Though some symptoms of exercising too much or too hard may appear obvious, such as muscle soreness/ tenderness and decreased performance, other symptoms, may not be so.   Psychological symptoms such as depression or increased anxiety and irritation may not be obvious associations with working out too much.  In fact, the line between clinical depression and OTC is blurred (Armstrong, L. and VanHeest, J. (2002) Sports Medicine 32, 185-209) as some researchers have pointed out.  Meaning the physical symptoms, which include immune system behavior, neurotransmitters (chemical messengers in the brain), as well as structural (organization of nerve tissue or “wiring”) in those with OTC and those with clinical depression being similar.  Nonetheless, recognizing symptoms of OTC is paramount to its prevention.  Untreated OTC leads not only to undesirable symptoms but can eventually lead to injury and/or illness.

The causes of OTC include:  Inadequate nutrition, psychological stress, abnormal environmental stress such as heat, cold, or humidity, excessive exercise coupled with inadequate rest, a lack of variety in the exercise routine, and /or a sudden increase in exercise intensity or volume.  The assortment of causes suggests everything, or every facet of your lifestyle is related and may contribute to OTC.  So the stress you have been tolerating at work (or other non-exercise events) may expedite a path to OTC.  Though conventional wisdom suggests a hard workout can mitigate stress, repeated stress will likely not be vanquished by repeated hard workouts.  Both require adequate rest to recover.

So how does one know if they are overtrained?  Check your mental or emotional state.  Muscle stiffness and soreness occurring as a result of a hard workout ought to be ameliorated by a few days’ rest.  However, with OTS feelings of irritability, lack of interest, or motivation often appear a few days following exercise, even if physical symptoms have abated. Such feelings occurring a few days following a workout do suggest you are overtrained.

One can also check their resting heart rate.  Does it run higher than usual?  Check it in the morning when you first are awake and in bed.  Check it again after getting out of bed a few minutes later (while standing).  Heart rate should be the same, if it’s not, OTS may be imminent.

Another way is to observe those around you.  Do they often think you exercise too
much?  Do you have a reputation for working out a lot? It’s hard to take it seriously but if others think you exercise a lot, and they think it enough to voice that opinion, they may be
right.

If early warning signs are ignored, injury, and or sickness, may occur.  One way or another, your body will make you stop if you don’t listen. There are steps one can take to prevent OTC

Keep a log.  You may already do that, diligently recording mileage, routes, dates, or sets, reps, weight lifted.  This is helpful to note performance decrements.  If decreased performance is consistent, it may be a sign you are heading for OTS.  Mental state is as important.  Consider adding additional info to your log such as how you felt before and after the workout.

Note your exertion level during your aerobic workouts.  You may already be checking your HR, it should be the same for the same level of exertion.  For example if you are walking on the treadmill at a 4% grade and your HR after 10 minutes begins trending higher
than usual, this could indicate OTC.  If you can’t check your HR, use one of the rate of perceived exertion (RPE) scales http://ahsmail.uwaterloo.ca/kin356/rpe/rpe/Borg%20RPE%20Scale.html.  If it is trending higher than usual at the same level of exertion, may be time for a break.

Periodize your workout.  Periodiaztion is a way to “manage” your exercise program.  Briefly, plan out your workouts in blocks of 6-12 weeks, where each block you have a different routine, or you change the exercise (such as stationary bike to elliptical
trainer).  Schedule a “light” week every month, where you exercise at a lower intensity than usual.  Build in days off, I recommend a week for every 10-12 weeks of exercise.  Or try
something like 2 days per month (days you would normally work out).  Finally, don’t compete with your workout partner, or rather, don’t take it too seriously.  We all know
the person who works out 6 days per week, intensely and never seems to have any
problems.  Keep in mind that each person has his or her own limits; just because someone you know works out at the crack of dawn each day for two hours doesn’t mean you should be able to as well.  As mentioned earlier, other aspects of life may be interfering with your
exercise performance (remember stress at work) differently than your workout partner.   Consequently, give them a few weeks; they may be realizing OTC symptoms of their own.

What to do if your suspect OTC.  First and foremost, take time off!  Rest for a few days; be sure you get adequate food/nutrition as well as sleep.  Also, try to change-up your routine by adjusting sets, reps, intensity, miles, frequency or the mode.  If you’re an endurance
athlete, try some cross training.  For instance try biking instead of running, hiking instead of biking, swimming instead of rowing.  If you are weight lifting, change the exercises, or try circuit training.  If it’s a sport, maybe it’s time to start the off-season, use the gym to keep in shape.  If it’s a racquet sport, try playing doubles instead of singles for a
while.  Also of importance, be sure once you start on a new routine, start implementing some of the aforementioned preventive measures.

Symptoms of OTC are simply your body’s way of telling you to take a break.  If symptoms are ignored, sooner or later you will likely be taking a break anyways, due to injury or
illness.  Also keep in mind, as mentioned earlier, the symptoms and etiology of OTC closely resembles that of clinical depression.  That being the case, if rest, changing your routine, or any of the other suggested treatments do not help, consider seeking farther help from a doctor or counselor.