Changes

** '''[[Heart Rate Variability]]''' has been suggested as another measure of recovery and [[Overtraining Syndrome]], but studies to date do not provide evidence of its usefulness. Measuring [[Heart Rate Variability]] requires a relatively expensive [[Heart Rate Monitor]] and is less convenient than checking [[Resting Heart Rate]] which can be measured with a [[Pulse Oximeter]].

** '''[[Orthostatic Heart Rate]]''' uses the difference in [[Heart Rate]] between lying down and standing up to detect [[Overtraining Syndrome]]. There is little evidence to support this metric.

* '''Infection or illness'''<ref name="OTPhysioReview"/><ref name="OTEcssPos"/><ref name="OTAdjust"/>. Like a major depression, [[Overtraining Syndrome]] tends to suppress the immune system resulting in more infections and illnesses, especially Upper Respiratory Tract Infections (colds). This can also manifest itself as a slower healing of minor cuts<ref name="OTAdjust"/><ref name="OTPhysioReview"/>, or a swelling of the lymph nodes<ref name="OTAdjust"/>. However, many of the symptoms of [[Overtraining Syndrome]] could be due purely to an illness, so it can be unclear if the illness is a symptom of [[Overtraining Syndrome]] or the symptoms of [[Overtraining Syndrome]] are actually just symptoms of the illness.

* '''Insomnia or disturbed sleep'''<ref name="OTPhysioReview"/>. [[Overtraining Syndrome]] tends to interfere with sleep, which in turn impairs recovery and rest, leading to a positive feedback cycle.