Reference power values for the jump squat exercise in elite athletes: A multicenter study

ABSTRACT

The present study aimed to provide reference values for lower-limb muscle power assessed during the incremental jump squat (JS) test in elite athletes (i.e., professional athletes competing at international level). We pooled data from all JS tests performed by elite athletes of different sports in two high-performance centres between 2015 and 2019, and computed reference values (i.e., terciles) for mean power (MP), mean propulsive power (MPP), and peak power (PP). Reference values were obtained from 684 elite athletes (458 male and 226 female) of 16 different sports (boxing, judo, karate, fencing, taekwondo, wrestling, basketball, soccer, futsal, handball, rugby union, badminton, tennis, long distance running, triathlon, and sprinting). Significant differences (p < 0.001) were found between male and female athletes for MP (7.47 ± 1.93 and 6.15 ± 1.68 W·Kg^?1, respectively), MPP (10.50 ± 2.75 and 8.63 ± 2.43 W·Kg^?1), and PP (23.64 ± 6.12 and 19.35 ± 5.49 W·Kg^?1). However, the velocity at which these power measures was attained seemed to be independent of sex (~0.95, 1.00 and 2.00 m·s^?1 for mean, mean propulsive, and peak velocity, respectively) and homogeneous across different sport disciplines (coefficient of variation <10%). These data can be used to classify athletes’ power capabilities, and the optimum velocity ranges provided here could be useful for training purposes.     

The role of practice in chess: A longitudinal study

We investigated the role of practice in the acquisition of chess expertise by submitting a questionnaire to 104 players of different skill levels. Players had to report their chess rating, the number of hours of individual and group practice, their use of different learning resources and activities, and whether they had been trained by a coach. The use of archival data enabled us to track the rating of some of the players throughout their career. We found that there was a strong correlation between chess skill and number of hours of practice. Moreover, group practice was a better predictor of high-level performance than individual practice. We also found that masters had a higher chess rating than expert players after only three years of serious dedication to chess, although there were no differences in the number of hours of practice. The difference that may explain the variation in rating is that masters start practising at an earlier age than experts. Finally, we found that activities such as reading books and using computer software (game databases, but not playing programs) were important for the development of high-level performance. Together with previous data and theories of expert performance, our results indicate limits in the deliberate practice framework and make suggestions on how best to carry out learning in chess and in other fields.     

Temperament, Emotion, and Cognition at Fourteen Months: The MacArthur Longitudinal Twin Study

200 pairs of twins were assessed at 14 months of age in the laboratory and home. Measures were obtained of temperament, emotion, and cognition/language. Comparisons between identical and fraternal twin correlations suggest that individual differences are due in part to heritable influences. For temperament, genetic influence was significant for behavioral observations of inhibition to the unfamiliar, tester ratings of activity, and parental ratings of temperament. For emotion, significant genetic influence was found for empathy and parental ratings of negative emotion. The estimate of heritability for parental report of expression of negative emotions was relatively high, whereas that for expression of positive emotions was low, a finding consistent with previous research. For cognition and language, genetic influence was significant for behavioral indices of spatial memory, categorization, and word comprehension. Shared rearing environment appears influential for parental reports of language and for positive emotions, but not for other measures of emotion or for temperament.     

Effects of an unsupervised pedometer-based physical activity program on daily steps of adults with moderate to severe asthma: a randomized controlled trial

Supervised exercise has shown benefits for subjects with asthma, but little is known about the effectiveness of unsupervised physical activity on this population. We investigated the effects of a 12-week unsupervised pedometer-based physical activity program on daily steps and on clinical and psychological parameters of adults with asthma. Clinically stable adults with moderate to severe asthma were encouraged to take daily 30-minute walks and were randomized to pedometer and control groups. The pedometer group received pedometers and individualized daily step targets. Changes in daily steps (average of steps taken during six consecutive days), six-minute walk test (6MWT), health-related quality of life, asthma control and anxiety and depression levels were assessed 12 weeks after intervention and 24–28 weeks after randomization. Thirty-seven participants were recruited and 30 completed the intervention. At 12 weeks, the groups differed significantly in daily steps (adjusted average difference, 2488 steps; 95% confidence interval [CI], 803 to 4172; p = 0.005) and in the 6MWT (adjusted average difference, 21.9 m; 95% CI, 6.6 to 37.3; p = 0.006). These differences were not significant 24–28 weeks after randomization. The program was effective in increasing daily steps of adults with moderate to severe asthma 12 weeks after intervention.     

Multiplicative Measurements of a Trait Anxiety Scale as Predictors of Burnout

The purpose of the present study was to investigate whether combining the two dimensions of anxiety (i.e., intensity and direction) by using a multiplicative model would strengthen the prediction of burnout. Collegiate athletes (N = 157) completed the Athlete Burnout Questionnaire as well as a trait version of the Competitive State Anxiety Inventory-2D. Three separate hierarchical regression analyses with four blocks were conducted to predict each one of the burnout subscales from anxiety intensity and direction while controlling for gender. The multiplicative variable for cognitive anxiety was a significant predictor of reduced sense of accomplishment (p < .01). Self-confidence was the only directional scale that predicted reduced sense of accomplishment, emotional/physical exhaustion, and devaluation (p < .01). In addition, gender was found to predict overall burnout in all three subscales as a control variable (p < .05). Conclusions and applied implications are drawn based on the results.     

New directions in the study of early experience

In this commentary, we review Greenough, Black, and Wallace's conceptual framework for understanding the effects of early experience, and illustrate the applicability of their model with recent data on the consequences for animals and human infants of the acquisition of self-produced locomotion.     

Incompatibility between pregnancy and educational projects,from the perspective of socially vulnerable adolescent women and men in Mexico

Research focused on adolescent pregnancy reports that this event acquires significance and has different consequences according to the context and social subjects who experience it. In this study, by means of a sample formed by adolescent women and men who are socially vulnerable in Mexico, with and without a history of pregnancy, we can see how this reproductive event turns into a factor of educational vulnerability and how their possibilities and expectations with respect to continuing in school are determined in a differentiated manner, according to gender. The findings show that adolescent pregnancy in vulnerable sectors is scarcely compatible with educational projects and that possibilities and expectations to continue in or re-enter the school system are determined by gender differences; these usually lead to fewer opportunities for adolescent women to return to school during or after pregnancy.