During physical activity, heat is generated as a result of muscle contractions. The body gets rid of the excess of accumulated heat by thermoregulation processes. The intensification of the sweating rate and the intensification of ventilation contribute to the violation of the water balance (loss of water and electrolytes). The total amount of water lost depends on the sex, body weight, level of physical activity, clothing and environmental conditions (temperature, humidity). Loss of fluid can be manifested by muscle cramps, worsening results, reduced concentration, increased heart rate and body temperature. How much fluid should be taken during activity to prevent dehydration? How to control the hydration of the body? Does only water have a lot? You will find the answer to these questions later in this article.
Recommendations regarding the consumption of liquids
We know the new position of the Academy of Nutrition and Dietetics, the Dietitians of Canada and the American College of Sports Medicine on the nutrition of physically active people and athletes – the study published in March this year underlines the importance of an individual approach to nutrition, thus hydration. When planning the demand for fluids, consider the lifestyle, the environment (temperature, humidity), the type of additional activity and anthropometry.
There are several irrigation strategies. The European Food Safety Authority estimates the daily need for liquids, which is the sum of water content from beverages and food products, in the amount of approx. 2 liters for women and approx. 2.5 liters for men (moderate physical activity and in moderate environmental conditions) ). Calculated per kilogram body weight is 30-45 ml / kg body weight, eg 70 kg × 30 ml = 2100. Also, you should compensate for fluid loss during activity.
How to estimate the need for liquids during the post-training period?
Appropriate hydration of the body is an extremely important aspect in the case of physically active people. You should pay special attention to its level being appropriate both before, during and after training.
A significant proportion of people practicing sports begin the physical activity with an inadequate level of hydration, and the reduced status of fluids negatively affects the exercises performed. To reach the correct level, you should provide before a workout in 2-4 hours 5-10 ml/kg body weight fluids – to obtain a straw shade of urine.
During the activity
The purpose of hydration during activity is to prevent dehydration reaching> 2% of body weight. It is estimated that during training, fluid loss can range from 0.3 l / h to even 2.4 l / h. Routine body mass measurements before and after completion of the activity give an idea of how much fluid should be taken during training. Some sports because of the specificity of the sport have limited ability to water (football, long-distance running). Therefore, care should be taken to ensure proper hydration before the activity and to equalize the fluids during breaks.
The standard amount of fluids that most athletes use during training is 0.4 to 0.8 l / h. Nevertheless, the number of fluids should be adjusted individually to the environmental conditions, the rate of perspiration, the type of discipline practiced, as well as the length and intensity of the training performed. In the case of training lasting up to an hour, water should compensate for fluid losses, and if the training is longer or high intensity, one should reach for isotonic drinks.
After finishing the training
The majority of active people end up training with a deficit of fluids. Water and electrolytes, which will minimize diuresis, should participate in the strategy of the body. Electrolytes can appear in the form of isotonic beverages or come from food. Liquids should be leveled in an amount of 125 to 150% of lost fluids – e.g. 1 kg of body weight from 1.25 to 1.5 liters of fluids. The loss of supplementation should be spread over time. In the case of a small loss, it will be up to approx. 2 hours, but if the losses exceed several liters, the replenishment may last up to 4-5 hours, approx. 700-600 ml for every 450 ml of lost fluids. After the activity, when dehydration is severe (> 5% of body weight) or if you need quick hydration (<24 h before activity or match), you should take about 1.5 l of fluid per 1 kg of lost body weight.
Along with this, we lose valuable electrolytes such as sodium (Na), chlorine (Cl), potassium (K), magnesium (Mg) and calcium (Ca). When supplementing losses, the greatest attention should be paid to sodium and chlorine – they account for 90% of lost electrolytes with sweat. In a liter of sweat, there is approx. 2-4 g of salt. Another mineral often overlooked by athletes is potassium; its deficiency may be associated with the formation of muscle contractions.
Sources of sodium and chloride salt, pork ham, bread, mackerel, parmesan, green olives.
Potassium sources: dried tomatoes, spinach, zucchini, fish, fruits – bananas, raisins, figs, hazelnuts, almonds.
Control your body
There are several ways to assess the level of hydration. One of the simplest that can be used during daily activities is the volume and color of urine, thirst and body weight. The body mass in active people maintaining a stable energy balance may reflect fluctuations in the status of liquids. Regular weight control in the morning can help you see the loss of fluids. This parameter is ideal as an indicator of liquids during activity. The method of measuring body mass before and after the performed activity informs us how much fluid we have lost. The color of the urine fits well with the state of hydration. The yellow color is a signal of dehydration, the straw suggests proper hydration of the body. Of course, it should be remembered that some light foods and food ingredients can change the color of urine. Another sign of hydration status is the feeling of thirst that occurs during fluid imbalance.
Too much fluid
The leadership of the body is a common phenomenon among active people. Receiving fluids exceeding their loss together with water, urine and replacement of their drinks with a low sodium content contribute to hyponatremia (<135 mmol / l). Recreational athletes are more exposed to guidance than people professionally practicing sports, due to lower physical activity and less fluid loss from sweat, and women due to lower body weight (low sweating rate). Signs of conduction (130 mmol / l) are weight gain, headache.
– drink regularly, even if you are not thirsty;
– eat products that are rich in water (watermelon, cucumber, pineapple), avoid excess alcohol;
– learn to recognize the signals of dehydration
mild (about 1-2% of body weight), symptoms of thirst, headache, weakness, dizziness, tiredness and drowsiness; medium (about 4% of body weight), symptoms of dry mouth, oliguria or anuria, lethargy, rapid heartbeat, reduced skin elasticity; severe (about 10% of body weight), extreme symptoms, thirst, no urine, faster breathing, hallucinations, changes in mental state, cold, wet skin. Severe odor can be life-threatening;
– monitor body weight. In the short term (1-2 days), every kilogram of loss is probably water;
– Pre-workout, monitor your weight every quarter in every season. Ambient temperature and humidity can affect the rate of perspiration;
– keep proper hydration while driving. Driving in a hot vehicle can increase the rate of perspiration. Even in an air-conditioned car, water losses can be high. It has been proven that the call of drivers is conducive to an increased number of mistakes made by them;
– start the day with a glass of water with lemon, and in the case of reduced immunity, add ginger;
– choose medium mineralized water every day (mineral composition)
500-1500 mg / l), on hot days reach for water with a high degree of mineralization (> 1500 mg / l);
– pay attention to electrolytes on training days, use also salt, eg Himalayan.Posted on: October 17, 2019