Fitness and health have been closely related ever since fitness was first defined, because this sport involves good physical shape built on good state of health. The state of health of the people who practice various sports is always in attention of the instructors. However, there are numerous sports which are rather spectacular, but practicing them exposes the sportsmen to particular risks. Such kind of problems can appear even in the sports for amateurs; there is, of course, specific pathology for every sport. Since the body is prone to different health problems, a factor which can provoke them is the volume and intensity of training. Long distance running and jogging are extremely popular forms of training.A frequent health problem in tennis is epycondylitis or 'the tennis player's elbow'. Weightlifting can lead to varicous veins or high blood pressure. Fitness tries to make every exercise useful for health and body esthetics. The type of training that is recommended is the complex one, including aerobic and anaerobic exercises. While doing aerobic exercises, the body satisfies its need of oxygen during effort. We are talking here about all types of resistance efforts, like long distance running, ski, rowing, fast walking, swimming, cycling, speed skating, etc. The consequences of these efforts are visible, first of all, at a cardiovascular and pulmonary level. This type of exercises are the most effective in burning calories and this is why they can easily burn fat tissue, as long as they last more than 40-45 minutes without stopping. The energetic support of these efforts comes from the fat acids which are mobilized from the adipose tissue. The efforts of anaerobic type are responsible for increasing force and muscular mass and for bone resistance. During this type of short and intensive effort the body cannot satisfy the need of oxygen. What happens is the so-called 'oxygen duty', recovered in the breaks between the efforts. The most typical example is the break between two series of exercises meant to work the same muscle. The effectiveness of fitness trainings is closely related to their weekly practice. There are a minimum number of trainings necessary for visible effects. For the programs of anaerobic type (force) the experts say that two trainings a week are necessary, each of 30-45 minutes. During these sessions, the whole body is trained every time. In the case of aerobic training (resistance), their weekly frequency must be increased to three, each between 20 and 60 minutes. Both types of training must be continued uninterruptedly for at least two or three months. After this period, a one-week active break is recommended. In this time the person must make lighter efforts like walking and gymnastics, the purpose being now recovery and relaxation. Starting from this minimum frequency, any supplementary training will make progress come sooner, as long as you avoid over-training or over-exerting. Deciding the optimum number of trainings, their volume and intensity depends a lot on the particularities and the possibilities of the person who practices the sport.