They do need reasonable exercise. If muscles are not used, they atrophy. Even weak patients can begin stretching on a regular basis and gradually increase the amount of stretching to maintain muscle tone. Humans, too, can benefit from stretching several times a day when they arise, at meal times, and bedtimes. Circle shoulders, circle elbows, lengthen neck, and feel all the muscles stretch.
Exercise can help chart the effectiveness of medication.
A weak patient can do a breath count at medication time, then again 2 hours later. Stronger patients can extend arms straight out in front of them and time how long they can hold their arms in the air. If these exercises are done on a regular basis in the morning, afternoon, and evening, the effectiveness of medication will be measured. Myasthenics should not exercise until they are completely weak. Just do a little at a time, then rest.