I Have To Finish My Hour On The Treadmill And

I have to finish my hour on the treadmill and will type back after that. I am very active, cardio and weight training and take long walks: 3 hours at a time. I felt faint today for a few minutes and my hands were shaky, this does not happen all the time but it scares me when it does. I am 54 years old and do not smoke and eat very healthy but do eat sweets at least once per day.