Title: Over-training and Weakened Immune Systems Word Count: 491 Summary: Over-training can cause physical and mental illness because of excessive intensity of training and not having sufficient time to rest and recover. Intense or prolonged exercise may cause large increases in cortisol levels and a decrease in the production of “T-cells,” a group of white blood cells that play a key role in the immune system. Keywords: infection, stress, diet Article Body: A lot of people are including exercise programs in their daily lives to gain muscle mass and reduce fat. Many however, make the mistake of training for extended hours to achieve their goals. Too much training may not give the results that these people are looking for. This practice may lead to fatigue and over-training. Over-training can cause physical and mental illness because of excessive intensity of training and not having sufficient time to rest and recover. This incident is common in weight-lifters, runners, and other athletes. Studies show that about 10-20% of athletes over-train. Athletes—professional or amateur carry a higher risk of getting sick. Over the past years, doctors caring for athletes have reported a rise of respiratory infections because of over-training. Health experts say that as individuals increase their total training load, the risk of illness also rises. This phenomenon can be attributed to the rise cortisol in the body. Cortisol is a vital hormone that is often referred to as the “stress hormone”. Intense or prolonged exercise may cause large increases in cortisol levels and a decrease in the production of “T-cells,” a group of white blood cells that play a key role in the immune system. The mental stress that are encountered by athletes may also impair the body's immune function. Expectations of coaches, family members, and other people can contribute to a drop in performance and the increase of acquiring infections. Injuries, the actual stress of competition may all aggravate psychological stress. Diminished immune systems encountered by athletes are resembles those that are experienced by people who undergo hypertension and sleep deprivation. In recent studies, highly stressed individuals had high incidences of respiratory ailments over a period of six months compared to unstressed individuals. Aside impaired immune system, men who over-train may also also experience a temporary reduction in sperm count and quality. This happens because the body literally kills itself during training and needs time to recuperate to build muscles and improve the body. Too much or too intense physical activity may reduce the level of hormones in the bloodstream and therefore affect sperm production. Sperm quality and production may return to normal after three days. Health specialists add that drinking a cup of coffee a couple of hours after training may help improve sperm quality and quantity because of the anti-oxidants it contain. People who over-train may also experience the following: .lack of energy .insomnia .headaches .dehydration .depression .decreased appetite .increased risk of injury .respiratory infection .muscle pains .high blood pressure Individuals who decide to make adjustments on their exercise routines are encouraged to consult doctors and other health professionals for workout advice. This is important because a lot of individuals tend to workout too much, improperly, and use the inappropriate equipments. Health professionals may device an appropriate workout program to complement one's health needs. Understanding proper workout and including a healthy diet in one's lifestyle may lead to improved health and overall well-being.