One condition that fits the description of causing syncope (fainting) but allowing the sufferer to exercise or requiring exercise and is not triggered by strong emotion is called "Vasovagal Syncope."
Vasovagal syncope is a common type of syncope that occurs due to a sudden drop in heart rate and blood pressure, leading to a temporary reduction in blood flow to the brain. This can cause a brief loss of consciousness. While it can be triggered by various factors, including strong emotions, pain, or standing for prolonged periods, it is also known to occur during or after physical exercise in some individuals.
During exercise, the body's demand for oxygen and nutrients increases, and the heart rate goes up to meet those demands. In some people with vasovagal syncope, this increase in heart rate can trigger a vagal response—a sudden stimulation of the vagus nerve—which leads to a paradoxical drop in heart rate and blood pressure, resulting in syncope. It's believed that certain individuals may be more prone to this response, especially during prolonged or intense exercise.
It's important to note that not everyone with vasovagal syncope experiences fainting during exercise, and the triggers and severity of syncope can vary among individuals. A proper medical evaluation is necessary to diagnose vasovagal syncope and rule out other potentially serious conditions that can cause fainting.
If someone experiences recurrent episodes of syncope during or after exercise or in other situations, it's crucial to seek medical attention for proper evaluation and management. A healthcare professional can conduct a thorough assessment, which may include a detailed medical history, physical examination, and possibly diagnostic tests to determine the underlying cause and provide appropriate recommendations for treatment and prevention.