You should drink water for running, but if you just pour water and ignore the electrolyte supply, even if you drink sports drinks, it may still cause “water intoxication”, which may be fatal.
In a study conducted in 2005, 13% of runners had hyponatremia; in 2009, 30% of runners in an extreme marathon in the United States had hyponatremia after 24 hours of running. In the past 20 years, dozens of people have died overseas due to water intoxication caused by exercise.
If the body drinks more water than the maximum continuous diuretic rate of 16cc per minute, the excess water will swell the cells and cause hyponatremia, which is commonly known as “water intoxication”.
Symptoms of water intoxication include dizziness, blurred vision, vomiting, weakness, rapid heartbeat, etc. In severe cases, there may also be convulsions, coma or even life-threatening. What is more important to note is the “potential” water intoxication, that is, hyponatremia that does not yet show the above symptoms, which is an unexploded bomb that threatens the health of the exerciser.
Sports water toxicity is caused by multiple factors
Exercise water toxicity is likely to occur in endurance sports with long exercise duration and low to moderate intensity, such as marathon, triathlon, cycling around the island, hiking and other sports. The causes of water intoxication in sports are still inconclusive. Possible factors include drinking too much water, excessive sweating resulting in sodium loss, continuous secretion of antidiuretic hormone (ADH), and too high or too low body mass index (BMI). It is generally believed that multiple factors contribute to the occurrence of water intoxication during exercise.
The chance of water intoxication from exercise will increase if you have the following conditions.
- Drinking too much water before and during exercise (more than 1500cc per hour)
- Weight gain after exercise
- Exercise for more than 4 hours
- Participating in unfamiliar races (climate, road conditions, insufficient supply information)
- BMI is too high or too low
- Too many hydration stations at sports events
- Too hot or too cold weather
- Take pain and anti-inflammatory medication before exercise
Can taking painkillers and anti-inflammatory drugs cause water intoxication during exercise? This has been a hot topic in recent years, and many studies have found this trend. Sports enthusiasts with joint degeneration or chronic sports injuries are not in the minority, and many rely on painkillers and anti-inflammatory drugs for a long time to continue to exercise. But almost all painkillers and anti-inflammatory drugs can lead to water retention in the body (such as swollen feet), and if you drink too much water while exercising, you are more likely to suffer from sports water intoxication. If you regularly take painkillers and anti-inflammatory drugs, or habit of taking drugs before exercise, be especially careful.
Diagnosis and prevention principle of blood sampling
The diagnosis is made by drawing blood to check the sodium concentration in the blood, which can be confirmed if it is lower than the normal value and occurs within 48 hours after exercise. The sodium level and the severity of symptoms will determine the treatment. In mild cases, water restriction and high-tension drinks are required, while in severe cases, urgent medical treatment is required.
To prevent water intoxication during exercise, the following 3 principles should be observed.
1. Proper hydration
- Drinking practice: Practice proper hydration during normal running practice, and follow the schedule during the race.
- Drink a small amount of water, about 500cc, 2 hours before the road race.
- It is best to refill the water once every 10~15 minutes during the road running, and drink 150~200cc of water in a single session.
- If you sweat a lot, it is better to replenish sports drink or salt water in time, not to drink plain water.
- You can eat a little bit salty two days before the race.
- Eat a balanced diet with plenty of fruits and vegetables to replenish sodium, potassium and magnesium ions.
2. Pay attention to the signs and symptoms
If you find yourself dizzy, inattentive, nausea and vomiting, weakness, rapid heartbeat, muscle cramps, etc. during exercise, even if you rest for more than 30 minutes and still no improvement, you should seek medical attention as soon as possible.
3. Take weight regularly
Exercisers can develop the habit of taking weight before and after exercise to grasp the body’s moisture status.
When exercising, the body water will be lost by a lot of sweating and skin evaporation, about 1000 ~ 1500cc per hour, if you continue to exercise for an hour, the body water loss will even reach 5000cc, equivalent to a sudden loss of weight 5 kg. Even if it is normal hydration, most people’s weight will still be slightly lighter than before exercise. In addition, it is impossible to eat too much during the exercise process, so if the weight after exercise than before the exercise increased by more than 1 kg, representing really drank too much water.
With the growing popularity of sports, the chance of sports water poisoning has increased greatly, and most of them occur in healthy sports enthusiasts. A special reminder that when exercising hydration should be the right amount at the right time, even if it is to participate in the competition should also be in accordance with the table exercise class, do not see the supply station to drink water to avoid regret.
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