If a little exercise is good for you, more must be better, right? Yes, but only up to a point. When it comes to exercise volume, there is a “dose-response relationship,” which means that the more you work out, the more benefits you will achieve, but there is a tipping point beyond which the amount of exercise you perform can do more harm than good. This point can be reached by one or both of the following two ways:

• Too much exercise without enough recovery
• Chronic underfueling

This tipping point is known as overtraining syndrome (OTS) and, in short, leads to a decrement in fitness level and possibly injury. Whether you are male or female, you are equally at risk for OTS, so recognizing the early signs and combating them can prevent detrimental fitness and health outcomes. Here are nine signs of overtraining to look out for:

1. Decreased performance.

The telltale sign of overtraining is a lack of improved performance, despite an increase in training intensity or volume. Decreased agility, strength and endurance, such as slower reaction timesand reduced running speeds are all common signs of overtraining.

2. Increased perceived effort during workouts.

Not only can overtraining decrease performance, it can also make seemingly effortless workouts feel unusually difficult. A clear sign of this is an abnormally elevated heart rate during exercise or throughout the day. If you are experiencing OTS, you may find that it takes longer for your heart rate to return to normal after a workout.

3. Excessive fatigue.

A few days of fatigue or “heavy legs” is expected at times. But fatigue will accumulate in a body that never has a chance to fully recover from previous workouts. Further, chronic, negative energy expenditure leads to something called “low energy availability,” which means that the body is consistently pulling from its own energy stores (carbs, protein, fat). This can be the result of too much training or too little fueling.

4. Agitation and moodiness.

Overtraining significantly affects your stress hormones, including cortisol and epinephrine. This hormonal imbalance can cause mood swings, unusual irritability and an inability to concentrate.

5. Insomnia or restless sleep.

Sleep ideally provides the body time to rest and repair itself. But overproduction of stress hormones, as mentioned above, may not allow you to wind down or completely relax, making sleep much less effective (which compounds chronic fatigue and moodiness).

6. Loss of appetite.

A hormone imbalance can also affect hunger and satiety mechanisms. More training should stimulate more appetite, but the physiological exhaustion of OTS can actually lead to appetite suppression.

7. Chronic or nagging injuries.

Overused muscles and joints can cause constant aches or joint pain. Pain that does not subside in two weeks (or so) should be considered a notable injury. Overtraining taxes all of the body's systems and also makes it more difficult to ward off infections. Thus, frequent illnesses and upper-respiratory tract infections (URTIs) are signs as well. Medical complications may also include low bone mineral density and low testosterone.

8. Metabolic imbalances.

Long-term low energy availability may lead to nutrient deficiencies, such as iron deficiency anemia, which have the potential to harm both health and performance. Medical complications can also involve the cardiovascular, gastrointestinal, endocrine, nervous or reproductive systems (e.g., menstrual cycle disturbances in women).

9. Psychological stress and/or depression.

Some people live for punishing workouts and grueling competitions. If this sounds like you, the inability to train or race (combined with an imbalance of hormones and lack of quality sleep) can significantly affect your psyche.

If you recognize these signs of overtraining in yourself, seek the help of a physician or other health professional to seek help. In some workout arenas, rhabdomyolysis is a right of passage, but it is important to understand that the kidneys shutting down is NOT the sign of an accomplished workout (but rather a sign of acute overtraining).

A better approach is to follow a periodized training program that includes both active recovery and complete rest. Rest can be frustrating, but recognize that a day or two spent on the foam roller is better than a day or two in a hospital bed. Recovery today not only allows for greater production tomorrow, but likely fewer missed training days over the next few months.