Evening electronic device use and sleep patterns in athletes

The present study aimed to investigate pre-sleep behaviours (including evening electronic device use) and sleep quantity in well-trained athletes. Seventy well-trained athletes (44 females, 26 males) aged 21 ± 4 y from a range of team and individual sports were asked to complete an online sleep diary for 7 days. The sleep diary included questions about pre-sleep behaviours (e.g. napping, caffeine intake), electronic device use in the 2 h prior to bedtime (e.g. type of device and duration of use) and sleep (e.g. time in bed, sleep onset latency). On average, athletes spent 8:20 ± 1:21 h in bed each night. Associations between age, time in bed and sleepiness suggested that younger athletes spent more time in bed (B = -0.05, p = 0.001) but felt sleepier (r = -0.32, p < 0.01) than older athletes. On average, athletes mostly used electronic devices for 0–30 min prior to sleep. The use of multiple devices in the evening was associated with more perceived difficulty in falling asleep (B = 0.22, p = 0.03), but no associations existed with other sleep variables. In summary, younger athletes may require later start times or improved sleep quality to resolve excessive sleepiness.     

Extended Validation of the Korean Version of the Quality of Life Survey

In this study, we examined the factor structure and reliability of the Korean Quality of Life (KQoL) survey and compared the KQoL survey to both the World Health Organization Quality of Life-Brief Version (WHOQOL-BREF) and the Satisfaction with Life Scale (SWLS). We also assessed associations between KQoL scores and physical activity (PA) participation. Participants were 557 (male = 281, female = 276) healthy Korean adults with ages between 18 and 71 years (M = 33.2, SD = 14.2). Results of confirmatory factor analyses confirmed the 7-subscale model and indicated acceptable values supporting convergent validity (χ² = 1,678.758, df = 443, p < .001, RMSR = .045, RMSEA = .071, TLI = .880, CFI = .892). Correlations of KQoL subscales with similar subscales of WHOQOL-BREF and with SWLS supported concurrent validity. Results confirm that the KQoL survey can assess multidimensional aspects of quality of life (QoL), including spiritual, physical, social, and psychological. KQoL scores were positively related to PA participation, in line with previous research supporting the positive association of PA with QoL.     

Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.     

Reliability and validity of field-based fitness tests in youth soccer players

This study aimed to establish between-day reliability and validity of commonly used field-based fitness tests in youth soccer players of varied age and playing standards, and to discriminate between players without (“unidentified”) or with (“identified”) a direct route to professional football through their existing club pathway. Three-hundred-and-seventy-three Scottish youth soccer players (U11–U17) from three different playing standards (amateur, development, performance) completed a battery of commonly used generic field-based fitness tests (grip dynamometry, standing broad jump, countermovement vertical jump, 505 (505COD) and T-Drill (T-Test) change of direction and 10/20 m sprint tests) on two separate occasions within 7–14?days. The majority of field-based fitness tests selected within this study proved to be reliable measures of physical performance (ICC?=?0.83–0.97; p?p?2 (7)?=?101.646, p?相似文献   

Corticospinal changes induced by fatiguing eccentric versus concentric exercise

The present study assessed neuromuscular and corticospinal changes during and after a fatiguing submaximal exercise of the knee extensors in different modes of muscle contraction. Twelve subjects performed two knee extensors exercises in a concentric or eccentric mode, at the same torque and with a similar total impulse. Exercises consisted of 10 sets of 10 repetitions at an intensity of 80% of the maximal voluntary isometric contraction torque (MVIC). MVIC, maximal voluntary activation level (VAL) and responses of electrically evoked contractions of the knee extensors were assessed before and after exercise. Motor evoked potential amplitude (MEP) and cortical silent period (CSP) of the vastus medialis (VM) and rectus femoris (RF) muscles were assessed before, during and after exercise. Similar reductions of the MVIC (?13%), VAL (?12%) and a decrease in the peak twitch (?12%) were observed after both exercises. For both VM and RF muscles, MEP amplitude remained unchanged during either concentric or eccentric exercises. No change of the MEP amplitude input–output curves was observed post-exercise. For the RF muscle, CSP increased during the concentric exercise and remained lengthened after this exercise. For the VM muscle, CSP was reduced after the eccentric exercise only. For a similar amount of total impulse, concentric and eccentric knee extensor contractions led to similar exercise-induced neuromuscular response changes. For the two muscles investigated, no modulation of corticospinal excitability was observed during or after either concentric or eccentric exercises. However, intracortical inhibition showed significant modulations during and after exercise.     

An examination of achievement-related behavior of high- and low-achieving inner-city pupils

Incorporating the academic engaged time model, the present study investigated behavioral differences between high- and low-achieving inner-city children. Two hundred observations of “on-task”-“off task” behavior of 136 children within the elementary grades (1 through 6) were noted during reading and mathematics lessons. Findings suggested that high- and low-achieving inner-city children spend a large proportion of time actively engaged in academic tasks, with high achievers spending somewhat more time than low achievers. No significant developmental trends were noted, and discrepant academic attainment levels of children are discussed in terms of an “academic learning time” model.     

Kindergarten reasoning and achievement in grades K-3

Performance of kindergarten children on reasoning (Piaget tasks of logical thinking), visual-motor integration, and verbal development was related to achievement scores in kindergarten, second grade, and third grade. Subjects were 52 children in the kindergarten classes of a middle-class, suburban/rural school. Reasoning and visual-motor integration were related to achievement on the Metropolitan Achievement Test at the end of kindergarten. For the 43 children remaining in second grade, there was a relationship between reasoning in kindergarten and achievement on the Reading and Math Concepts sections of the Iowa Test of Basic Skills. For the 38 children remaining in third grade, kindergarten reasoning was related to total and Vocabulary scores of the California Achievement Test. Kindergarten visual-motor integration and verbal development were not related to achievement test performance at the end of the second and third grade for these subjects. Early intervention programs that encourage the development of thinking and match the child's reasoning to his academic tasks may stimulate both reasoning and achievement.     

Interscorer reliability of the Minnesota Percepto-Diagnostic Test-Revised

This study investigated the interscorer reliability between a novice and a professional psychologist for the Minnesota Percepto-Diagnostic Test-Revised (MPDT-R). The sample consisted of 30 individuals (18 males and 12 females) who were referred to the Applied Neuroscience Institute of the University of Maryland Eastern Shore. Results from the study indicated that for three of the four MPDT-R scores there was a significant positive correlation between expert and novice scoring criteria. Implications for the assessment of perceptual-motor problems using the MPDT-R are discussed.