The determination of energetic metabolism used during a tennis match, will help us to orientate the physical preparation of the tennis player. Numerous articles exist on this theme. One of the conclusions of some authors is that tennis has a metabolic profile typical in a sport of long duration and low intensity. This statement does not take into account many aspects that can influence the erroneous interpretation of the analysed variables. The conclusion that we reach is that tennis is especially demanding with alactic anaerobic metabolism (ATP-PCr) and aerobic metabolism and to a lesser degree lactic anaerobic metabolism. We should avoid the belief that tennis is a sport of low intensity and long duration. Tennis is a very intense sport. The values of oxygen consumption throughout a match are about 65% of VO2max (non.published study with K4bxb, Cosmed). To this work intensity, the principal sources of energy are muscular glucogen (partly oxidised and partly used anaerobically) and intramuscular trigliceroids (oxidised) and some energetic reuse of lactate. In long matches, there is the possibility that the reserves of glucogen dry up. So it is interesting to take relevant nutritional measures.<\/p>\n\n