This document discusses the effects of exercise on various body systems. It describes how exercise improves brain function and maintains neuronal health. It also explains how short intense exercise relies on ATP-CP and glycolysis while prolonged exercise uses aerobic metabolism. Exercise causes acute cardiovascular changes like increased heart rate and cardiac output to boost oxygen delivery. Long-term adaptations to endurance training include increased blood volume, stroke volume and maximal cardiac output. The lungs show short-term increases in ventilation and blood flow during exercise but less long-term adaptation.

1. EXERCISE PHYSIOLOGY
Department of Physiology
Faculty of Medicine
Universitas Sumatera utara

2. Systemic Responses to
Exercise

3. NEUROMUSCULAR FUNCTIONS AND
ADAPTATIONS TO EXERCISE
 Exercise maintains neuronal health by improving
blood flow to the brain and by increasing brain
levels of growth factors that promote optimal
function of neurons.
 Recent study in humans has concluded that
exercise improves brain function and reduces the
risk of cognitive impairment associated with aging.

4. NEUROMUSCULAR FUNCTIONS AND
ADAPTATIONS TO EXERCISE
 Humans skeletal muscle can be divided into several
different classes based on the histochemical or
biochemical characteristics of the individual fibers.
 Neural adaptations:
↑ maximal motor unit recruitment
↑ synchronous recruitment of motor units

6.  SO motor units are recruited first during incremental
exercise, followed by a progressive increase in
FOG and FG motor unit recruitment as exercise
intensity increases.
 Both endurance and resistance exercise training
have been shown to promote a fast-to-slow shift in
skeletal muscle fiber types but does not result in
complete transformation of all fast fibers.
 Training adaptations: increases in muscle size from
hypertrophy and hyperplasia.

7. METABOLIC RESPONSES TO EXERCISE:
INFLUENCE OF DURATION AND INTENSITY
Short-term, Intense Exercise
• During high-intensity, short-term exercise (i.e., two
to twenty seconds), the muscles’ ATP production is
dominated by the ATP-PS system.
• Intense exercise lasting more than twenty seconds
relies more on anaerobic glycolysis to produce
much of the needed ATP.
• High-intensity events lasting longer than forty-five
seconds use a combination of the ATP-PC system,
glycolysis, and the aerobic system to produce the
needed ATP for muscular contraction.

8. METABOLIC RESPONSES TO EXERCISE:
INFLUENCE OF DURATION AND INTENSITY
Prolonged Exercise
 The energy to perform prolonged exercise (i.e.,
more than ten minutes) comes primarily from
aerobic metabolism.
 A steady-state O2 uptake can generally be
maintained during prolonged, low-intensity
exercise.

9. METABOLIC RESPONSES TO EXERCISE:
INFLUENCE OF DURATION AND INTENSITY
Incremental Exercise
• The maximal capacity to transport and utilize O2
during exercise (maximal oxygen uptake, or VO2
max) is considered to be the most valid
measurement of cardiovascular fitness.
• Indeed, incremental exercise test (also called
graded exercise test) are often employed to
determine a subject’s cardiovascular fitness.
• These tests are usually conducted on a treadmill or
a cycle ergometer.

11. • Oxygen uptake increase in linear fashion during
incremental exercise until VO2 max is reached.
• The physiological factors that influence VO2 max
include:
– The maximum ability of the cardiorespiratory system to
deliver oxygen to the contracting muscle.
– The muscle’s ability to take up the oxygen and produce
ATP aerobically.

14. CARDIOVASCULAR FUNCTIONS AND
ADAPTATIONS TO EXERCISE
 With the start of exercise, cardiovascular function
changes by:
↑ Heart rate
↑ Ejection fraction
↑ Stroke volume
↑ Cardiac output
↑ Redistribution of Q in favor of contracting skeletal
muscle
↓ Vascular resistance
↑ Muscle blood flow

16.  Muscle Contraction
 Venous Return
 End Diastolic Volume  Contractility
 Stroke Volume  Heart
Rate
 Cardiac Output
 Cellular Respiration
Sympathetic
Stimulation
 Muscle Vascular
Resistance
 Muscle Blood
Flow
 a-vO2∆
 Oxygen Extraction
 Oxygen ConsumptionAcute cardiovascular
adaptations that combine to
increase oxygen
consumption during
exercise

17. CARDIOVASCULAR FUNCTIONS AND
ADAPTATIONS TO EXERCISE
 Cardiovascular adaptations to training are
extremely important for improving endurance
exercise performance, and preventing
cardiovascular disease
 The more important of these adaptations are:
↑ Plasma volume
↑ Red cell mass
↑ Total blood volume
↓ Systolic and diastolic blood pressire
↑ End diastolic dimensions and ventricular volumes
↑ Maximal stroke volume
↑ Maximal cardiac output

18. Training For
Long -Term Endurance
 Plasma Volume  Red Cell
Mass
 Blood Volume
 Venous Return  Ventricular Volume
 End Diastolic Volume
 Maximal Stroke Volume
 Muscle Capillary Density
 Maximal Muscle Blood Flow
 Oxygen Delivery
 VO2max
Exercise to VO2max
 Maximal Cardiac Output
Chronic adaptations
of the CV system
after exposure to
training for long
term endurance.
Adaptations are
related to their
affect during both
maximal &
submaximal
exercise

19. Training For
Long-Term Endurance
 Plasma Volume  Red Cell Mass
 Blood Volume
 Venous Return  Ventricular Volume
 End Diastolic
Volume
 Stroke Volume  Sympathetic Stimulation
 Heart Rate
Submaximal
Steady State Exercise
Chronic adaptations
of the CV system
after exposure to
training for long
term endurance.
Adaptations are
related to their
affect during both
maximal &
submaximal
exercise

20. PULMONARY ADAPTATIONS TO EXERCISE
 After the onset of exercise there is:
A rapid ↑ in ventilation
A similar rapid ↑ in pulmonary blood flow
An improved VE vs Q relationship in the lung
↑ Lung compliance
Airway dilation and ↓ resistance to air flow
 The lungs and pulmonary circulation do not express
the degree of long-term adaptations to exercise.
The improvement are more determined by
muscular and cardiovascular function.

22. Endocrine Adaptations to
Exercise