A sportolás (futás pl) miért erősíti az immunrendszert?

Aki tud angolul annak bemasolom:

Light or moderate running boosts our body’s natural immune system by circulating protective cells through the body faster, to attack and eliminate bacteria, viruses and fungi. Infection fighters, such as Natural Killer Cells, macrophages, immunoglobins, white blood cells, and other antibodies, are produced in the bone marrow, lungs, and spleen, and have a clean up effect on foreign invaders.

Another theory holds that the increase in body temperature when we run may inhibit the growth of bacteria, thus reducing its foothold in the body. Other exercise scientists believe that regular running helps rid the lungs of airborne bacteria and viruses that cause URTI, while others believe exercise causes the loss of carcinogens through increased sweat and urine loss.

Interestingly, active people also experience lower rates of colon cancer and breast cancer. Researchers think moderate exercise boosts the body’s immune system, attacking viral malignancies that have viral origin. It’s also thought that the faster passage of food through exerciser’s digestive tract reduces the contact time of carcinogens. And fit people are less likely to be overweight and have lower body fat, which can cause cancers.

However running can be a two-edged sword. Over-training can suppress normal immune function, so getting the right balance of frequency, intensity and duration of running or general fitness workouts is critical. Runners can easily go from vibrantly health and energy to toppling over the abyss, and picking up any virus and infections going around, if they overdo things

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