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The female

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Title: The female


1
The female athlete
Corso di Laurea in Scienze Motorie Prof
G.Galanti A.A. 2003/2004
2
Until 1970 women were barred from official
partecipation in the marathon. This restriction
resulted from a misconception that women were
physiologically unsuited for endurance activity.
Yet,at the 1984 Los Angeles Olympic Games , Joan
Benoit won the gold medal in the first-ever
Olympic marathon for women with a time of
022452. Her time would have won 11 of the
previous 20 mens Olympic marathons!
3
Sex-specific differencesBody composition
Until puberty, boys and girls do not
differ significantly in heigth
weigth girth bone with fat-mass
fat-free mass Sex-specific differences in
body composition appeares at puberty and are
due to the hormonal
influences.
4
Sex differences in FFM changes
with age
5
Hormonal influences on body composition
Testosterone (men) ? ?
bone formation ? muscle mass
Estrogens (women)
? ?growth rate of bone
broadening the pelvis breast development ?
fat deposition (thighs and hips)
6
Sex diffences in body composition at the end of
puberty (mean values)
Kg
7
Sex diffences in body composition with aging
Relative body fat values for average,
untrained women and men
Relative body fat () Women Men 20-24
13-16 22-25
15-20 24-30 18-26 27-33
23-29 30-36 26-33
30-36 29-33
Age group years 15-19 20-29
30-39 40-49 50-59 60-69

8
Sex differences in physiological responses to
acute exercise
? Neuromuscolar ? Cardiovascular ? Respiratory ?
Metabolic
9
Sex differences in physiological responses to
acute exercise
? Neuromuscolar ?Cardiovascular ?Respiratory ?Meta
bolic
10
Differences in strength
In terms of absolute strength, women have been
regarded as the weaker sex, but when lower-body
strength is expressed relative to FFM,
differences between women and men disappeares!
Strength ratio (men/women)
11
Differences in strength
For the same amount of muscle, there are no
differences in strength between sexes, though
women possess smaller muscle fiber
cross-sectional areas and less muscle mass than
men
12
Sex differences in physiological responses to
acute exercise
? Neuromuscolar ?Cardiovascular ?Respiratory ?Meta
bolic
13
Cardiovascular responseto acute exercise
women have higher submaximal HR than men
maximum HR is the same in both sexes Cardiac
Output (CO) for the same absolute rate of work
is the same in both sexes increase of CO in
women is primarly due to an increase in HR,
more than in stroke volume
14
Cardiovascular responseto acute exercise
  • Women lower stroke volume is related to
  • ?smaller heart size related to their smaller body
    surface area (lower testosterone levels)
  • ? Smaller blood volume, also related to smaller
    body size

15
Sex differences in physiological responses to
acute exercise
? Neuromuscolar ? Cardiovascular ? Respiratory ?
Metabolic
16
Changes in aerobic capacity (VO2 max)
  • VO2 max CO x A-V diff

17
VO2max in normal women
  • The average womans VO2max is only 70 to 75
    that of the average man.
  • The main causes of this differences are
  • womens greater fat mass
  • lower hemoglobin levels
  • lower maximal cardiac output

18
VO2 max in male and female athletes
  • The highest VO2max reported in literature for a
    female athlete is 77ml/Kg/min, that of a Russian
    cross-country skier.
  • The highest value for a male athlete was reported
    in Norwegian cross-country skier, who achieved a
    value of 94 ml/Kg/min

19
Womens adaptations to chronic exercise
  • Women respond
  • to physical training
  • in the same manner
  • as men do

20
Effect of training on body composition in women
  • ? Fat-free mass (generally much less than man)
  • ? Fat mass
  • ? Relative fat
  • ? Total body mass

This changes are more related to total energy
expenditure than to sex differences.
21
Effect of resistence training on womens muscular
strength
Women can experience a relevant increase in
strength (20 to 40) as a result of resistence
training, and the magnitude of these changes is
similar to that seen in men. These gains are due
primarly to neural factors, in fact womens
increase in muscle mass is generally small
because of their low testosterone levels.
22
Cardiovascular effects of endurance training
Cardiovascular adaptations to endurance training
are not sex specific. So, trained women have
lower rest and submaximal HR higher cardiac
size (physiological hypertrophy) higher stroke
volume higher maximal cardiac output
largest blood volume higher muscular capillary
density
than sedentary ones.
23
Metabolic adaptation
  • Women can improve their VO2max by 10 to 40 with
    endurance training (same seen in men)
  • As in men, the magnitude of of change depends on
  • initial level of fitness
  • intensity and duration of training session
  • frequency of training

24
Medical problems in female athlete
25
Female athlete triade
  • In 1992 the Task Force on Womens Issues of the
  • American College of Sports Medicine described
  • the female athlete triade as a syndrome of 3
    medical,
  • often interrelated, entities that can occur in
  • female athlete
  • Menstrual dysfunctions until amenorrhea
  • Eating disorders
  • Osteoporosis

26
Menstrual dysfunction
  • Eumenorrhea normal menstrual function
  • Oligomenorrhea abnormally infrequent or scant
    menstruation
  • Amenorrhea absence of menstruation
  • Primary amenorrhea absence of menarche in women
    18 years of age
  • Secondary amenorrhea lack of menstruation in
    women who previously had been eumenorrheic

27
The Pituitary gland I
28
The Pituitary gland VI Anterior lobe
Hypothalamic Controlling Factors
  • FSH stimulated by GnRH (gonadotropin-realising
  • hormone)
  • LH stimulated by GnRH
  • PROLACTIN stimulated by PRH (prolactin-realising
  • hormone)
  • Inibited by PIH
    (prolactin-inibiting hormone)

29
The Pituitary gland IVAnterior lobe
  • MAJOR
  • FUNCTIONS
  • Controls the amount of T3 and T4 produced
    and released by the thyroid gland
  • Controls the secretion of hormones from the
    adrenal cortex
  • Stimulates breasts developement and milk
    secretion
  • TARGET ORGAN
  • Thyroid gland
  • Adrenal cortex
  • Breasts

HORMONE TSH ACTH PROLACTIN
30
The Pituitary gland VAnterior lobe
  • TARGET ORGAN
  • Ovaries, Testes
  • Ovaries, Testes
  • MAJOR
  • FUNCTIONS
  • Initiates growth of follicles inthe ovaries
    and promotes secretion of estrogen from the
    ovaries. Promotes developement of sperm in
    testes.
  • Promotes secretion of estrogen and
    progesterone and causes the follicle to rupture,
    releasing the ovum. Causes testes to secrete
    testosterone

HORMONE FSH LH
31
Secondary amenorrhea in athletes
  • The prevalence of secondary amenorrhea among
    athletes is not well documented, but is estimated
    to be 5 to 40 (2-3 in general population),
    depending on the sport and the level of
    competition. Prevalence appears to be greater in
    those who train many hours each day and in those
    who train at very high intensities.

32
Secondary amenorrhea in athletes
  • The causes of secondary amenorrhea in athletes
    are unknown, however the two principal causes
    seem to be
  • inadeguate nutrition
  • hormonal changes related to exercise stress
    might disrupt GnRH secretion which is needed to
    direct the normal menstrual cycle

33
Eating disorders in female athletes
Eating disorders must be considered among the
most serious problems facing female athletes
today, considering the severe physiological
conseguences of this disorder (until death) and
the extraordinary costs of specific treatment.
34
Eating disorders in female athletes
Athletic trainers and coaches, who are the people
closest to the elite athletes , should be able to
suspect eating disorders and recognize the
seriousness of the problem, in order to refer the
athlete to a person specifically trained in
dealing with this kind of problems.
35
Eating disorders
The two most commonly diagnosed eating disorders
are anorexia nervosa and
bulimia nervosa
36
Eating disordersAnorexia nervosa
anorexia nervosa is characterized by refusal
to maintain more than the minimal normal weight
based on an age and heigth distorted body
image intense fear of fatness or gaining
weigth amenorrhea
Prevalence about 1 in females from ages 12 to 21
37
Eating disordersBulimia nervosa
bulimia nervosa is characterized by reccurent
episodes of binge eating a feeling of lack of
control during these binges purging behaviour,
which can include self induced vomiting, laxative
use and diuretic use
Prevalence about 1 in females from ages 12 to 21
38
Eating disordersAnorexia athletica
Anorexia athletica is characterized by an
intense fear of gaining weigth or becaming fat
even though one is under-weigth A weigth loss
of at least 5, resulted from a reduction of
total energy intake with extensive exercise
reported use of self-induced vomiting or use of
laxative or diuretics
39
Anorexia athletica problem dimension
Prevalence of anorexia athletica is not
well understood, however some reserchers have
estimated the prevalence to be as 50 for elite
athletes in higher risks sports.
40
Eating disordersAnorexia athletica
As in the general population , female athletes
are exposed at a higher risk than male
athletes. The high risk sports can be grouped
into 3 categories Appearence sports figure
skating, gymnastic, body building, ballet
Endurance sports distance running, swimming
Weight-classification sports horse racing,
boxing, wrestling
41
Warning signs for eating disorders in female
athletes
  • Warning signs for anorexia nervosa
  • Dramatic loss in weigth
  • A preoccupation with food, calories and weigth
  • Wearing baggy or layered clothing
  • Relentless, excessive exercise
  • Mood swings
  • Avoiding food-related social activities

Adapted from National Collegiate Athletic
Association
42
Warning signs for eating disorders in female
athletes
  • Warning signs for bulimia nervosa
  • A noticeble weigth loss or gain
  • Excessive concern about weigth
  • Bathroom visits after meals
  • Depressed moods
  • Strict dieting followed by eating binges
  • Increased criticism of ones body

Adapted from National Collegiate Athletic
Association
43
Osteoporosis
44
1820 Lobstein described a deteriorated
human bone and defined this pathology as
osteoporosis (osteon porous)1941
Albrigth described osteoporosis as a decreased
production of osteoid by the osteoblasts
Osteoporosis First Descriptions
45

Osteoporosis Recent Definitions
An age-related disorder characterized by a
reduced bone mass and an increase in
susceptibility to fracture, in the absence of
other recognisable causes of bone
loss. (Consensus Development Conference 1987)
An disorder characterized by increased
skeletal fragility due to decreased bone mass and
to microarchitectural deterioration of bone
tissue. (Consensus Development Conference 1996)
46
Osteoporosis
  • The principal complications of osteoporosis are
    the fractures in particular sites
  • proximal femur
  • Vertebral body
  • Distal radius (Colles fracture)

47
Peak bone mass
  • Troughout childhood, bone mass increases linearly
    with skeletal growth.
  • A rapid incresease in density occurs during
    puberty, as much as 40.
  • Bone density continues to increase for several
    years until maximum bone mass is achieved (peak
    bone mass)

48
Peak bone mass
Genetic Influences (75)
Mechanical factors
Peak Bone Mass
Hormonal factors
Nutritional factors
49
Bone remodellingannual rate of 25 in trabecular
bone, 2-3 in compact, cortical bone
50
Age-related bone loss
  • Following attainment of peak bone mass, a gradual
    loss of bone occurs with ageing, in both sexes.
  • In women, bone loss before menopausa is small
    (lt1 per annum), accelerating in the 5 years
    postmenopausal period to 1-2 per annum.

51
OsteoporosisMain causes
Estrogen deficiency inadeguate calcium
intake inadeguate physical activity
52
Osteoporosis Epidemiology
OSTEOPOROSIS
interests two main groups of people women
beyond menopausa lack of
estrogens elderly women and men
carence of vit D ? ? PTH reducted
physical activity reducted calcium
dietary apport
53
Female young athletes at risk of osteoporosis
Premature osteoporosis is not frequent in female
athletes. It generally results as a conseguence
of the secondary amenorrhea (lack of estrogens
influence on bone tissue) and the eating
disorders (inadeguate calcium intake). So, the
best way to prevent osteoporosis in female
athletes is to prevent , or correct at their
onset, the menstrual and the eating disorders .
54
Female athlete triade
Eating disorders
Amenorrhea
Inadeguate calcium intake
Lack of estrogens Influence on bone tissue
Osteoporosis
55
Correlation between bone density,mentrual
function and physical activity
Bone Mineral Content (mg/BSA)
Am Amenorrheic Eu
Eumenorreich
56
Osteoporosisprevention
In developing people exercise and a calcium rich
diet allow the achievement of an higher value of
bone mass peak, that is a fondamental step in
the prevention of osteoporosis
57
Osteoporosisprevention
Evidence certainly suggests that Increased
physical activity adeguate calcium intake
adeguate caloric intake is a sensible approach
to preserve the integrity of bone, at any age
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