In fitness, like in any other sport, correct performing of exercises is essential. Even if a program is well dosed, divided and individualized, as long as the exercises are not done correctly, no one can expect to achieve the results he/ she expected. Moreover, there could be a risk for his/ her body health and integrity. Special attention must be paid to the condition of the spine, which could suffer from pathological deformation of the type of cifosis, scoliosis, lordosis or combined problems. These cases are more to be dealt with in the field of kinetic therapy, medical gymnastics, etc. In the other cases, the natural curves of the spine must always be protected and maintained in a safe condition. In order to reduce the risk of injury, the sportsman must be careful not only with the correctness of the exercises, but also with fortifying spine muscles. The major joints of the body (the coxofemural joints and the joints of the elbow and the knee) must not be neglected, since they are the most exposed to effort. Regarding the correctness of the exercises, it is recommended that the normal amplitude of a joint not be forced. If the purpose of the training is to increase the mobility of the joints, the body must be carefully warmed up before the flexibility exercises. All the body must be warmed up with aerobic exercises for about 5-10 minutes. This is necessary for gradually increasing the temperature of the whole body, so implicitly of the joints which are going to be involved in the effort. For the same purpose, the stretching exercises are extremely important and effective. Their dosing must be carefully graduated and at the beginning a very short period (8-10 seconds) must not be exceeded. The technique of performing the exercises is constantly improved, so that the sportsman can reach skills which will be very useful when he/ she tries to learn new and more complex exercises. From the large area of force exercises, one must avoid the positions which involve a moment of pressure of the spine and the partial repetitions which do not open or close a joint completely. In the case of efforts during which the body is prone to repeated shocks, like running, jumping, special attention must be paid to techniques meant to dampen, to soften the impact. In sports which encourage deformation, partial development of the body, like cycling, tennis, football, it is necessary to try and maintain a balance between the muscle groups which are less involved in effort during specific training and the ones overexerted. Compensating exercises can always be found for every agonist or antagonist muscle. This way the joints involved in exercising are much better protected. It is also very important to vary the exercises regularly in order to avoid routine, which is very frustrating for the sportsman who trains constantly, for a long time, in the same program. The effort must be carefully dosed so that the sportsmen avoid both overtraining and training below the level of minimum effectiveness. If you consider these aspects of individual or collective training, the effectiveness of your training will definitely improve.