Power of the cross-country skier - Need for mineral salts

Requirements for mineral salts

In the "power of the cross-country skier, the achievement of the ration of mineral saltsit is the most difficult aspect to cope with; for those who move 1.0-3.0 liters of water per day with sweating alone, the need for potassium and magnesium increases significantly.

Also in diuresis BUT especially in SWEATING, the salts (by means of some chemical-physical processes of a passive or active nature) follow the water and are dispersed; this means that their intake MUST increase in relation to metabolic needs and sweat losses. However, this is a very SUBJECTIVE aspect since, among cross-country skiers, there is a strong heterogeneity regarding the ability to sweat; the most effective method to evaluate this characteristic is the detection of the water balance by means of double weighing, a before and after the activity. In this way it is possible to establish how much water it is necessary to drink for supplementary purposes before, during and after the performance, and how many salts (Mg, K, Na, Cl) should be integrated in it. Let's say that, among the salts most dispersed with sweating, Mg is the one towards which it is easier to suffer from depletion, while sodium chloride (NaCl), being often in EXCESS in the diet, does not create problems of any kind. The lack of these elements causes, through different and independent mechanisms from each other: impairment of muscle contractile efficacy, cramps, systemic fatigue and loss of nervous lucidity; therefore, in order to avoid the decline in the sporting performance of the cross-country skier, it is advisable to guarantee the intake of salts in the diet and integrate them with the rehydrating drink.
NB. It is essential that the supply of salts is CONSTANT since, unlike water, they require much more time to move inside the various compartments of the organism.
First of all, keep in mind that through sweating it is possible to lose up to 10% and more of your body weight, even increasing the risk of collapse or death! Fortunately, in sports (except for extreme competitions such as the 100km of the Sahara) these are more unique than rare events, while losses of 2 to 5% are much more frequent. For a 70kg long-distance runner, sweating and losing 1.5kg (-2%) of liquids means starting to feel a strong sense of thirst, accompanied by a principle of "oppression" and generalized malaise; reaching -3.5kg (-5%) he will inexorably face a decline in performance that reaches 30% of the personal average, associated with an increase in the perception of effort, the appearance of skin spots, drowsiness, apathy, nausea and decreased concentration and emotional stability.
To estimate more accurately what are the real needs of sodium, chlorine, potassium and magnesium to be respected in the power of the cross-country skier, it is advisable to take into consideration a couple of numbers; first of all, we expose the water / salt ratio in the sweat loss:

QUANTITFICATION OF HYDRO-SALINE LEAKS WITH SPORT

Water loss (ml)

Loss of salts (g)

900

1,5

1800

3,0

2700

4,5

3600

6,0

9000

7,5

9900

9,0

secondly, it is appropriate to highlight the relationship BETWEEN the salts themselves dispersed through sweating:

RATIO OF ELECTROLYTES IN THE SWEAT - AVERAGE VALUES

Sodium (Na)

Chlorine (Cl)

Potassium (K)

Magnesium (Mg)

10-60%

30-50%

4-5%

0,02-6%

Availability of the Athlete