Ch 9 Physiology &
Exercise
Chapter by Carol L Christensen
In Women In Sport
Notes by N. Bailey
Introduction to the
Chapter
Chapter Focus:
 physiological
differences and
similarities
&
Other physiological concerns
Records Improving
Performance records improving for
both men and women
 Women are closing the gap
 For both aerobic capacity & speed
events
 Much overlap between the sexes
 Look at data on page 180

Factors Affecting
Performance Differences




Hormonal differences ate menarche
Socio-cultural differences:
Clothing, activity level, lack of
opportunities for women, lower monetary
rewards
Social myths: women are more easily
injured, media coverage that
marginalizes women athletes, gender
roles
Physiology &
Performance
Pre-puberty and Puberty
 Aerobic Capacity
 Anaerobic Capacity or Power
 Muscle Strength and Physiology
 Body Composition

Puberty
12 yrs: Average age of puberty for girls
 Prior to that differences accounted for
by differential training and skills, not
physiology
 Boys mature 2 – 3 years later
 Mature male larger size due to
increased length of growth period

Aerobic Capacity
Females at a disadvantage de to
smaller size (fewer rbc, lower
hemoglobin concentration, smaller
heart, lungs, and lower blood volume
 15% to 25% disadvantage
 Performance records demonstrate that
this difference can be somewhat
overcome with training and coaching

Anaerobic Capacity or
Power
Women have less muscle mass
 And lower Anaerobic Power
 AnT Anaerobic threshold is related to
endurance performance.
 The point where anaerobic energy
sources are used at the cell site
 When lactic acid accumulates
 Women can’t maintain as fast a pace

Strength
No differences in muscle tissue itself
 Differences in strength greater than
that for anaerobic and aerobic power
 Large overlap, but generally women
have 66% of the strength of men
 Upper body, 56% as strong as men
 Lower body, 72% as strong
 No Difference in fast and slow twitch

Body Composition
Female athletes closer to male athlete
counterparts than to untrained women
 Average young woman 22 to 24%
body fat
 Average woman athlete 17 to 14%
 Average 60 yr- old woman professor ?
 Average untrained male: 14 – 16%

Response: Environment
Conditions
Temperature Regulation
 Hot Environments
 Cold Environments
 Altitude
 Air Pollution

Importance of Topic
Various environments impose
demands on the body during exercise
 In extreme conditions all are affected
 With moderate changes some people
are affected and some are not
 Responders experience symptoms
with mild conditions v. Non-responders

Temperature
Regulation
Hyper- & hypothermia occurs in
extreme temps & are life threatening
 Exercise increases metabolism &
therefore, heat
 Okay in cold climate, a problem in hot
 Hot environment: sweat 90% heat loss

Temperature
Mechanisms
Convection: wind blowing on body
 Conduction: contact with colder or
warmer surface
 Radiation: heat transfer through
electromagnetic waves
 Evaporation of sweat that we
mentioned in the last slide

Hot Environments
Higher heart rate, higher sweat rate,
increased glucose use for energy,
increased blood flow to the skin
 Responses help maintain temperature
 Men & women with similar aerobic
fitness levels respond similarly to heat
 In extremes disadvantaged because of
greater surface area to gain heat

Safety Precautions
Heat stroke, exhaustion & dehydration
 Drink plenty of fluids, especially water
 Reduce intensity, duration
 Avoid hottest part of the day
 Acclimatization: reduced sweat
rate,earlier onset, increase plasma
volume takes about 14 days

Cold Environments
Greater oxygen consumption during
sub-maximum work
 Increased glucose use for energy
 Less blood flow to the skin
 Hypothermia and frostbite
 Dress in layers, dry clothing, protect
the hands and the head

Different Responses?
In general, similar physiological
responses
 Women at greater risk: greater surface
area relative to body mass helps cool
 Less muscle mass produces less heat
 With proper precautions both men and
women withstand cold temperatures

Altitude
Low level of oxygen=hypoxia
 Higher heart rates, increased
ventilation, reduced aerobic power
 Endurance performance is impaired
 Adaptations: 4 to 6 months
 Increases in hematocrit, hemoglobin,
myoglobin and rbc attenuates hypoxia

Air Pollution
At high levels: chest tightness,
difficulty deep breathing, eye irritation,
headaches, dry throat
 Endurance performance impaired by
high carbon dioxide
 Smog alerts: exercise indoors, avoid
car exhaust
 Men and women affected equally

Responses To Training
Virtually the same for all individuals
 Altered by environmental conditions &
substances like drugs & alcohol
 Increases in heart rate, cardiac output,
ventilation, and metabolism
* When fitness levels are similar no sex
differences

General Response
Regular program of exercise results in
increased VO2 Max, strength, power
and speed.
 Type of training influences type of
response – specificity principle
 Training programs should be based on
capacities, skills and abilities, not sex
 Men will gain more than women

Specific Training
Responses

Training depends upon particular
stressors. For example:
Yoga for strength and flexibility
 Weight training for strength & loss of
body fat
 For Strength increase resistance
 For endurance increase reps

For Strength and
Endurance
Lift 2 to 3 days per week
 Do at least one set of 8-12 repetitions
 Choose a weight that causes fatigue at
the end of the last repetition
 Better to underestimate the weight at
first in order to prevent muscle injury

Gender Differences
Women’s earliest strength increase
result of increased muscle fiber
recruitment
 Men’s earliest increase due to
increase in muscle fiber size
 After several weeks of training women
also experience hypertrophy

Anaerobic Training
Interval training for 50 to 400 meter
runs
 Timing of the work and rest intervals
determines the specific training result
 For most running games require both
aerobic and anaerobic training
 Wind sprints= anaerobic + aerobic
training needed for running games

Stretching
Never stretch a cold muscle
 Warm up by walking, jogging before
stretching
 Static stretch better than ballistic
 Stretch the muscle until slight tension
is felt, not pain. Hold for 15 to 60
seconds
 No evidence of injury prevention

Warming Up & Cooling
Down
Gradual adjustment to increase
demands of exercise: oxygen
delivered to muscle cells, decreased
time for muscle contraction
 Do low intensity activity similar in
nature to the workout activity
 Cool down – same activity only less
intensity. Best time to stretch

Special Physiological
Concerns
Menarche
 Menstruation
 Menopause
 Pregnancy
 Osteoporosis
 Injuries

Menarche
Training at young age may delay onset
of puberty or maybe not
 Trained females begin menstruation
from .5 to 2.5 years later
 No evidence that delay is harmful in
any way
 Early maturing girls may drop out of
sport so we find these data

Menstruation
Research results unclear about effects
on performance
 Individual variability obscures any
patterns of performance.
 Some evidence suggests that regular
exercise decreases incidence and
severity of painful menstrual periods

Menstrual Disruption
Higher incidence of menstrual
disruption in younger, highly motivated
athletes, in intensively trained athletes,
and in sports that emphasize lean
body type
 Amenorrhea related to osteoporosis
 Female Athletic Triad also a concern

Menopause
A drop in circulating hormones,
especially estrogen
 Hot flashes not harmful
 Not much studied
 No difference in ability to improve
fitness levels
 Exercise recommended for fat control
& delay effects of aging

Pregnancy
Increased blood volume, cardiac
output, fat and weight distribution,
changes in most systems
 No difference between athletes and
non-athletes in major disorders
 Athletes shorter periods of labor and
fewer complications

Recent Research
Exercising pregnant women have
higher ventilation volumes, higher
ratings perceived exertion, energy
expenditure
 Don’t do maximum effort
 High risk pregnancy – avoid exercise
 Most benefit from exercise: 3days per
week; non-weight bearing

Osteoporosis
4 times more likely in women
 Three major risk factors: low estrogen,
low calcium, lack of physical activity
 Prevention should start in the teen
years
 ERT recommended
 Low impact exercises

Injuries
In most activities no difference in injury
rates
 Anterior cruciate ligament injuries the
exception to this rule
 Difference in injury rate probably not
related to anatomy
 Prevention and rehabilitation methods
the same; get into “good shape”
