What are the benefits of swimming in summer?

　　Many people know that swimming plays an important role in improving the cardiovascular system. As everyone knows, swimming itself is also a "double-edged sword". Improper exercise may cause a sudden increase in blood pressure, causing stroke, cerebral infarction, and even sudden death. So, there are cardiovascular disease Patients must consult their doctor whether they can swim, and based on their physical condition, healthy , participate in activities safely.

　　Swimming is a "double-edged sword" for cardiovascular health”

　　Continuing to swim is beneficial to the cardiovascular system. It increases the volume of the heart and makes the myocardial contraction stronger. heart rate Slowing down, stroke volume increases, blood vessel walls thicken and become more elastic, and the efficiency of the cardiovascular system improves. In addition, it creates resistance with water during swimming, which has the effect of losing weight and maintaining body shape, and is beneficial to controlling blood pressure, blood lipids, blood sugar, etc.

　　However, swimming can also cause a sudden increase in blood pressure in patients with hypertension, which may induce stroke and cerebral infarction. If the amount of swimming is too high, patients with heart disease may suffer from insufficient blood supply during exercise, causing coronary artery ischemia and vasospasm, which may lead to myocardial infarction and sudden death.

　　Cardiovascular patients should do enough homework before swimming”

　　First, you should check your body, fully understand your health status, and ask your doctor to provide swimming recommendations. It should be noted that patients with high blood pressure, especially those with refractory hypertension who are difficult to control with medication, have the potential risk of inducing stroke and should absolutely avoid swimming. Patients with severe heart disease should be more cautious when swimming, such as those with severe congenital heart disease, rheumatic valvular disease, coronary heart disease Patients with serious arrhythmia and other diseases can only stay away from swimming.

　　Secondly, be fully prepared before entering the water before swimming. Even in summer, you should warm up for 10 to 15 minutes first and move your joints and muscles to prevent cramps caused by too cold water. Wear appropriate swimming suits and swimming caps, and prepare swimming goggles, earplugs, floating objects, nose clips, etc. Replenish some energy before swimming, but don't drink alcohol. The blood vessels are dilated after drinking, which will accelerate the contraction of blood vessels when swimming, which will cause people to feel uncomfortable, and the body's reserves of drinking water will increase when swimming. Grape Excessive consumption of sugar can cause hypoglycemia. Alcohol can also affect the brain's judgment and increase the chance of swimming accidents.

　　Be careful not to swim immediately before or after meals, because swimming on an empty stomach will affect appetite and digestive function, and may also cause dizziness and fatigue during swimming.； Swimming with a full stomach can affect digestion and cause stomach cramps, even vomiting, stomach ache ； Do not eat immediately after swimming, and do not swim after strenuous exercise. Otherwise, the overload of the heart and the sharp drop in body temperature will weaken the resistance and cause cold , pharyngitis, etc. If you have a cold, especially a viral cold, you should not swim. Swimming may further induce complications such as myocarditis and lung infection.

　　Three things to note when swimming

　　1. The amount of swimming exercise should be moderate. Some people have to swim until they are exhausted as soon as they swim, which is not conducive to fitness. Don't swim for too long. Generally speaking, swimming for a long time can cause tachycardia and muscle strain, which can lead to dizziness and chest tightness.

　　2. The water temperature should be appropriate. Choose a suitable swimming place and time, as well as a suitable water temperature to avoid unnecessary risks, and do not swim in the sun for a long time. If you feel a little tired while swimming, you should stop swimming.

　　3. Don’t stay in the water for too long. After staying in water for a certain period of time, the blood flow on the body surface expands. skin From pale to light red, skin changes from cold to warm； If you stay too long, the body temperature will dissipate more heat than it generates, and goosebumps and chills will appear on the skin. For patients with cardiovascular disease, these reactions can cause drastic changes in the amount of blood returned to the heart, and this stimulation can be fatal.

　　Finally, rinse your whole body with clean water after swimming. If you are in an open-air swimming pool, it is best to rest in the shade after landing, apply sunscreen on exposed parts of the body, and wrap a bath towel around the body to protect the skin. Replenish water and energy in a timely and appropriate amount, monitor blood pressure and heart rate, and rest appropriately.