There is a disparity in the information about the heritability of the response of muscle anaerobic metabolism to exercise and the use of explosive power, as well as a lack of information concerning the genetic determinants of this form of work, as measured using different specific physical tests. We applied a battery of some of the commonly employed procedures (Ergojump, Wingate, maximal accumulated oxygen deficit, excess post-exercise oxygen consumption, and delta lactate concentration) to a group of 32 Caucasian male twins, 8 monozygotic and 8 dizygotic pairs, who had similar environmental backgrounds. Results were studied using a heritability index (HI). Zygosity was determined using the identity of erythrocyte antigens, protein and enzyme polymorphism and human leucocyte antigen serologic types between co-twins. Significant HI values (P< 0.05) were found in the following tests: maximal 5 s power (HI = 0.74) and total power in a 30 s interval (HI = 0.84) in the Wingate test, maximal lactate concentration (HI = 0.82) and delta lactate concentration (HI = 0.84) in the maximal progressive test, as well as in the 2nd (HI = 0.93) and in the 3rd min (HI = 0.92) of recovery after the deficit test. In this study, the most relevant findings were: firstly, significant HI values for many of the variables studied; secondly, the HI values of the parameters used to evaluate explosive power were higher than those of lactic acid capacity and thirdly, the HI of certain variables from different tests measuring, in theory, similar qualities, were different.