Influence of Laboratory Index on match performance. A comparison study to evaluate physical performance in professional soccer players of an Italian Elite Team.

OBJECTIVE: It was hypothesized that activity exercise at professional levels could lead to an increase in metabolic levels and a decrease in performance parameters. These trends are explained by physical activity as a cellular stressor. SUBJECTS AND METHODS: We used an algorithm, Laboratory Index which evaluates salivary cortisol, CK and d-ROMs, collected previously from elite Italian soccer players, compared to InStat Index. The last one estimates analytically the athlete's performance in soccer pitch, applying the Heath Maps. RESULTS: A good agreement between the two Index was obtained, especially for two players, who showed an ideal combined trend. CONCLUSIONS: We would investigate the clinical and activity profile of soccer players with the aim of providing information for the development of training strategies. Also, the performances, during training and match time, are an objective evaluation of the athlete's physical preparation. As a consequence, the combination of two Index could be used for a new approach to the sports world.

On the comparison of Feller and Ornstein-Uhlenbeck models for neural activity.

Diffusion processes have been extensively used to describe membrane potential behavior. In this approach the interspike interval has a theoretical counterpart in the first-passage-time of the diffusion model employed. Since the mathematical complexity of the first-passage-time problem increases with attempts to make the models more realistic it seems useful to compare the features of different models in order to highlight their relative performance. In this paper we compare the Feller and Ornstein-Uhlenbeck models under three different criteria derived from the level of information available about their parameters. We conclude that the Feller model is preferable when complete knowledge of the characterizing parameters is assumed. On the other hand, when only limited information about the parameters is available, such as the mean firing time and the histogram shape, no advantage arises from using this more complex model.