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Aging and exercise. Prof.G.Galanti. Corso di Laurea in Scienze Motorie A.A. 2003/2004.
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Aging and exercise Prof.G.Galanti Corso di Laurea in Scienze Motorie A.A. 2003/2004
What physiological changes occur during aging that affect exercise tolerance? Does intense physical activity pose any healt risks for aging athletes? How trainable are middle-aged and older adults?
Sport performance of older athletes Age related changes in:• body composition• cardiorespiratoty endurance• muscle strength• tolerance of enviromental stress…how do they affect performance How training can improve the older athlete’s fitness and performance
Changes in body composition Starting from 30s: • fat-free mass progressively decreases • decreased muscle and bone mass • fat mass progressively increases • increased dietary intake • decreased physical activity • reduced ability to mobilize fat
Changes in body composition swimmers % body fat Training can delay age-related changes in body composition runners
Sport performance of older people In older people, decreases in sport performance result from decrements in both muscular and cardiovascular endurance and strength.
Sport performance of older athletes How does aging affect sport performance? Along with aging, peak performances in both endurance (running, swimming, cycling) and strength sport decreases by about 1% to 2% per year, starting between ages 25 and 35.
Changes in aerobic capacity (VO2 max) VO2 max = CO x A-V diff
Changes in aerobic capacity (VO2 max) Changes in VO2 max among normally active men Age VO2max % change from (yr) (ml/Kg/min) 25 years 25 35 45 52 63 75 47,7 43,1 39,5 38,4 34,5 25,5 ------- - 9,6 - 17,2 - 19,5 - 27,7 - 46,5
Changes in aerobic capacity (VO2 max) % change = (final VO2max - initial VO2max) Initial VO2 max Comparing aging men and women for the % change in VO2 max,they both show a decline of 1% per year (10% per decade), caused by: • in maximum heart rate • in stroke volume
Maximum heart rate (Max HR=220-age) • Stroke volume • VO2 max
Maximum heart rate • sympathetic nervous system activity electrophysiological alterations • max heart rate
Stroke volume With age arteries begin to lose their elasticity and to reduce capability of vasodilatation peripheral resistence stroke volume
The decline in endurance performance, aerobic capacity, and cardiovascular function are more the result of a decrease in activitythan of aging; in fact if body composition and physical activity are kept costant, reduction in VO2max is only about 5% per decade (in elite senior athlete even less than 1-2%per decade)
VO2 max in highly trained older men Older athletes who had been continued to train highly are able to maintain there VO2 max, but not to prevent physiological age related changes: • Max HR decrease by about 5 to 7 beats/min /decade • body weigth decrease slightly • body fat increase significantly Between age 30 and 50 years aging itself doesn’t decrease aerobic capacity (though afer 50s VO2max decreases despite training)
Changes in respiratory function Respiratory function decreases with age, primarily because of a loss of elasticity in the lung tissue and in the chest wall. During middle and older age, endurance training can significantly reduce these changes
Changes in strength Strength is reduced with aging This is the result of : •Decrease in physical activity • Decrease in muscle mass (athrophy) Strength training can maintain or increase the muscle fiber cross-sectional area in older people
Training in aging adults•reduces decline in cardiovascular and respiratory functions•reduces decline in aerobic capacity (VO2 max)•reduces muscular athrophy and loss in strength
Training cannot arrest the process of biological aging, but it can lessen the impact of aging on performance
1820 :Lobsteindescribed 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
Osteoporosis Recent Definitions ‘An age-related disorder characyerized 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 characyerized by increased skeletal fragility due to decreased bone mass and to microarchitectural deterioration of bone tissue. (Consensus Development Conference 1996)
Osteoporosis bone mass bone density Bone Mineral Density (BMD) is used to divide 4 categories of patients: I Normal II Osteopenia (low bone mass) III Osteoporosis IV Severe osteoporosis
Osteoporosis The principal complications of osteoporosis are the fractures, in particular: • proximal femur • Vertebral body • Distal radius (Colle’s fracture)
Peak bone mass Troughout childhood, bone mass increases linearly with skeletal growth. A rapid increase 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 Influences (75%) Mechanical factors Peak Bone Mass Nutritional factors Hormonal factors
Bone remodellingannual 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. After 50s men loose about the 0,4% per annum of the total body calcium, that is a quite small quantity.
Age-related bone loss In women, bone loss before menopausa is small (<1% per annum), accelerating in the 5 years postmenopausal period to 3-6% per annum, then it reduces at about 1% per annum. In the first decade of menopausal women loose about the 15% of the bone mass. At the age of 70 loss can reach the 30%.
OsteoporosisMain causes • Estrogen deficiency • Inadeguate calcium intake • Inadeguate physical activity
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
Female athlete triade 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 : • Eating disorders • Menstrual dysfunctions until amenorrhea • Osteoporosis
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 .
Female athlete triade Eating disorders Amenorrhea Inadeguate calcium intake Lack of estrogens Influence on bone tissue Osteoporosis
Correlation between bone density,mentrual function and physical activity Bone Mineral Content (mg/BSA) Am= Amenorrheic Eu= Eumenorreich
Osteoporosisprevention In developing people exercise and a calcium rich diet (1200mg/die) allow the achievement of an higher value of bone mass peak, that is a fondamental step in the prevention of osteoporosis
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