What change in exercise tolerance might be observed in a patient with Myasthenia Gravis?

Myasthenia Gravis is characterized by a weakness of the skeletal muscles, primarily due to an autoimmune response that affects the communication between nerves and muscles. One of the hallmark symptoms of this condition is fluctuating muscle strength, which tends to worsen with prolonged activity or exertion. As a result, patients often experience decreased strength with activity.

During exercise or increased physical demands, individuals with Myasthenia Gravis may initially function normally but then show a marked reduction in strength and endurance, particularly after sustained effort. This phenomenon is sometimes referred to as "fatigable weakness," where muscle strength decreases after activity and may improve with rest. Hence, decreased strength with activity accurately reflects the expected change in exercise tolerance for these patients.

Other options do not align with the typical presentation of Myasthenia Gravis. Improved stamina, increased energy levels, and normalization of muscle function would not be expected outcomes, as these conditions are contrary to the fatigue and weakness commonly associated with the disease.