Effects of Exercise
Responses to Exercise.
There Are Two Kinds of
Response to Exercise
 Immediate, short-term responses that last
only for the duration of the exercise itself and
the recovery period.
 Chronic responses, which are long-term
adaptations to exercise bouts. We call the
summation of the chronic adaptations the
training effect.
Acute Cardiovascular Responses
to Exercise
 Effects on cardiac output (Q).
At rest, cardiac output is 4 to 6 litres per
minute; That is.
70 beats per minute x 8- ml per beat.
= 5.6 litres per minute.
Cardiac output increases linearly with in the
intensity of exercise up to exhaustion.
Effects on Stroke Volume
 Stoke volume increases, because more blood
is returning to the heart (venous return), for
exercise levels up to 40-60% of a persons
maximum capacity.
 Therefore maximal stroke volume occurs
during sub maximal work.
Increases in Heart Rate
 The heart rate increases as exercise intensity
increases, up to maximum heart rate values.
This is called tachycardia.
 Note remember your maximum heart rate is
approximately 220 – your age.
Effects of Systolic Blood
Pressure
 Systolic blood pressure increases linearly
with increasing exercise intensity, because of
increased cardiac output.
 For example, at rest systolic blood pressure is
120mmHg whilst during exercise it may
reach 180mmHg.
Effects on Blood Plasma
Volume
 The blood plasma volume usually decreases
during strenuous exercise, especially in hot
weather, because of increased sweating.
 In turn this leads to the loss from the body of
water and electrolytes.
Effects on Blood Acidity
 Blood acidity increases, because of increased
amounts of lactic acid circulating the body
Effects on the Muscle Glycogen
Content
 There is a decrease in muscle glycogen
content during strenuous exercise, as
glycogen is being used as a primary energy
source.
Effects on Coronary Blood Flow
 Coronary blood flow increases about fivefold
during strenuous exercise, in order to supply
oxygen to meet the increased demands of the
cardiac muscle.
Effects on Blood Flow
 Blood flow to the working muscles and skin
increases because of:
 Increased cardiac output.
 Greater distribution of blood away from nonworking areas to active muscles.
Effects on Blood Flow
 Therefore:
 80-85% Q goes to the working muscles, because of
the relaxation of precapillary sphincters.
 Blood flow to the kidneys and the abdomen
decreases, because of the contraction of the
precapillary sphincters.
 Blood flow to the lungs increases as the right
ventricle increases its activity during exercise.
Effects on the Arteriovenous
Oxygen Difference (a-VO2
diff.)
 When the body is at rest, the arterial oxygen
concentration is 19ml per 100 ml, while the venous
oxygen concentration is 13ml per 100 ml.
 Therefore 6ml per 100ml of oxygen is being used
by the working muscles. That is:
aVO2 diff = 6.
 During strenuous exercise, the venous oxygen
concentration can drop to 2ml per 100ml. That is: aVO2 diff = 17ml.
Task most important part of the
lesson
Fill in table on training effects of vascular
system.
Fill in table on training effects upon the athletes
heart,
Adaption
Outcome
Acute Respiratory
Adaptations to Exercise
Effects on Ventilation
 Ventilation increases from 6 litres per minute
at rest to more than 100 litres per minute
during exercise. This is achieved by
increases in;
 Respiration rate: from 15 to 40-50 breaths per
minute.
 Tidal volume: from 10% of vital capacity to
more than 50% of vital capacity.
Effects on Lung Diffusion
 During strenuous exercise there is a threefold
increase in oxygen diffusion from the alveoli
to the blood.
Effects on Oxygen Uptake or
Volume of Oxygen Consumed
(VO2)
 Oxygen uptake (VO2) is the amount of
oxygen taken up and used by the body. It
reflects the total amount of work being done
by the body.
 During strenuous exercise there can be a
twenty-fold increase in VO2 which increases
linearly with increases in the intensity of the
exercise.
Effects on Oxygen Uptake or
Volume of Oxygen Consumed
(VO2)
 As a person approaches exhaustion, his or her
VO2 will reach a maximum above which it
will not increase further.
 This figure is his or her VO2 Maximum;
that is, the largest amount of oxygen that a
person can utilize within a given time (for
example, 50 litres per minute).