The effects of exercise on the incidence of certain diseases
Heart disease
 Regular exercise increases heart efficiency, and makes heart contraction more
efficient (ie more powerful).
 It increases blood HDL (high density lipoprotein) levels. HDLs carry cholesterol
away from the tissues back to the liver, where they are secreted into bile. So HDLs
are beneficial and reduce the risk of heart disease. LDLs carry most of the
cholesterol in the blood. They deliver cholesterol to the cells. LDLs increase the
incidence of atheroma. The ratio of plasma LDL cholesterol : plasma HDL
cholesterol is important: the ______________ the ratio, the lower the risk of
atheroma.
 Artery wall elasticity is maintained improved/improved by regular exercise.
 Resting heart rate is lowered; this decreases the ‘loading’ (strain) on the heart.
 Resting blood pressure is lowered, meaning that less effort is needed for the heart to
pump.
 Exercise may lead to weight loss, which would decrease the loading on the heart.
Circulatory problems eg atheroma
 Exercise reduces stress.
 Regular exercise reduces the amount of adrenaline release (adrenaline promotes the
breakdown of glycogen for respiration).
 Exercise increases the metabolism of fats.
 Exercise increases HDL and lowers LDL.
 The points above contribute to reducing the chance of atheroma being deposited on
the inner lining of the arteries.
Varicose veins
 Frequent muscle contraction improves blood flow and prevents blood accumulation
in the veins.
 It prevents loss of elasticity in vein walls.
 The points above lower the chance of blood backflow blocking valves or overstretching vein walls.
Respiratory disease
 Exercise improves gas flow/ventilation per breath.
 This prevents the accumulation of microbes in the lungs.
 It also prevents fluid accumulation, that increases the risk of atheroma.
687318950
Page 1 of
2
GUIDELINES FOR NUTRITION
Fat
GUIDELINES
UNDERLYING PRINCIPLE
-
Our diets contain more than enough fat to
supply the essential fatty acids/uses eg fuel for
muscle respiration once glucose and stores of
glycogen are used up.
Excess fat is stored as fat reserves.
A high intake of saturated fatty acids is
associated with high levels of blood cholesterol
and increases the risk of atherscelosis.
Plant fats - usually unsaturated
Animal fats usually saturated
reduce total fat consumption
-
shift the balance in fat
consumption from saturated to
unsaturated fatty acids
* revise from mod 1
-
-
monounsaturated fats are better
than saturated or
polyunsaturated fats
reduce salt intake
Sugar -
-
(more salt necessary eg if doing
strenuous exercise in hot climate
reduce sugar intake
Additives
-
Fibre -
-
Salt -
a large proportion are safe and
useful but some are unnecessary
with potentially adverse side
effects for sensitive people.
eg one in a million are sensitive to
E102 - (tartrazine)
eat a high fibre diet
Modern diets tend to supply more than enough
salt - eg salt in prepared foods and other
packaged foods.
NaC1 is important in maintaining tendency of
blood to take up water.
Na+ & C1- have major roles in nerve impulse
transmission.
Excess dietary salt can cause fluid retention
(oedema) & may contribute to high blood
pressure (hypertension)
Salt loss from excessive sweating & inadequate
intake can cause heat exhaustion
Allows bacteria to grow on teeth, producing
acids which dissolve the outer surface (enamel)
causing tooth decay.
Glucose can be obtained by breaking down
carbohydrates.
Glucose (the respiratory substrate) is stored as
glycogen in the liver.
Surplus glucose is converted to fat for long term
storage in fat cells eg under the skin
SOLUBLE FIBRE - binds CHOLESTEROL
into a complex that cannot be absorbed from the
intestine so it is passed out in stools.
Important in small intestine - slows digestion
and absorption; products are released over a
longer time (important to diabetics).
INSOLUBLE FIBRE - important in colon.
Absorbs water and swells; stretches walls of
intestine and stimulates perostalsis.
Speeds up passage of food through colon and
so reduces the time for possible carcinogens
to be in contact with intestinal wall.
Reduces the risk of constipation, piles and colon
cancer.
687318950
Page 2 of
2