"Starting a Series on Target Heart Rate for Different Goals" simply introduces the topic, and stresses that different heart rates provide different benefits.
As always, I also publicize my articles in DeHaan Services ("The New Target Heart Rate Series").
Writing Tip
When you realize that a topic is too large for an individual article, write a series.
Ensure that each article stands on its own, but link back (if your site permits) to earlier topics if they are helpful for the current item.