Calculation of quotients Ve/LA and Vco2/LA at selected pH differentiate between different endurance performance of subjects. However, the physiological background which may explained additionally the respiratory regulation of acid-base status still remained unclear. The range between maxLAss and maxHss is larger at subjects who increased their ventilation in a larger amount. Surprisely, these are not more endurances subjects but those whith lower endurance. They reached acidosis at lower absolute exercise intensity. More enduranced subjects showed a tendency for increasing fat meatbolism and decreased carbohydrate (CHO) metabolism when water was drinking. When CHO solution was drinking than this phenomenon is not presented so significantly. Endurance training decrease CHO uptake at the same absolute exercise intensity, especially the part coming from exogenous (drinking) sources. In contrast, we have not observed the increase of FAT metabolism. Probably the present calculations which showed the rate of oxydation (g/min) wa not sufficient, because the same amount of substrate release more energy when FAT is metabolized. Therefore additional calculations should be made by using indirect calorimetry. The isometric training at 50% of maximal isometric contraction did not increased the duration of isometric contraction at this intensity. At 40% intensity the increase of duration of contraction is related to increased deoxygenation due to increased activation (IEMG). At 30% intensity the increase of duration of muscle contraction is accompained by larger oxygenation and blood volume. The selection of intensity of endurance training based on LT and OBLA is not based on physiological background. Therefore, this training principle of endurance training praxis should deserve general revision. High frequency fatigue may occure also during natural exercise and not only during electrically stimulated muscles. Surface EMG can not differentiate between subtypes of pheripheral fatigue. Determination of peripheral fatigue by using method of double twitch method results in a similar conclussions as when train stimulus pattern is using. The method, which uses the active resistance of water during controlled mechanical power swimming is not appropriate. The relationship between the force and speed during swimming is useful for quantitative estimation of swimming technique. It may help coach to estimate strategy of swimming trainng to be more technically or power oriented. The pain in region of patella (knee) may be significantly reduced by influencing on activation between muscles and intramuscular activation. In contrast, the influence of electrostimulation did not beneficially influenced exsisted pain.