Going outdoors is good for you. Not just because it gets you active, either, although any activity is better than none, but because being in a natural environment promotes positive anti-stress changes in the body as well as the mind.
Similarly, deep breathing and yoga-type activities can have tremendous positive impacts. They’re not going to cure cancer, but they might help you manage your blood pressure with less medication.
If you needed another reason, or a purely practical reason, to interact with nature and develop some kind of meditation practice, there you go.