This study aimed to investigate why futsal players decide to dribble. For this purpose, we analysed 396 trials comprising the dribbles (n = 132), passes (n = 131) or shots (n = 133), performed by 70 male futsal players. Passing and shooting angles, and interpersonal distance, including their rates of change (velocity and variability), were regarded as measures of interpersonal coordination tendency and a comparison was made among dribbling, passing and shooting situations. In addition, the variables identified as constraints on deciding to dribble were analysed in relation to age categories, dribbling outcomes and futsal court zone. Results revealed that passing and shooting angles, and interpersonal distance showed higher variability in dribbling than in passing and shooting situations. The findings allowed us to conclude that decision-making on dribbling was influenced by the variabilities of passing angles as well as shooting and interpersonal distance, and that success in dribbling was affected by the variability of interpersonal distance. Such variabilities were interpreted concerning their meaning of risk and/or uncertainty in the execution of motor skills.

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Considering the critical role permanence has on predictions related to the contextual interference effect, this study sought to determine whether the manifestation of the effect depends on the time interval separating the acquisition phase (AQ) from the retention test (RT). Four groups of blocked (BL) and four groups of random practice (RD) performed 90 trials of a dart throwing task (AQ) and were tested exclusively after 10 minutes (BL10 and RD10), 24 hours (BL24 and RD24), 7 days (BL7 and RD7) or 30 days (BL30 and RD30). In the AQ, blocked groups performed three blocks of trials, with each block consisting of throwing the darts from one of three distances (2 m, 2.6 m and 3.2 m). For the random groups, the trial order was pseudo-randomized. The results indicated superior performance of RD24, compared to BL24, but no difference was found between the groups tested after 10 minutes, 7 days or 30 days. Thus, our results do not support the notion that higher contextual interference promotes immediate learning benefits nor long-term retention of internal representations. Nevertheless, future research should further investigate the processes underlying the contextual interference effect, since short-term gains (24 h) were found.

No abstract

This paper offers theoretical, empirical, and simulated evidence that momentum regularities in asset prices are not anomalies. Within a general, frictionless, rational expectations, risk-based asset pricing framework, riskier assets tend to be in the loser portfolios after (large) increases in the price of risk. Hence, the risk of momentum portfolios usually decreases with the prevailing price of risk, and their risk premiums are approximately negative quadratic functions of the price of risk (and the market premium) theoretically truncated at zero. The best linear (CAPM) function describing this relation unconditionally has exactly the negative slope and positive intercept documented empirically.