320 research outputs found
Binge Drinking: Subtypes and Associations in Young Adults
Binge drinking has been common practice and a rite of passage for many young adults in the college population. The practice of binge drinking has continued even as binging is associated with several cognitive deficits. One unanswered question still remains: namely, at what levels of binge drinking do these cognitive deficits associate? To investigate this question, three different groups of binge drinkers (low, moderate, and heavy) were compared on two measures of cognition: intelligence (IQ) and executive working memory (EWM) capacity. The binge groups were also compared to non-bingers and abstainers to further investigate how they differed in EWM capacity and IQ. Lastly, correlations were made between binge density and the cognitive measures. Based on the previous literature, the following hypotheses were made: (1) low, moderate, and heavy binge clusters would emerge from the cluster analyses, (2) the heavy and moderate cluster would exhibit decreased performance in the two cognitive domains in comparison to the low cluster, (3) the binge density measure would be negatively correlated with the cognitive measures, and (4) the low, moderate, and heavy clusters would exhibit lower EWM capacity and IQ scores in comparison with non-bingers and abstainers. Some of the obtained data support that different binge subtypes are indeed differentially associated with both EWM capacity and IQ in young adults who binge. However, the mixed findings illustrate that additional longitudinal research is merited
Effects of combined strength and power training on physical performance and interlimb asymmetries in adolescent female soccer players
Purpose: This study examined the effects of an 8-week combined strength and power training (CSPT) intervention on physical performance and inter-limb asymmetries in adolescent female soccer players.
Methods: Thirty-seven adolescent female soccer players (age: 16.1±1.1 yrs) were randomly assigned to a control (CG, n = 18) and experimental group (EG, n = 19). EG performed CSPT twice a week, which consisted of strength and power exercises that trained the major muscles of the lower body and trunk musculature. Pre- and post-intervention tests included unilateral and bilateral horizontal and countermovement jump tests, a 40-m sprint test (10 and 30-m split times), a 10-m sprint with a 180º change of direction (COD) test and a multiple COD test (V-cut test). Asymmetries were also analyzed in the unilateral tests.
Results: Significant group by time interaction of the improvement between pre and post-tests were observed for speed (Effect size (ES): -1.30 to -1.16) and COD tests (ES: -0.62 to -0.61) but not in jumping (ES: -0.09 to 0.28) and inter-limb asymmetries tests (ES: -0.13 to 0.57). Conclusions: The short-term in-season CSPT program induced greater speed and COD performance improvements compared to soccer training alone in adolescent female soccer players
Enhancing high-intensity actions during a basketball game after a strength training program with random recovery times between sets
To examine the effects of a strength training program with random recovery times between sets in consideration of several physical parameters, high-intensity actions (HIA), and spatial exploration index during a simulated basketball game. Twenty male basketball players (age: 19.45 ± 4.36 years) were assigned randomly, either to strength training group (n = 10), or a control group (n = 10). The strength training included: parallel back squat and bench press exercises, twice a week for the duration of 10 weeks, with two blocks of 5 sets × 5 repetitions interspersed with variable passive recovery (range = 15–35 sec.) between sets, and constant passive recovery (3-min) between blocks with the load that maximized propulsive power output. The pre- and post-test assessments included jumping (bilateral and unilateral), change-of-direction, straight sprinting, and a 5-on-5 full-court situation. The external training load was assessed using the local positioning system, and the internal load was recorded with the use of individual heart rate monitors. A significant interaction effect (group x time) was observed on countermovement jump (CMJ), unilateral right hops, high-intensity accelerations and decelerations, and peak accelerations and decelerations in the 5-on-5 full-court situation. Relative improvements observed and recorded in the training group on unilateral right hops, accelerations, and decelerations were correlated. Similar results were observed on 0–25m sprints, high-intensity decelerations, peak accelerations, and decelerations. Strength training paired with random recovery times enhanced physical and game-related aspects in the observed basketball players
Rotational flywheel training in youth female team sport athletes: could inter-repetition movement variability be beneficial?
Background: The aim of this study was to analyse the effects of an inter-repetition variable rotational flywheel training program (Variable) over standard rotational flywheel training (Standard).
Methods: Twenty-four youth female team-sports players were randomly assigned to both training groups (Variable, n = 12; Standard, n = 12), which consisted of 1 set of 3 rotational flywheel exercises x 10-12 repetitions, biweekly for a period of 6-weeks. The participants included in Variable group were instructed to perform the movement randomly in one of the three directions (0º, 45º right, and 45º left). Measurements included reactive strength, jumping, change of direction, and sprinting tests; patellar tendon condition was also assessed.
Results: Substantial improvements were found in vertical jump with left leg (16.9%), lateral jump with right leg (13.6%), and patellar condition in left leg (4.1%) for Standard group, but also in reactive strength index in right leg landing (33.9%), vertical jump with right (10.1%) and left leg (12.0%) for Variable group. A significant interaction effect (group x time) was observed on patellar condition in right leg (F = 10.02, p < 0.01, η 2 = 0.37), favoring Variable group.
Conclusions: Rotational flywheel training programs were beneficial for youth-female team-sports athletes, although the movement variability may play a key role to develop different and specific physical adaptations
A comparison of 3 different unilateral strength training strategies to enhance jumping performance and decrease interlimb asymmetries in soccer players
Purpose: This study compared the effects of performing different unilateral strength training interventions on unilateral and bilateral jumping performance and their related asymmetries in young soccer players.
Methods: Forty-five male young (U-17) soccer players were randomly assigned to three eccentric overload training programs: The first group executed the same volume with both legs starting with the weaker leg (SVW, n=15), the second group carried out the double volume with the weaker leg and also starting with the weaker leg (DVW, n=15), and the third group performed the same volume with both legs starting with the stronger leg (SVS, n=15). Jumping performance assessment included a single-leg horizontal jump test, a triple single-leg horizontal jump test, a bilateral countermovement (CMJ) jump test and unilateral countermovement jump test. Asymmetries were also analyzed in the unilateral jumping tests.
Results: CMJ was improved (effect size [ES]: 0.27-0.48) and CMJ asymmetry was possibly reduced (ES: 0.08-0.24) in all groups. Substantial improvements were found in triple hop (ES: 0.52-0.71) in SVW and DVW, and triple hop asymmetry was substantially decreased (ES: 0.88) in DVW. Between-group analysis showed a substantial better performance in triple hop and horizontal hop with right leg in SVW and DVW compared to SVS.
Conclusions: Unilateral strength training programs were shown to substantially improve bilateral jumping performance, while unilateral jumping was substantially enhanced in those groups that started the training session with the weaker leg. Finally, between-limbs asymmetries in the triple hop were mainly reduced through performing the double volume with the weaker leg
Determining the reliability and usability of change of direction speed tests in adolescent female soccer players: a systematic review
INTRODUCTION: This review aimed 1) to describe the most common tests used for assessing change of direction (COD) performance; 2) to detail the reliability of current COD tests; 3) to provide an overview of current intervention strategies used to improve COD performance in adolescent female soccer players.
EVIDENCE ACQUISITION: A computerized search was conducted in the PubMed, Cochrane Plus and Web of Science (from 1995 to January 2020) for English and Spanish language and peer-reviewed investigations.
EVIDENCE SYNTHESIS: A total of 221 studies were identified, with only 16 meeting the specific search criteria. The main findings were that eleven different tests have been used to assess COD performance with intraclass correlation coefficient and coefficient of variation values between 0.72-0.99 and 1-10.6%, respectively. The number of CODs performed during each test ranged from 1 to 9 within a range of 45º to 180º and with a duration 10 s.
CONCLUSIONS: Findings indicate that the reliability of the COD tests seems to depend on: the equipment used, the surface tested on and the technical level of the soccer player. These results should be interpreted with caution as they may be influenced by the period of growth and maturation, the playing position of the player and the period of the soccer season. Finally, strength and power drills could be considered as appropriate to improve COD performance
Acute effect of repeated sprints on inter-limb asymmetries during unilateral jumping
The aim of the present study was to investigate the effects of multiple repeated sprints on unilateral jump performance and inter-limb asymmetries. Eighteen recreationally active males performed three single leg countermovement jumps (SLCMJ) as baseline data. The repeated sprint protocol was 6 x 40 m with 20 seconds of passive rest between each sprint. This protocol was conducted four times, each set separated by four minutes of rest. Within that rest period, subjects performed one SLCMJ on each limb after two minutes of rest. A one-way ANOVA showed significant reductions (p < 0.05; ES = -0.52 to -0.99) in jump height on both limbs after each set relative to baseline. Inter-limb asymmetries increased at each time point and ranged from 7.62-14.67%, with significant increases in asymmetry seen after sets three (p = 0.046) and four (p = 0.002). Significant increases in sprint time were shown between sprints one and six in each set (p ≤ 0.01). A fatigue index (%) was also calculated and showed an exponential increase from 5.74% (set one) to 13.50% (set four), with significant differences between all sets (p < 0.001) with the exception of sets three and four. Results from this study show that a 6 x 40 m repeated sprint protocol is a sufficient dose for implementing acute fatigue in recreationally active subjects. This was manifested by reductions in jump height at all time points and jump height asymmetries after the third and fourth sets. These findings indicate that jump height from unilateral jump testing may be a useful metric to use during the monitoring process in recreationally trained athletes
Effects of direction-specific training interventions on physical performance and inter-limb asymmetries
This study analyzed the effects of two different training programs on functional performance and inter-limb asymmetries in basketball players. Twenty-four elite youth basketball players were randomly assigned to a training program including variable unilateral horizontal movements (VUH, n = 12) or unilateral lateral movements (VUL, n = 12). Eccentric-overload training (EOT) was performed twice a week for a six-week period. Functional performance assessment included a countermovement jump test, unilateral multidirectional jumping tests (i.e., lateral, horizontal, and vertical), a rebound jump test, a limb symmetry index, a 25 m linear sprint test, and several change of direction (COD) tests. Within-group analysis showed substantial improvements in almost all functional tests in both groups (ES = 0.35−0.89). Furthermore, almost all jumping asymmetries were improved in both groups (ES = 0.38−0.69) except for vertical jumping asymmetry in VUL (ES = −0.04). Between-group analyses showed a substantial and possibly better performance in vertical jumping asymmetry and 5 m in VUH compared to that of VUL, respectively. In contrast, lateral jumping with left (ES = 1.22) and right leg (ES = 0.49) were substantially greater in VUL than in VUH. Specific force-vector training programs induced substantial improvements in both functional performance tests and inter-limb asymmetries, although greater improvements of lateral and horizontal variables may depend on the specific force vector targeted
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Inter-limb asymmetries are associated with decrements in physical performance in youth elite team sports athletes
Actually, there is scarce literature looking for the relationship between inter-limb asymmetries and performance in youth elite team sports. The main purpose of this cross-sectional study was to examine the relationships between inter-limb asymmetries and physical performance in youth elite team-sports players. A secondary objective was to evaluate the presence of between-sexes differences in inter-limb asymmetries in elite youth team sports players. Eighty-one young elite team-sports athletes (age: u-14 to u-18) performed the star excursion balance test in the anterior direction (SEBT ANT), a single leg vertical countermovement jump test (SLCMJ), the one leg hop test for distance (OLHT), a 30 m sprint test, and the V-cut test. Inter-limb asymmetries were calculated for SEBT ANT, SLCMJ and OLHT. Pearson r was used to analyse the relationships between inter-limb asymmetries and physical performance. Results showed significant (p Ë‚ 0.05) but small (r = 0.26) relationships between SLCMJ asymmetries and 30 m sprint time for the total group. Significant negative correlations with small to moderate magnitude of correlation were also found between SLCMJ asymmetries and SLCMJ performance on the lowest performing limb for the total group (p < 0.05; r = -0.26), males (p < 0.01; r = -0.48) and females (p < 0.05; r = -0.30). Moreover, significant negative correlations with moderate and large magnitude were also present between OLHT asymmetries and OLHT performance on the lowest performing limb for the total group (p < 0.01; r = -0.44), males (p < 0.01; r = -0.56) and females (p < 0.01; r = -0.64). No correlations were observed between asymmetries and either the V-cut test or SEBT ANT performance. No correlation were observed between SEBT ANT asymmetries and physical performance. In addition, when comparing asymmetry values between sexes there were no significant differences in vertical (p = 0.06) and horizontal (p = 0.61) jumping tests. However, there were significant differences in asymmetry between sexes in the ANT SEBT (p = 0.04). In conclusion, the current study indicated that jumping asymmetries were associated with decrements in sprint speed and jumping performance. Therefore, assessing inter-limb asymmetries would be recommended to improve training interventions for youth elite team-sports athletes
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