When it says unnecessary work, do not engage in unnecessary work on Sundays, especially servile work. To emphasize the distinction between Sunday and weekdays, even the manner of work should be different to express the holiness of Sunday. Therefore, we must minimize bodily exertions on Sunday, and consider Sunday as a day of rest.
It is also prudent to concentrate better on God and glorify Him. Consequently, avoiding exhaustive activities such as intense sports on Sunday, which can make you completely tired, is in harmony with the meaning of Sunday: a day of repose, allowing you to gather strength for serving God throughout the week and to focus more on God on Sunday.
Of course, engaging in a walk or sports is acceptable in moderation. It should be moderate to prepare you to be more focused on Sunday as a day of holiness and rest.
Dear visitors of Gloria Dei and all who have already written or who will write a personal message to me. I am grateful for your attention, your kindness, for your spiritual support and especially for your sacrifices and prayers for me. God may reward you!