With an earlier-than-usual heat wave arriving again this summer, health management has become an urgent concern for those who enjoy outdoor exercise. In fact, the French Open tennis tournament held in May took place amid an early heat wave, and quite a few players were unable to perform at their best due to heat cramps and other conditions. World-class tennis star Jannik Sinner complained of cramps and dizziness during his match and was eliminated earlier than expected, while Jakub Mensik of the Czech Republic collapsed on the court from cramping symptoms after a grueling battle of more than four hours, leaving the venue in a wheelchair.
As such, a heat wave poses a serious threat not only to ordinary people but also to athletes with world-class physical conditioning. Heat cramps are a warning signal from the body that the temperature regulation system has begun to malfunction. The problem is that many people dismiss heat cramps as merely "a muscle cramp."
When exercising for a long time in a high-temperature environment, electrolytes such as sodium and potassium are excreted along with sweat. This interferes with the muscles' normal contraction and relaxation functions, resulting in sudden and strong muscle contractions. This condition is called heat cramps, and it mainly appears in the calf, thigh, abdomen, and arm muscles.
In summer, there are not a few cases in which people overestimate their physical condition and continue exercising even after cramps occur. However, if proper rest is not taken at this stage, symptoms such as dizziness, reduced concentration, headache, and nausea may appear. In severe cases, it can progress to heatstroke, in which the temperature regulation function becomes paralyzed. This is why exercise should be stopped immediately when symptoms appear such as a sudden decrease in sweating, hot and dry skin, or repeated cramps in the legs.
Heat cramps do not end as merely momentary pain. When cramps recur, muscles remain in an excessively tense state, which can strain the muscles, ligaments, and tissues around the joints. In particular, when lower-body cramps recur, microscopic damage accumulates in the muscle fibers, which can lead to a long-term decline in muscle function.
In Korean medicine, herbal medicines using various medicinal ingredients are prescribed to aid the recovery of damaged muscles and prevent muscle atrophy. A representative example is sagwarak, made by removing the seeds and skin from the fruit of the sponge gourd, a member of the gourd family, and then drying it. It has mainly been used to relieve fever, bleeding, and inflammation, but it has recently been found that components contained in sagwarak, such as phenolic acids and flavonoids, promote muscle growth.
According to a paper published by the Spine and Joint Research Institute of Jaseng Hospital of Korean Medicine in the international academic journal "Journal of Muscle Research and Cell Motility," sagwarak showed effects of increasing the survival rate of muscle cells, promoting cell proliferation, and protecting against muscle cell death. The research team induced muscle atrophy by treating muscle tissue isolated from laboratory mice with a high dose of "dexamethasone," a steroid-class drug, and then treated it with sagwarak extract at concentrations of 100, 200, and 400 μg/mL. As a result, the size and number of "myotubes," the cells that form muscle fibers, increased in proportion to the concentration of sagwarak.
In summer, when the heat continues, preventing heat-related illnesses in advance by considering the exercise environment is just as important as professional treatment. As much as possible, avoid outdoor exercise between 11 a.m. and 5 p.m., when temperatures are high. It is also good to replenish sufficient water and electrolytes before and after exercise, and to develop the habit of drinking water regularly even before feeling thirsty.
Cramps are a clear danger signal sent by the body. Exercise started for health should not end up harming one's health instead. Exercise in a heat wave cannot be overcome by willpower alone. Above all, it is important to monitor one's physical condition and not push too hard.
