Week 9: Exercise and Exercise Physiology in Young People

Question 1

Trend for muscle size in childhood (increasing age)

Answer 1

Increases from 42-54% of body weight in boys 5-17 years old

Greater increase in muscle mass in males vs females (due to the presence of testosterone)

Question 2

Trend for body composition in males VS females
(DURNG CHILDHOOD)

Answer 2

Girls have higher percentage body fat and fat mass due to estrogen which drives body fat

Boys have higher fat free mass

Question 3

Change in haematocrit during childhood

Answer 3

50% in a new born –> dropping to 30%

Gradually increases back with age

Question 4

Change in blood, red blood cells and haemoglobin during childhood

Answer 4

Blood: 300-400ml in infant –> 5L in adult

RBC: Gradual increase with age

Haemoglobin: Correlated to body mass
–> more in males than females

Question 5

Change in White blood cells and platelets with age

Answer 5

WBC: Decrease with age
* Elderly people have reduced immune function

Platelets: No change with age

Question 6

What is Lung VS Heart size proportional too?

Answer 6

Lung size - Proportional to HEIGHT

Heart size - Proportional to WEIGHT

Question 7

Normal BP for an infant?

Answer 7

85-95 Systolic / 45-50 Diastolic

Question 8

Change in alveoli in childhood

Answer 8

20 million at birth
INCREASES TO
300 million at 8 YO

Question 9

Trend for respiration during ageing

Answer 9

Decreased respiration rate with increasing age

INVERSE RELATIONSHIP

Question 10

Why do Prepubertal girls have lower relative VO2 Max Values?

Answer 10

• Due to it being relative to body weight, due to them being lighter (on average) results in a lower VO2 max value
• Plus may also have a smaller heart and lungs?

Question 11

Children VS Adults differences in performance for:
1. Cardiovascular
2. Respiratory
3. Movement economy
4. Thermoregulation

Answer 11

TLDR: shorter strides –> work harder to keep same pace/intensity as adult –> smaller ❤️ –> lower SV and CO –> HR needs to increase because CO = HRxSV

1. Higher HR at max vs submax workloads
   –> SV and CO lower in children
2. Less efficicent ventilation (shallow breathing)
3. Shorter, faster strides –> causing higher oxygen cost during running –> lower aerobic reserve at submax workloads
4. Lower sweat rate
   Lower sweat production
   Higher surface area to mass ratio

Question 12

What are the 5 Domains of Childrens development?

Answer 12

1.Physical health and well being
2. Social competence
3. Emotional maturity
4. Language and cognitive skills
5. Communication skills and general knowledge

Question 13

What are the 3 social determinants of health in growth and development?

Answer 13

Socioeconomic. political and cultural context

Daily living conditions

Individual health-related factors

Question 14

Ways to prevent injury or burnout in children?

Answer 14

Avoid year long participation in one single sport

Altering participation when multiple rep squads or teams

Acting on injury at the earliest sign (checkin in at regular intervals)

Question 15

What sort of Strength based exercises should children do?

Answer 15

Large muscle groups

Body weight exercises (preferred)

Completing full range of motion