Age and Sex Considerations in Sport and Exercise Flashcards
What are some physiological responses to acute exercise when a person is growing?
• Strength • Cardiovascular, respiratory function • Metabolic function – Aerobic capacity – Running economy – Anaerobic capacity – Substrate utilization • Strength as muscle mass with age – Peaks at ~20 years for women – Peaks at 20 to 30 years for men • Strength, power, skill require myelination – Peak performance requires neural maturity – Boys experience marked change at ~12 years – Girls more gradual, linear changes
What are some physiological responses in terms of the CV system when a person is growing?
• Resting and submaximal blood pressure
– Lower than in adults (related to body size)
– Smaller hearts, lower peripheral resistance during
exercise
• Resting and submaximal stroke volume, HR
– Lower SV: smaller heart, lower blood volume
– Higher HR: almost compensates for low SV
– Slightly lower cardiac output than an adult
– (a-v-)O2 difference will increase to further compensate
• Maximal HR higher than in adults
• Maximal SV lower than in adults
• Maximal cardiac output lower
– Limits performance: less O2 delivery
– Not a serious limitation for relative workloads
What are some physiological responses to acute exercise in terms of lung function when a person is growing?
• Lung function – Lung volume increases with age – Peak flow rates increase with age – Postpuberty: girls’ absolute values lower than boys’ due to smaller body size
What are some physiological responses to acute exercise in terms of metabolic function when a person is growing?
– Increases with age
– Related to muscle mass, strength, cardiorespiratory
function
What are some CV changes in response to acute exercise in a growing person?
• Cardiorespiratory changes during exercise
accommodate muscles’ need for O2
• Cardiorespiratory changes with age permit
greater delivery of O2
– V•O2max in L / min increases with age (boys, girls)
– V•O2max in ml / kg / min steady with age in boys
– V•O2max in ml / kg / min decreases with age in girls
– L / min more appropriate during growth year
How would one approach scaling data for size?
• V•O2max relative to body weight is
considerably different from absolute values,
as shown in figure 17.7
• Using body surface area or weight to the
0.75 power is the best way to reduce the
effect of body size on data
What are some physiological responses to acute exercise in children?
• Children’s economy of effort worse than
adults’
– Child’s O2 consumption per kilogram > adult’s
– With age, skills improve, stride lengthens
• Endurance running pace increases with age
– Purely result of economy of effort
– Occurs regardless of V•O2max changes, training
status
Explain the differences between a child’s vs. an adult’s anaerobic capacity for exercise?
• Children limited anaerobic performance compared to adults • Lower glycolytic capacity in muscle – Less muscle glycogen – Less glycolytic enzyme activity – Blood lactate lower – Mean and peak power increase with age • Resting stores of ATP-PCr similar to adults’
What are the endocrine responses to acute exercise in a child?
– Exercising growth hormone and insulin-like growth
factor surge higher than in adults
– increased Stress response to exercise compared to adults
– Hypoglycemic at exercise onset
– Immature liver glycogenolytic system
What are substrate utilisation responses to acute exercise in a child?
– Relies more on fat oxidation compared to adults
– Exogenous glucose utilization high
How do body weight & composition respond to physical training in a child?
– Respond to physical training similarly to adults
– Training - decreased body weight/fat mass, increased FFM
– Significant bone growth
Is weight lifting safe for children to engage in?
• Weight lifting safe and beneficial – Should be prescribed, supervised – Low risk of injury – Protects against injury – Child: strength gains only via neural mechanisms, no hypertrophy – Adolescent: neural + hypertrophy
Describe some changes in regards to aerobic training in children?
– Little or no change in V•O2max
– Performance increased due to improved running economy
Describe some changes in regards to aerobic training in adolescents?
– More marked change in V•O2max
– Likely due to increase in heart size, SV
What are some physiological responses to anaerobic training in a child?
– increased Resting PCr, ATP, glycogen
– increased Phosphofructokinase activity
– increased Maximal blood lactate
Can adult anaerobic training programs be utilised to train a child?
• Adult anaerobic training programs can be
used with children and adolescents
– Be conservative to reduce risk of overtraining, injury,
loss of interest
– Explore variety of activities and sports
What are the typical physical activity patterns among youth?
• Physical activity patterns established in
childhood carry into adulthood
• Intervention strategies aimed at getting
children more active have been mostly
ineffective
Explain sports performance and specialisation in children/young adults?
• Sport performance in children and
adolescents improves with growth and
maturation
• Early specialization in one sport reduces
“fun” physical activities - reduced lifelong
physical activity
Explain thermal stress in children?
– Children have a larger surface area:mass ratio
– decreased Evaporative heat loss (less sweat)
– Slower heat acclimation
– Greater conductive heat loss, gain
• More research needed; be conservative
Explain a child’s growth when training?
– Little or no negative effect on height
– Affects weight, body composition with intensity
– Peak height velocity age unaffected
– Rate of skeletal maturation unaffected
• Maturation with training: effects on markers
of sexual maturation less clear
