Provide me with a some ideas on healthy activities I can do in nature.

Getting out in nature alone or with friends is healthy both physically and psychologically. If you are looking for an activity that will require you to be out in nature you could consider bushwalking. Many national parks have walking trails of varying length and difficulty. Golf is also a healthy outdoor activity that you can do with a small group of friends or colleagues. If the beach is more your style then bodyboarding, surfing and snorkling are beach activities that you can do solo or in a group.