial when prescribed & supervised as injury risk is low
- weight training protects against injury
- strength gains in children only occur through neural mechanisms (no hypertrophy) whereas adult gains are both
Lecture 17:
What are some physiological adaptations children experience with aerobic training?
- in adolescents?
Children experiences little to no change in VO2 max but performance increases due to improved running economy
- adolescents have more marked change in VO2 max (likely due to increase in heart size & SV)
Lecture 17:
What are 3 key physiological adaptations/effects of anaerobic training in children?
1.) increased resting PCr, ATP, & glycogen levels
2.) increased phosphofructokinase (PFK) activity
3.) increased maximal blood lactate level/threshold
Lecture 17:
How does thermal stress differ in children vs adults & how does it influence children’s exercise?
There is an increased surface area-mass ratio in children and decreased evaporative heat loss (lowered sweat levels) in children
- slower heat acclimation in children but slow to cool down
- greater conductive heat loss & gain
Lecture 17:
How does exercise influence growth with training?
- exercise has little or no negative effect on height
- training affects body weight & body composition (with intensity)
- exercise does not affect peak height velocity nor rate of skeletal maturation
