1. Postgraduate Diploma in Diabetes Education
(PDDE
lec 2 Nutrition therapy: Diabetes
Mellitus and physical activates
Metabolic Responses to Exercise
Prepared by Dr. Siham Mohamed
Osman Gritly
Dr. Siham Gritly
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2. Metabolic Responses to Exercise
• During exercise, skeletal muscle is the most
important tissue in the body for glucose
uptake.
the contracting muscles produce their own
insulin-like effect, causing the rapid uptake of
glucose from the blood.
Dr. Siham Gritly
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3. • Other hormones such as epinephrine
(adrenaline), glucagon and cortisol assess to
maintain and increase blood glucose levels
during exercise
• Avoiding hypoglycemia or hyperglycemia can
also be achieved by increasing or
decreasing, respectively, the amount of
carbohydrate ingested before planned exercise
Dr. Siham Gritly
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4. blood glucose response to exercise will vary
depending on:
•
•
•
•
•
blood glucose level before starting activity,
the intensity of the activity,
the length of time you are active,
and changes you’ve made to insulin doses.
Sometimes people experience a drop in blood
glucose during or after exercise, so it is very
important to monitor your blood glucose, take
proper precautions, and be prepared to treat
hypoglycemia
Dr. Siham Gritly
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5. Metabolic effects of exercise in type
2 diabetes
• During exercise,
• oxygen consumption may increase by as much
as 20-fold,
• To meet its energy needs, skeletal muscle uses
its own stores of glycogen and triglycerides, as
well as free fatty acids (FFAs) derived from
the breakdown of adipose tissue triglycerides
and glucose released from the liver.
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6. • Muscle glycogen; is the chief source of energy
during the early stages of strenuous exercise,
• with increasing exercise duration the
contribution of circulating glucose and
particularly NEFAs become more important as
muscle glycogen gradually depletes.
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7. Energy fuel for exercise
• Glucose (glycolysis)
• Glycogen (glycogenlysis)
• Triglyceride (triaceylgelesrol) lypolysis
• Protein (gluconeogensis)
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8. Muscle glycogen store is the first source
of glucose for the exercising muscle
when no glycogen;- the process of
glycogenolysis started and follow
by gluconeogenesis in the liver to
make glucose available (main
function of the liver is to release
glucose through glycogenolysis
and gluconeogenesis )
if no enough glucose after 3 hours
of heavy exercise athletes enter to
a condition known as
hoypglycemia (low glucose level in
Dr. Siham Gritly
the blood)
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9. Oxidative metabolism and anaerobic
metabolism are both used for provision of
energy during exercise
• Adenosine triphosphate (ATP) is the principal highenergy phosphate molecule that enables muscle
contraction (immediate energy sources).
• Phosphocreatine (PCr) is another high-energy
compound containing a high-energy phosphate bond
that can be hydrolysed to provide energy and
resynthesize ATP:
• Oxygen delivery during strenuous exercise is
limited by cardiovascular function.
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10. immediate energy for exercising muscles
• immediate energy - used in first 10-30
seconds of vigorous exercise; ATP creatine
phosphate (ATP-CP) system used;
creatine phosphate contributes a phosphate to
ADP to make ATP; 1 creatine phosphate (CP)
= 1 ATP;
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11. short-term energy for exercising muscles
• short-term energy - used approx. 30 - 90
seconds into vigorous exercise;
• uses glycolysis to break down glucose to
pyruvate to lactate (lactic acid);
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12. long-term energy for exercising muscles
• long-term energy - used approx after 2 min of
vigorous exercise;
• uses glycolysis, citric acid cycle (kreb’s
cycle), and electron transport chain to fully
oxidize glucose;
• 1 glucose = 36 ATP (max);
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13. Low- to moderate-intensity aerobic exercises
that can be sustained for a long time (more
than 20 minutes) use some glucose, but more
fat for fuel.
fat providing energy during
exercise that occurs at a lower
intensity but not adequate
for high intensity exercise
such as sprints
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14. Unlike glycogen stores, the body’s fat stores can usually
provide more than 70,000 kcalories and fuel hours of
activity without running out.
Abundant energy from the breakdown of fat can
come only from aerobic metabolism.
during low-intensive
exercise, fatty acid (FA)
oxidation contributes
considerably to total energy
provision for hours or even
days as long as there is
sufficient oxygen to allow
fat metabolism to occurSiham Gritly
Dr.
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15. Major body systems and Metabolic Responses
to Exercise
• Endocrine response to exercise;
• Response of the Cardiovascular System to
Exercise
• Response of the Skeletal System to Exercise
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16. Endocrine system
the endocrine system is a system of
glands, (ductless) each of which
secretes a type of hormone. hormone
is directly released into the
bloodstream to regulate the body
functions.
field of study dealing with the
endocrine system endocrinology
Hormones are secreted by a variety of glands
in response to altered conditions in the body.
Each hormone travels to one or more specific
target tissues or organs, where it elicit a
specific response to maintain homeostasis
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17. • Hormones regulate various human
functions, including;
• metabolism,
• growth and development,
• body tissues (the physical and chemical processes
of the body),
• sexual development and function
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18. The major glands of the endocrine system
the hypothalamus, (link the
nervous system to the endocrine
system via the pituitary gland
pituitary, (secretes nine hormones
that regulate homeostasis)
thyroid,
parathyroids,
adrenals,
pineal gland, (melatonin that
helps to regulate sleep/wake)
the reproductive organs (ovaries
and testes).
The pancreas; insulin and
glucagon
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19. Response of hypothalamus to blood
glucose level
The hypothalamus is a part
of the brain involved in the
control of involuntary
activity in the body; contains
many centers of neural
control such as
temperature, hunger, appetite
and thirst
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20. • Most hormones are secreted from the glands
that produce them under the influence of
stimulating hormones from the
hypothalamus.
• These hormones in turn are activated by
releasing hormones from the pituitary gland
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21. 1-Endocrine Response to Exercise
• Many hormones play a role in physical
exercise; the endocrine response to exercise
can improve organ function, physical fitness
and overall psychological state.
• without hormones, exercise would be limited.
• Vigorous exercise, in particular, might improve
endocrine function.
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22. Hormones important in physical exercise
• Hormones important in physical exercise
include;
1-testosterone from the testes,
2-norepinephrine or adrenalin and cortisol
from the adrenal glands
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23. 3- thyroxin from the thyroid gland
4- human growth hormone -- also called HGH
or somatotropin -- from the pituitary gland.
5-insulin and glucagon from the pancreas,
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24. Functions of Insulin during and
after exercise
1- Stimulation of glucose uptake into most cells
of the body,
2- Inhibition of glucose release from the liver,
3- Inhibition of the release of fatty acids from
storage tissue,
4-Facilitation of protein synthesis in the body's
cells,
5- Stimulation of the re-synthesis of muscle
glycogen after exercise
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25. 2-Response of the Cardiovascular
System to Exercise
• The heart is a muscle that is required to
contract continuously throughout the life to
deliver oxygen to all organs in the body and
breathe out carbon dioxide
• Blood vessels connect the heart and lungs so
that carbon dioxide can be removed from the
blood and oxygen can be added to the blood.
• The heart then pumps this blood throughout
the body.
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26. • Exercise places an increased demand on the
cardiovascular system to pump more oxygen to
supply the working muscle to produce energy
(aerobic oxidation).
• Oxygen demand by the muscles
increases, more nutrients are needed and more
waste is created.
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27. The heart is a four-chambered
organ consisting of right and left halves.
Two of the chambers, the left and
right atria, are entry-points into the
heart, while the other two
chambers, the left and right
ventricles, are responsible for
contractions that send the blood
through the circulation. The circulation
is split into the pulmonary and
systematic circulation.
The role of the right ventricle is to
pump deoxygenated blood to the lungs
through the pulmonary trunk and
pulmonary arteries. The role of the left
ventricle is to pump newly oxygenated
Dr. Siham
blood to the body through the aorta Gritly
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28. Functions of The Cardiovascular
System during exercise
The cardiovascular system serves five important
functions during exercise:
• 1- Delivers oxygen to working muscles
2- Deoxygenates blood by returning it to the
lungs
3- Transports heat from the center to the skin
4- Delivers nutrients and fuel to active tissues
5- Transports hormones
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29. Cardio-respiratory endurance
Cardio respiratory endurance is
the ability of the body’s circulatory
and respiratory systems to supply
fuel during sustained physical
activity”
Cardio-respiratory endurance; is
the amount of oxygen individuals
are able to take in and oxidized it
for energy production to be used
for working muscles
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30. benefit to increases cardio
respiratory endurance
• the most important benefit to increases cardio
respiratory endurance is an increased VO2max
which is the body’s ability to deliver oxygen and
nutrients to the cells, lead to;.
• Lower risk of heart disease
• Reduced Risks of type 2 diabetes
• Lower Blood pressure
Dr. Siham Gritly
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31. The skeletal system consists of;
bones, ligaments and tendon
bones, ligaments which
connect bones to other
bones and cartilage
Tendons connect muscle
tissue to bone and although
more elastic than
ligaments, have a greater
strength than muscle
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32. Four basic functions of skeletal
system
• The skeletal system comprises of 206 bones
and provides four basic functions:
• Support for tissues and muscle
• Protection for vital organs
• Movement through bones and attached
muscles
• Storage for minerals and immature blood
cells
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33. Effect of exercise on the skeletal system
• Exercise may improve to maintain healthy bones
• bone responds to mechanical stresses. When
mechanical stresses are applied, more mineral
salts are deposited and more collagenous fibres
are produced.
• The physiological response to exercise is
dependent on the intensity, duration and
frequency of the exercise as well as the
environmental conditions.
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34. • During physical exercise, requirements for
oxygen and substrate in skeletal muscle are
increased, as are the removal of metabolites
and carbon dioxide.
• Chemical, mechanical and thermal stimuli
affect alterations in metabolic, cardiovascular
and ventilatory function in order to meet these
increased demands
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35. skeletal muscle is powered by one and only one
compound... adenosine triphosphate (ATP. However, the
body stores only a small quantity of this 'energy
currency' within the cells and its enough to power just a
few seconds of all-out exercise. So the body must
replace or resynthesize ATP on an ongoing basis
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36. References
• American Diabetes Association (2002). Clinical Practice
Recommendations:2002. Diabetes Care 25 (suppl. 1):S64-S68.
• Sareen Gropper, Jack Smith and James Groff, Advanced Nutrition and
Human Metabolism, fifth ed. WADSWORTH
• Melvin H Williams 2010; Nutrition for Health, Fitness and Sport. 9th
ed, McGraw Hill
• Heymsfield, SB.; Baumgartner N.; Richard and Sheau-Fang P. 1999.
Modern Nutrition in Health and Disease; Shils E Maurice, Olson A.
James, Shike Moshe and Ross A. Catharine eds. 9th edition
• Guyton, C. Arthur. 1985. Textbook of Medical Physiology. 6th
edition, W.B. Company
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37. • Sigal RJ, Kenny GP, Wasserman DH, CastanedaSceppa C. 2004. Physical Activity/Exercise and
Type 2 Diabetes. Diabetes Care 27: 2518-2539.
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