Transcript Diapositiva 1 - University of Verona

ATTIVITA’ MOTORIE PER LA PREVENZIONE
Prof. Antonio Cevese
Prof. Massimo Lanza
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LEGENDA II SEMESTRE
Tirocinio in Attività motorie e Sportive Adattate --- ApaES
Attività motorie per la prevenzione -- AMP
Farmacologia delle attività motorie e sportive --- F
Economia e Diritto applicati Principi di Diritto --- D
Economia e Diritto applicati Gestione Economica ---
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Age-related decline in physical activity: a
synthesis of human and animal studies
JAMES F. SALLIS
Med. Sci. Sports Exerc., Vol. 32, No.
9, pp. 1598–1600, 2000
1. What is the age of greatest decline for male and female
subjects?
2. What are differences in declines for various types and
intensities of physical activity?
3. How do results of human studies compare with those of
animal studies?
What is the age of greatest decline for male and
female subjects? The three studies of humans produced
strikingly similar results. Summarizing across measures, the ages of greatest decline
were 13–16 in the Dutch study (10), 12–15 or 15–18 in the Finnish study (8), and 15–
18 in the U.S. study (2). The Caspersen et al. study (2) clearly showed that the annual
rate of decline is much greater during adolescence than during adulthood.
There is evidence of a physical activity decline in many species, ranging from insects
and rodents to monkeys.
These results are seen in both cross-sectional and longitudinal studies. Over the
adult age range, rodents decrease their overall activity levels by approximately 50%.
Declines during adulthood occur at a much slower rate than during adolescence. A
surprising finding was that male subjects decline more in physical activity than
female subjects, especially during youth.
Aging and Preventive Health
Ronan Factora
•Cardiology: Atrial Fibrillation, Cardiac Arrhythmias, Heart Failure, Peripheral Arterial Disease,
Preventative Cardiology, Syncope
•Dermatology: Photo Aging
•Endocrinology: Erectile Dysfunction, Diabetes, Osteoporosis, Male Hypogonadism
•Gastroenterology: Colorectal Neoplasia
•Hematology/Oncology: Anemia, Multiple Myeloma, Breast Cancer Screening, Prostate Cancer
•Infectious Disease: Immunization for Adults
•Nephrology: Slowing Progression of Renal Disease
•Neurology: Alzheimer's Disease, Antiplatelet Agents in Secondary Stroke Prevention, Carotid
Vascular Disease, Dizziness, Low Back Pain, Parkinson's Disease, Stroke, Tremors
•Psychiatry and Psychology: Delirium, Depression, and Other Mood Disorders
•Pulmonary Disease: Chronic Obstructive Pulmonary Disease
•Rheumatology: Gout, Osteoarthritis
•Women's Health: Breast Cancer Risk Assessment and Prevention, Cervical Cancer Screening and
Prevention, Menopause, Osteoporosis, Urinary Tract Infections in Adults
Factors that have been identified as comprising the frailty phenotype include the
loss of muscle mass, muscle weakness, poor endurance or energy, slowness, and
low physical activity.
Homeostatic reserve is defined as the redundancy of physiologic functions present
in human systems that is used to overcome acute and chronic health insults. The
frailty phenotype can be used as a marker indicating a critical threshold in decline
of homeostatic reserve. It also has been hypothesized to be a contributing factor to
progression of chronic disease states, development and worsening of geriatric
syndromes, and decline in ability to perform activities of daily living
Physical activity
Engagement in physical activity often declines with increasing age. Benefits of
regular exercise have been studied extensively and are myriad, including
reduction in risk of heart attack and stroke, improvement of diabetic control,
stress reduction, improvement of pulmonary function, reduction of osteoarthritic
pain and stiffness, and reduction of depressive symptoms. Beyond the benefits
associated with chronic disease processes, physical activity in and of itself
helps to maintain pulmonary and cardiac function, as well as musculoskeletal
mass and tone.
Targeted exercise types may also help specific areas of weakness and reduce the risk of
functional decline. Exercise types include:
•weight training,
•cardiovascular fitness,
•balance training,
•flexibility training.
Each type has its benefits. Strength training through use of resistance exercises helps
to maintain muscle bulk and tone. Exercise of large muscle groups used in weight
bearing helps to maintain mobility (for example, quadriceps strength is needed to
maintain the ability to stand and properly ambulate). An example of this is in
maintaining arm and leg strength to be able to perform light and heavy lifting needed
to do housework. Such exercises can also be beneficial in maintaining the ability to
participate in leisure (gardening, golfing) and social activities (dancing). With reduced
use, slow twitch fibers eventually atrophy and convert to fatty tissue, with consequent
reduction in muscle bulk, function, and potential decline in physical functional
capacity.
With greater amounts of exercise, greater benefits can be derived from it. The
maintenance and increase of reserve functional capacity are important concepts in the
elderly population. Homeostatic reserve allows an individual to overcome the results
of acute insults to health. The presence of a greater amount of homeostatic reserve
allows an individual to recover more quickly and more completely from acute declines
in health. Decline in homeostatic reserve in all systems as a part of the aging process is
generally recognized. This is accelerated by chronic disease processes and acute
illness. The consequence is an impaired ability to recover from acute illness, the
potential for permanent impairment, and development of a new functional baseline.
Normal aging is associated with changes in body composition. Lean muscle mass
declines and percentage of body fat increases. Caloric intake has been demonstrated
to decline with increasing age in several observational studies. Several factors
associated with normal aging contribute to this decline. These include a reduction in
the senses of smell and taste, increased cholecystokinin production leading to earlier
and more pronounced satiety with small meals, and reduced gastric motility
Age-Related Changes That Affect Appetite
Sensory Changes: Decreased odor perception; Increase in taste thresholds; Decline in
taste sensitivity
Gastrointestinal Tract Changes: Earlier satiation; Reduced fundal compliance; Delayed
gastric emptying
Hormonal Changes: Increased serum leptin; Decreased serum testosterone; Increased
serum cholecystokinin
Increased inflammation-mediated cytokines: IL-1, TNF-α, IL-6, and ciliary neurotrophic
factor
Central Nervous System Changes: Decreased opioid receptor activity; Reduction in
physical activity ; Decline in resting metabolic rate
Interventions for cognitive function
Cognitive impairment and dementia occur commonly in the elderly population, and
increases in incidence with in those older than 65 years. Several studies have analyzed
risk factors for development of dementia, specifically Alzheimer's disease. Beyond
health risk factors such as diabetes, hypertension, and hyperlipidemia, several lifestyle
factors such as economic background, level of education, physical activity, and leisure
activities have been studied to determine a link between them and risk for cognitive
decline.
Curr Sports Med Rep. 2010 Jul-Aug;9(4):214-9.
Physical activity and cardiac protection.
Lee IM.
Abstract
Epidemiologic data clearly show that men and women with higher levels of physical
activity have lower rates of cardiovascular disease. While the precise biologic
mechanisms for this relation have not been elucidated completely, several plausible
mechanisms involving traditional and novel cardiovascular risk factors have been
described.
150 min.wk(-1) of moderate-intensity aerobic activity, or the equivalent in vigorous, or
moderate plus vigorous activities, is sufficient to reduce risk. There is a dose-response
relation in that additional amounts of physical activity exceeding this level are
associated with additional reductions in cardiovascular disease risk.
300 min.wk(-1) of moderate-intensity aerobic activity, or the equivalent in vigorous, or
moderate plus vigorous activities, for additional health benefits. Among patients with
established coronary artery disease, physical activity also reduces all-cause and
cardiovascular disease mortality rates
Nutr Metab Cardiovasc Dis. 2010 Jul;20(6):467-73. Epub 2010 Apr 15.
Physical activity and cardiovascular disease prevention in women: a review of the
epidemiologic evidence.
Bassuk SS, Manson JE.
Abstract
Epidemiologic studies suggest that as little as 30 minutes of moderate-intensity
physical activity per day can lower the risk of developing cardiovascular disease in
women. Sedentary individuals who become physically active even at older ages derive
cardiovascular benefits. Physical activity appears to slow the initiation and progression
of CVD through salutary effects not only on adiposity but also on insulin sensitivity,
glycemic control, incident type 2 diabetes, blood pressure, lipids, endothelial function,
hemostasis, and inflammatory defense systems. Public health initiatives that promote
moderate increases in physical activity may offer the best balance between efficacy
and feasibility to improve cardiovascular health in sedentary populations.
Physical Activity and Cardiovascular Health
Lessons Learned From Epidemiological Studies Across Age, Gender,
and Race/Ethnicity
Eric J. Shiroma, MSc; I-Min Lee, MBBS, ScD
(Circulation. 2010;122:743-752.)
In 1953, Morris et al published the findings from a study showing that bus conductors
in London, who spent their working hours walking the length of the buses as well as
climbing up and down the stairs of the English double-decker buses to collect fares,
experienced half the coronary heart disease (CHD) mortality rates of their driver
counterparts, who spent their day sitting behind the wheel. Investigators hypothesized
that it was the physical activity of work that protected the conductors from developing
CHD, at the same time realizing that other factors may also play a role because the
conductors were smaller in size, as evidenced by their smaller uniform sizes. Thus was
born the field of “physical activity epidemiology”: formal epidemiological
investigations into the associations of physical activity with many health outcomes.
1.
What is the magnitude of the association between physical activity and CHD/CVD?
2.
Is there a dose-response relation between physical activity and CHD/CVD? If so, what is the
shape of the dose-response curve?
3.
Can physical activity ameliorate the increased risk of CHD/CVD associated with adiposity?
“Greater amounts of activity appear to provide greater benefit but the shapes of any doseresponse relations have not been well defined.”
The concept of “dose” in physical activity studies has been applied variously to the total volume
of energy expended or the intensity, duration, or frequency of physical activity, with most data
available are on the total volume.
The available data, however, are consistent with the 2008 federal physical activity guidelines
that require at least 150 min/wk of moderate- or 75 min/wk of vigorous-intensity aerobic
physical activity and that state that additional benefits occur with 300 min/wk of moderate- or
150 min/wk of vigorous-intensity aerobic physical activity.
Physical Activity and Public Health
Updated Recommendation for Adults From the American College of
Sports Medicine and the American Heart Association
William L. Haskell, PhD, FAHA; I-Min Lee, MD, ScD; Russell R. Pate, PhD, FAHA;
Kenneth E. Powell, MD, MPH; Steven N. Blair, PED, FACSM, FAHA;
Barry A. Franklin, PhD, FAHA; Caroline A. Macera, PhD, FACSM;
Gregory W. Heath, DSc, MPH, FAHA; Paul D. Thompson, MD; Adrian Bauman, PhD, MD
Circulation published online Aug 1, 2007;
Primary Recommendation—To promote and maintain health, all healthy adults aged 18 to 65
yr need moderate-intensity aerobic (endurance) physical activity for a minimum of 30 min on
five days each week or vigorous-intensity aerobic physical activity for a minimum of 20 min on
three days each week. Combinations of moderate- and vigorous-intensity activity can be
performed to meet this recommendation. For example, a person can meet the recommendation
by walking briskly for 30 min twice during the week and then jogging for 20 min on two other
days. Moderate-intensity aerobic activity, which is generally equivalent to a brisk walk and
noticeably accelerates the heart rate, can be accumulated toward the 30-min minimum by
performing bouts each lasting 10 or more minutes. Vigorous-intensity activity is exemplified by
jogging, and causes rapid breathing and a substantial increase in heart rate. In addition, every
adult should perform activities that maintain or increase muscular strength and endurance a
minimum of two days each week. Because of the dose-response relation between physical
activity and health, persons who wish to further improve their personal fitness, reduce their risk
for chronic diseases and disabilities or prevent unhealthy weight gain may benefit by exceeding
the minimum recommended amounts of physical activity. (Circulation. 2007;116:000-000.)
Muscle-Strengthening Activity
To promote and maintain good health and physical independence, adults will benefit
from performing activities that maintain or increase muscular strength and endurance
for a minimum of two days each week. It is recommended that 8–10 exercises be
performed on two or more nonconsecutive days each week using the major muscle
groups. To maximize strength development, a resistance (weight) should be used that
allows 8–12 repetitions of each exercise resulting in volitional fatigue. Musclestrengthening activities include a progressive weight-training program, weight bearing
calisthenics, stair climbing, and similar resistance exercises that use the major muscle
groups.
Activity Dose
The term dose is used frequently in descriptions of physical activity, but it can be
interpreted in several ways—as the total amount of physical activity (i.e., total energy
expended) or as the intensity, duration, or frequency of activity. Although many
studies have included a measure of the total amount of physical activity (which may be
used to characterize participants as ‘‘active,’’ ‘‘moderately active,’’ or ‘‘inactive’’ for
example), relatively few observational studies have included details on the kinds of
activity carried out or the duration and frequency of each bout of activity. In brief, the
total amount of physical activity is a function of its intensity, duration and frequency.
Accordingly, vigorous intensity activities (those having > 6.0 metabolic equivalents or
METs) carried out for a particular duration and frequency generate greater energy
expenditure than moderate-intensity activities (3.0 to 6.0 METs) of the same duration
and frequency.
Cardiorespiratory fitness, lipid/lipoprotein profiles, blood pressure, fasting plasma
insulin, postprandial lipidemia and weight control all appear to be affected beneficially
with intermittent bouts of physical activity. In several studies the effects of
accumulated short bouts are similar to those seen with continuous bouts of physical
activity lasting ≥ 30 min.
Resistance training at least twice per week provides a safe and effective method to
improving muscular strength and endurance by 25% to 100% or more. It is
recommended that 8–10 exercises be performed on two or more nonconsecutive days
each week using the major muscles. A resistance (weight) should be used that results
in substantial fatigue after 8–12 repetitions of each exercise. The emerging evidence
on musculoskeletal health benefits and the potential population-wide effects of
promoting skeletal health support the need for a public health recommendation that
includes resistance exercise.
Cardiovascular Effects of Exercise: Role of Endothelial Shear Stress
JOSEF NIEBAUER, MD, JOHN P. COOKE, MD, PHD, FACC
Stanford, California
Experimental, epidemiologic and clinical studies have provided strong evidence that physical
exercise has beneficial effects on multiple physiological variables affecting cardiovascular health
(lipoprotein levels, rest blood pressure and heart rate, carbohydrate tolerance, neurohormonal
activity). Regular exercise has been shown to slow the progression of cardiovascular disease and
to reduce cardiovascular morbidity and mortality. More recently, exercise-induced increases in
blood flow and shear stress have been observed to enhance vascular function and structure. By
increasing the release of nitric oxide and prostacyclin, shear stress augments endothelium-
dependent vasodilation and inhibits multiple processes involved in atherogenesis and
restenosis. In this review we discuss the underlying mechanisms by which exercise-induced
blood flow and shear stress exert their salutary effects on cardiovascular remodeling.
(J Am Coll Cardiol 1996;28:1652– 60) q1996 by the American College of Cardiology
There is substantial evidence garnered from clinical and animal studies that regular aerobic
exercise can alter vessel structure. The progression of coronary lesions can be inhibited and, in
some cases, regression of disease can be observed in patients who modify their cardiovascular
risk factors and engage in regular aerobic exercise. It is estimated that an average of 1,500
kcal/week must be spent on leisure time physical activity to halt progression of disease, whereas
regression is only observed in patients expending an average of 2,200 kcal/week. This latter
degree of energy expenditure is equivalent to 5 to 6 h/week of moderate exertion in the form of
aerobic exercise.
There is a significant correlation between regular physical exercise and an increase in the lumen
diameter of coronary arteries. Men who reportedly had a physically active occupation or a
generally active life-style had larger than expected coronary arteries. The marathon runner
Clarence De Mar, whose epicardial vessels were found to be “two or three times the normal
size” . Vigorously active Masai tribesmen who died of noncardiovascular causes and had no
clinical evidence of coronary artery disease had as much coronary atherosclerosis at autopsy as
American men but had patent arterial lumens because of the large size of their epicardial
vessels.
Intensive aerobic exercise promotes collateral formation or expansion of the microvasculature,
or both. When sublingual nitroglycerin was administered, the arteries of the marathoners
showed a 200% greater increase in vasodilation than did those of the sedentary group.
Flow-Mediated Vasodilation
The two principal forces acting on the blood vessel are pulsatile stretch and shear stress.
Pulsatile stretch is determined by fluctuation in arterial pressure and is a force exerted at a
vector that is perpendicular to the longitudinal axis of the vessel. Shear stress is determined by
blood flow and is a tractive force exerted at a vector that is parallel to the long axis of the vessel.
The essential role of the endothelium in exercise-induced flow-mediated vasodilation has been
confirmed in exercising dogs. Exercise-induced epicardial coronary vasodilation was observed
during treadmill running. Marked vasoconstriction was found up to 6 days after balloon
denudation of the endothelium. Flow-mediated vasodilation is largely due to the release of
endothelium-derived relaxing factor (EDRF) . EDRF was first described in 1980 by Furchgott and
Zawadzki and is now known to be nitric oxide (NO) derived from the metabolism of L-arginine to
L-citrulline by NO synthase. Like other nitrovasodilators, NO exerts its effect on vascular smooth
muscle by activating soluble guanylate cyclase to produce cyclic guanosine monophosphate
Mechanotransduction of Flow-Mediated Vasodilation
Recent investigations have shed light on the mechanisms by which the endothelium senses and
transduces the stimulus of flow. An endothelial potassium channel is known to be activated by
flow. The mechanisms by which ion channels are activated by flow remain obscure, but they
probably involve shear stress-mediated deformation of cytoskeletal elements . The activity of an
endothelial potassium channel also appears to be required for the flow-induced (but not
receptor mediated) release of NO from vascular segments or cultured endothelial cells.
Intriguingly, this same signal transduction pathway is involved in the flow-induced transcription
of transforming growth factor-beta1 (TGF-beta1). Thus, the initial response to an increase in
flow (vasodilation) and the later response (change in vascular structure) may share a common
mechanotransducer .
Chronic Effects of Flow on Vascular Reactivity: Can regular exercise alter vascular reactivity so as
to enhance vasodilation? Regular exercise can exert beneficial effects on vascular reactivity, and
these salutary changes are due to exercise-induced increases in blood flow. Long-term changes
in flow exert their effects on endothelium-dependent vasodilation by modulating the expression
of NO synthase.
Mechanisms of Flow-Induced Alterations in Vascular Structure
Can regular exercise affect vascular structure and promote patency? The answer appears to be
in the affirmative, and exercise-induced changes in blood flow probably contribute to this
beneficial effect. Vessels are capable of significant remodeling in response to long-term changes
in flow. In various animal models, vigorous endurance-type exercise training enlarges the
diameter of coronary arteries. In the canine carotid artery, increases in blood flow enlarge vessel
diameter; this change is associated with an increased rate of protein turnover, providing
evidence that structural adaptation occurs in response to increased flow.
Flow-Released NO Opposes Atherogenesis
Animal studies indicate that an exercise intervention may reverse endothelial dysfunction. The
beneficial effects of exercise on endothelium-dependent vasodilation may have significant
consequences for vascular structure as well as vascular reactivity. In addition to its effects on
vasomotion, NO is known to antagonize key processes involved in atherogenesis, including
monocyte adherence and chemotaxis, platelet adherence and aggregation and vascular smooth
muscle proliferation .
Evidence for sex differences in cardiovascular aging and adaptive
responses to physical activity
Beth A. Parker • Martha J. Kalasky •David N. Proctor
Eur J Appl Physiol (2010) 110:235–246
the paper will: (1) briefly review known sex differences in cardiovascular aging, (2) detail
emerging evidence regarding observed cardiovascular outcomes in investigations of exercise and
physical activity in older men versus women, (3) explore mechanisms underlying the differing
adaptations to exercise and habitual activity in men versus women, and (4) discuss implications
of these findings with respect to chronic disease risk and exercise prescription.
Sex differences in cardiovascular system aging are evident at rest, during acute physiological
challenges (exercise, orthostasis, environmental stress), and in response to pharmacological
drug infusions
Observed age differences in the cardiovascular system between the sexes
Resting characteristics
Older women appear to exhibit greater declines in resting parameters that may augment their
cardiovascular disease risk. For example, a recent study of 1,333 healthy individuals (ages 10–
89) free of heart disease and hypertension revealed that peak early mitral annular velocity (E’)
deteriorates more significantly with age in women than in men. A reduced E’ reflects reduced
left ventricular relaxation (i.e., impaired diastolic filling) and is correlated with decreased
exercise capacity in both healthy adults as well as patients with cardiovascular disease.
It is well-documented that muscle sympathetic nerve activity increases to a greater extent
with age in women than men, and this finding has also been proposed as a factor contributing
to the greater influence of advancing age on hypertension and cardiovascular disease
progression in women
Middle-aged hypertensive women—but not men—exhibited reduced cardiovagal baroreflex
sensitivity, which was correlated to a higher systolic blood pressure. these sex differences in
autonomic function could be a potential mechanism underlying the higher prevalence of
hypertension in older women.
Exercising central hemodynamics
There are also sex differences in the effect of age on central (i.e., cardiac and pressor) responses
to large muscle mass dynamic exercise. Maximal cardiac output decreases more steeply in the
later decades (ages 60–90) in older men ([age 60) than older women, as the slope of the
decrease in cardiac output is over two-fold higher in older men versus women. A similar trend
was observed with respect to maximal oxygen uptake in the same study. Similarly, maximal
cardiac power output and reserve decrease by 20–25% in men across the ages 20–75,
correlating with a similar (21%) decrease in left ventricular mass, whereas the same variables
are preserved in aging women. In contrast, older women exhibit an exaggerated pressure
response to exercise relative to their younger counterparts. This exaggerated pressor response is
not as pronounced in older men.
Exercising peripheral hemodynamics
Sex differences in peripheral hemodynamic responses to leg exercise. Although leg blood flow
and vascular conductance responses during graded leg cycling exercise are reduced with age in
both chronically endurance-trained or very sedentary men, normally active older men (i.e., men
who are neither extremely sedentary nor highly trained, as defined by oxygen uptake values
falling within the 20–80th percentile of age and sex-specific norms) do not exhibit attenuated
leg blood flow responses when compared with young men. However, a demographically similar
group of normally active older women demonstrated blunted leg hyperemic and vascular
conductance responses relative to their young counterparts during the same mode of
submaximal exercise.
Balance between central and peripheral hemodynamics
Maximal cardiac output was positively correlated with peak femoral blood flow in young and
older men but not in women (in either age group). Aging is associated with a more pronounced
sex difference in the relationship between the pumping capacity of the heart and peripheral
vascular reserve
Vascular responses to non-exercise stimuli
Forearm blood flow responses to infusions of the vasoconstrictor endothelin-1 as well as
endothelin A and B (ETA and ETB, respectively) receptor antagonists in middle-aged and older
men and women. Older men demonstrated significantly greater dilation to the ETA receptor
antagonist, suggesting that men are under greater ETA-mediated vasoconstrictor tone
than older women. Age-related changes in vasoconstrictor tone and the regulation of
peripheral vascular resistance are sex-specific in older adults
Age-related changes in vasoconstrictor tone and the regulation of peripheral vascular
resistance are sex-specific in older adults
The influence of acute and chronic physical activity on modifying certain biomarkers of
cardiovascular aging also demonstrates sex specificity in older humans. Increased walking
frequency measured over a 24-month period in the Activity Counseling Trial was predictive of
reduced aortic pulse wave velocity, an index of arterial stiffness, in older women but not in men.
Aerobic training significantly increased peak calf blood flow and vascular conductance in older
men while only marginally increasing these responses in older women.
In men, matching older versus young men for fitness abolished the age-associated decline in
peak calf conductance, whereas in women, the reduction in peak calf conductance with age
persisted despite matching older and younger subjects for fitness.
Vascular responses to non-exercise stimuli are influenced by chronic exercise differentially in
older men versus women. Conduit artery vasodilation (with brachial artery flow-mediated
dilation, or FMD) in response to 5 min forearm ischemia in both sedentary and fit older men and
women relative to young controls: fitness did not distinguish between conduit dilator responses
in men, whereas older sedentary women exhibited significantly lower brachial artery dilator
function than older fit women or young women. Moreover, exercise training resulted in a
beneficial training adaptation (i.e., improved brachial vasodilation) in older sedentary women
only.
Possible explanations for sex-dependent adaptive responses to physical activity with
advancing age
Young women exhibit augmented brachial artery flow-mediated dilation and beta adrenergic
mediated forearm vasodilation relative to young men. Moreover, the forearm vasodilatory
response to acetylcholine as well as peak calf reactive hyperemia are higher in women, while
the forearm vasoconstrictor response to norepinephrine and calf vasoconstrictor response to
cold pressor and isometric handgrip maneuvers are blunted in women relative to men. Sex
differences in adrenergic/vasodilator receptor density, sympathetic vascular transduction, and
downstream signaling in the vasculature could underlie attenuated vasoconstrictor responses in
women when compared with men.
Influence of sex hormones
The influence of female sex hormones in young women and the relatively abrupt cessation of
their production at menopause have been shown to have a significant influence on both
systemic and local indicators of cardiovascular function.
There is an interaction between recreational physical activity and steroid hormones in
postmenopausal women such that higher physical activity is associated with lower levels of
steroid hormone levels (both testosterone and estradiol) in postmenopausal women. In
contrast, in men, higher levels of physical activity are positively associated with total and free
testosterone. Therefore, it is possible that the modulation of the cardiovascular system by
physical activity in older adults is in part affected by endogenous levels of sex hormones that
differ between men and women.
Different acute and/or chronic doses of exercise are required to evoke certain cardiovascular
adaptations in men versus women. Both young and older women exhibited a greater rise in
shear rate across increasing knee extensor work rates than young or older men. Adaptations to a
9–12 week aerobic exercise training protocol in young adults: young men did not exhibit
changes in resting or exercising cardiac output following training, whereas women
demonstrated reduced cardiac outputs both at rest and during exercise. Conversely, exerciseinduced reductions in splanchnic blood flow with training were significantly less following
training in men but not women.