Once I added in intervals and HIIT training into my workout plan, I wanted to see how it changed my resting heart rate, and it did! My RHR went down 10 beats after being diligent with those workouts. Keeping track and seeing this progress really gives me motivation (beyond the skinny jeans) to stay focused.
If you like to track your resting heart rate, there is a great free app from Azumio. Check it out here:
It works by placing your index finger on the camera and in just a few seconds your heart rate appears!