MODULE 9 - MICRONUTRIENTS AND EXERCISE

WHAT ARE MICRONUTRIENTS

Micronutrients - Vitamins and minerals

They do not produce energy themselves but are involved in processes that help in energy production.

They are needed only in small quantities in the body.

Deficiencies and excesses can affect health.

VITAMINS

Organic substances

Produced by plants during photosynthesis

Provitamins are inactive precursors to vitamins

Classified as WATER soluble and FAT soluble

WATER SOLUBLE VITAMINS

Mostly act as coenzymes

Disperse easily in body fluids

Excess is excreted in the urine

Deficiencies can develop in about 4 weeks of inadequate intake

FUNCTIONS OF WATER SOLUBLE MICRONUTRIENTSName

Function

Food Sources

FAT SOLUBLE VITAMINS

Dissolve and stored in body's fatty tissues

Should not be consumed in excess - toxic

Not easily excreted from the body

FUNCTIONS OF FAT SOLUBLE VITAMINS

Functions Of Vitamins

MINERALS

Consist mostly of metallic substances

Essential for life - balanced diet provides sufficient minerals

Provide structure - formation of bones and teeth

FUNCTIONS OF MINERALS

Minerals & Exercise

• Excessive sweating during exercise causes loss of body water and related minerals.

• Mineral loss should be replaced following exercise through well-balanced meals.

• Single-mineral supplementation is ill advised unless prescribed because of potential adverse consequences.

a) ENERGY YIELDING NUTRIENTS

B Vitamins and Energy Metabolism

B-vitamins participate in energy metabolism (releasing energy from nutrients)

Athletes with high energy expenditures have increased requirements for B vitamins. However, eating more food (energy intake that achieves energy expenditure) provides the extra B-vitamins that are needed.

Vitamin/mineral deficiencies impair physical performance, physical work capacity, endurance, oxygen consumption, cardiovascular function, muscle strength, or resistance to fatigue.

b) VITAMINS AND MINERALS FOR BLOOD FORMATION

Iron is required for a number of key functions in the body:• Iron is an important in transporting oxygen in the blood and in

the muscles.

• Iron is involved in the electron transport system. This system controls the release of energy from cells.

• Iron is required for red blood cell production.

• Iron is required for a healthy immune system

IRON AND EXERCISE RELATED FUNCTIONS

IRON SOURCES

Iron is widely distributed in food but the rate of absorption differs.

Plants contain NON-HEME iron(absorption <5%)

Meat contains HEME iron (15 - 18%)

IRON AND EXERCISE RELATED FUNCTIONS

Most of the iron in the body is combined with Haemoglobin

Iron deficiency leads to ANAEMIA causing sluggishness, loss of appetite, decreased ability to sustain activity

Anaemia negatively affects aerobic exercise and ability to perform heavy training

SORTS ANAEMIA

Hard exercise results in an increase in the volume of plasma in the blood.

This can dilute haemoglobin levels and incorrectly suggest that there is a problem with iron status.

This condition is known as ‘sports anaemia’.

It is most likely to occur in the early stages of a training program or when training load is increased.

c) ANTIOXIDANT MICRONUTRIENTS

ANTIOXIDANT ROLE OF VITAMINS

Free radical : Highly reactive atom/ molecule that contains at least one unpaired electron.

Antioxidant : Prevents the oxidation of other molecules.

Thereby preventing cellular damage.

Vitamins A, C, E and beta carotene are powerful antioxidants

Why do athletes need antioxidants?Aerobic activity metabolism increases the production of free

radicals

Pentane is produced during exercise (as a result of lipid peroxidation) and if not removed from the body can have adverse effects on the pulmonary system function

Exercise & Immunity

Exercise, stress and illness have an effect on immunity.

Moderate exercise boosts the body's immune defenses to last for a couple of hours.

Exhaustive exercise for a long period of time severely affects the body's first line of defense (immune system) against infection.

Activity:

Find the foods that are rich in antioxidants(word puzzle)

d) OTHER MICRONUTRIENTS AND INFLUENCE

CALCIUM AND OSTEOPOROSIS

Osteoporosis is the loss of bone density

Osteopenia is a midway condition where bones weaken and risk of fracture is increased

Adequate calcium intake and weight-bearing exercise prevent bone loss

OSTEOPOROSIS RISK FACTORS

Phosphorus:

Essential component of ATP

Combines with lipids to form phospholipids

Regulate cellular metabolism

Magnesium:

Vital role in glucose metabolism - break down to produce energy

Synthesis of lipids and proteins

Function of nervous system

Minerals & exercise

Strenuous exercise may lead to the loss of these four trace elements:

1. Chromium2. Copper3. Manganese4. Zinc

Functions of Copper:

• Help your body utilize iron

• Reduce tissue damage caused by free radicals

• Maintain the health of your bones and connective tissues

• Help your body produce the pigment called melanin

• Keep your thyroid gland functioning normally

• Preserve the myelin sheath that surrounds and protects your nerves

Functions of Chromium:

• Help maintain normal blood sugar and insulin levels

• Support normal cholesterol levels

Functions of Zinc:

• Help balance blood sugar

• Stabilize your metabolic rate

• Prevent a weakened immune system

• Support an optimal sense of smell and taste