ORIGINAL ARTICLE K. Chamari á S. Ahmaidi á J. Y. Blum á O. Hue A. Temfemo á C. Hertogh á B. Mercier C. PreÂfaut á J. Mercier Venous blood lactate increase after vertical jumping in volleyball athletes Accepted: 3 February 2001 / Published online: 5 May 2001 Ó Springer-Verlag 2001 Abstract The aim of this study was to test the hypoth- esis that venous blood lactate concentrations [La ± ]) would vary from the beginning of brief exercise. Maxi- mal vertical jumping was used as a model of brief intense exercise. Eleven healthy male volleyball players, aged [mean SE)] 18.5 0.7) years, performed three exercise tests with dierent protocols, each separated by quiet seated recovery periods of 45 min. After the ®rst test, consisting of a single maximal jump [lasting @0.6 s for the pushing phase, and in which the subjects jumped 64 2.2) cm], forearm venous [La ± ] increased signi®cantly with respect to rest at 1 min t 1 ), 3 min t 3 ), and 5 min t 5 ) of recovery. The second test, comprising six maximal jumps, each separated by 20-s recovery periods, resulted in an unchanged [La ± ] with respect to the baseline value. After the third test [i.e., six consecutive maximal jumps that lasted a total of 7.36 0.33) s], [La ± ] increased sig- ni®cantly at t 3 and t 5 with respect to the pre-test value F=10.3, P<0.001). We conclude that a signi®cant ve- nous [La ± ] increase occurs after vertical jumping. This result may be explained by the activation of lactic an- aerobic metabolism at the very onset of exercise, which participates in energy production and/or in the resyn- thesis of the phosphocreatine that was used during such brief exercise. Keywords Brief exercise á Glycolysis á Lactate á Volleyball athletes Introduction During muscular exercise, energy production depends upon both anaerobic and aerobic metabolism. Margaria et al. 1964) have suggested that lactic anaerobic me- tabolism contributes to energy production after 20 s of exercise. More recently, however, our group Mercier et al. 1991) showed that venous blood lactate concen- tration [La ± ]) increased signi®cantly after 6 s of intense exercise, and it was concluded that lactic anaerobic me- tabolism probably contributes signi®cantly to energy production during such short-duration, intense exercise. In the same way, Gaitanos et al. 1993) showed that 50% of the working energy in a 6-s intense sprint was pro- vided by alactic anaerobic metabolism and 50% by the glycolytic pathways. Finally, Balsom et al. 1992) hy- pothesized that lactic anaerobic metabolism would con- tribute to energy production even from the very ®rst second of exercise. This hypothesis is supported by the fact that glycolysis and glycogenolysis are immediately activated by the Ca 2+ that is released by muscular con- traction Chasiotis et al. 1982). Study of the possible activation of the glycolysis pathways at the beginning of exercise would be of interest for sports that include ex- tremely brief eorts. Volleyball, for example, requires a short, but intense eort i.e., maximal vertical jumping that is performed repetitively during both training and competition). Maximal vertical jumping seems an ap- propriate model for intense and extremely brief exercise because this task lasts for about 0.5 s Hertogh et al. 1992). In order to test the hypothesis that lactic anaer- obic pathways are already activated from the very ®rst seconds of exercise, venous blood [La ± ] was measured in healthy male volleyball players after vertical jumping. In Eur J Appl Physiol 2001) 85: 191±194 DOI 10.1007/s004210100415 K. Chamari á S. Ahmaidi &) á A. Temfemo Laboratoire de Recherche ``APS et Conduites Motrices: Adaptations-ReÂadaptations'', Faculte des Sciences du Sport, AlleÂe P. Grousset, 80025 Amiens Cedex, France E-mail: said.ahmaidi@ca.u-picardie.fr Tel.: +33-3-22827903 Fax: +33-3-22827844 J.Y. Blum á B. Mercier á C. PreÂfaut á J. Mercier Laboratoire de Physiologie des Interactions, HoÃpital Arnaud de Villeneuve, 34295 Montpellier Cedex 05, France K. Chamari Centre National de la MeÂdecine du Sport, 1003, Tunis, Tunisia O. Hue á C. Hertogh Laboratoire ACTE, UFR-STAPS Antilles-Guyane, Campus de Fouillole, 97159 Pointe aÁ Pitre Cedex, France