Is there any exercise I can do while getting hit by a mound?

If I start getting hit by Moundaro, I plan to try doing some exercise as well.
Can you recommend some exercises to do when getting hit by a mound?

Lately, ever since I strained my back while working out, my back starts hurting immediately whenever I do exercises that involve using my lower back.
As a result, my desire to exercise has gradually decreased, so I don't want to do overly strenuous workouts from the start.

Please recommend some good exercises!