| dc.description.abstract | Strength training is typically performed with the intention to increase the skeletal muscle force-generating capacity. For an optimal outcome, it has been argued that repetitions should be carried out with maximal intended velocity (MIV), to stimulate the nervous system effectively. However, it is unclear if the application of MIV would result in a larger neuromuscular activation during dynamic strength training. Therefore, the purpose of this thesis was to investigate strength training repetitions at various intensities, with and without MIV, and to examine whether the outcome was affected by the training status. This thesis included 11 strength-trained male athletes (TG; 25 ± 4 years) and 12 strength-untrained males (CG; 23 ± 2 years), and measured maximal strength, muscle morphology, and surface-electromyography (EMG) in m. vastus lateralis (VL) and m. rectus femoris (RF) of the quadriceps in a knee extension apparatus during dynamic repetitions of 0 %, 30 %, 50 %, 70 % and 90 % of one repetition maximum (1RM), respectively. The results revealed that the time to maximal muscle activation was shorter for all intensities in both VL and RF, except for 90% of 1RM in RF (CG), when MIV was applied (P< 0.05). The MIV also induced a higher maximal muscle activation in TG at 0 %, 30 % (VL and RF), 50 %, and 90 % (VL) of 1RM, while this difference was present at 0 % (RF) and 30 % (VL) of 1RM in CG (all P < 0.05). There were no apparent differences between TG and CG in maximal muscle activation; however, the TG had higher knee extension 1RM, thigh muscle mass, and fat mass. In conclusion, these results reveal that MIV induces a shorter time to maximal muscle activation and, at least in part, a higher maximal muscle activation, regardless of the initial training status of the subjects. As the initial phase of concentric muscle action is thought to be of critical importance for neural factors and their adaptation to strength training, these findings may indicate that the greater neural stimulation induced by MIV may be beneficial for optimal effects on the skeletal muscle force-generating capacity. | |