The female athlete athlete The female athlete athlete Corso di Laurea in Scienze Motorie Prof G.Galanti A.A. 2003/2004

Until 1970 women were barred from official partecipation in the marathon. 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 02:24:52. Her time would have won 11 of the previous 20 men’s Olympic marathons!

Sex-specific differences Body composition Until puberty, boys and girls do not differ significantly in: heigth weigth heigth weigth girth bone with girth bone with fat-mass fat-free mass fat-mass fat-free mass Sex-specific differences in body composition appeares at puberty and are due to the appeares at puberty and are due to the hormonal influences. hormonal influences.

Sex differences in FFM Sex differences in FFM changes with age changes with age

Hormonal influences on body composition Testosterone Testosterone (men) (men)   bone formation  bone formation  muscle mass  muscle mass Estrogens Estrogens (women) (women)   growth rate of bone  growth rate of bone broadening the pelvis broadening the pelvis breast development breast development  fat deposition (thighs and  fat deposition (thighs and hips) hips)

Kg Sex diffences in body composition at the end of puberty (mean values)

Sex diffences in body composition with aging Relative body fat values for average, untrained women and men untrained women and men Relative body fat (%) Women Men Age group years years

Sex differences in physiological responses to acute exercise  Neuromuscolar  Cardiovascular  Respiratory  Metabolic

Sex differences in physiological responses to acute exercise  Neuromuscolar  Cardiovascular  Respiratory  Metabolic

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)

For the same amount of muscle, there are no differences in strength between sexes, though women possess smaller though women possess smaller muscle fiber cross-sectional areas and less muscle mass than men Differences in strength

Sex differences in physiological responses to acute exercise  Neuromuscolar  Cardiovascular  Respiratory  Metabolic

Cardiovascular response to 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

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 Cardiovascular response to acute exercise

Sex differences in physiological responses to acute exercise  Neuromuscolar  Cardiovascular  Respiratory  Metabolic

Changes in aerobic capacity (VO2 max) VO2 max = CO x A-V diff

VO2max in normal women The average woman’s VO2max is only 70% to 75% that of the average man. The main causes of this differences are: women’s greater fat mass women’s greater fat mass lower hemoglobin levels lower hemoglobin levels lower maximal cardiac output lower maximal cardiac output

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

Women respond to physical training in the same manner as men do Women’s adaptations to chronic exercise

Effect of training on body composition in women  Fat-free mass (generally much less than man)  Fat-free mass (generally much less than man)  Fat mass  Fat mass  Relative fat  Relative fat  Total body mass  Total body mass This changes are more related to total energy expenditure than to sex differences.

Effect of resistence training on women’s 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 women’s increase in muscle mass in fact women’s increase in muscle mass is generally small because of their low testosterone levels.

Cardiovascular effects of endurance training Cardiovascular adaptations to endurance training are not sex specific. So, trained women have: lower rest and submaximal HR lower rest and submaximal HR higher cardiac size (physiological hypertrophy) higher cardiac size (physiological hypertrophy) higher stroke volume higher stroke volume higher maximal cardiac output higher maximal cardiac output largest blood volume largest blood volume higher muscular capillary density higher muscular capillary density …………than sedentary ones. …………than sedentary ones.

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

Medical problems in female athlete in female athlete Medical problems in female athlete in female athlete

Female athlete triade In 1992 the Task Force on Women’s Issues of the In 1992 the Task Force on Women’s 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 : female athlete : Menstrual dysfunctions until amenorrheaMenstrual dysfunctions until amenorrhea Eating disordersEating disorders OsteoporosisOsteoporosis

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

The Pituitary gland I GH GH Growth hormone TSH Thyroid-stimulating hormone Thyroid-stimulating hormone Prolactin ACTH ACTHAdrenocorticotropin FSH Follicle-stimulating hormone LH Luteinizing hormone Anterior lobe

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

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

The Pituitary gland V Anterior lobe TARGET ORGAN TARGET ORGAN Ovaries, Testes MAJOR FUNCTIONS FUNCTIONS Initiates growth of follicles inthe ovaries and promotes secretion of estrogen from the ovaries. Promotes developement of sperm in testes. 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 Promotes secretion of estrogen and progesterone and causes the follicle to rupture, releasing the ovum. Causes testes to secrete testosterone HORMONEFSHLH

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.

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

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.

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.

Eating disorders The two most commonly diagnosed eating disorders are: anorexia nervosa and anorexia nervosa and bulimia nervosa bulimia nervosa

Eating disorders Anorexia nervosa anorexia nervosa is characterized by: refusal to maintain more than the minimal normal weight based on an age and heigth refusal to maintain more than the minimal normal weight based on an age and heigth distorted body image distorted body image intense fear of fatness or gaining weigth intense fear of fatness or gaining weigth amenorrhea amenorrhea Prevalence: about 1% in females from ages 12 to 21

Eating disorders Bulimia nervosa bulimia nervosa is characterized by: reccurent episodes of binge eating reccurent episodes of binge eating a feeling of lack of control during these binges a feeling of lack of control during these binges purging behaviour, which can include self induced vomiting, laxative use and diuretic use purging behaviour, which can include self induced vomiting, laxative use and diuretic use Prevalence: about 1% in females from ages 12 to 21

Eating disorders Anorexia athletica Anorexia athletica is characterized by: an intense fear of gaining weigth or becaming fat even though one is under-weigth 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 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 reported use of self-induced vomiting or use of laxative or diuretics

Anorexia athletica: problem dimension Prevalence of anorexia athletica is not well 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.

Eating disorders Anorexia athletica As in the general population, female athletes are exposed at a higher risk than male athletes. 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 ‘Appearence sports’: figure skating, gymnastic, body building, ballet Endurance sports: distance running, swimming Endurance sports: distance running, swimming Weight-classification sports: horse racing, boxing, wrestling Weight-classification sports: horse racing, boxing, wrestling

Warning signs for eating disorders in female athletes Warning signs for anorexia nervosa: 1.Dramatic loss in weigth 2.A preoccupation with food, calories and weigth 3.Wearing baggy or layered clothing 4.Relentless, excessive exercise 5.Mood swings 6.Avoiding food-related social activities Adapted from National Collegiate Athletic Association

Warning signs for eating disorders in female athletes Warning signs for bulimia nervosa: 1.A noticeble weigth loss or gain 2.Excessive concern about weigth 3.Bathroom visits after meals 4.Depressed moods 5.Strict dieting followed by eating binges 6.Increased criticism of one’s body Adapted from National Collegiate Athletic Association

OsteoporosisOsteoporosis

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 Osteoporosis First Descriptions First Descriptions

Osteoporosis Osteoporosis Recent Definitions 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)

Osteoporosis The principal complications of osteoporosis are the fractures in particular sites: proximal femur Vertebral body Distal radius (Colle’s fracture)

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)

Peak bone mass Genetic GeneticInfluences (75%) (75%) Genetic GeneticInfluences (75%) (75%) Mechanical Mechanical factors factors Mechanical Mechanical factors factors Hormonal Hormonal factors factors Hormonal Hormonal factors factors Nutritional Nutritional factors factors Nutritional Nutritional factors factors Peak Bone Mass

Bone remodelling annual rate of 25% in trabecular bone, 2-3% in compact, cortical bone

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 (<1% per annum), accelerating in the 5 years postmenopausal period to 1-2% per annum.

Osteoporosis Main causes Estrogen deficiency Estrogen deficiency inadeguate calcium intake inadeguate calcium intake inadeguate physical activity inadeguate physical activity

Osteoporosis Epidemiology OSTEOPOROSIS interests two main groups of people: women beyond menopausa lack of estrogens elderly women and men elderly women and men carence of vit D   PTH carence of vit D   PTH reducted physical activity reducted physical activity reducted calcium dietary apport reducted calcium dietary apport

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.

Eating disorders Inadeguate calcium intake intake Amenorrhea Lack of estrogens Lack of estrogens Influence on bone tissue Osteoporosis Female athlete triade

Correlation between bone density,mentrual function and physical activity Bone Mineral Content (mg/BSA) Am= Amenorrheic Eu= Eumenorreich

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 Osteoporosis prevention

Evidence certainly suggests that : Increased physical activity Increased physical activity adeguate calcium intake adeguate calcium intake adeguate caloric intake adeguate caloric intake is a sensible approach to preserve the integrity of bone, at any age Osteoporosis prevention