Light physical labor and activity benefit invalids by strengthening muscles, improving circulation, and boosting morale.

Original passage

Inactivity is the greatest curse that could come upon most invalids. Light employment in useful labor, while it does not tax mind or body, has a happy influence upon both. It strengthens the muscles, improves the circulation, and gives the invalid the satisfaction of knowing that he is not wholly useless in this busy world. He may be able to do but little at first, but he will soon find his strength increasing, and the amount of work done can be increased accordingly.