Transcript Slide 1

Prof K. Sivapalan
Department of Physiology,
Faculty of Medicine,
University of Jaffna
• Evolution: hunter-gatherer
• Body Composition: Muscles (40%)and Bones
• Motor Centers in Brain: Cerebellum and Basal ganglia,
Motor Cortex, Brain Stem and Spinal Cord
• Control of physical activity: Neocortex [on the basis of
short and long term health, physical and other
benefits] vs Limbic System [on the basis of emotion]
• Technology: Automation and communication →
comfort → unhealthy life style
• Tissues: “USE IT OR LOSE IT”
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• Energy intake = exercise energy expenditure + energy
needed for all other functions ± body energy content
• Inadequate energy intake: ↓ muscle mass; ↓bone density;
↑risk of fatigue, injury, and illness and reproductive
dysfunction.
• Eating: exercise before or after - after for glycaemic control.
• Vitamins and minerals: Vitamins B, C, D, E and beta carotene
and minerals like calcium, iron, zinc, magnesium and
selenium – ?weight reduction and diet restriction.
• Fluid & electrolytes: dehydration and hyponatremia (muscle
cramps)
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• Enzymes for oxidation of Fat- ↑,
Carbohydrate- ↓
• ↑ oxidative capacity, ↓ glycogen depletion
• ↑ insulin sensitivity and ↓ leptin level
• When Energy Intake >Energy Expenditure,
↑ serum cholesterol and phospholipids.
• Sprint- ↑post-exercise metabolism –weight
reduction.
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• Regular exercise reduces the risk of type 2 diabetes in
overweight/obese individuals.
• Regular walking exercise: increased energy consumption, and
decreased FBG, HbA1c, and TG levels. Better response if
done after dinner.
• Incidence of complications of type II diabetes might be
reduced by implementing a regular walking exercise program.
• Moderate exercise: muscular uptake of glucose exceeds
hepatic glucose production, and blood glucose decline during
the activity.
• Plasma insulin levels concomitantly fall, making the risk of
exercise-induced hypoglycemia low as long as the individual
is not injecting insulin or taking insulin secretagogues.
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• Hypertrophy
• Feed arteries in rats: young- increase in
number of vessels, old- increased cross
sectional area of the vessels
• Gene expression: heat shock proteinsmaintain homeostasis, facilitate repair from
injury and preserve muscle function in aging.
• Anabolic effect of nutrient intake- prevent
sarcopenia in old age.
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Muscle
Tendon
Joint Capsule - Fascia
Articular Cartilage
Epiphyseal cartilage
Bone
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• Articular cartilage volume: proportional to physical activity – exercise
in older women did not show increase.
• Postmortom findings in Horse: increase in hyaline cartilage, calcified
cartilage and subchondral bone thickness- ? Growing children.
• Joint form: development after birth is modified primarily through
differential rates of articular cartilage proliferation across articular
surfaces.
? By the magnitude and orientation of stresses in the articular
cartilage.
• Epiphysial growth is stimulated by weight bearing.
• Bone mass and architecture: Load-bearing is an important functional
influence. Bone's adaptive response to load-bearing depends on
functional strains. Remodeling – along the line of stress.
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• Excessive weight bearing on epiphysis - damage and
stunting.
• Injuries to muscles and bones occur by over use,
accidents and foul play in games.
• More physically active individuals had more knee
abnormalities.
• ? Running and osteoarthritis- may depend on preexisting health of the joint.
• Stress of competitive sports overweigh the benefits of
exercise by the action of stress hormones.
• Effects of exercise in illnesses like viral infections, liver
diseases and kidney diseases need consideration.
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• Antibody production: optimal in moderate exercise, suppression in
intense exercise.
• This transient suppression returns to normal in 24 hours. ? Can
become a chronic depression of acquired immunityif intense
exercise continues- may be due to elevated circulating stress
hormones, alterations in the pro/anti-inflammatory cytokine balance
• Exercise alters the number and function of neutrophils, monocytes
and natural killer cells- ?anti inflammatory effect of exercise.
• Prophylactic effect on insulin resistance, atherosclerosis, tumour
growth and neurodegeneration. ? Antiinflammatory effect
• Enhanced anti-tumour immunity: ?protection against
postmenopausal breast cancer and cancers of colon, endometrium,
lung and pancreas.
• AIDS: Moderate physical activity may slow HIV disease progression.
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• Improved pulmonary function at rest and exercise
[greator operating lung volumes]
• ?increased incidence of respiratory infection?immuno-suppression by exercise.
? Cool air and dust load of hyperventilation.
? Body temperature fluctuations- exercise and bathing.
• Exercise induced asthma- ?triggered by cool air
• Significant benefits from exercise training in Acute
Exacerbation of Chronic Obstructive Pulmonary Disease,
COPD, and conditions that are common co-morbidities
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• Thrombotic risk increases with aging-↑fibrinogen, factor VII, PAI-1
and plasma viscosity. Regular physical exercise ↓ risk
• Acute exercise [unaccustomed strenuous physical exertion]:
transient activation of the coagulation system, accompanied by an
increase in the fibrinolytic capacity.
• Acute exertion may precipitate ischeamic cardiac problems due to:
– Increased coagulability
– ?reduced plasma volume and haemo-concentration
– Rupture of a small, inflamed, coronary plaque and the activation
of thrombogenic factors
• Long-term moderate or strenuous physical activity is associated with
a considerable reduction in cardiovascular morbidity and mortality.
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• Resting heart rate, heart rate recovery, exercise HR, and exercise
blood pressure: strong association in runners and swimmers, less in
walkers and least in sedentary.
• Larger end diastolic volume and wall thickness, more in males [not
exceeded the limit of resolution].
• Transport capacity: ↑blood flow and capillary exchange.
Structural- cross-sectional area and angiogenesis- vascular
remodelling. Functional- control of vascular resistance.
• Improve endothelial function, vascular smooth muscle function,
antioxident systems, heat shock proteins, ↓inflammation.
• While strenuous exercise increases oxidative metabolism and
produces a pro-oxidant environment, regular moderate physical
activity promotes an antioxidant state and preserves endothelial
function.
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• Lowering BP: A bout of afternoon exercise interrupted with short rest
periods is recommended
• After Coronary Bypass: improved exercise capacity associated with
restorations of peripheral oxygen utilization in both patients with and
without Diabetes.
• Congestive Heart Failure: Aquatic exercise improves exercise
capacity and muscle function in patients with the combination of CHF
and DM
• Intermittent Claudication: no improvement observed in experiment on
old women.
• Exercise training: effective antioxidant and anti-atherogenic therapy
• Adverse events observed:12.2% for SBP, 10.4% for TG, and 13.3%
for HDL-C. About 7% of participants experienced adverse responses
in two or more risk factors.
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• Early life stress- maternal separation- ?reversed by
exercise in rats.
• Reduction of depression and fear of falling in older
persons by physical training
• Exercise training resulted in significant improvements in
depressive symptoms, fatigue and aspects of quality of
life
• Exercise with integrated cognitive and motor
coordination, may help with preservation of global ability
in elders at risk of cognitive decline – observed in
Chinese old subjects
• Other suggested benefits- improved problem solving
ability and feeling of wellbeing
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• Exercise 5-6 hours before sleep time enhances sleep
-In animals- exercise increases NREM sleep.
• Six months of training improved sleep in elderly.
• Participation in an exercise training program had
moderately positive effects on sleep quality in middleaged and old.
• Moderate treatment efficacy for the reduction of
apnea-hypopnea index [AHI] in sedentary
overweight/obese adults: Exercise seems to improve
the mobility, fatigue, and sleep quality in Stage IV lung
and colorectal cancer patients.
• Physical exercise could be an alternative or
complementary approach to existing therapies for
sleep problems.
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• Working Capacity (at HR170) is decreased in luteal and menstrual
phases
• Strenuous exercise: delayed puberty, luteal phase deficiency, oligoamenorrhea or anovulation – disturbance of GnRH pulsatility due to ?
inadequate energy intake.
• Hypoestrogenemia: premature osteoporosis. Most cases are
reversible with dietary and exercise modifications.
• Safe limits of exercise in pregnancy depend on previous exercise
habits.
• Pre-eclampsia: improved blood flow, reduced blood pressure,
enhanced placental growth and vascularity, increased activity of
antioxidant enzymes, reduced oxidative stress and restored vascular
endothelial dysfunction.
• Menopausal symptoms- [night sweats, mood swings, and irritability]
reduced by aerobic training.
• High impact sports activities may produce urinary incontinence
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• Sexuality enhancement in male subjects was proportional to fitness.
(frequency of various intimate activities, reliability of adequate
functioning during sex, percentage of satisfying orgasms, etc)
• ↓Sexual activity following cardiac events: fear of coital death or reinfarction, dyspnea, anxiety, angina pectoris, exhaustion,
depression, loss of libido, impotence, partners anxiety or concern,
and feeling of guilt.
• Patient that can climb one or two flights of stairs can keep his marital
sexual life without running further risk of cardiac symptoms
• ?Risk of Myocardial Infarction during sexual activity is three times
higher [Sex act as acute exercise]
• Regular exercising- protective effect, improved sexual activity
• Erectile dysfunction is often improved by physical activity.
• Adolescents indulge in sexual activities due to lack of recreation
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• Prostate cancer: positive benefits for improving
surgical outcomes, reducing symptom experience,
managing side effects of radiation and
chemotherapy, improving psychological health,
maintaining physical function, and reducing fat gain
and muscle and bone loss.
• Increase survivorship by 50%-60% in breast and
colorectal cancers.
• In the wide range of cancer populations, both young
and old, and with curative and palliative intent,
exercise is well tolerated and benefits the patient
psychologically and physically.
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• The proportion of the aged population is increasing
and minor illness will render them dependent
• Exercise training was feasible and effective in reducing
fear of falling and improving dynamic balance and
isometric strength in institutionalized older people with
fear of falling.
• Older women can effectively change the decline in
physical ability associated with aging by exercising.
• The 60-65 year group was capable of converting
physical activity into health benefits in both the short
and long term.
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• There is much evidence that a moderate amount of exercise
is needed for the maintenance of functional integrity of all
body systems.
• It is important for growth and development of children
• Exercise can readily produce a 10 to 20% improvement in
strength and aerobic power, effectively postponing functionally
important thresholds for some 10 to 20 years.
• In the west, regular exercise is rapidly gaining widespread
advocacy as a preventative measure in schools, medical
circles and in the popular media
• In a Medical Faculty in India, of those who were currently
exercising(50%), the proportion of boys was (62%) more
compared to girls (38%). Lack of time, laziness, and
exhaustion from academic activities were identified as
important factors for not doing exercise.
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• 5–17 years:
– at least 60 minutes of moderate to vigorous-intensity
physical activity daily.
• 8–64 years: [in bouts of minimum of10 minutes]
– at least150 minutes of moderate-intensity aerobic
physical activity weekly, or
– At least 75 minutes of vigorous-intensity aerobic
physical activity weekly, or
– an equivalent combination.
• > 64 years:
– as above depending on their abilities and conditions.
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