Waking Heart Rate:
Checking your pulse rate immediately upon waking in the morning is a good practice to adopt. Do it before you get out of bed. Later, emotions, activity, and digestion will confound the analysis. Also, take your pulse in the same position each time; standing heart rate is slightly higher than seated heart rate which is slightly higher than lying-down heart rate.
If your waking heart rate on a given day is elevated by more than seven beats per minute over your average for the preceding week, be on notice that you may be developing overtraining syndrome. When assessing your heart rate, keep in mind that there is likely to be a downward trend in your resting heart rate correlating with increasing cardiovascular fitness. This can mask an elevated waking heart rate if you do not keep track of changes in your resting heart rate over time.
Another test performed upon waking is the "Three-Second Test." It involves monitoring how you feel during the first three seconds after awakening in the morning. The instant you wake-up you should feel either a bit drowsy or refreshed but relaxed. If, instead, upon opening your eyes you are consumed with nervous energy - an uncomfortable jittery feeling - there is a good chance that your pulse is elevated and you have dipped into an overtrained, catabolic state.
The “waking jitters” reflects neurotransmitter disturbances associated with overstimulation of the sympathoadrenal system (adrenal glands + nervous system). This is an early-stage indicator of overtraining. If overtraining persists, jitteriness yields to lethargy; and chronic fatigue and inability to emotionally “get up” for training or competition (known as “staleness” in the sports world) become the dominant symptoms. At this point, you are suffering from adrenal exhaustion in which the neuroendocrine system is incapable of mounting a full response to exercise. Specifically, catecholamines (adrenaline and norepinephrine) levels become depressed as a result of overtraining.
The catecholamines are the “biological juice” that drives exercise. They regulate virtually every aspect of exercise, including: blood flow distribution, cardiac contractility, energy mobilization, and mind-muscle communication.A blunted catecholamine response to exercise can severely hamper performance.
-Thank to Rob Faigin for the awesome info on Natural Hormone Enhancement