P409 (Chap 17)

stroke volume

During both submaximal and maximal exercise, a child's smaller heart and blood volume result in a lower _____ ____than in adults. In partial compensation, a child's heart rate is higher than an adult's for the same exercise intensity.

similar

Endurance performance improves with aerobic training. Adolescents are ____ to adults in their improvement.

limits

Even w/increasedHR, a child's cardiac output remains less than an adults. In submaximal exercise, an increase in the (a-VO2 difference ensures adequate oxygen delivery to the active muscles. But at maximal work rates, oxygen delivery _____ performance in activities other than those in which the child merely needs to move his or her body mass, such as running.

width, density

Exercise affects bone _____, _____, and strength.

size, number

Fat storage occurs through both increases in the ____of existing fat cells and increases in the ____of fat cells. It appears that as existing fat cells become full, they signal the need for the development of new fat cells.

neural maturation

Gains in strength with growth also depend on _____ ______because neuromuscular control is limited until myelination is complete, usually around sexual maturity.

physiologically

Girls mature physiologically about ___ years earlier than boys do.

two, 50%

Growth in height is very rapid during the first ____years of life, with a child reaching ___of adult stature by age 2. After that, the rate is slower throughout childhood until a marked increase occurs near puberty.

same, 12.5, 14.5

Growth in weight follows the ____trend as height. The peak rate of weight increase occurs at age ____ in girls and age ____ in boys.

body

Heart size is directly related to ____ size, so children have smaller hearts than adults. As a result of this and smaller blood volume, children have a smaller stroke volume capacity. A child's higher maximum heart rate can only partially compensate for this lower stroke volume, and thus maximal cardiac output is lower than that of an equally trained adult.

accurate, maturation

However, expressing VO2max relative to body weight might not provide an _____estimate of aerobic capacity. Such VO2max values do not reflect the significant gains in endurance performance capacity that are noted with both _______ and training.

muscle mass

In boys, the rate of ____ ____ increase peaks at puberty, when testosterone production increases significantly. Girls do not experience this sharp increase in muscle mass.

mass, doesn't

Lab studies suggest that children may be more susceptible to injury or illness from thermal stress because they have a greater ratio of body surface area to ____when compared to adults. However, the number of reported cases _____ support this.

volumes

Lung _____ increase until physical maturity.

sarcomeres, existing

Muscle length increases through the addition of ______and by increases in the length of ______ sarcomeres.

hypertrophy

Muscle mass increases in boys and girls result primarily from fiber ______ with little or no hyperplasia.

adolescense

Muscle mass increases steadily along with weight gain from birth through _______.

16, 20, 18, 25

Muscle mass peaks in girls between ages ____ and ____ and in boys between ages ___and ____, although it can be further increased through diet and exercise.

nerve fibers

Myelination of ____ ____must be complete before fast reactions and skilled movements are fully developed because myelination speeds the transmission of electrical impulses.

12, 14, 16, 18

The peak rate of height growth occurs at age ___in girls and age ___in boys. Full height is typically attained at age ___in girls and age ___in boys.

adolescence

The period of life between the end of childhood and the beginning of adulthood is known as ______. The onset of puberty marks the beginning of this.

physical maturity

The point at which the body has attained the adult physical form is known as ______ ______.

low

The risk of injury from resistance training in young athletes is relatively ____ , and the programs they should follow are much like those for adults.

muscle, similar

Unlike adults, preadolescents who resistance train experience little change in _____ size. Mechanisms of strength gains in adolescents are ____ to those in adults.

body size

Until physical maturity, maximal ventilatory capacity and maximal expiratory ventilation increase in direct proportion to the increase in ____ ____ during maximal exercise.

21, 15

VO2max expressed in liters per minute, peaks between ages 17 and ____ years in males and between 12 and ___ years in females, after which it plateaus for several years and then steadily decreases.

25, 12

When VO2max is expressed relative to body weight, it plateaus in males from ages 6-___ years before it begins to decline. In females, the decline in VO2max is small from ages 6-__ years but becomes more substantial starting at about age 13.

smaller, stride

When expressed relative to body weight, a child's VO2max is _____than an adults when VO2 is expressed relative to body weight. One factor has been identified to explain this difference: the difference between children and adults in _____ frequency for the same fixed-pace run.

slowly

Young boys acclimatize to heat more _____ than adults do. Data are not avaliable for girls.

balance, coordination, nervous

_____ , agility, and _______improve as children's ______systems develop.

bone mineral density

_____ _____ _____ is known as the mass of bone per unit volume. Decreased _____ _____ _____ increases the risk of fractures.

strength

_____ improves in children as muscle mass increases with growth and development.

exercise, diet

_____, along with an adequate_____, is essential for proper bone growth.

growth

______ is known as an increase in the size of the body or any of its parts.

infancy

______ is known as the first year of life.

maturation

______ is known as the process by which the body takes on the adult form and becomes fully functional. It is often defined by the system or function being considered.

myelination

______ is known as the process of acquiring a myelin sheath.

childhood

______ is the period of life between the first birth day and the onset of puberty.

puberty

______ is the point at which a person becomes physiologically capable of reproduction.

ossification

______ is the process of bone formation.

increases

A child's anaerobic capacity ______ with anaerobic training.

VO2max, VO2max,

Aerobic training in preadolescents does not alter _____ as much as would be expected for the training stimulus, possibly because _____ depends on heart size.

lower, glycogen, phosphofructokinase

Anaerobic capacity is _____ in children than adults, which may reflect children's lower muscle ______ content, lower concentration of the key rate-limiting enzyme ________, or decreased activity of lactate dehydrogenase.

lower

Anaerobic mean and peak power outputs are _____ in children than in adults, even when scaled for body mass.

aerobic

As pulmonary and cardiovascular function improve with continued development, so does _____ capacity.

15, 25, testosterone, estrogen

At physical maturity, the body's fat content averages ___% in young men and ___% in young women. The differences are caused primarily by higher _______levels in males and higher ______levels in females.

body

Blood pressure is directly related to _____ size: It is lower in children than in adults but increases to adult levels in the late teen years, both at rest and during exercise.

teen

Blood pressure levels go up to that of an adult's during _____ years.

loss, increase

Body composition changes with training in children and adolescents are similar to those seen in adults-____ of total body weight and fat mass and _____ in fat-free mass.

BMD

Bone mineral density increases significantly throughout childhood and adolescence, peaking in early adulthood. High-impact load-bearing exercise can substantially ______ BMD.

development

Changes that occur in the body starting at conception and continuing through adulthood is known as ______. The differentiation along specialized lines of function, reflecting changes that accompany growth.

conductive

Children appear to have greater ______ heat loss than adults, which may place children at greater risk for hypothermia in cold environments.

evaporative, less

Children are limited in their ______ heat loss compared to adults because children sweat ____ (less sweat is produced by each active sweat gland).

insulin, stress, fat

Children have a different _____ and _____ hormone response and rely on greater ____ oxidation for fuel during exercise.

phosphofructokinase

Children have a lower glycolytic capacity possibly because of a limited amount of ________ or lactate dehydrogenase.

lactate

Children have lower _____ concentrations in both blood and muscle at maximal and sub maximal rates of work.

limited, glycolytic

Children's ability to perform anaerobic activities is _____ because a child has a lower _____ capacity.

neurological

Prepubescent children can improve their strength with resistance training. These strength gains are attributable to ______ factors, with little or no change in the size of the muscle.

motor skill coordination, activation

Strength gains achieved from resistance training in preadolescents results primarily from improved _____ _____ ____ , increased motor unit _____, and other neurological adaptations.

diet, exercise, heredity

The amount of fat accumulation depends on ____, ____habits, and _____.

endurance, body weight

The child's lower VO2max value (L/min) limits _______ performance unless _____ _____is the major resistance to movement, as in distance running.

hypertrophy. myofibrils

The increase in muscle mass with growth and development is accomplished primarily by ______ of individual muscle fibers through increases in their myofilaments and _____.