Potassium-sodium balance, as part of the body’s overall electrolyte balance, is an extremely important part of the relative constancy of the internal fluid environment (homeostasis). How does this fragile balance depend on diet, exercise and stress? Can we regulate it ourselves?
Sodium Sodium plays an essential role in a number of vital processes in the body. It is essential for maintaining the osmolarity of the extracellular fluid. It determines the emergence of the action potential, the transport of organic substances across the cell membranes, the alkaline-acid balance of the blood, the activity of some enzymes and others.
With a daily intake of 5-15 g of salt, take 2-6 g of sodium. The need for this element amounts to 1-3 g per day. Sodium deficiency is rare due to the presence of enough sodium in food.
However, deficiency can occur with profuse sweating and complete refusal to consume salt. In this case, it leads to muscle cramps and disorders in the absorption of carbohydrates. Overdoses (over 13-14 g per day) are considered toxic. Sodium is excreted by the kidneys, gastrointestinal tract and skin. In bodybuilding, sodium does not need to be obtained additionally through food supplements.
Potassium is the major cation in the intracellular space. With a normal diet, about 80-100 mmol is taken daily and the same amount is excreted – 10% through the intestines and about 90% through the kidneys. Potassium deficiency leads to hypoglycemia, heart disorders, acute muscle cramps. Included in most quality formulas of complex vitamins and minerals. Intake over 18 grams is toxic and harmful to health.
Some studies have linked low potassium levels to high blood pressure. Two or three coffees a day cause potassium deficiency in the body. Alcoholics and sweet tooths also often suffer from potassium deficiency. Abrupt weight loss with a low-carb diet also leads to lower potassium levels in the body. The symptoms are a feeling of weakness and weakening of reflexes.
Potassium deficiency explains muscle cramps in people involved in fitness and other sports. This metal has been shown to stimulate nitrogen retention, leading to increased muscle mass. It also supports glycogen metabolism, which again stimulates muscle hypertrophy.
Research shows that potassium deficiency negatively affects the maximum performance of exercise in sports. Due to the difficult innervation of the muscle, the muscle contractions are blocked. When potassium stores are low, the levels of available nitrogen and muscle mass decrease.
The anabolic effect of potassium is related to cell hydration. A well-charged cell sends an anabolic signal. Conversely, a dehydrated cell causes catabolic reactions. Potassium plays an important role in the accumulation of glycogen in muscle. Glycogen attracts a large amount of water, which enhances the anabolic signal.
This metal is also needed in the production of sufficient amounts of growth hormone. Potassium also has an anti-catabolic effect – it neutralizes the ammonia obtained during the breakdown of proteins.
Regulation of potassium-sodium balance
The kidneys are known to regulate the amount of water, sodium, potassium and other electrolytes in the body. Diuretics are rightly considered one of the main categories of banned drugs in sports, which is mainly associated with electrolyte imbalance.
The kidneys play a key role in regulating the concentration of potassium and sodium in plasma. When the body has difficulty maintaining the potassium-sodium balance due to severe physiological conditions and severe stress, the activating hormone aldosterone is released, which has a regulatory role.
The potassium-sodium pump is a biological structure located in the inner membrane of the mitochondria of eukaryotic cells. Its function is to transport sodium and potassium ions in and out of the cell through active transport. A major part of the potassium-sodium pump is the Na + / K + -translocating ATPase protein. The difference in ions inside and outside the cell generates the vital electrical membrane gradient on which muscle contractions directly depend.
High intensity training
With the increased need for higher blood volume during high-intensity training, if the requirements for delivering the necessary amounts of oxygen and nutrients to the muscles are not met, the athlete is at enormous risk of a number of negative deviations.
Nutrients do not nourish the working muscle. During high-intensity aerobic exercise, sodium deficiency occurs, toxic lactate levels increase, and it is difficult to eliminate waste products from the body. This is a signal for the release of the stress hormone aldosterone. Its role at this time is compensatory, reabsorbing the released sodium, and this leads to water retention in the body.
Problems with the effects of aldosterone on sodium also apply to potassium. The kidneys are subjected to severe stress, and the osmotic balance is disturbed. The negative effects on the athlete are drastic. Another important deviation associated with low sodium levels is impaired heart, brain and liver function.
Some substances used for doping change the electrolyte balance of the body. Oral or parenteral abuse of glucocorticosteroids can also cause electrolyte disturbances. The use of anabolic steroids often leads to elevated levels of potassium, sodium, calcium and phosphates, resulting in dangerous heart disorders.
Elevated sodium levels are often found in athletes due to the abuse of dietary supplements. Many athletes take sodium bicarbonate and sodium citrate in order to increase their athletic performance. The negative effect is expressed in gastrointestinal disorders accompanied by diarrhea (especially when using sodium bicarbonate as a supplement).