My pulse was up because of the exercise, so I think I was able to feel it more. As of recently, I haven't been as lightheaded, but sometimes I'm short of breath. As far as the dizziness it can be caused by a variety of different things. Blood loss and dehydration are more serious causes. Neurological problems are a potential source with strokes and TIA's as potential causes.
Migraines are a possible cause of dizziness.
Medication side-effects are common causes of dizziness with many different medications causing this complaint. Autonomic dysfunction, more common in older men, can lead to dizziness. Cardiac causes of dizziness are usually due to fast or slow arrhythmias. A diagnosis of psychogenic dizziness should be made only after all other causes have been excluded. The work-up for dizziness is guided by the symptoms and the suspicions of the doctor.