Ch 9 Physiology & Exercise

1
Ch 9 Physiology Exercise

• Chapter by Carol L Christensen
• In Women In Sport
• Notes by N. Bailey

2
Introduction to the Chapter

• Chapter Focus
• physiological differences and similarities
• Other physiological concerns

3
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

4
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

5
Physiology Performance

• Pre-puberty and Puberty
• Aerobic Capacity
• Anaerobic Capacity or Power
• Muscle Strength and Physiology
• Body Composition

6
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

7
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

8
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 cant maintain as fast a pace

9
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

10
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

11
Response Environment Conditions

• Temperature Regulation
• Hot Environments
• Cold Environments
• Altitude
• Air Pollution

12
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

13
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

14
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

15
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

16
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

17
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

18
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

19
Altitude

• Low level of oxygenhypoxia
• 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

20
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

21
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

22
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

23
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

24
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

25
Gender Differences

• Womens earliest strength increase result of
  increased muscle fiber recruitment
• Mens earliest increase due to increase in muscle
  fiber size
• After several weeks of training women also
  experience hypertrophy

26
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

27
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

28
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

29
Special Physiological Concerns

• Menarche
• Menstruation
• Menopause
• Pregnancy
• Osteoporosis
• Injuries

30
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

31
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

32
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

33
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

34
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

35
Recent Research

• Exercising pregnant women have higher ventilation
  volumes, higher ratings perceived exertion,
  energy expenditure
• Dont do maximum effort
• High risk pregnancy avoid exercise
• Most benefit from exercise 3days per week
  non-weight bearing

36
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

37
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