Exercise/Sports Physiology
Learning Objectives
• Definitionsi. Aerobic vs. anaerobic
ii. Isometric vs. Isotonic
iii. Acute response vs. exercise training
• Sk muscleATP synthesis pathway
Aerobic exercise training
Anaerobic exercise training
• Motor and Autonomic control
• CVS- B.P; HR; CO; VR; Flow redistribution;
training.
• RS- Ventillation; Oxygen extraction; EPOC;
Training
Exercise Classification
Energy System
Time Course
1. Adenosine
triphosphate–
creatine phosphate
system;phosphagen
sys : 8 – 10 s
2. Glycogen Lactic acid
system: 0.5- 2.5 min
3. Oxidative
phosphorylation:
hrs
Which of the following sources can
produce the greatest amount of ATP per
minute over a short period of time?
A) Aerobic system
B) Phosphagen system
C) Glycogen-lactic acid system
D) Phosphocreatine system
E) Stored ATP
Which of the following athletes is able to
exercise the longest before exhaustion
occurs?
A) One on a high-fat diet
B) One on a high-carbohydrate diet
C) One on a mixed carbohydrate–fat diet
D) One on a high-protein diet
E) One on a mixed protein–fat diet
Most of the energy for strenuous exercise that
lasts for more than 5 to 10 seconds but less
than 1 to 2 minutes comes from which of the
following sources?
A) Adenosine triphosphate (ATP)
B) Anaerobic glycolysis
C) Oxidation of carbohydrates
D) Oxidation of lactic acid
E) Conversion of lactic acid into pyruvic acid
Effect of diet on the rate of muscle glycogen
replenishment after prolonged exercise.
Effect of duration of exercise as well as type of diet on
relative percentages of carbohydrate or fat used for
energy by muscles:
Aerobic exercise training
Anaerobic exercise training
1. Energy stores: increase
in myocyte gly-cogen
stores.
2. Metabolism: increases
mitochondrial size and
numbers and increase
in myoglobin content
1. Hypertrophy: increase
in the cross-sectional
area of type IIa and IIx
muscle fibers by adding
new myofibrils to the
myocytes.
2.Neural recruitment:
3. Metabolism and energy
stores:
Effects of training on muscle mass and performance.
MOTOR AND AUTONOMIC CONTROL
Peripheral Nervous System
• Alpha-Motor neurons:
• Motor units:
• Muscle sensors: Mus spindle, Golgi tendon
organs, Mus afferents
• Cardiovascular receptors
Central nervous system
1. Somatic: The premotor cortex, supplemental
motor cortex, and basal ganglia aid in motor
program development. This motor program is
then executed by the primary motor cortex
and signaled via the corticospinal tract. The
cerebellum coordinates leg and foot movements d
2. Autonomic:
Autonomic systems
are required to
redistribute flow. This
is accomplished via
sympathetic
feedforward and
feedback pathways
3. Senses:
• Vision plays a major role in pro-viding
information about potential obstacles and the
nature of the terrain.
• Hearing plays a lesser role, but it does help
provide clues about the location of other riders,
gearing, and under-the-tire terrain.
• The vestibular system provides information
regarding linear acceleration (otolith organs) and
head position when scanning the path ahead and
looking for items on either side of the path.
CARDIOVASCULAR SYSTEM
Arterial Pressure
Cardiac Output
Heart Rate
Stroke Volume
Venous return
Flow redistribution
Cardiac adaptation to long term training
Aerobic
• Volume-induced cardiac
hyper trophy.
• This type of hypertrophy
increases both the LV
chamber diameter and LV
wall mass and likely is
caused by the high venous
return and preload
accompanying exercise.
• This adap tation increases
resting EDV and SV.
Anaerobic
• Anaerobic exercise training,
which involves repeatedly
forcing the LV to eject
against an elevated MAP,
stimulates a LV hypertrophy.
• Such hypertrophy is characterized by an increase in LV
wall thickness but a
decrease in lumen diameter.
Vascular adaptation to long term training
• Training increases the ability of skeletal and
cardiac muscle to vasodilate, probably
through increased nitric oxide pro-duction.
• Over time, angiogenesis increases capillary
density and, thereby, decreases the distance
for diffusional exchange of O2 and nutrients
between blood and myocytes.
• Which of the following parameters is
decreased during moderate exercise?
(A) Arteriovenous O2 difference
(B) Heart rate
(C) Cardiac output
(D) Pulse pressure
(E) Total peripheral resistance (TPR)
Q. During exercise, total peripheral resistance (TPR)
decreases because of the effect of
(A) the sympathetic nervous system on splanchnic
arterioles
(B) the parasympathetic nervous system on skeletal
muscle arterioles
(C) local metabolites on skeletal muscle arterioles
(D) local metabolites on cerebral arterioles
(E) histamine on skeletal muscle arterioles.
Q. During exercise, there is an increase in a
person’s
a. Stroke volume
b. Diastolic pressure
c. Venous compliance
d. Pulmonary arterial resistance
e. Total peripheral resistance
Olympic athletes who run marathons or perform cross country
skiing have much higher maximum cardiac outputs than nonathletes. Which of the following statements about the hearts
of these athletes compared to non-athletes is most accurate?
A) Stroke volume in the Olympic athletes is about 5% greater at
rest
B) Percentage increase in heart rate during maximal exercise is
much greater in the Olympic athletes
C) Maximum cardiac output is only 3% to 4% greater in the
Olympic athletes
D) Resting heart rate in the Olympic athletes is significantly
higher
RESPIRATORY SYSTEM
Ventilation
Oxygen
extraction
Excess postexercise oxygen consumption
Training
1. Ventilation: Maximal alveolar ventilation and
VE both increase.
2. Arteriovenous oxygen difference increase:
decreased diffusional distance between
blood and myocytes due to increased
capillary density, and increased blood flow
,Hb also increases .
3. Oxygen uptake:
The increase in CO,
alveolar ventilation,
and a-v O2 difference
combine to increase
maximal O2 uptake
during training.
Which of the following statements about respiration in
exercise is most accurate?
A) Maximum oxygen consumption of a male marathon runner is less
than that of an untrained average male
B) Maximum oxygen consumption can be increased about 100% by
training
C) Maximum oxygen diffusing capacity of a male marathon runner
is much greater than that of an untrained average male
D) Blood levels of oxygen and carbon dioxide are abnormal during
exercise