Excerpt — Heart Rate Training
Improve your endurance by knowing what affects your heart rate
One of the most valuable long-term pieces of information you can gather is resting heart rate.
Technical difficulties in heart rate monitors may cause irregular numbers
Several conditions may cause your heart rate numbers to skip all over the place.
Monitor heart rate to avoid overtraining and staleness
You can use heart rate data to indicate too much training in the early stages, what we refer to as acute overtraining, or overreaching.