80% of 1RM) was more effective to velocity improvement. Further, this type of strength training can reduced the risk of injuries compared to heavy resistance training regimens. Finally, this training method can be used with athletes of short resistance training experience as has beeen shown favorably in previous studies with soccer players (Gorostiaga 2004; L��pez-Segovia blog of sinaling pathways 2010). Only one previous study has investigated the muscular power output in the squat in soccer players (Requena, 2009). Yet, no studies have analysed the power output in the full squat exercise in this population. Maximal peak power output reported in the present study was 1181 �� 188W, with an external load equivalent to the 86% of body weight. This result was very similar compared to the values (1149W) claimed by Requena (2009) among semi-professional soccer players.

However, these researchers used the traditional half squat exercise and not the full squat movement. Although similar peak power outputs (1181 vs. 1149) were reported between theses two studies, ours was equivalent to 86% of players body weight, while the experiment conduced with semi-professional soccer players was obtained with 112.5% of BW. These differences could be explained by a different range of motion of these two exercises (half vs. full squat), by different measuring equipment, and by distinct kinematic parameters. Thereby a load equivalent to 55% of 1RM in the half squat represents in a full squat approximately 30�C45% of the subjects maximum capability (Baker 2001).

It is also possible that the differences could be linked to the players experience in resistance-training programs. Baker (2001) observed that professional rugby players produced maximal peak power values with a load equivalent to 104% bodyweight, while in a group of college rugby players the percentage obtained was lower (92%), close to our results. Furthermore, both studies (ours and of Baker, 2001) were conduced with participants who had limited resistance-training experience. Nevertheless, these results seem to indicate that power output could be a determinant factor to identity full squat performance at different levels. Like in loaded countermovement jump, the power output obtained in full squat with lighter loads was more related as running velocity approaches maximum (Table 3).

These relationships are in accordance with the findings of Murphy (2003) showing that at initial acceleration, the application of reactive strength is longer and the stretch shortening cycle is slower that in the last meters of the sprint. The major relationships observed in the last sprint stages Carfilzomib may also indicate individual ability to produce muscle force at higher velocities, and also a better neuromuscular activation during the stretch shortening cycle. The current study showed that the T10 correlated significantly with the average power during the full squat with 30 and 40kg (r= ?0.591, ?0.