Nutrition II

1
Nutrition II

• Micronutrients and Water

2
Vitamins (2 types)

• Classification of Vitamins
• Fat soluble A, D, E, K
• Water soluble C, B complex
• Require a daily supply
• Are water soluble vitamins potentially harmful
  when taken in excess?

3
Antioxidant Role of Vitamins

• Chemical reactions often result in formation
  intermediate products.
• Reactive intermediates are highly unstable.
• A free radical is a highly reactive intermediate
  species that has an unpaired electron. A free
  radical might look like this.

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Antioxidant Role of Vitamins

• Buildup of free radicals creates oxidative stress
  that increase potential for cellular damage.
• Oxidative damage, another name for the chemical
  reaction that free radicals cause, can lead to a
  breakdown or even hardening of lipids, which
  makeup all cell walls.
• If the cell wall is hardened (lipid peroxidation)
  then it becomes impossible for the cell to
  properly get its nutrients, get signals from
  other cells to perform an action (such as firing
  of a neuron) and many other cellular activities
  can be affected. In addition to the cell walls,
  other biological molecules are also susceptible
  to damage, including RNA, DNA and protein
  enzymes.

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Antioxidant Role of Specific Vitamins

• To combat the free radical chain propagation
  effect, the body uses antioxidants (chemical
  electron sinks) which quench the biochemical
  fire. The antioxidants include enzymes such as
  glutathione peroxidase, catalase and superoxide
  dismutase.
• Vitamin C, vitamin E, and A, beta carotene ,
  coenzyme Q10, grape seed extract and others are
  potent antioxidants.

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Megadoses of Vitamins

• Does not improve exercise performance or
  potential to sustain intense physical training
• Can be toxic at high doses

SuperHealthPills
7
Vitamin Supplementation?

• Not necessary if diet is healthy
• Multivitamins are safe (100 RDA)
• Benefits those with marginal intake
• Supplementation above the RDA may be toxic and 40
  years of research does NOT support ergogenic
  benefit.

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Minerals

• Inorganic elements
• Two types
• Major (macrominerals) gt 100 mg/day
• Trace (microminerals) lt 100 mg/day
• Major functions
• Provide structure in forming bones
• Maintain normal heart rhythm, nerve conduction,
  muscle contractility
• Help regulate cellular metabolism

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Calcium

• Bone teeth formation, muscle action, blood
  clotting, nerve impulse transmission
• Important for preventing osteoporosis
• RDI adults 1200 mg/day (5 glasses milk)
• Found in dairy products and vegetablesHigh
  protein diets leach calcium from bones and
  promote osteoporosis

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Calcium

• Lack of calcium contributes to osteoporosis
• Female athlete triad
• Disordered eating
• Osteoporosis
• Amenorrhea

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Electrolytes

• What are electrolytes?
• A mineral that when dissolved in the body becomes
  an ionic conductor
• Sodium, potassium, and chlorine
• Electrolytes modulate fluid movement within
  bodys various fluid compartments.

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Iron

• Important component of hemoglobin
• Dietary sources of iron roast beef, eggs, dark
  poultry, lentils, spinach
• Inhibitors of iron absorption phytic acid (whole
  grains) polyphenols (tea, coffee, other
  beverages), zinc and calcium
• Iron deficiency is known as anemia(Symptoms
  shortness of breath, fatigue)

13
Water

• Of all essential nutrients, water most important
• Without water, death occurs within days
• Where is water stored in the body?
• Intracellular 65
• Extracellular 35
• Intravascular
• Intercellular or interstitial fluid between
  cells
• Miscellaneous stores, e.g. cerebrospinal fluid,
  eye and ear fluid, saliva
• Much of fluid lost through sweating comes from
  extracellular, primarily blood plasma.

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Water

• Functions of body water
• Bodys transport and reactive medium
• Absorption of heat with minimal changes in body
  temperature
• Watery fluids lubricate
• Provides structure and form to body through
  turgor
• Sedentary adult in thermoneutral environment
  requires about 2.5 L of water daily.
• Fluids 1200 ml
• Food 1000 ml
• Metabolism 350ml

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Water

• Water Balance

• Sedentary water loss
• 1250 mL urine
• 100 mL feces
• 850 mL skin
• 350 mL lungs
• Hot exercise water loss
• 500 mL urine
• 100 mL feces
• 5000 mL skin
• 700 mL lungs

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Water, Glucose, and Electrolytes

• Consume 400 to 600 mL of fluid immediately before
  exercise, subsequent ingestion 250 mL _at_ 15 min.
• To optimize water carbohydrate absorption
• fluid temperature and volume
• use a 6 carbohydrate electrolyte solution.
• Adding sodium to rehydration beverage maintains
  plasma osmolarity.
• What is hyponatremia?