Article on Sodium and Athletes, good info on Aldosterone too....(long)

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Sodium, Your Secret Weapon by Scot Abel

In ancient times, salt was precious. It was traded as the most valued

of all commodities, and having a good supply of salt was as close to

life insurance as you could get. Age-old aphorisms like " salt of the

earth " and " worth your salt " remind us how important salt has always

been.

So all the modern-day phobias surrounding salt and sodium seems to

present us with a paradox: how could something so vital to survival in

one era be considered so deadly in another?

The answer may surprise you. The anti-sodium campaign actually began

as a commercial movement to sell different foods and snacks, under the

guise of being healthier. Much like the low-fat movement,

manufacturers care more about selling products than they do about

scientific accuracy.

As soon as the low-sodium content advertisements were shown to create

dividends, other food and supplement companies followed suit, to the

point where consumers started to believe that low-sodium was good, and

salt, in general, was bad. People failed to see that they had been

internalizing advertising, not actual scientific information.

For generations, manufacturers have marketed their products by

bombarding the public with what ingredients their brand either does or

does not have to make their product sell better than the

competition's. Like sheep, consumers followed along, buying the " low

fat this " or " no sodium that " product, without asking themselves why.

In regard to sodium intake, studies are coming in regularly refuting

its bad reputation and negative impact on human health, performance,

and physiology.

Even after thousands of years, human biochemistry and physiology

haven't changed much. Although few of us toil under the sweltering sun

any more, our bodies' need for electrolytes hasn't changed. In fact,

the metabolic needs of high-performance athletes probably most closely

resembles the needs of our ancient forefathers, especially in regard

to electrolyte ingestion.

Studies in Canada at McGill and McMaster Universities have concluded

that unless one has a specific and serious condition that would

preclude him from taking in salt, then salt intake will produce no

negative health problems, and could actually be health promoting. As a

matter of fact, only 10% of hypertension cases have a known cause, and

in almost all of these cases, the cause was either genetic or stress

related.

For all you short attention span types out there, here is the bottom

line: high-performance athletes should not avoid sodium. They should,

in fact, ensure that they get adequate amounts of sodium every day to

prevent negative metabolic consequences, and to promote maximum

performance. That's all. You may be excused.

Everyone else, keep reading.

Why Sodium?

Athletes eat for different reasons. Three of the main ones are: 1) as

a preventive measure to help stay free from illness 2) for fitness, to

ensure optimum energy stores, recuperation, and restoration 3) for

bodybuilders especially, to produce a cosmetic effect, i.e. a leaner,

harder physique.

Non-athletes eat for a variety of other reasons.

If you're an athlete concerned about maximizing your performance (you

have no business being an athlete otherwise), you should know that a

high-sodium diet fulfills all three of the above. In fact, many

problems with athletic performance or sub-maximal athletic

performance, even failure to improve, begin when athletes reduce or

eliminate sodium from their diets. These ill effects can last for a

long time.

While sodium is the primary focus of this article, no nutrient acts on

the metabolism by itself. Any discussion on sodium is incomplete

without mentioning potassium, and the hormone aldosterone.

As an electrolyte, sodium is the positively charged ion on the outside

of the living cell. Cations, anions, and ions exist in an exact

balance outside and inside cells, so that a change in the balance of

one or more cations or ions will cause a change in other cations and

ions in order to maintain cell integrity. Simply put, sodium is

responsible for regulating blood volume and blood pressure, although

it serves other functions as well.

During a set of high-intensity muscle contraction blood pressure

rises. This is a primary response of high-intensity training. During

high-performance exercise, the metabolism of the body is better served

by a higher blood volume since this translates into better oxygen and

nutrient delivery to working cells. Just as importantly, a higher

blood volume results in a more efficient removal of fatigue toxins.

A low sodium intake translates into a lower blood volume, and over

time this is disastrous to an athlete. Even in healthy people, low

blood volume leads to a myriad of problems. Studies at the University

of Bonn concluded that a low-sodium diet (and the resulting lower

blood volume) was more health-threatening than the hypertension that

the low-sodium diet was intended to fix.

For athletes, the effects are even more profound. In a low-sodium

situation, the resulting low blood volume delivers less oxygen and

nutrients to working muscles, and also allows for greater accumulation

of fatigue toxins that might not otherwise occur with a normal or

higher blood volume. This results in reduced recuperation and overall

weakness. It's the last thing a hard-training athlete wants, but it's

what happens when you eliminate crucial electrolytes from your diet.

The consequences of a sodium-reduced diet.

A low-sodium diet makes the situation even worse in regard to optimum

electrolyte metabolism, because potassium is dependent on sodium to be

effective for a number of reasons. Potassium's primary

responsibilities are the regulation and control of skeletal and

cardiac muscles. The vagus nerve, which controls heartbeat, is totally

dependent on potassium.

Potassium is the positively charged ion inside of the cell. While its

independent functions in the control of muscles have been pointed out,

potassium itself is dependent on sodium to maintain cell integrity:

the exact balance of cations and ions inside and outside cell walls.

How does potassium get into the muscle cell in the first place? Sodium

delivers it. The cell wall is partially permeable to sodium. It takes

three molecules of sodium to get one molecule of potassium inside the

cell, through a process called " active transport. " Sodium is the

chaperone, and potassium can't get into the cell without it.

Therefore, for optimum cell integrity and optimum potassium delivery,

there must be ample sodium present.

This is even more crucial in athletes where electrolyte balance and

exchange takes place more rapidly and is more crucial for optimum

performance. Also, since the active transport of potassium inside the

cell by sodium is metabolically expensive, the activity of

sodium-potassium pumps can be adjusted by the thyroid hormones in

order to regulate resting caloric expenditure and basal metabolic rate

(BMR).

It follows, then, that in a prolonged low-sodium situation, the body

may lower BMR in order to control this metabolically expensive

function. This spells disaster for the dieting bodybuilder or

competing athlete who wants his BMR as high as possible, not lowered

by a body compensating for costs it cannot afford to incur.

Even more importantly in this metabolic circumstance is that cell

integrity is jeopardized and less potassium can be delivered less

often to the cell. This is disastrous for any serious athlete.

Obviously, it's the most negative electrolyte situation for a

bodybuilder to be in.

Here's how a body could get into such a state of disarray. The primary

avenue for the loss of sodium is through sweat glands. No one, except

our ancient forefathers, sweats as much as high-performance athletes

and bodybuilders.

Top athletes sweat as much as our ancient forefathers did.

A typical combination of high-intensity training, interval cardio

activity (two sessions per day), and persistent tanning produces an

exorbitant loss of sodium through the skin. Combine this with a nearly

fanatical effort by bodybuilders and other athletes to exclude sodium

from their diets, and you can see how a bad situation can become chronic.

In an emergency situation, the body can only maintain some kind of

cell integrity by sending potassium (a positively charged ion) outside

the cell to replace the sodium that should be there. The metabolic

consequence is weakened cell integrity. Sometimes this causes

depolarization between electrically charged ions, and potassium

leaving the cell leads to muscle weakness, cramps, listlessness, and

lethargy.

Note that it's not the low-calorie diets that produce these physical

and psychological symptoms — it's due to a prolonged lack of sodium

intake. The problem can be understood better by discussing the hormone

aldosterone. We can also understand why sodium undeservedly gets a bad

rap, and how to remedy the situation.

Aldosterone

In a normal metabolic situation, electrolyte balance is delicately

maintained by urinary output. The kidneys regulate the concentration

of plasma electrolytes of sodium, potassium, and calcium by matching

almost exactly the amounts ingested to the amounts excreted. The final

amounts of sodium and potassium excreted in the urine are regulated by

the needs of the body.

Athletes get into trouble when they eliminate sodium from their diet,

because their bodies are regularly losing so much of it through sweat

and cellular activity. This produces the negative stress response of

the release of the hormone aldosterone. Normally, people have low

levels of circulating aldosterone. It's a hormone released in response

to metabolic or physiological stress.

The release of this hormone serves several functions. The main effect

of aldosterone secretion is a reabsorption of sodium through the

distal tubules of the kidneys. Thus sodium that normally would have

left the body is retained because of the presence of this hormone.

Normal individuals can excrete 30 grams (that's right, 30,000

milligrams) of sodium a day when aldosterone isn't present. This is an

average person, not a hard-training athlete. When aldosterone is

present, there's no sodium in the urine at all.

Most importantly, water always follows sodium because sodium is

positively charged while water is negatively charged. Therefore, the

more sodium excreted, the more water leaves the body. But since, in

the presence of aldosterone, sodium is reabsorbed and kept in the

body, and water follows sodium, water too isn't excreted. The result

is water retention

There's another side to the aldosterone hormonal response, which can

also spell disaster for an athlete. Not only does aldosterone cause

reabsorption of sodium, but because of this, aldosterone secretion

also causes a pronounced excretion of plasma potassium.

Again, in the absence of aldosterone virtually no potassium is

excreted in the urine. When aldosterone secretion is maximal, however,

there's up to 50 times more potassium excreted than what is initially

filtered by the kidneys. A reexamination of the situation reveals that

a negative situation exists in such a physiological environment.

First, sodium is reabsorbed. Second, because water follows sodium,

there's water retention, which in turn creates an osmotic imbalance.

Third, because aldosterone also produces pronounced potassium

excretion, the result is further muscular weakness, cramping,

performance infringement, and a very flat, tired-looking physique.

This whole misunderstanding of electrolyte function has led to

ridiculous myths and misapplications of proper nutrition in the

athletic and bodybuilding communities. One of the most bizarre is the

practice of taking a potassium chloride (Slow-K) supplement just

before a show.

There are two problems with potassium supplementation. First, it's

impossible to load potassium inside a cell: cell equilibrium is always

maintained in exact ratios. If a certain amount of potassium enters a

cell, the identical amount must leave.

The second problem is that an excess of potassium in the blood

triggers aldosterone secretion, which leads us back to all of the

negative metabolic conditions associated with aldosterone, mentioned

earlier. It's a vicious cycle, which can easily be prevented.

Estimating your sodium needs is relatively easy. The rule of thumb is

two grams of sodium for each liter of water replacement. Since most

athletes are under-hydrated, water needs should also be assessed.

150-pound athletes (both male and female) who train at high intensity

levels should drink at least two or three liters of water per day.

200-pound athletes should be drinking a minimum of three to four

liters, and athletes over 225 pounds should drink a minimum of four to

six liters.

You need 2 grams of sodium for each liter of fluid replacement.

At two grams per liter of fluid replacement, it's obvious that most

athletes do not take in nearly enough sodium. For example, a 225-pound

athlete would need to ingest between eight and twelve grams of sodium

daily. That's right, 8,000 to 12,000 mg a day.

The way to ensure ample sodium intake is through the prodigious use of

salty condiments. Sea salt, ketchup, mustard, barbecue sauce, etc. are

smart choices to ensure ample amounts of sodium.

However, beware of monosodium glutamate (MSG). Although it's high in

sodium, MSG had been shown to be a negative partitioning agent, which

means that it may channel nutrients toward fat storage, whether the

nutrients contain fat or not. Ingesting MSG can also trigger a

catabolic response.

Avoid monosodium glutamate, salt's evil cousin.

One easy way to ensure adequate sodium intake is by eating pickles on

a daily basis. Pickles on average contain about 20 to 30 calories and

almost a gram of sodium, so chopping them up into your food makes good

sense, as does eating them as a snack.

We've all seen hockey players and other athletes taking post game IV

drips come playoff time to replace lost electrolytes. Often these IV

drips are no more than saline solution; which, as you probably know,

is just a fancy name for salt water.

Ordinary salted water-pack tuna is a lot cheaper and easier to find

than reduced-sodium tuna. It also tastes better, and is another good

source of sodium. While we're on the subject, let me say that

bodybuilders have got to get over this " suffering " shtick when it

comes to diet. You are allowed to eat food that tastes good, and

eating good-tasting food will make it much easier to stay on a

prolonged diet.

Don't forget that we're talking about sodium, and not table salt.

Table salt is sodium chloride (NaCl; about 40% sodium, and 60%

chloride), and many brands of table salt also contain added iodine.

This can cause problems for some people's metabolisms, and of course

sodium ends up taking the blame. Avoid the issue and use sea salt instead.

Finding foods preserved with sodium phosphate is also useful. Sodium

phosphate is one of the best intracellular buffers around, fighting

the metabolic acidosis that training can cause. Taking in 3-4 grams of

sodium phosphate can increase both aerobic and anaerobic performance.

Athletes who have been trying to avoid sodium for prolonged periods of

time and who switch to this high-sodium approach will experience a

temporary osmotic imbalance resulting in water retention. This initial

effect is only the body's attempt to hold on to the sodium so rarely

given to it.

Water retention is temporary, and will dissipate as long as sodium and

water intake remain high. The athlete will then notice a higher volume

of urinary output, more sweating, the appearance of a leaner, harder

physique, and more pumped and full muscles in the gym.

If you have followed the scientific information in this article, then

you understand the importance of " real sodium " in your diet. You

should never have to worry about " too much, " because any excess will

be excreted. Increasing your sodium and water intake is an easy and

effective way to improve " in the gym " performance, and contribute to

the cosmetic appearance of the physique at the same time.