Covid-19 has reminded us that it is our immune system that protects against infection and disease. In this context, studies have once again shown that moderate sport and exercise strengthen the immune system - especially regularly and outdoors in the fresh air.
The emphasis is on MODERATE - STRESS-FREE and with JOY. It is known that there is a fine balance in competitive athletes to achieve on one hand high performance but still making the training as stress-free as possible. Because too much tension causes the release of the stress hormone cortisone which suppresses the immune system. On the other hand having fun with exercise the happiness hormone endorphin is released and the whole body relaxes. Moderate activities such as all forms of walking, running, cycling and swimming are recommended - as long as it is stress-free and fun.
If you don't have time for outdoor sports you can participate virtually in the Tour de France or the Ironman triathlon in Hawaii on your home trainer - preferably at the open window.
Fresh air not only strengthens the immune system, it are also good for your eyes.
In winter, in particular, people spend more time indoors and use digital media more often. The eyes tend to be dry. Screens have LED backlighting, which is stressful for the eyes and sight. Yellow filter glasses are worthwhile for people who work a lot on screens. This filters the unpleasant blue LED light. Do not take cheap products but get advice from the optician. And don't forget - active breaks are good regeneration.