Part 2: Minerals: Sodium, Potassium & Chlorine

Sodium, potassium and chlorine, collectively termed electrolytes, remain dissolved in the body fluids as electrically charged particles, or ions. Sodium and chlorine represent the chief minerals contained in the blood plasma and extracellular fluid.

Electrolytes modulate fluid exchange within the body's fluid compartments, promoting a constant well-regulated exchange of nutrients and waste products between the cell and its internal fluid environment. Potassium is the chief intracellular mineral.

Sodium and potassium ions establish the proper electrical gradient across cell membranes. the difference in electrical balance between the cell's interior and exterior surfaces facilitates nerve impulse transmission, stimulation and action of muscles, and proper gland functioning.

Electrolytes also maintain plasma membrane permeability and regulate the acid-base qualities of the bodily fluids, particularly the blood.

Part 2: Minerals: Iron (2)

Should athletes take an iron supplement?

Only if there is severe anemia due to severe training, but you have to be cautious as excessive iron can be toxic and damaging. Excessive iron accumulation can contribute to diabetes, liver disease and heart disease and joint damage.

The best is to use serum ferritin as a guideline Values below 20mcg/l for females and below 30mcg/l for males indicate depleted reserves.

Latest findings support current recommendations to use iron supplements for nonanaemic physically active women with low ferrtitin levels. Supplementation in these case exert little effect on haemoglobin concentration and red blood cells volume. Any improved exercise capacity most likely comes from increased muscle oxidative capacity, not increases in the blood's oxygen transport capacity.

Part 2: Minerals: Iron

Yesterday evening I did 50 laps (2.5km) of the Tropicana pool in 1 hour and I now feel like an iron-man ha!ha! Today, I will do the treadmill at 11am at True Fitness (my settings are o.5 inclination and 11 km/hr for 30 minutes flat- not bad for someone nearing 40 yrs, weighing 85 kg).

The body normally contains between 2.5 and 4.0 grams of trace mineral iron. Seventy to 80% exists in functionally active compounds, predominantly with haemoglobin red blood cells (85% of functional iron). It increases the blood's oxygen-carrying capacity 65 times.

Physically active individuals should include normal amounts of iron-rich foods in their diet. E

Exercise -Induced Anaemia: Fact or Fiction?

Interest in endurance sports, combined with increased participation of women in these activities, has focused research on the influence of intense training on the body's iron status. The term sports anaemia frequently describes reduced haemoglobin levels approaching clincial anaemia (12 g/dl women; 14 g/dl men). Some maintain that strenuous training creates an added demand for iron that often exceeds its intake. This taxes iron reserves and eventually leads to depressed haemoglobin synthesis and/or reduction in iron-containing compounds within the cells's energy transfer system. Individuals susceptible to an "iron-drain" could experience reduced exercise capacity because of iron's crucial role in oxygen transport and use.

Intense physical training theoretically creates an augmented iron demand from three sources:

1. Small loss of iron in sweat
2. Loss of haemoglobin in urine from red blood cells destruction with increased temperature, spleen activity, and circulation rates and from jaring of the kidneys and mechanical trauma from feet pounding the running surface.
3. Gastrointestinal bleeding with distance running that is unrelated to age, gender, or performance time.

However, there is no evidence to indicate that these factors stain an athlete's iron reserves and precipitate clinical anaemia if iron intake remains at recommended levels.

To be continued tomorrow

Part 2: Minerals: Magnesium

Only about 1% of the body's 20 to 30 grams of magnesium is found in the blood, with the rest inside cells of body tissues and organs. About 400 enzymes that regulate metabolic processes contain magnesium.

Conflicting data exists concerning the possible effects of magnesium supplements on exercise performance. All in all, there is no solid data to recommend magnesium supplements to athletes.

Part 2: Minerals: Phosphorous

Phosphorous combines with calcuim to form hydroxyapatite and calcium phosphate - compounds to give rigidity to bones and teeth.

Phosphorous also serves as an essential component of intracellular cAMP and the intramuscualr high-energy ATP (the cell's unit of energy). Phosphorous also combines with lipids to form the lipid bilayer of cells.

Phosphorous also buffers acid end products of energy metabolism, hence some coaches recommend consuming "phosphate drinks" to reduce the acid effects of intense exercise and enhance oxygen release from red blood cells.

Part 2: Minerals: Calcium

Calcium, the body's most abundant mineral, combines with phosphorous to form bones and teeth. These 2 minerals represent about 75% of the body's total mineral content, or about 2.5% of body mass.

In its ionized form (about 1% of 1200mg of endogenous calcium), calcium functions in muscle stimulation, blood clotting, transmission of nerve impulses, activation of enzymes, synthesis of calcitriol and transport fluid across membranes. It also may contribute to easing premenstrual syndrome, preventing colon cancer and optimizing blood pressure regulation.

There is much information on the role of calcium supplements etc but we will deal with how exercise is related to bone health.

Exercise Provides Benefits

Mechanical loading through dynamic exercise slows the rate of skeletal aging. Regardless of age or gender, children or adults who maintain an active lifestyle have significantly greater bone mass than sedentary counterparts.

Benefits of regular exercise on bone mass accretion are greatest during childhood and adolescence. These benefits often accrue to the seventh and eight decades of life. The decline in vigorous exercise with a sedentary lifestyle with aging closely parallels the age-related bone mass loss.

The osteogenic effect of exercise and everyday amounts of physical activity becomes particularly effective during the growth periods of childhood and alolescence and may reduce fracture risk later in life.

Part 2: Minerals: Bioavailability

The body varies in its capacity to absorb and use the minerals in food. For example, spinach contains considerable calcium, but only about 5% of it becomes absorbed. The same holds true for dietary iron, which the intestines absorbs with an average efficiency of 5 to 10%. Factors that affect the bioavailability of minreals in food include:

Type of food: The small intestine readily absorbs minerals contained in animal products because they do not contain plant binders and dietary fibers that hinder digestion and absorption.

Mineral-mineral interaction: Many minerals have the same molecular weight and hence competes for intestinal absorption. This makes it unwise to consume an excess of any one mineral.

Vitamin-mineral interaction: Various vitamins interact with minerals in a manner that affects mineral bioavailability. From a positive perspective, vitamin D facilitates calcium absorption, while vitamin C improves intestinal absorption of iron.

Fiber-mineral interaction: High fiber intake blunts the absorption of calcium, iron, magnesium, and phosphate by binding them and causing them to pass unabsorbed throught the digestive tract.

Part 2: Minerals: Role

Whereas vitamins catalyze chemical processes without becoming part of the reaction's byproducts, some minerals become part of the body's structures and existing chemicals.

Minerals serve 3 broad roles in the body:

1). Minerals provide structure in forming bones and teeth.
2).Function - maintain heart rhythm/muscle contractility/acid-base balance.
3).Minerals regulate cellular metabolism by becoming consituents of enzymes and hormones that modulate cellular activity.

Part 2: Minerals

Approx 4% of the body's mass consists 0f 22 mostly metallic elements collectively called minerals. Minerals serve as constituents of enzymes, hormones, and vitamins they combine with other chemicals (e.g calcium phosphate in bone, irno in heme of hemoglobin) or exists singularly (e.g free calcium and sodium in body fluids).

The minerals essential to life seven major minerals (required in amounts >100mg daily) and 14 minor trace minerals (need less than 100mg daily).

Most minerals occur freely in nature - mainly in waters of rivers, lakes, and oceans.; in topsoil; and beneath the earth's surface. Minerals exist in the root system of plants and the body structure of animals that consume plants and water containing minerals.

Part 2: Vitamins supplements - the competitive edge?

More then 50% of competitive athletes take some form of supplements on a regular basis, either to ensure adequate micronutrient intake or to achieve an excess with the hope of enhancing performance and training responsiveness.

When vitamin-mineral deficiencies appear in active people, they often occur among;

1) vegetarians or groups with low energy intake (dancers, gymnasts, weight-class athletes who strive to maintain or reduce body weight)

2) those that eliminate one or more food groups diet, or

3) individuals who consume large amounts of processed foods and simple sugars with low miconutrient density (e.g.endurance athletes)

For the above individuals, a multivitamin-mineral supplement at recommended doses can upgrade the micronutrient density of their diet.

However, more than 50 years of research does not support the wisdom of using vitamin (and minerals) supplements to improve exercise performance, the hormonal and metabolic responses to exercise, or ability to train arduosly in healthy persons with nutritionally adequate diets.

MEGAVITAMINS

Some athletes take megadoses of vitamins or at least 10 times and up to a 1000 times the RDA, hoping to improve performances. Such practice is harmful as excess vitamins behave as chemicals.

Part 2: Vitamins - Exercise, Free radicals & Antioxidants

The benefits of exercise are well known, but he possibility for negative effects remains controversial. Potentially negative effects occur because elevated aerobic exercise metabolism increase free radicals could possibly overwhelm the body's natural defenses and pose a health risk of oxidative stress.

Free radicals also play a role in muscle injury and soreness from eccentric muscles actions and unaccustomed exercise.

But while free radical are released with exercise, the body's antioxidant defense are also increased. These muscle enzymes and antioxidant system "upregulate" with training adaptations. This thus deals with oxidative stress in exercise and is believed to have benefits for various cancer and heart diseases.

Important questions?

1) are physically active individuals more prone to free-radical damage,

Research shows that the natural antioxidant system in well-nourished people responds adequately to increased physical activity.

and 2) are protective agents with antioxidant defenses in well-nourished people respond adequately to increased physical activity.

Some studies show that taking antioxidant supplements may reduce free radical formation, or augment the natural body defense system. There are some evidence that vitamin E may reduce markers of oxidative stress with extreme exercise. But the evidence is equivocal.

Part 2: Vitamins - Needs

Why do people take supplements? In Malaysia, the alternative medicine and supplement industry is estimated to be six times the size in monetary terms compared to the pharmaceutical ethical (medicine) market. Across the world the ratio ranges from two to twelve times the size of the ethical market. It is big business.

I am not here to support or decry the food supplement industry, neither is this book written to promote any particular type of product. I know that this section will be controversial, but let’s all throw away any commercial interests we might harbour, and just look at the facts. What I will do in this section is to:

a. Highlight various supplements
b. The marketing claims being made
c. Consider the validity of these claims valid and the opinion of health experts

Firstly, what are some of the reasons health food companies claim that we must take supplements?

a. Loss of vitamins and minerals in our modern food processing
b. Nutritional deficiencies in our diet despite taking adequate calories
c. Stresses of modern living and the need for higher levels of these nutrients than our diets can supply
d. Depletion of vital nutrients such as B-vitamins, vitamin C and antioxidants due to urban factors such as smoking, alcohol and pollution

ODA VS RDA

The wellness industry has mushroomed worldwide over the last three to five years, and Malaysia is no exception. Its advocates propose that the traditional “health care model” is sickness and disease driven. The wellness industry seeks to promote health rather than treat diseases when they strike. It is like looking at the health of a person as being half full (health promoting elements) than being half empty (sickness). Therefore, the focus is on what can promote optimal health and how to fill the glass.

So which nutrients and vitamins do you need and in what amounts? Opinions vary. The Recommended Dietary Allowances (RDA) have been accepted as the standard since the 1940’s. Some researchers are now proposing that the RDAs falls short of what it needs to adequately nourish the body to promote optimal health. The RDA’s were used as the bottomline measure to get by in life and to prevent nutritional deficiencies.

On the other hand, the wellness movement has replaced the RDA’s with Optimum Dietary Allowances, or ODA’s. It is argued that optimal health requires nutrient intakes beyond what the RDA’s advocate and what diet alone can supply. ODA’s are about getting ahead in health, not just getting by (RDA’s).

For instance, the RDA of vitamin E is 30 IU (what you would get from eating 3 balanced meals a day). The ODA for vitamin E is 400-1,600 IU, which means you have to eat 10 meals a day, which is obviously undesirable. Alternatively, to get 400 IU of vitamin E you have to eat 1.5 pounds of sunflower seeds or drink 8 gallons of soymilk daily.

Part 2: Vitamins - Role of Vitamins

I won't go on a long listing of vitamins and its role, but in short, vitamins contain no useful energy for the body; instead they serve as essential link and regulators in metabolic reactions that release energy from food.

Vitamins also control tissue synthesis and protect the integrity of cell's plasma membrane.The water soluble vitamins play an active role in energy metabolism.

Talk in SS2

Part 2: Vitamins - Nature of Vitamins

People are pushing all sorts of vitamins out in the market. The truth is that over the course of a year,the body requires only about 350gram of vitamins from the 862kg of food consumed in well-balanced meals by the average adult.

With proper nutrition from a variety of food sources, the physically active person or competitive athlete need not consume vitamins and supplements. That is a big "if" they consume a proper nutrition.

Some foods are rich in vitamins eg greeny leafy vegetables and roots of plants produce vitamins during photosynthesis. Animals from my knowledge don't produce them (except vitamin D), but get them from consuming plants, grains and fruits or eating another animal.

KINDS OF VITAMINS

13 types of vitamins have been isolated, identified and given RDAs.

Fat-soluble:-A,D,E,K
Fat soluble vitamins dissolve and remain in the body's fatty tissues, obviating the need to ingst them daily. They should not be consumed in excess without medical supervision.

Water-soluble:-C, B-complex
Act largely as coenzymes. They disperse in the bodily fluids.