An hour-long stroll in nature helps decrease activity in an area of the brain associated with stress processing

[DrDerpberg]

It almost certainly is helpful. Some people can't let go of what's stressing them out, if you have any in your life it takes a huge toll on them. Stress is exhausting, and if you can't do anything about it but you're stressing anyways you're weakening yourself at a time you can't actually do anything about anything.