A recent question was asked about ongoing shortness of breath with training. While often this simply reflects fitness level it is VERY important to be aware that exercise can be the first way that a medical condition becomes symptomatic. This is because exercise is a stress on the body. Usually a good stress, but if there is a hidden disease process it may become symptomatic for the first time when you exercise. For example, ongoing shortness of breath can be a symptom of asthma, heart disease, anemia or a hormonal imbalance. So, if the symptom persists you should see your doctor to make sure that there is not a more serious cause of your symptom.
Dr. Jim Bovard, Sport Medicine Physician.