203 research outputs found

    Relationship between physical capacity and match performance in semiprofessional Australian rules football

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    This study investigated the relationship between physical performance and match performance in Australian Rules Football (ARF). Thirty-six semiprofessional ARF players participated in this study. Physical capacity was measured using a 3-km time trial. Match performance was measured throughout the 2013 season through 2 methods: direct game involvements (DGIs) per minute and a recording of coaches\u27 vote after the game. The main finding of the study was that 3-km time trial performance was a significant predictor of DGI per minute (p ≤ 0.05). In addition, the number of senior games played was also significant in predicting DGI per minute (p ≤ 0.05). Furthermore, the number of senior games significantly correlated with coaches\u27 votes (p ≤ 0.05). There were no significant relationships between 3-km time trial and coaches\u27 vote. The results highlight the importance of developing physical capacity in the preseason period; the players who were better performers in the 3-km time trial had a greater number of DGIs per minute. This information is important to consider in preseason planning to ensure sufficient time is dedicated to developing physical capacity in the training program, as it is directly associated with performance. In addition, this research also highlights the importance of playing experience in relation to team selection. Playing experience, as measured by the number of senior games played, had a significant relationship with both measures of match performance

    The relationship between isometric and dynamic strength in college football players

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    Previous research has demonstrated the importance of both dynamic and isometric maximal strength and rate of force development (RFD) in athletic populations. The purpose of this study was to examine the relationships between measures of isometric force (PF), RFD, jump performance and strength in collegiate football athletes. The subjects in this study were twenty-two men [(mean ± SD):age 18.4 ± 0.7 years; height 1.88 ± 0.07 m; mass 107.6 ± 22.9 kg] who were Division I college football players. They were tested for PF using the isometric mid thigh pull exercise. Explosive strength was measured as RFD from the isometric force-time curve. The one repetition maximum (1RM) for the squat, bench press and power clean exercises were determined as measures of dynamic strength. The two repetition maximum (2RM) for the split jerk was also determined. Vertical jump height and broad jump was measured to provide an indication of explosive muscular power. There were strong to very strong correlations between measures of PF and 1RM (r = 0. 61 - 0.72, p \u3c 0.05). The correlations were very strong between the power clean 1RM and squat 1RM (r = 0.90, p \u3c 0.05). There were very strong correlations between 2RM split jerk and clean 1RM (r = 0.71, p \u3c 0.05), squat 1RM (r = 0.71, p \u3c 0.05), bench 1RM (r = 0.70, p \u3c 0.05) and PF (r = 0.72, p \u3c 0.05). There were no significant correlations with RFD. The isometric mid thigh pull test does correlate well with 1RM testing in college football players. RFD does not appear to correlate as well with other measures. The isometric mid thigh pull provides an efficient method for assessing isometric strength in athletes. This measure also provides a strong indication of dynamic performance in this population

    Evidence for a non-genomic action of testosterone in skeletal muscle which may improve athletic performance: Implications for the female athlete

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    This review will focus on the proposed second mode of testosterone action (now termed non-genomic) that appears to occur independently of the traditional transcriptional mechanism in mammalian skeletal muscle cells which may enhance skeletal muscle contractile properties. This mechanism of testosterone action differs from the traditional pathway, originating at the cell membrane, having a rapid onset of action, requiring second messengers to execute its effects and is insensitive to inhibitors of traditional androgen receptor action, transcription and protein synthesis. Importantly, unlike the traditional action of testosterone in skeletal muscle, this non-genomic pathway is shown to have a direct acute effect on calcium-dependent components important for the contractile process. The changes within the contractile apparatus may enhance the ability of the muscle to produce explosive power during athletic performance. Rapid increases in Inositol triphosphate mass and calcium release from the sarcoplasmic reticulum have been reported in rodent skeletal muscle cells, and a rapid androgen (dihydrotestosterone)- induced increase in peak force production has been recorded in intact rodent skeletal muscle fibre bundles while showing increases in the activity of the Ras/MAP/ERK mediated pathway. Because the non-genomic action of testosterone is enhanced during increases in exposure to testosterone and is acute in its action, implications for athletic performance are likely greater in females than males due to natural fluctuations in circulating testosterone levels during the female menstrual cycle, reproductive pathology, and changes induced by hormonal contraceptive methods. Research should be undertaken in humans to confirm a pathway for non-genomic testosterone action in human skeletal muscle. Specifically, relationships between testosterone fluctuations and physiological changes within skeletal muscle cells and whole muscle exercise performance need to be examined

    Modeling the repetitions-in-reserve-velocity relationship:a valid method for resistance training monitoring and prescription, and fatigue management

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    Establishing a relationship between repetitions left in reserve and the mean absolute velocity (RIR-velocity relationship) during resistance training (RT) could allow for objective monitoring, prescription, and real-time adjustment of the training load and set-volume. Therefore, we examined the goodness of fit and prediction accuracy of general and individual RIR-velocity relationships in the free-weight back squat exercise. The effects of sex, training status and history, as well as personality traits, on the goodness of fit and the accuracy of these relationships were also investigated. Forty-six resistance-trained people (15 females and 31 males) performed a one-repetition maximum (1RM) test, and two repetitions to failure (RTF) tests 72 h apart. We found greater goodness of fit of individual RIR-velocity relationships compared to general RIR-velocity relationships. Individual, but not general RIR-velocity relationships established in the first testing session yielded acceptable prediction accuracy of RIR (mean error <2 repetitions) in the subsequent testing session, regardless of the load used. Similar results were obtained when both general and individual RIR-velocity relationships were averaged across the loads, suggesting that a single RIR-velocity relationship covering a range of loads can be used instead of traditional RT methods, potentially allowing for better fatigue management and more efficient adaptation

    Factors influencing overweight children\u27s commencement of and continuation in a resistance training program

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    Background: In light of the child overweight and obesity problem in Australia, resistance training programs have been trialled as an innovative way of assisting children increase lean body mass and reduce body fat. The purpose of this study was to investigate the factors influencing overweight children\u27s participation in a resistance training trial program. Method: Parent-child pairs who participated in the trial program were invited to take part in a follow-up individual interview to discuss their program experiences. In total, 22 semi-structured interviews were conducted with 11 parent-child pairs. Results: The factors found to be most relevant to program commencement among parents were a desire for their child to lose weight and gain confidence, the proximity of the venue, and no cost for participation. For children, the most relevant factors were the opportunity to build strength and improve fitness and having supportive parents who facilitated program initiation. The factors most relevant to continuation for parents were the quality of the program management, being able to stay for the sessions, the child\u27s improved weight status, coordination, and confidence, and no cost for participation. Weight loss and improved confidence were also motivators for continuation among the children, along with pleasant social interaction with peers and trainers and ongoing parental support. Conclusion: Different factors variably influence program commencement and program continuation in both parents and children. This has important implications for future interventions that aim to successfully recruit and retain intervention participants

    A review of cricket fielding requirements

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    Cricket is played in three formats at elite level: Test, One Day and Twenty20. Fielding is an important component of cricket, as all players are obliged to field. However, there is a paucity of literature on fielding compared with that on batting and bowling. We review the available literature in terms of technical, mental, physiological and physical factors important to fielding, to identify knowledge gaps and better understand the performance requirements of fielding in cricket

    Velocity loss is a flawed method for monitoring and prescribing resistance training volume with a free-weight back squat exercise

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    Purpose: The aim of this study was to examine the goodness of fit, prediction accuracy, and stability of general and individual relationships between velocity loss and the percentage of completed repetitions out of maximum possible (VL-%repetitions) in the free-weight back squat exercise. The effects of sex, training status and history, as well as personality traits, on the goodness of fit and the accuracy of these relationships were also investigated. Methods: Forty-six resistance-trained people (15 females and 31 males) performed a one-repetition maximum (1RM) test, and two repetitions to failure (RTF) tests, 72 h apart. RTF tests were performed with 70, 80, and 90% of 1RM with 10 min inter-set rest. Results: The findings question the utility of using general and individual VL-%repetitions relationships to prescribe training volume with free-weight back squats as (1) the agreement in the %repetitions completed until reaching a given velocity loss threshold across two consecutive testing sessions was unacceptable, regardless of the load used; and (2) the ability of general and individual VL-%repetitions relationships to predict %repetitions in a subsequent testing session were poor (absolute errors > 10%). Sex, training status and history, and personality traits did not affect the goodness of fit of general and individual VL-%repetitions relationships or their prediction accuracy, suggesting potential generalisability of those findings among resistance-trained populations. Conclusions: VL-%repetitions relationships do not seem to provide any additional benefits compared to costless, traditional methods and hence should not be used for monitoring and prescribing resistance training with a free-weight back squat exercise

    The influence of different length between match microcycles on neuromuscular, hormonal and perceptual responses in professional rugby league players

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    Optimal recovery between matches is critically important in team sports. Indeed, altered neuromuscular performance, hormone levels and increased fatigue can manifest in under recovered team sport athletes. However, the recovery patterns in these variables in the days following professional rugby league matches is unknown. The purpose of this study was to examine the influence of different between-match training periods on neuromuscular, hormonal and perceptual measures in professional rugby league players. Following familiarization, 12 professional rugby league players from the same team were assessed for changes in countermovement jump (CMJ) (force, power, flight time), perceptual responses (fatigue, well being and muscle soreness) and salivary hormone (testosterone (T) and cortisol (C)) levels during 5, 7 and 9 day periods between matches. Measures were taken 4h prior to the initial match, and then 1, 2, 4, 6*, 7*, 8* and 9* days following (*depending on group). All training was prescribed by the coaches and monitored using the session-RPE method. Lower daily training load was completed on the 5-day compared with the 7 and 9-day conditions (p\u3c0.05). Some CMJ variables (flight time and flight time:contraction time), perception of fatigue, well-being and muscle soreness were reduced in the 2 days following the match in each condition (p\u3c0.05). All CMJ variables returned to near baseline values following 4 days in each condition. Both CMJ maximum and relative power were lower in the 7 day condition when compared with the 9 day condition (p\u3c0.05). Fatigue levels were reduced at 48 h in the 7 and 9-day groups (p\u3c0.05) but had returned to baseline in the 5-day group. All perceptual measures returned to baseline levels prior to the following match in each condition and followed changes in training load. Salivary T and C did not change in response to the match. These results show that neuromuscular performance and perception of fatigue are reduced for at least 48 h following a rugby league match but these can be fully recovered within 4 days. CMJ variables involving flight time appear to be best for assessing acute fatigue caused by a match, and variables involving power may be useful in assessing accumulated fatigue. The perceptual measures were sensitive to both acute fatigue and accumulated fatigue. The salivary hormone analyses were of limited value for assessing recovery. These findings show that with correct training, it is possible to recover neuromuscular, perceptual and endocrine measures within 4 days after a rugby league match

    Selective influences of maximum dynamic strength and bar-power output on team sports performance: a comprehensive study of four different disciplines

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    This study examined the selective influences of one-repetition maximum (1RM) values [assessed in the half-squat (HS)] and bar-power production [assessed in both HS and jump squat (JS) exercises] on the physical performance of male and female team sport athletes from four different sports. Three-hundred and three elite players (31 Olympians) from four different disciplines (47 male soccer players, 58 female soccer players, 28 male handball players, 58 female handball players, 49 male rugby players, and 63 male futsal players) participated in this study. The physical tests were performed over 2 consecutive days for soccer and rugby players, and in 1 day for the remaining athletes. On the first day, rugby and soccer athletes performed squat jumps (SJ), countermovement jumps (CMJ), and HS 1RM. On the second day, they executed HS and JS tests (to assess the maximum bar-power output) and the linear and change-of-direction (COD) speed tests. For the other players, the sequence of the measurements was the same; however, they did not perform the HS exercise. Athletes were separated, using a median split analysis, into two distinct groups, according to their bar-power output in both JS and HS exercises and their performance in HS 1RM. The magnitude-based inferences method was used to examine the differences between “higher” and “lower” performance groups. Overall, the bar-power outputs were better connected to improved acceleration, speed, and jump performance than the 1RM measures. From these findings, it is possible to infer that players able to produce higher bar-power outputs are likely to sprint faster and jump higher. Therefore, coaches involved in team sports are strongly encouraged to use the bar-power method to evaluate the athletic performance of their players

    Factors influencing overweight children's commencement of and continuation in a resistance training program

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    Background: In light of the child overweight and obesity problem in Australia, resistance training programs have been trialled as an innovative way of assisting children increase lean body mass and reduce body fat. The purpose of this study was to investigate the factors influencing overweight children's participation in a resistance training trial program. Method. Parent-child pairs who participated in the trial program were invited to take part in a follow-up individual interview to discuss their program experiences. In total, 22 semi-structured interviews were conducted with 11 parent-child pairs. Results. The factors found to be most relevant to program commencement among parents were a desire for their child to lose weight and gain confidence, the proximity of the venue, and no cost for participation. For children, the most relevant factors were the opportunity to build strength and improve fitness and having supportive parents who facilitated program initiation. The factors most relevant to continuation for parents were the quality of the program management, being able to stay for the sessions, the child's improved weight status, coordination, and confidence, and no cost for participation. Weight loss and improved confidence were also motivators for continuation among the children, along with pleasant social interaction with peers and trainers and ongoing parental support. Conclusion. Different factors variably influence program commencement and program continuation in both parents and children. This has important implications for future interventions that aim to successfully recruit and retain intervention participants.This study was funded by the Telstra Foundatio
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