1. The first one includes all the sports that use the technique of respiratory stop or blocking. The most typical among these are force sports such as athletic weight throwing, weightlifting, body building, gymnastics etc. In short, we might say that here the anaerobic extreme is concerned – the one which imposes apnea (blocking the thorax and respiration). The main advantage of diaphragm blocking is the rising, for the moment, of the explosive force of the sportsman. A rise in execution speed for maximum force efforts has also been observed. The classic example is the snatch of weightlifting in which force and speed are simultaneously implied on the basis of respiratory blocking.
This respiratory blocking, inevitable in the above-mentioned sports, has also some disadvantages. Among these we could mention high pressure values in the thorax, abdomen and skull, high pressure on blood vessels with low feed-back through the veins etc. Thus, due to the rising of pressure inside the eyes the aggravation of previous short-sightedness is possible. Also, in the inferior limbs, varicose veins can either appear or worsen. Effort in exclusively anaerobic conditions increases rigidity both in the blood vessels and in the muscles.
2. The second big group is the one of sports that do not use respiratory stop. Here we enter the realm of purely aerobic effort. The typical examples are running races, swimming, cycling etc. – generally efforts on long and very long distances. In these events the muscular force implied is little – medium at most – the stress affecting the cardiovascular component and leading to increased cardiac frequency and pulmonary ventilation.
There is also a third category – mixed sports, both aerobic and anaerobic, in which the two techniques alternate. This is the case of sports games, contact sports, rhythm breaking in medium distance running races, etc. In the case of fitness, as both types of effort – aerobic and anaerobic – are present, apnea, as well as effort without respiratory blockage, is used. As far as correct respiration is concerned, there is a general rule stating that one should breath out during the most difficult part of the movement (the positive or concentric course) and breath in during come-back (the negative or eccentric course). Within these courses, we can have or not have a respiratory stop/ blockage. If we have it, it will occur at the critical point of the course.
Another breathing rule is the one that takes into consideration the dilatation of the thorax. In this case, breathing in is done on the course which allows thorax expansion, and breathing out on the movement that contracts it. In both cases, breathing in is done through the nose – in order to filter and warm up the air flow and breathing out is done through the mouth in order to be faster and more efficient.