If you don’t move enough, you weaken your immune system. But too much or too strenuous physical activity also has negative effects since the number of killer cells decreases and their activity can become impaired for several days. It is therefore important to be physically active every day, but without overdoing it, for example by practising extreme sports. If exercise is too strenuous and exhausting, it will rather tend to weaken your immune system. The best form of physical activity is that which you can do outdoors. A brisk walk or working in the garden is enough to have a good effect. A quote from one of the more well-known medical journals – the Journal of American Medical Association – has the following to say about physical activity:

“There is no current or future medicine that could contribute as sustainably to lasting health as a lifelong program of physical exercise.”

The World Health Organization (WHO) says something similar:

“For better health, people of all ages should engage in at least 30 minutes of moderate-intensity physical activity – such as brisk walking – on most, if not all, days of the week.”

Physical activity is therefore not only an important factor for the immune system. It is also highly beneficial for many other aspects of health: strengthening the heart and its function, better stress management are just a few such examples. One reason for this is that exercise increases the production of endorphins (which can also be called “happy hormones”. These also have a positive effect on the immune system. So, a brisk walk in nature is very invigorating and strengthening. It particularly boosts the immune system. If you can get out into the woods for such a walk, the effect is even better. This is because the terpenes given off by trees boost the activity of the body’s own killer cells. The air in the forest is also very good for your health because of its high content of negatively charged oxygen ions (which among other things deactivates pathogenes).