From childhood to adulthood, increases in muscle mass (even in the absence of a training program) are primarily due to
A) fiber hypertrophy
B) fiber hyperplasia
C) neurological mechanisms
D) multinucleation

A) fiber hypertrophy

Fat deposits increase through childhood and adolescence due to
A) increases in size of fat cells
B) increases in number of fat cells
C) increases in size and number of fat cells
D) increases in fat deposits outside fat cells

C) increases in size and number of fat cells

High levels of muscle strength, power, and skill are not possible in children until ________________ occurs.
A) aerobic training
B) an increase in heart size
C) enhanced growth hormone secretion
D) nerve myelination

D) nerve myelination

Why does maximal heart rate decrease with age?
A) heart fatigue
B) adrenergic receptor desensitization
C) slower nerve conduction
D) less calcium availability

B) adrenergic receptor desensitization

Why do adolescent girls have lower maximal ventilatory volumes compared to adolescent boys?
A) estrogen limits lung elasticity
B) testosterone enlarges airways
C) lung volumes are related to body size
D) alveolar surface area is larger in boys

C) lung volumes are related to body size

Which of these bioenergetic systems is relatively unchanged from childhood to adulthood?

A) ATP-PCr
B) anaerobic glycolytic
C) aerobic
D) oxidative phosphorylative

Which fuel substrate do children rely on more during aerobic exercise?
A) protein
B) carbohydrate
C) nucleic acids
D) fat

D) fat

Aerobic training in children leads to improved running performance primarily because of
A) increased maximal heart rate
B) increased maximal stroke volume
C) improved running economy
D) increased arterial oxygen-carrying capacity

C) improved running economy

Why are children at higher risk for excessive convective heat transfer?
A) higher surface-area-to-mass ratio
B) lower total blood volume
C) lower sweat secretion
D) lower surface-area-to-mass ratio

A) higher surface-area-to-mass ratio

The state of a child or adolescent's maturity can be defined by all of these except
A) chronological age
B) height
C) skeletal age
D) stage of sexual maturation

B) height

Other than physically supporting the body, bone serves an important function as a(n)
A) collagen reservoir
B) predictor of peak muscle mass
C) index of neurological development
D) calcium reservoir

D) calcium reservoir

An isolated short-term high-impact exercise program in childhood leads to increases in bone mineral density that can persist for up to
A) 3 months
B) 1 year
C) 4 years
D) 10 years

C) 4 years

Bone mineral density peaks around the ages of
A) 25 to 35 years
B) 15 to 17 years
C) 10 to 12 years
D) 50 to 55 years

A) 25 to 35 years

Muscle mass in childhood is about ______% of body weight and increases with age until it peaks around ______% of body weight in young men.
A) 25, 30
B) 15, 35
C) 15, 25
D) 25,45

D) 25,45

From ages 14 to 20 in girls, fat-free mass ______________ and fat mass _______________.
A) decreases, increases
B) plateaus, increases
C) increases, increases
D) increases, decreases

B) plateaus, increases

From ages 14 to 20 in boys, fat-free mass _______________ and fat mass _______________.
A) increases greatly, increases slightly
B) increases slightly, increases greatly
C) increases greatly, decreases
D) increases slightly, plateaus

A) increases greatly, increases slightly

Peak rates of growth in body weight occur at age _______ in girls and ______ in boys.
A) 11, 13
B) 12.5, 14.5
C) 13.5, 16
D) 14, 18

B) 12.5, 14.5

The best form of exercise for increasing bone mineral density in children is
A) bicycling
B) swimming
C) kayaking
D) basketball

D) basketball

Puberty is an important marker of the shift from childhood to adolescence. (T/F)

True

Peak height velocity occurs between ages 15 and 17 for both boys and girls. (T/F)

False

Testosterone leads to faster closure of the growth plate in long bones. (T/F)

False

Muscles lengthen as children grow by adding more sarcomeres to myofibrils. (T/F)

True

The peak rates of growth in height and weight occur
A) at the same time
B) about 6 months apart
C) about 2 years apart
D) about 3 years apart

C) about 2 years apart

Physical activity is necessary for the development of motor ability. (T/F)

True

Motor ability in girls plateaus after puberty because of all of the following factors EXCEPT
A) increased fat deposition
B) enhanced testosterone production
C) lower muscle mass
D) decreased physical activity

B) enhanced testosterone production

Recommendations for children include _____ minutes of moderate to vigorous physical activity per day.
A) 30
B) 40
C) 50
D) 60

D) 60

Resistance training leads to strength gains in children through which mechanism?
A) neural mechanisms
B) fiber hypertrophy
C) fiber hyperplasia
D) sarcomere lengthening

A) neural mechanisms

Although the mechanisms by which aerobic training leads to enhanced aerobic performance in adolescents are still unclear, it is likely that ________________ may play a role.
A) increased maximal heart rate
B) increased maximal stroke volume
C) improved ru

B) increased maximal stroke volume

Anaerobic training in children leads to increased anaerobic capacity due to all of the following EXCEPT
A) increased resting levels of PCr, glycogen
B) increased glycolytic enzyme activity
C) increased maximal blood lactate levels
D) increased calcium ava

D) increased calcium availability

Resistance training is dangerous to proper bone and muscle development in children. (T/F)

False

With aerobic training in children, VO2max undergoes little or no change. (T/F)

True

With both resistance and aerobic training, children exhibit a(n) ______________ in fat mass and a(n) ________________ in fat-free mass.
A) decrease, decrease
B) increase, plateau
C) decrease, increase
D) increase, decrease

C) decrease, increase

Which of these cardiovascular variables is higher during a single bout of submaximal exercise in children (compared to adults)?
A) blood pressure
B) stroke volume
C) cardiac output
D) heart rate

D) heart rate

Why is the arterial-venous oxygen difference during a single bout of exercise higher in children than in adults?
A) higher cardiac output
B) higher arterial oxygen content
C) higher muscle blood flow
D) higher stroke volume

C) higher muscle blood flow

Why does stroke volume increase from childhood through adolescence to adulthood?
A) heart size increases
B) heart rate decreases
C) red blood cell volume increases
D) capillary oncotic pressure increases

A) heart size increases

As children grow into adolescence and then adulthood, why does maximal oxygen uptake increase?
A) Cardiorespiratory capacities increase.
B) Arterial oxygen saturation increases.
C) Arterial-venous oxygen difference increases.
D) Bohr shift is less pronoun

A) cardio respiratory capacitates increase

Anaerobic capacity is lower in children than in adults for all of the following reasons EXCEPT
A) lower glycolytic enzyme activity
B) faster lactate accumulation
C) limited glycogen stores
D) lower content of glycolytic enzymes

B) faster lactate accumulation

Compared to adults, children have
A) lower peripheral resistance
B) increased blood pressure response
C) decreased muscle perfusion
D) increased stroke volume

A) lower peripheral resistance

Aerobic capacity peaks between _______ and ______ years of age in girls.
A) 9, 12
B) 12,15
C) 15, 18
D) 21, 24

B) 12, 15

Muscle strength increases with age in part because of neurological maturity. (T/F)

True

In children, stroke volume is higher while heart rate is slower during a bout of endurance exercise, meaning that cardiac output values in children are similar to those in adults. (T/F)

False

Maximal oxygen uptake is a clear, unequivocal indicator of aerobic capacity in children. (T/F)

False

Because children are smaller than adults, running economy is often better in children. (T/F)

False

Starting around the onset of puberty, the strength per kilogram body mass in boys ________________ and strength per kilogram body mass in girls _______________.
A) increases, decreases
B) decreases, increases
C) increases, plateaus
D) plateaus, decreases

C) increases, plateaus

Children are at an increased risk of heat-related injuries because of
A) a lower ratio of body surface area to mass
B) reduced ability to absorb heat from the environment
C) lower sweat rate
D) greater capacity for evaporative heat loss

C) lower sweat rate

Children secrete more sweat per sweat gland than adults, helping children dissipate heat more easily through evaporation. (T/F)

False

Exercise training may affect all of the following aspects of growth and maturation EXCEPT
A) weight
B) body composition
C) sexual development (especially in girls)
D) height

D) height