Your target heart rate is the point during exercise at which you reach maximum benefits of physical activity. The number is slightly different for everyone, but the more often you can reach it, the healthier you are likely to be. But Dr. Edward Laskowski, co-director of Mayo Clinic Sports Medicine, says the actual number is less important than the effort and mindset to reach it on a regular basis.
I like this quote best: "...the actual number is less important than the effort and mindset to reach it on a regular basis."