ch7 - age- and sex-related differences and their implications for resistance exercise

Question 1

why should young children strength train?

Answer 1

no evidence of downsides, plus osteogenic benefits of physical activity are essential for skeletal remodeling and growth

Question 2

what bone area is used to determine biological age?

Answer 2

the left wrist

Question 3

what is the Tanner method?

Answer 3

visually assessing the development of identifiable secondary sex characteristics

Question 4

what are the five Tanner classifications?

Answer 4

Stage 1: the immature, preadolescent state, stage 5: full sexual maturation

Question 5

downsides of Tanner method?

Answer 5

invasive nature of the procedure, should not be used by strength and conditioning professionals

Question 6

what is the most realistic and feasible means of estimating biological age?

Answer 6

from somatic assessments; somatic age reflects the degree of growth in overall stature or smaller, subdimensions of the body (e.g., limb length).

Question 7

what are some examples of somatic assessment?

Answer 7

longitudinal growth curve analysis, percentages and predictions of final adult height, and the prediction of age from peak height velocity (PHV), which is defined as the age at maximum rate of growth during the pubertal growth spurt

Question 8

downsides to peak height velocity?

Answer 8

young athletes may be at an increased risk of injury; age 12 in females and age 14 in males (due to alterations in center of mass, muscle imbalances, and the relative tightening of the muscle-tendon units spanning rapidly growing bones)

Question 9

how much of the body is muscle mass at birth and adulthood?

Answer 9

at birth, 25% of a child’s body weight; by adulthood, about 40%

Question 10

when does peak muscle mass occur?

Answer 10

between the ages of 16 and 20 years in females and between 18 and 25 years in males unless affected by resistance exercise / diet

Question 11

where does the majority of bone formation occur?

Answer 11

in the diaphysis (primary ossification center), which is the central shaft of a long bone, and in the growth cartilage (secondary ossification center), which is located at three sites in the child: the epiphyseal (growth) plate, the joint surface, and the apophyseal insertions of muscle-tendon units (when the epiphyseal plate becomes completely ossified, the long bones stop growing)

Question 12

at what age are most bones fused?

Answer 12

by the early 20s

Question 13

why are cartilage injuries devastating?

Answer 13

may disrupt the bone’s blood and nutrient supply and result in permanent growth disturbances (e.g., skeletal undergrowth, skeletal overgrowth, or malalignment of bone)

Question 14

danger of ligament tears?

Answer 14

may produce an epiphyseal plate fracture in a child

Question 15

who is more at risk for epiphyseal plate fractures – children or adolescents?

Answer 15

adolescents, due to growth spurt

Question 16

when do peak gains in strength typically occur in boys?

Answer 16

about 1.2 years after peak height velocity and 0.8 years after peak weight velocity, with body weight being the clearer indicator (also when it occurs in girls but with more variation in relationship of height/bw)

Question 17

when is peak strength attained?

Answer 17

by age 20 in untrained women and between the ages of 20 and 30 in untrained men

Question 18

why should a trainer expect a limit to childhood strength gains?

Answer 18

the myelination of many motor neurons is incomplete until sexual maturation (without myelination, fast reactions and skilled movements cannot be successfully performed)

Question 19

what kind of strength gains can untrained preadolescent children get following short-term (8 to 20 weeks) resistance training programs?

Answer 19

roughly 30% to 40%, variables: biological age of the child, program design, quality of instruction, and background level of physical activity

Question 20

how permanent are strength gains in children?

Answer 20

impermanent and tend to return to untrained control group values during the detraining period; this finding must be considered in light of the many other commitments that youth or young athletes may have (e.g., competitive playing schedule, schoolwork, time to interact with peers)

Question 21

benefits of resistance exercise for children?

Answer 21

bone density, favorably alter selected anatomic and psychosocial parameters, reduce injuries in sport and recreational activities, and improve motor skills and sport performancel; decrease in body fat, improvements in insulin sensitivity, and enhanced cardiac function among obese children and adolescents (widespread evidence of a physical inactivity crisis)

Question 22

why might youth enjoy resistance training?

Answer 22

it is not aerobically taxing and provides an opportunity for all participants to experience success

Question 23

paradox of sports vs lifting?

Answer 23

the forces placed on the joints of young athletes during sport participation may be far greater, and more difficult to anticipate, than those generated from resistance training programs

Question 24

men vs women: eccentric strength?

Answer 24

eccentric strength may be more similar between men and women than concentric strength when compared relative to fat-free mass

Question 25

power output in women relative to men?

Answer 25

about 63% of men’s; similar findings regarding power output were obtained in presumably untrained women; and in maximal vertical jump and standing long jump scores

Question 26

what kind of short-term gains in hypertrophy are similar between sexes?

Answer 26

up to 16 weeks

Question 27

broad description of female athlete triad?

Answer 27

interrelationships between energy availability, menstrual function, and bone mineral density from train for prolonged periods of time with insufficient caloric intake

Question 28

concise description of female triad?

Answer 28

osteoporosis, disordered eating (anorexia/bulimia), amenorrhea (>3 months)

Question 29

side effects of amenorrhea?

Answer 29

bone stress fractures, endocrine and gastrointestinal complications, and sporting performance decrements

Question 30

a female middle-distance runner who fails to consume sufficient levels of calcium, vitamin D, and protein may be at what physical risks?

Answer 30

increasing the likelihood of entering into a negative energy balance and experiencing the early onset of female athlete triad

Question 31

explanations for insufficient energy intake?

Answer 31

lack of a biological drive to match activity-induced energy expenditure, or clinical eating disorders

Question 32

sports with higher risk of eating disorders?

Answer 32

those with subjective scoring based on aesthetics (e.g., dance or gymnastics)

Question 33

most significant factor in ACL injury risk in females?

Answer 33

neuromuscular deficiency, which ultimately leads to abnormal biomechanics (increased dynamic knee valgus upon contact with the ground)

Question 34

how much does competitive weightlifting decline with age?

Answer 34

1% to 1.5% per year until approximately age 70, after which a more dramatic decrease occurs

Question 35

factors affecting loss of bone with age?

Answer 35

physical inactivity and hormonal, nutritional, mechanical, and genetic factors

Question 36

explanation for muscle decline after 30?

Answer 36

a decrease in the cross-sectional areas of individual muscles, along with a decrease in muscle density, reductions in tendon compliance, and an increase in intramuscular fat; seems to be most pronounced in women and appears to result from physical inactivity and gradual denervation of muscle fibers.

Question 37

which decreases more with age – strength or power?

Answer 37

power, due to reduction in fiber size, fiber number and the gradual denervation of muscle fibers

Question 38

what kind of risk do seniors face from falls?

Answer 38

pain syndromes, joint dislocations, skeletal fractures, limitations on daily functional activities, and a reduction in self-confidence; permanent disability, institutionalization, and fatalities. risk factors include decrements in muscle strength and power, reaction time, and impaired balance and postural stability

Question 39

significance of activity before (preactivation) and immediately following (cocontraction) contact with the ground?

Answer 39

important mediator of braking and dynamic stabilization in both young and old individuals

Question 40

how do preactivation and cocontraction work?

Answer 40

preactivation increases stiffness of the limb using fast stretch reflexes to better prepare the limb for ground contact; cocontraction is a motor control strategy that dynamically stabilizes the joint; however, due to the simultaneous activation of both the agonist and antagonist muscle groups crossing the same joint, net joint moments and agonistic force outputs are reduced. seniors rely on increased levels of muscle cocontraction as a compensatory mechanism to offset their increased balance difficulties and to minimize postural sway

Question 41

how can older adults offset natural reductions in preactivation (wrt: breaking/stabilization)?

Answer 41

low-intensity plyometrics, balance and dynamic stabilization exercises, and proprioception training to develop the ability to react more efficiently with the ground

Question 42

a coach wants to raise a senior’s activity to prevent falls. why might this be misguided?

Answer 42

seniors must engage with, and adhere to, multidimensional programs that incorporate elements of both resistance and balance training, and seniors should overload progressively to promote a challenging training environment, and training should be completed on a frequent basis to provide individuals with a sufficient training dosage

Question 43

benefits of strength training in older adults?

Answer 43

gait speed, stair climbing ability, balance, and overall spontaneous activity

Question 44

resistance training can improve nitrogen retention – why is this significant?

Answer 44

can have a positive effect on muscle protein metabolism

Question 45

why should valsalva be discouraged in seniors?

Answer 45

the sudden rise in systolic and diastolic blood pressure that the technique creates; especially true for adults with a history of cardiovascular disease (heart arrhythmias, angina) or cerebral conditions (i.e., stroke, dizziness)

Question 46

rep range/volumes for seniors?

Answer 46

one set of 8 to 12 repetitions at a relatively low intensity (e.g., 40% to 50% 1RM) to higher training volumes and intensities (e.g., three sets per exercise with 60% to 80% of 1RM), depending on needs, goals, and abilities

Question 47

when can seniors do high-velocity power exercises?

Answer 47

upon completion of a general resistance training program

Question 48

rep/volume for increasing power in healthy older adults?

Answer 48

one to three sets per exercise with a light to moderate load (40% to 60% 1RM) for 6 to 10 repetitions with high repetition velocity

Question 49

training frequency for older adults?

Answer 49

twice per week during initial adaptation period, due to recovery length

Question 50

adolescence

Answer 50

the period between childhood and adulthood

Question 51

biological age

Answer 51

can be measured in terms of skeletal age, somatic (physique) maturity, or sexual maturation

Question 52

childhood

Answer 52

period of life before the development of secondary sex

Question 53

development

Answer 53

the natural progression from prenatal life to adulthood

Question 54

growth

Answer 54

increase in body size or a particular body part

Question 55

maturation

Answer 55

the process of becoming mature and fully functional

Question 56

menarche

Answer 56

menstruation

Question 57

osteopenia

Answer 57

Osteopenia is defined by a bone mineral density between −1 and −2.5 standard deviations (SD) of the young adult mean

Question 58

osteoporosis

Answer 58

a bone mineral density below −2.5 SD of the young adult mean. a clinical condition characterized by low bone mass and an increased susceptibility to fractures (as opposed to active bone deterioration, which this could be confused for)

Question 59

sarcopenia

Answer 59

loss of muscle mass and strength