Nutrition II

Nutrients

Carbohydrate

Fat

Protein

Macronutrients

Vitamins

Minerals

H2

O

Micronutrients

Micronutrients and H2O

vitamins and minerals

found in variety of foods

balanced diet no supplementation (Ca++)

Vitamins Accessory nutrients (C,H,O)

Supplied thru diet (except D)

Manufactured during photosynthesis

Types of Vitamins Lipid soluble

- A, D, E, and K

Water soluble- C- B: B1, B2, B6, B12, niacin, folic acid

Lipid Soluble

Should not be consumed in excess

E.g. kidney damage 20 excess D

Water Soluble Generally not stored

Excess is voided

Role of Vitamins Links & regulators in energy

releasing reactions

Control tissue synthesis

Supplementation

Proper Diet Repeated Use

Supplementation

However?

Supplementation Exceptions:

- C- B – folic acid- B1 and B6 (some athletes)

- B12 in vegetarians

Antioxidant Role Free radicals - highly chemically

reactive molecules/fragments Produced in body:

- O2-, H202, OH-

Produced in environment:- smoke, pollutants, medications

Antioxidant Role free radicals oxidative

stress/cellular damage

oxidation of LDL atherosclerosis

Oxidataive stress cell deterioration, advanced aging, CA, DM, CAD

Antioxidant Vitamins A (& precursor -carotene), C , E

Protect plasma membrane

-carotene & C CA

E & -carotene CAD, blood clots

Recent Research roundworm life by 50%

synthetic drugs that mimic: superoxide dismutase catalase

persist longer than vitamins

Vitamins and Exercise B-complex – coenzymes for CHO,

lipid, & protein catabolism energy

Contribute to Hb synthesis (RBC)

Megavitamins 10-1000x RDA

Excess vitamin Result

C serum uric acid gout

B6 Liver disease/nerve damage

B2 Impaired vision

E Headache, fatigue,blurred vision, GI disturbance, muscular weakness,

low BG

A Nervous system toxicity

D Kidney damage

Minerals Elements Constituents of enzymes,

hormones, vitamins Combine w/ other chemicals

(calcium phosphate in bone, heme blood)

Critical for certain processes (muscle contraction)

Minerals Naturally occurring Supplementation unnecessary

(except Ca, Fe) Excess can be toxic

Roles of Minerals

Structure (bones/teeth)Function:

- heart rhythm- muscle contraction- neural conductivity- acid-base balance

Roles of Minerals

Regulation Cell metabolism

(enzymes/hormones)

Balance catabolism/metabolism electrolytes

Calcium Osteoporosis :

- less bone density to start- reduced intake teenage years- activity- estrogen / menopause

Other factors: smoking, alcohol abuse

Prevention Ca++ supplementation Vitamin D availability Estrogen therapy W/b activities (consistent) Avoid excessive meat, salt, coffee,

alcohol

Prevention

20 amenorrhea estrogen

Phosporus

Provides rigidity to bones & teeth Essential to ATP, CP Combines w/ lipids plasma

membrane Buffer acids produced 20 heavy

exercise

Magnesium

Involved in: anabolism of serum glucose

liver/muscle glycogen catabolism of glucose, fatty acids,

AA anabolism of lipids & proteins nerve conduction and muscle

action

Iron Found in:

- hemoglobin- myoglobin- cytochromes

Iron-deficiency anemia hemoglobin conc. Sluggishness Loss of appetite Reduced capacity for exercise Common in

Iron-deficiency anemia in Females Pregnancy

Menstruation

Vegetarian diet- animal Fe more readily absorbed

Iron RDA

Age Iron (mg)

Children 1 – 10 10

Males 11 – 18 12

19 10

Females 11 – 50 15

51 10

Pregnant 30

Lactating 15

Exercise-Induced Anemia? Loss of iron thru:

- Perspiration- Urine 20 RBC destruction & temp.- Spleen activity- Mechanical RBC destruction

Probably minimal

Supplementation? Hematological work-up Accumulate to toxic level and

contribute to: Liver disease DM Heart damage / CAD Joint damage

Electrolytes Na+ - blood plasma/extracellular

Cl- - blood plasma/extracellular

K++ - chief intracellular

Na+ and Cl- Modulate fluid exchange

Regulate exchange of nutrients and wastes between cell and external medium

Na+ and K++ Establish electrical gradient across

cell membranes for: Nerve impulses Muscle contraction Gland function

Na+ induced HTN 1/3 of individuals w/ HTN

Typical diet exceeds RDA by 10x

Not always the problem

Minerals & Exercise Excessive loss Impair heat tolerance &

performance Cramps Exhaustion Heat stroke

Minerals & Exercise

Good diet

Glass of OJ replaces Ca, K, Mg lost in 3 L of perspiration

Supplementation

Water 40 – 60% of body mass

65 – 75% of muscle

50% of body fat

Water 62% extracellular

38% intracellular

Functions of Water Transport and reactive medium

- diffusion of gases- transportation of nutrients,

gases, & wastes Heat-stabilizing Lubricates joints Structure & form

Water RegulationInput (ml) Outpu

t(ml)

Food 1000

Urine 1250

Fluids 1200

Feces 100

Metabolism

350 Skin 850

Lungs 350

Total 2550

Total 2550

Water Regulation in Hot Weather during Exercise

Input (ml) Output

(ml)

Food 1000 Urine 500

Fluids 1200 Feces 100

Metabolism

350 Skin 5000

Lungs 700

Total 2550 Total 6300

Water and Exercise 100% relative humidity

- evaporation impossible- loss of cooling mechanism

No humidity- optimum cooling- excessive fluid loss plasma volume circulatory strain

Assessing Fluid Loss Accurate body weight pre- and

post-exercise

1 lb. BW = 450 mL (15 oz.) dehydration

Hyponatremia Water intoxication 20:

Loss of electrolytes (Na+)

Large ingestion of water

Hyponatremia Dilution of extracellular Na+

Headache, confusion, malaise, nausea, cramping, coma, pulmonary edema, death

Hyponatremia Usually during prolonged exercise

Do not consume > 1 L / hr.

Include some Na+

Include glucose facilitate glucose-sodium transport