Lecture 5 - Micronutrients

Question 1

What is the role of micronutrients in physical activity?

Answer 1

Many are involved in energy metabolism

-Mg Fe Ca Na K niacin NADH, riboflavin FADH

Question 2

Who might be more affected by micronutrient deficiency?

Answer 2

While marginal deficiencies may not affect a sedentary person, they may have a more profound effect when metabolic rate is high
-Might not be able to tell if you don’t stress the system and the marginal deficiencies wont present symptoms
○ Stressing thee system will reveal the deficienciees more

Question 3

What might prolonged strenuous activity performed on a regular basis may result in?

Answer 3

○ Increased losses
○ Increased rates of turnover

Increased intake may compensate for the increased need bit it may not

Question 4

which athletes are at greater risk of deficiency?

Answer 4

Teenagers, need to support normal health growth and development and the training on top of that.
-Peak bone mass being developed.

Question 5

which mineral does not have a blood marker?

Answer 5

Ca

-no marker but always stable in blood casue they are pulled from bones to maintain levels

Question 6

What is the major cause of Fe loss during activity?

Answer 6

Microischaemia is the major cause Microbleeding from the gut

-Excessive sweating and urine contribute little

Question 7

What is foot srtrikes hemolysis and who does it happen to?

Answer 7

the mechnaical destruciton fo red blood cells in the foot does exist in runners but Fe is salvaged(there is no loss of Fe)
○ Jumping breaks blood cells

Question 8

What might intensive sports trigger?

Answer 8

• Intensive sport may trigger hepcidin bursts, which leads to blockage of Fe release from gut

Question 9

What is hepcidin?

Answer 9

Controls Fe entry into body

Question 10

Where can Fe be stored?

Answer 10

In intestinal cells

Question 11

What happens when Fe enters the cell?

Answer 11

we take away an e- to hold it theree

Question 12

What is ferroportin?

Answer 12

Mechanisms to prevent Fe overload cause high Fe is toxic
-controlled by hepcidin because it blocks the entry of Fe into the body. Could be absorbing it so inkate could be good but whether or not it gets into the body is of concer.

Question 13

What can hepcidin burst look like?

Answer 13

Low Fe intake but in reality they arent

Question 14

What is the evolution of Fe deficiency?

Answer 14

Ferritin decreased

If declines too low to provide tissues with sufficient Fe, there is an increase in the transferrin receptor

• Hm MCV MCH are still normal
• Nonaneamic Fe deficiency

If continues, RBC become microcytic

MCV and MCH become low

Fe deficiency with microcytosis and or hypocy with microcytosis and othchromia

Hb falls then you have Fe deficiency anaemia

Question 15

What is the role of Fe in exercise?

Answer 15

Carries O2

Energy metabolism

Question 16

What is the prevalence of Fe deficiency in adolescents?

Answer 16

20%

Question 17

What is Fe depletion without anemia?

Answer 17

reduced oxidative capacity (decreased mito)

• Can still inmpact performance eveen if oyua rent anaemic
• Work performance will be stunted

Question 18

What is the key factor of Fe deficiency anemia?

Answer 18

reduced O2 carrying capacity

Question 19

What is oxidative stress?

Answer 19

When exercise we produce free radicals by using O2 which isnt completely reduced and forms O2 intermediates or ROS
• During normal metabolism oxygen is utilized in the mito for eneergy profuciton

Question 20

What is the most dominant source of ROS?

Answer 20

Mitochondria

-Only accounts for 0.15% of total O2 consumption (VO2) turns into ROS

Question 21

What is the Most vulnerable targets for ROS?

Answer 21

○ Protein lipid DNA

Question 22

What is exercise induced oxidative stress?

Answer 22

Exercise increases VO2 which translates to a greater O2 uses
○ ROS also depends on intensity

This results in an increase in ROS production
-Increase in ROS depends on workload

Question 23

What does ROS do?

Answer 23

can elicit damage,
fatigue
can impair recovery
they can also play important roles in skeletal muscle function and metabolism

Question 24

What is hormesis?

Answer 24

if exposed to something in low dose continually, or high dose occasionally you can have beneficial adaptations that happens.

• Ex: exercise is a continuous low stress
• We don’t want really high continual stress frequently

Question 25

What is the role of ROS in the body?

Answer 25

Impotant molecular messangers that react with redox ssensitive proteins
-These regulate many physiologucla processes

Question 26

Which physiological processes does ROS regulate?

Answer 26

○ Insulin sensitivity
○ Vasodilation
○ Mitochondrial biogenesis
○ Immune response
○ Growth factor signalling
○ Force production

Question 27

Can cells adapt to ROS the more you exercise?

Answer 27

Cells adapt to ROS becoming more resistant to the adverse effects of oxidative stress

Question 28

Which mechanisms are positively affected by ROS?

Answer 28

○ Increased antioxidant enzymes. DNA repair systems, mitochondria, heat proteins

○ Positively affect muscle remodelling (hypertrophy)

Question 29

Is antioxidant supplementation detrimental to exercise adaptation?

Answer 29

May reduce the actue exercise antioxidant repsons and impair endurance training iinduced increases in antoiioxidant enzyme levels

Question 30

What are the results of acute and chronic antioxidant supplementation?

Answer 30

• Acute supplementation before exercise may enhance performance requiring single bout

• Chronic supplementation has no effect on performance and may attenyste improvements due to training
○ Especially tryd for high intensity exercise performance