Why do I get dizzy when exercising? It used to feel so good to do it

Maybe Overexertion. Monitor your heart rate while you exercise and make sure it is not exceeding the recommended maximum for your age. If you are over excercising or your heart it beating too rapidly then it can cause dizziness. Also various heart arrhythmias can cause dizziness. Futhermore if you hyperventilate during exercise then that will can also make you dizzy. Visit your doctor for heart and ear studies.