Low blood pressure sometimes occurs after exercise -- a condition called postexercise hypotension. This condition may last for a few minutes or as long as 13 hours. Postexercise hypotension is caused by a temporary decrease in blood flow to the area of the brain that controls your blood pressure.
Low blood pressure causes lightheadedness, dizziness, weakness and headache. These symptoms may cause you to fall or faint. Other symptoms include confusion, difficulty thinking and neck pain. (Ref 3) Your vision may be blurred, and your skin may be pale, cold or clammy. Shallow, rapid breathing may also occur. (last ref) See your doctor if you experience these symptoms, as they can be a sign of more serious medical conditions such as stroke or heart attack.