I know that you still have a long way to go before your retirement day comes. But this early, you should be able to make your own long-term plan based on your realistic capabilities (physical strength).

Start planning when you are still working. Think of activities which you enjoy but which you have no time to do. For instance, if you love gardening, you may plan on how to develop or rehabilitate your neglected garden. You may prepare to resume a hobby in woodworking or sewing, to study or to travel to places you liked or have not seen before.

Take up hobbies which are less strenuous like reading and which may have moneymaking possibilities like sewing, growing flowers, herbs or house plants, raising animals, repairing analog tv, cooking, and tutoring.
Join in social activities which you can start in your active years and continue after you have retired. Try and involved your family and friends in these.