Local contextual processing of abstract and meaningful real-life images in professional athletes.

We investigated the effect of abstract versus real-life meaningful images from sports on local contextual processing in two groups of professional athletes. Local context was defined as the occurrence of a short predictive series of stimuli occurring before delivery of a target event. EEG was recorded in 10 professional basketball players and 9 professional athletes of individual sports during three sessions. In each session, a different set of visual stimuli were presented: triangles facing left, up, right, or down; four images of a basketball player throwing a ball; four images of a baseball player pitching a baseball. Stimuli consisted of 15 % targets and 85 % of equal numbers of three types of standards. Recording blocks consisted of targets preceded by randomized sequences of standards and by sequences including a predictive sequence signaling the occurrence of a subsequent target event. Subjects pressed a button in response to targets. In all three sessions, reaction times and peak P3b latencies were shorter for predicted targets compared with random targets, the last most informative stimulus of the predictive sequence induced a robust P3b, and N2 amplitude was larger for random targets compared with predicted targets. P3b and N2 peak amplitudes were larger in the professional basketball group in comparison with professional athletes of individual sports, across the three sessions. The findings of this study suggest that local contextual information is processed similarly for abstract and for meaningful images and that professional basketball players seem to allocate more attentional resources in the processing of these visual stimuli.

Reliability of squat and countermovement jump tests in children 6 to 8 years of age.

The aim of this study was to determine the reliability of the squat jump test (SJ) and countermovement jump test (CMJ), in fifty-six children (30 girls and 26 boys) with ages ranging from 6 to 8 years. Each subject performed two evaluation sessions (T1, T2) with seven days between tests. The results show that the CMJ test has a high intratrial reproducibility in T1 and T2 measured through intraclass correlation coefficient (ICC ≥ 0.95). The ICC for the SJ test had a high value (0.99) only in T1. The variability for both tests among children under 9 years of age is higher than those reported for adult subjects in other studies. The intersession reliability was questionable with a high methodical error (ME= 9.86-15.1%, for the SJ and CMJ, respectively) and a significant worsening of the results of CMJ in T2 (p < .05).

Could the deep squat jump predict weightlifting performance?

This research was carried out with the aim of describing the deep squat jump (DSJ) and comparing it with the squat (SJ) and countermovement (CMJ) jumps, to introduce it as a strength testing tool in the monitoring and control of training in strength and power sports. Forty-eight male subjects (21 weightlifters, 12 triathletes, and 15 physical education students) performed 3 trials of DSJ, SJ, and CMJ with a 1-minute rest among them. For the weightlifters, snatch and clean and jerk results during the Spanish Championship 2004 and the 35th EU Championships 2007 were collected to study the relationship among vertical jumps and weightlifters' performance. A 1-way analysis of variance (ANOVA) showed significant differences between groups in the vertical jumps, with the highest jumps for the weightlifters and the lowest for the triathletes. An ANOVA for repeated measures (type of jump) showed better results for DSJ and CMJ than SJ in all groups. A linear regression analysis was performed to determine the association between weightlifting and vertical jump performances. Correlations among the weightlifting performance and the vertical jumps were also calculated and determined using Pearson r. Results have shown that both CMJ and DSJ are strongly correlated with weightlifting ability. Therefore, both measures can be useful for coaches as a strength testing tool in the monitoring and control of training in weightlifting.

Chronic neural adaptation induced by long-term resistance training in humans.

While it is known that resistance training causes changes in the central nervous system (CNS) in the initial stages of training, there have been few studies of cumulative or sustained neural adaptation to resistance training beyond the initial periods. To further investigate this we compared the electromyographic (EMG) response to transcranial magnetic stimulation (TMS) during voluntary contractions of ten subjects who have been training for more than 2 years, resistance-training (RT) group, and ten subjects that have never participated in resistance training (NT). The active motor threshold for biceps brachii was obtained during voluntary elbow flexion at 10% of maximal voluntary contraction (MVC). TMS was also delivered at 100% of the maximal stimulator output while the participants exerted forces ranging from 10 to 90% of MVC. Evoked force, motor-evoked potential (MEP) amplitude and latency from biceps brachii was recorded for each condition to explore changes in corticospinal excitability. The evoked force was significantly lower in the RT group in comparison with the NT group between 30 and 70% of MVC intensity (P<0.05). At 90% of MVC, nine subjects from the RT group showed an absence in the evoked force while this occurred in only five subjects from the NT group. The MEP amplitude and latency changed significantly (P<0.001) with increasing levels of contraction, without significant difference between groups. These results indicate that changes in the CNS are sustained in the log-term practices of resistance training and permit a higher voluntary activation at several intensities of the MVC.