Personal Fitness can be increased by time, distance and intensity. Interval Training varies the intensity of your workout increasing your heart rate at intervals. Progress can be achieved by pushing yourself further. Start by walking and add sprints every quarter mile. The beginner can first train for a half mile and sprint as far as you can after a quarter mile. Then cool down to a walk and stretch. Each time you train increase the distance. 5K which is 3.11 miles is a goal for athletes. Some parks like Caloosa Park in Boynton Beach allow you to run and do aerobics at intervals.