Mineral nutrients: Why they are so important for you as an athlete
Mineral loss in sports - what you should know about it
Classification of mineral nutrients
The mineral nutrients belong to the micronutrients. You can find out more about micronutrients HERE.
The classification of minerals is again based on their quantitative occurrence in the body. This is important to understand why different terms are used in connection with minerals.
Trace elements occur in amounts less than 50mg/kg body weight. Understandably, this also means that they have to be supplied in smaller quantities.
Thus, trace elements are needed in μg- mg range.
Important trace elements are: Copper, selenium, iodine, zinc, iron, fluorine
Iron is an exception. Although iron is counted among the trace elements, it occurs in amounts of 60mg/kg body weight.
As the name suggests, bulk elements occur in higher quantities in our bodies. They occur in amounts above 50mg/kg body weight, and must be supplied in correspondingly higher amounts.
So the recommendations are in the gram range.
Important quantity elements are: Calcium, potassium, sodium, magnesium
The bulk elements just mentioned are usually referred to as electrolytes. Why is that?
The background of the different designation is chemical. In an aqueous environment, the above-mentioned bulk elements are mostly present in ionized form as anions and cations. For this reason they are called electrolytes.
Sodium (Na+), potassium (K+), calcium (Ca2+) and magnesium (Mg2+), for example, are present as cations – i.e. positively charged.
In contrast, anions – i.e. negatively charged – are chloride (Cl-) or the salts of sulfuric acid, which are also called sulfates (SO42-).
Effects of fluid loss during sports
Sweating occurs during physical exertion. This leads to a significant reduction in the body weight of the athlete during training or competition.
This weight loss is primarily due to fluid loss.
The loss of fluid depends on several factors: The intensity of exertion plays a role, as do environmental influences such as altitude or heat. The individual body constitution also has a great influence on the amount of sweat.
Strenuous training sessions can result in a fluid loss of 2-3 liters per hour. If the loss is not compensated, severe performance losses will occur.
It is said: If the body weight drops by 2%, there is a 20% drop in performance!
However, through sweat goes not only water but also minerals
lost However, these electrolytes are essential for maintaining the
The following overview shows the amounts of micronutrients contained in one liter of sweat:
Amount in mg/liter of sweat
700 – 1.500
200 – 480
20 – 40
4 – 20
0,5 – 1
0,5 – 0,9
0,3 – 1,61
0,03 – 0,05
We will go into a little more detail about the four minerals that are lost in large quantities through sweat.
Functions of minerals lost through sweat
Sodium makes up 0.15% of the human body. For a person who weighs 60kg, this corresponds to about 90g. For an athlete who weighs 80kg, the sodium content is 120g.
95% of sodium is present in the extracellular space. This is the fluid outside the cell, e.g. blood plasma, tissue and lymph fluid. The remaining 5% is found within the cell.
Sodium plays an important role in various processes in our body:
- Regulation salt-water balance
- Maintenance blood pressure, blood volume
- Stimulus transmission Nerve impulses
- Muscle contraction
- Regulation body temperature
- Regulation acid-base balance
Sodium is excreted in sweat in considerable amounts. An exact number cannot be determined here, since sodium loss varies from person to person.
It is also important to remember that sweat is hypotonic, which means that the loss of water through sweat is always greater than the loss of sodium.
Nevertheless, care must be taken to ensure that sodium loss through sweat is not too great. If this happens, it is called hyponatremia – a sodium deficiency.
This leads to premature fatigue and the well-known muscle cramps.
The risk of hyponatremia is particularly high during high outdoor temperatures and long competitions such as ultra-events or triathlons.
Another important mineral is potassium.
Potassium is found in adults in amounts of approximately 1.6 – 2 grams per kg of body weight. In contrast to sodium, potassium is mainly found inside the cell – i.e. intracellularly. Only 2% of the potassium is found extracellularly.
Potassium also has a number of important tasks and controls important body functions such as:
- Regulation and maintenance of electrolyte and fluid balance
- Regulation of the so-called osmotic pressure (water content of the cells), together with sodium and chloride.
- Muscle contraction
- Transmission of nerve impulses, transmission of electrical impulses (= stimulus transmission), nerve function
- Involvement in protein biosynthesis (e.g. muscle formation).
- Energy release, supports the utilization of carbohydrates
- Maintenance of rhythmic cardiac work and contraction of cardiac muscle cells, together with magnesium.
- Regulation fluid balance
- Regulation pH value
Under physical stress, plasma potassium concentration increases. That is: Potassium release from active muscles increases, which can be a contributory cause of physical exhaustion during long-term exercise. However, the potassium is transported back from the extracellular space to the muscle after exercise by the Na/K+- pump.
Nevertheless, an undersupply of potassium can result from intense physical exertion. This results in muscle dysfunction and can even lead to paralysis in exceptional extreme cases.
Even though the risk of potassium deficiency is lower than that of sodium deficiency, it makes a lot of sense to take in additional potassium during high stress.
Of all the minerals in the human body, calcium is found in the greatest quantity.
99% of calcium is found in teeth and bones. It can therefore be guessed that calcium plays an important role in bone and tooth formation.
The 1% of the total calcium pool that is not stored in bones and/or teeth is mainly found in the extracellular fluid. There calcium fulfills important regulatory and control tasks such as:
- Regulation of energy metabolism (release of hormones for digestion and fat metabolism, involved in insulin production and carbohydrate metabolism)
- Regulation of nerve signal transmission (transmission of nerve impulses)
- Involvement in the release of neurotransmitters
- Supportive function for regeneration and muscle relaxation
- Control cell and enzyme activities
- Involvement in blood clotting (enables formation of blood clotting factors).
Calcium also plays a role in muscle contraction, which is important for athletes.
For those who want to know more: Calcium plays a role in electrochemical coupling. Electrochemical coupling describes the conversion of the action potential into a muscle contraction. In this process, the electrical potential of a nerve cell is converted into a mechanical movement.
Another mineral that is lost through sweat is magnesium.
Magnesium is found in almost all of our cells. In total, about 24 grams of magnesium are found in the human body.
Of these 24g, 60-65% are in the skeleton, 40% in soft tissues, and 1% in extracellular fluid.
Magnesium performs several important tasks in our body. Among others:
- cofactor in enzyme function (influence on energy metabolism and protein synthesis)
- Participation in ATP formation = energy production
- Muscle function (relaxation)
- Stimulus transmission nerves/muscles
- Electrolyte balance
- Blood pressure regulation
- Involvement in the synthesis of DNA and RNA, and thus in the formation of new cells and proteins, e.g. for muscle formation and maintenance.
- Strengthens the immune system by inhibiting pro-inflammatory processes
Particularly interesting for athletes are the effects of a magnesium deficiency on the muscles.
Thus, a deficiency can lead to muscle weakness, muscle tremor or muscle cramps, among other things. However, the role of magnesium in triggering muscle cramps has long been overestimated.
More often, localized misuse or overuse is the cause of muscle cramps.
A severe magnesium deficiency can also lead to cardiac arrhythmias, decreased pumping efficiency, and decreased blood flow to the heart. There is subsequently an increased prevalence for myocardial disease.
For this reason, magnesium is used in the prevention of heart attacks.
How to compensate for the loss of minerals during exercise
It is recommended to use sports products with extra added minerals, especially for long-lasting endurance efforts.
Therefore contain all our training and competition drinks. Calcium citrate, potassium citrate, magnesium citrate and rock salt (sodium). And this needs-oriented in the optimal amount to compensate for the loss of minerals through sweat.
Another tip for hot days is to add high-salt snacks. Soletti or salty crackers can definitely be snacked on during a long bike ride, for example.
It’s also okay to use salty foods when preparing breakfast. Eating a high-salt dinner the day before is another way to prepare yourself for extreme stress in the heat.
However, the deliberate intake of high amounts of salt should not be interpreted as a generally valid dietary recommendation. On rest days or low-intensity training phases, you should not consciously eat a salt-heavy diet.
The “salty tips” mentioned are a small help to counteract sodium loss: however, special sports nutrition containing minerals during exercise cannot be replaced with them to prevent the negative effects described.
 Nutrition of Man 6.A.; Ibrahim Elmadfa, Claus Leitzmann; utb.