Once you have found your preferred exercise, its time to begin programming a weekly schedule. Well, actually there is one more thing you should take into consideration before embarking upon your quest for aerobic health. If you want to do it right, you must constantly measure your aerobic training heart rate to reap the greatest benefits from your training. This is especially easy to program if you get yourself one of those handy heart rate monitors that automatically tell you when you’re surpassing your target pulse rate. But the big question still remains: what is my target heart rate? This is easy to calculate, just subtract your age from 220 then multiply the resulting number by .75. Here’s a sample for a 40 year old: 220 – 40 = 180 x .75 = 135. That means that the ideal exercising heart rate for a forty year old is 135.