This study investigated adaptations to a novel form of strength training in comparison with adaptations to conventional leg curler training. It was carried out under the standards of the Helsinki Declaration and approved by the ethics committee of the University of Heidelberg. 18 untrained male subjects performed 4 weeks of low resistance – high repetition knee extension exercise. Nine of them trained on a conventional weight resistance device (leg curler, CON/ECC group, 6x 25 repetitions/session), with loads equivalent to 70 % of the concentric one-repetition maximum (1RM) in both the concentric and eccentric phase of movement. The other 9 trained on a newly developed computer-driven device (CON/ECC-OVERLOAD group, 3x 25 repetitions/session), with the concentric load equivalent to 70 % of the concentric 1RM and the eccentric load equivalent to 70 % of the eccentric 1RM (on average 2.32 x the concentric 1 RM). Biopsies were taken from the right m. vastus lateralis and analysed for the contents of marker mRNAs (myosin heavy chain isoforms, glycolytic enzymes, myoglobin, VEGF), using real time RT-PCR quantitation. Statistical analyses were performed using 2×2 repeated measures ANOVA. The post hoc Tukey test was used for between-test differences and a Student’s paired t-test for comparing pre- and post-training from each group.The training resulted in significantly increased peak torque (+5%; p ≤ 0.05) and a tendency to increased muscle cross sectional area (+4%; p = 0.092) for the CON/ECC OVERLOAD group but not for the CON/ECC group. Strength endurance capacity was only significantly increased (+8%; p < 0.05) in the CON/ECC group. The RT-PCR analysis yielded no significant training induced differences in any of the marker mRNAs in the biopsies of the CON/ECC group. In the CON/ECC-OVERLOAD group, significantly increased myosin heavy chain (MHC) IIa (+30%) and lactate dehydrogenase (LDH) A (+70%) mRNAs were found, together with a tendency for increased MHC IIx mRNA (average 3-fold, but large variation; p = 0.056) and high correlations between the changes in MHC IIx and LDH A mRNAs (r = 0.97, p = 0.001). These results indicate a shift towards a faster, more glycolytic type of gene expression pattern in the m. vasti laterales of the CON/ECC-OVERLOAD group in response to training. We suggest that the increased eccentric load in the CON/ECC-OVERLOAD training leads to distinct adaptations towards a stronger, faster muscle.