166 results on '"McGuigan, Michael R."'
Search Results
2. Implementing a velocity-based approach to resistance training: the reproducibility and sensitivity of different velocity monitoring technologies
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Jukic, Ivan, King, Andrew, Sousa, Colby A., Prnjak, Katarina, and McGuigan, Michael R.
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- 2023
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3. Modeling the repetitions‐in‐reserve‐velocity relationship: a valid method for resistance training monitoring and prescription, and fatigue management
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Jukic, Ivan, primary, Prnjak, Katarina, additional, Helms, Eric R., additional, and McGuigan, Michael R., additional
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- 2024
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4. Variations in strength-speed-power performance across the season: Do true changes occur in elite rugby players?
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Loturco, Irineu, Bishop, Chris, Zabaloy, Santiago, Moura, Túlio B. M. A., Ramos, Maurício S., Pereira, Lucas A., McGuigan, Michael R., Loturco, Irineu, Bishop, Chris, Zabaloy, Santiago, Moura, Túlio B. M. A., Ramos, Maurício S., Pereira, Lucas A., and McGuigan, Michael R.
- Abstract
This study aimed to determine, through the use of a highly sensitive statistical tool, whether real changes in performance were present; and compare the rates of meaningful variations in strength, speed, and power parameters at different time-points during the competitive season in national team rugby players. Thirty-two players were assessed 5 times across the season using the following tests: squat jump and countermovement jump tests; 30-m sprint velocity; and one-repetition maximum (1RM) in the half-squat and bench-press exercises. A repeated-measures analysis of variance was conducted to test for differences between successive time-points. Individual coefficients of variation values were used to set target scores for post-measurements and examine whether changes in performance parameters were greater than the natural test variance, thus providing an indication of whether “true changes” occurred. No significant changes were detected in the vertical jump height, 1RM measures, and sprint velocity and momentum throughout the 11-month period (P > 0.05). True changes occurred much more frequently for strength-power measures than for sprint velocity and momentum. Elite rugby union players did not exhibit significant variations in neuromuscular performance across the competitive period, when a group-based analysis was conducted. However, at the individual level, “true changes” in strength-power-(but not in speed-) related qualities were consistently observed over the competitive season.
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- 2024
5. The load-velocity relationship in the jump squat exercise
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Loturco, Irineu, McGuigan, Michael R., Pereira, Lucas A., Pareja-Blanco, Fernando, Loturco, Irineu, McGuigan, Michael R., Pereira, Lucas A., and Pareja-Blanco, Fernando
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The purpose of this study was to test the load-velocity relationship in the jump squat (JS) exercise using three different velocity parameters (mean velocity [MV], mean propulsive velocity [MPV], and peak velocity [PV]). Twenty-six male rugby union players (24.3±3.9 years; 1.81±0.09 m; 101.3±15.4 kg) performed a progressive loading test in the JS with loads corresponding to 20, 40, 60, and 80% of the half-squat 1RM (equivalent to 24, 46, 70, and 94% of the estimated JS-1RM). MV, MPV, and PV were continuously recorded during all attempts using a linear velocity transducer. Linear regression models were used to determine the relationships between JS loads and MV, MPV, and PV. Bar-velocity outputs demonstrated high levels of consistency and reliability (coefficient of variation ≤ 5% and intraclass correlation coefficient ≥ 0.90). The predictive power of MV, MPV, and PV were ≥ 91%, for all tested variables (P < 0.0001). The equations and bar-velocity values provided in this study can be used by coaches to precisely determine and prescribe JS training loads, from very-light to heavy loading conditions (i.e., ~20-100% JS 1RM).
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- 2023
6. The optimum power load: A simple and powerful tool for testing and training
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Loturco, Irineu, Iacono, Antonio Dello, Nakamura, Fábio Y., Freitas, Tomás T., Boullosa, Daniel, Valenzuela, Pedro L., Pereira, Lucas A., McGuigan, Michael R., Loturco, Irineu, Iacono, Antonio Dello, Nakamura, Fábio Y., Freitas, Tomás T., Boullosa, Daniel, Valenzuela, Pedro L., Pereira, Lucas A., and McGuigan, Michael R.
- Abstract
Purpose: The optimal power load is defined as the load that maximizes power output in a given exercise. This load can be determined through the use of various instruments, under different testing protocols. Specifically, the "optimum power load" (OPL) is derived from the load-velocity relationship, using only bar force and bar velocity in the power computation. The OPL is easily assessed using a simple incremental testing protocol, based on relative percentages of body mass. To date, several studies have examined the associations between the OPL and different sport-specific measures, as well as its acute and chronic effects on athletic performance. The aim of this brief review is to present and summarize the current evidence regarding the OPL, highlighting themain lines of research on this topic and discussing the potential applications of this novel approach for testing and training. Conclusions: The validity and simplicity of OPL-based schemes provide strong support for their use as an alternative to more traditional strength-power training strategies. The OPL method can be effectively used by coaches and sport scientists in different sports and populations, with different purposes and configurations.
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- 2022
7. Squat and countermovement jump performance across a range of loads: A comparison between Smith machine and free weight execution modes in elite sprinters
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Loturco, Irineu, McGuigan, Michael R., Freitas, Tomás T., Nakamura, Fábio Y., Boullosa, Daniel A., Valenzuela, Pedro L., Pereira, Lucas A., Pareja-Blanco, Fernando, Loturco, Irineu, McGuigan, Michael R., Freitas, Tomás T., Nakamura, Fábio Y., Boullosa, Daniel A., Valenzuela, Pedro L., Pereira, Lucas A., and Pareja-Blanco, Fernando
- Abstract
The aims of this study were to: 1) provide and compare the height achieved during Smith machine (SM) and free weight (FW) loaded jumps executed over a wide spectrum of loads (40–120 % of body mass [BM]); and 2) test the difference between loaded and unloaded squat jump (SJ) and countermovement jump (CMJ) attempts in ten highly trained male sprinters. On the first visit, athletes performed unloaded SJ and CMJ, loaded SJ with loads corresponding to 40, 60, 80, 100, and 120 % BM, and loaded CMJ at 100% BM using an Olympic barbell (FW). On the second visit, they performed loaded SJ and CMJ tests under the same loading conditions on the SM device and, subsequently, a half-squat one-repetition maximum (1RM) assessment. The relative strength (RS = 1RM/BM) of the athletes was 2.54 ± 0.15. Loaded SJ performance was similar between SM and FW, and across all loading conditions. Differences in favour of CMJ (higher jump heights compared with SJ) were superior in the unloaded condition but decreased progressively as a function of loading. In summary, sprinters achieved similar SJ heights across a comprehensive range of loads, regardless of the execution mode (FW or SM). The positive effect of the countermovement on jump performance is progressively reduced with increasing load.
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- 2022
8. Using cluster and rest redistribution set structures as alternatives to resistance training prescription method based on velocity loss thresholds
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Jukic, Ivan, primary, Helms, Eric R., additional, McGuigan, Michael R., additional, and García-Ramos, Amador, additional
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- 2022
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9. Influence of Physical and Technical Aspects on Change of Direction Performance of Rugby Players: An Exploratory Study
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Freitas, Tomás T., primary, Alcaraz, Pedro E., additional, Calleja-González, Julio, additional, Arruda, Ademir F. S., additional, Guerriero, Aristide, additional, Mercer, Valter P., additional, Pereira, Lucas A., additional, Carpes, Felipe P., additional, McGuigan, Michael R., additional, and Loturco, Irineu, additional
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- 2021
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10. Variations in the Physical Performance of Olympic Boxers over a Four-Day National Qualifying Tournament
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Loturco, Irineu, primary, McGuigan, Michael R., additional, Freitas, Tomás T., additional, Bishop, Chris, additional, Alcaraz, Pedro E., additional, Romano, Felipe, additional, Alves, Mateus, additional, Reis, Valter P., additional, Pereira, Lucas A., additional, and Franchini, Emerson, additional
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- 2021
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11. Effects of training on sand or hard surfaces on sprint and jump performance of team-sport players: A systematic review with meta-analysis
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Pereira, Lucas A., Freitas, Tomás T., Marín-Cascales, Elena, Bishop, Chris, Mcguigan, Michael R., Loturco, Irineu, Pereira, Lucas A., Freitas, Tomás T., Marín-Cascales, Elena, Bishop, Chris, Mcguigan, Michael R., and Loturco, Irineu
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We examined the effectiveness of training on sand and compared the effects of sand and hard surface training programs on the sprint and jump performance of team-sport players. PubMed MEDLINE, SPORTDiscus, and Web of Science databases were used in the literature search. A total of 377 records were initially identified, and 6 studies comprising 136 athletes were included in the meta-analysis. Precomparisons and postcomparisons showed that sand training interventions were effective at improving both jump and sprint capacities. When comparing sand and hard surfaces, no significant differences in favor of any of the interventions were observed. In summary, this review revealed that sand training is an efficient strategy to improve jump and sprint performances in team-sport players. Moreover, sand surfaces produced similar gains to those observed after hard surface training schemes. Strength and conditioning coaches and sport scientists who work with team sports can use both sand and hard surface training programs as part of their regular training practices, during distinct phases of the season.
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- 2021
12. Range of motion is not reduced in national-level New Zealand female powerlifters
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Spence, Alyssa-Joy, Helms, Eric R., Mcguigan, Michael R., Spence, Alyssa-Joy, Helms, Eric R., and Mcguigan, Michael R.
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Spence, A-J, Helms, ER, and McGuigan, MR. Range of motion is not reduced in national-level New Zealand female powerlifters. J Strength Cond Res 35(10): 2737–2741, 2021—Some research suggests male powerlifters have less range of motion (ROM) in several directions about the shoulder and hip compared with sedentary men. In addition, those differences may be more pronounced in groups with higher strength levels and more years of experience. However, there is no information on ROM in female powerlifters. The purpose of this study was to evaluate single-joint ROM in competitive female powerlifters and determine whether single-joint ROM would be an effective predictor of strength in this population. Twelve female powerlifters and 12 female recreationally trained age-matched controls attended one testing session. Subjects reported their years of training experience, frequency, and average duration of training sessions. Active ROM measurements were collected at the shoulder, hip, and knee, using goniometry. There was no significant difference (p > 0.05) between groups for age, height, body mass, training experience, and training frequency. Powerlifters reported significantly greater (p ≤ 0.05) training durations than recreationally trained women. Powerlifters had significantly greater shoulder horizontal abduction on the right side (p = 0.022, g = 0.97), but no other ranges were significantly different between groups, and no ranges were significantly related to strength. Powerlifting does not seem to affect shoulder, hip, or knee ROM differently than recreational resistance training in women. Single-joint ROM was not an effective predictor of strength in female powerlifters.
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- 2021
13. Performance and reference data in the jump squat at different relative loads in elite sprinters, rugby players, and soccer players
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Loturco, Irineu, McGuigan, Michael R., Freitas, Tomás T., Valenzuela, Pedro L., Pereira, Lucas A., Pareja-Blanco, Fernando, Loturco, Irineu, McGuigan, Michael R., Freitas, Tomás T., Valenzuela, Pedro L., Pereira, Lucas A., and Pareja-Blanco, Fernando
- Abstract
The aims of this study were to compare the outcomes and provide reference data for a set of barbell mechanical parameters collected via a linear velocity transducer in 126 male sprinters (n = 62), rugby players (n = 32), and soccer players (n = 32). Bar-velocity, bar-force, and bar-power outputs were assessed in the jump-squat exercise with jump-squat height determined from bar-peak velocity. The test started at a load of 40% of the athletes' body mass (BM), and a load of 10% of BM was gradually added until a clear decrement in the bar power was observed. Comparisons of bar variables among the three sports were performed using a one-way analysis of variance. Relative measures of bar velocity, force, and power, and jump-squat height were significantly higher in sprinters than in rugby (difference ranging between 5 and 35%) and soccer (difference ranging between 5 and 60%) players across all loads (40-110% of BM). Rugby players exhibited higher absolute bar-power (mean difference = 22%) and bar-force (mean difference = 16%) values than soccer players, but these differences no longer existed when the data were adjusted for BM (mean difference = 2.5%). Sprinters optimized their bar-power production at significantly greater relative loads (%BM) than rugby (mean difference = 22%) and soccer players (mean difference = 25%); nonetheless, all groups generated their maximum bar-power outputs at similar bar velocities. For the first time, we provided reference values for the jump-squat exercise for three different bar-velocity measures (i.e., mean, mean propulsive, and peak velocity) for sprinters, rugby players, and soccer players, over a wide range of relative loads. Practitioners can use these reference values to monitor their athletes and compare them with top-level sprinters and team-sport players.
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- 2021
14. Implementation and efficacy of plyometric training: Bridging the gap between practice and research
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Watkins, Casey M., Storey, Adam G., McGuigan, Michael R., Gill, Nicholas D., Watkins, Casey M., Storey, Adam G., McGuigan, Michael R., and Gill, Nicholas D.
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Watkins, CM, Storey, A, McGuigan, M, and Gill, ND. Implementation and efficacy of plyometric training: Bridging the gap between practice and research. J Strength Cond Res 35(5): 1244-1255, 2021-Plyometric training is an effective method for improving speed and acceleration. However, a gap seems to exist between research recommendations and practitioner's actual programs. Some reports suggest as many as 400 jumps per session, while anecdotally some strength and conditioning coaches are using as few as 15-40 jumps even with elite athletes. Thus, the purposes of this study were to obtain a clearer understanding of the practitioner's perspective on plyometric training strategies as compared to literary recommendations and to compare any trends across competition level or sport categories. An integrative mixed-methods model was used. Globally, 61 strength and conditioning practitioners completed an anonymous online survey, containing 5 sections: 1. Sport and coaching background information, 2. Plyometric training focus, 3. Periodization strategy, 4. Plyometric program details, and 5. Efficacy of plyometrics for sport performance. Questions included yes/no, multiple choice, Likert scale, percentage-based, and open-ended questions. The majority (70.5%) of respondents reported regularly implementing plyometric training and overwhelmingly (96.7%) reported positive athlete feedback surrounding its perceived efficacy. Findings confirmed that many practitioners regularly use significantly lower session volumes than previous literary recommendations (p < 0.05). In addition, significant differences were noted in many program details across competition level and sport category including volume periodization, exercise choice, and plyometric intensity. Practitioners may want to reflect on these reported group differences when building training programs best suited for their athletes. Meanwhile, future research should consider these reported perspectives when formulating intervention
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- 2021
15. Variations in the physical performance of olympic boxers over a four-day national qualifying tournament
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Loturco, Irineu, McGuigan, Michael R., Freitas, Tomás T., Bishop, Chris, Alcaraz, Pedro E., Romano, Felipe, Alves, Mateus, Reis, Valter P., Pereira, Lucas A., Franchini, Emerson, Loturco, Irineu, McGuigan, Michael R., Freitas, Tomás T., Bishop, Chris, Alcaraz, Pedro E., Romano, Felipe, Alves, Mateus, Reis, Valter P., Pereira, Lucas A., and Franchini, Emerson
- Abstract
The aim of this study was to examine changes in body mass (BM) and power-related measures in Olympic boxers during an official qualifying boxing tournament. Fourteen elite amateur boxers from the Brazilian National Team (eight men and six women) participated in this study. Athletes performed three fights in four days against the same opponent of the same weight-category. Before and immediately after every fight, BM, countermovement jump (CMJ) height, and power production in the bench-press and half-squat exercises were assessed in the same order and on the same time of the day. A two-way repeated-measures ANOVA with the Bonferroni post-hoc analysis was used to determine the variations between pre-and post-measures. The statistical significance was set as p < 0.05. The athletes were able to maintain their baseline weight and physical performance throughout the experimental period, as shown by the lack of significant changes in BM, CMJ height, and upper-and lower-limb power output. Throughout a four-day qualifying tournament, the BM and power-related performance of Olympic boxers were not affected either by match execution or by successive matches. As scoring actions are highly dependent on muscle power, it is likely that these combat athletes are able to maintain optimal levels of performance across consecutive matches.
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- 2021
16. Time Course of Neuromuscular, Hormonal, and Perceptual Responses Following Moderate- and High-Load Resistance Priming Exercise
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Harrison, Peter W, James, Lachlan P, Jenkins, David G, McGuigan, Michael R., Schuster, Robert W., Kelly, Vincent G, Harrison, Peter W, James, Lachlan P, Jenkins, David G, McGuigan, Michael R., Schuster, Robert W., and Kelly, Vincent G
- Abstract
PURPOSE: The aim of this study was to map responses over 32 hours following high-load (HL) and moderate-load (ML) half-squat priming.METHODS: Fifteen participants completed control, HL (87% 1RM), and ML (65% 1RM) activities in randomized, counterbalanced order. Countermovement jump (CMJ), squat jump (SJ), saliva testosterone, saliva cortisol, and perceptual measures were assessed before and 5 minutes, 8 hours, 24 hours, and 32 hours after each activity. Results are presented as percentage change from baseline and 95% confidence interval (CI). Cliff delta was used to determine threshold for group changes.RESULTS: SJ height increased by 4.5% (CI = 2.2-6.8, Cliff delta = 0.20) 8 hours following HL. CMJ and SJ improved by 6.1% (CI = 2.1-7.8, Cliff delta = 0.27) and 6.5% (CI = 1.2-11.8, Cliff delta = 0.30), respectively, 32 hours after ML. No clear diurnal changes in CMJ or SJ occurred 8 hours following control; however, increases of 3.9% (CI = 2.9-9.2, Cliff delta = 0.26) and 4.5% (CI = 0.9-8.1, Cliff delta = 0.24), respectively, were observed after 32 hours. Although diurnal changes in saliva hormone concentration occurred (Cliff delta = 0.37-0.92), the influence of priming was unclear. Perceived "physical feeling" was greater 8 hours following HL (Cliff delta = 0.36) and 32 hours after ML and control (Cliff delta = 0.17-0.34).CONCLUSIONS: HL priming in the morning may result in small improvements in jump output and psychophysiological state in the afternoon. Similar improvements were observed in the afternoon the day after ML priming.
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- 2021
17. Effects of Resistance Training on Running Economy and Cross-country Performance
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BARNES, KYLE R., HOPKINS, WILL G., MCGUIGAN, MICHAEL R., NORTHUIS, MARK E., and KILDING, ANDREW E.
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- 2013
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18. Power training in elite young soccer players: effects of using loads above or below the optimum power zone
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Loturco, Irineu, Pereira, Lucas A., Reis, Valter P., Bishop, Chris, Zanetti, Vinicius, Alcaraz, Pedro E., Freitas, Tomás T., and McGuigan, Michael R.
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This study aimed to examine the effects of two jump squat (JS) training programs involving different loading ranges in under-20 soccer players during a preseason period. Twenty-three elite young soccer players performed sprint speed (at 5-, 10-, and 20-m), change-of-direction (COD) speed, JS peak-power (PP), and countermovement jump (CMJ) tests pre and post four weeks of training. Athletes were pair-matched in two groups according to their optimum power loads (OPL) as follows: lower than OPL (LOPL; athletes who trained at a load 20% lower than the OPL) and higher than OPL (HOPL; athletes who trained at a load 20% higher than the OPL). Magnitude-based inferences were used to compare pre- and post-training measures. Meaningful increases in the PP JS were observed for both groups. Likely and possible improvements were observed in the 5- and 10-m sprint velocity in the LOPL group. Meanwhile, possible and likely improvements were observed in the CMJ, 5- and 10-m sprint velocity, and COD speed in the HOPL group. Overall, both training schemes induced positive changes in athletic performance. Soccer coaches and sport scientists can implement the JS OPL-based training schemes presented here, either separately or combined, to improve the physical performance of youth soccer players.
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- 2020
19. Changes in the Eccentric Phase Contribute to Improved Stretch-Shorten Cycle Performance after Training
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CORMIE, PRUE, McGUIGAN, MICHAEL R., and NEWTON, ROBERT U.
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- 2010
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20. Influence of Strength on Magnitude and Mechanisms of Adaptation to Power Training
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CORMIE, PRUE, MCGUIGAN, MICHAEL R., and NEWTON, ROBERT U.
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- 2010
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21. Adaptations in Athletic Performance after Ballistic Power versus Strength Training
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CORMIE, PRUE, MCGUIGAN, MICHAEL R., and NEWTON, ROBERT U.
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- 2010
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22. The Relationship Between Isometric and Dynamic Strength in College Football Players: 2152: Board #123 May 30 8:00 AM - 9:30 AM
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Nelson, Arnold G., McGuigan, Michael R., and Winchester, Jason B.
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- 2008
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23. Resistance Training and Reduction of Treatment Side Effects in Prostate Cancer Patients
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GALVÃO, DANIEL A., NOSAKA, KAZUNORI, TAAFFE, DENNIS R., SPRY, NIGEL, KRISTJANSON, LINDA J., MCGUIGAN, MICHAEL R., SUZUKI, KATSUHIKO, YAMAYA, KANEMITSU, and NEWTON, ROBERT U.
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- 2006
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24. Muscle fiber characteristics in patients with peripheral arterial disease
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MCGUIGAN, MICHAEL R. M., BRONKS, ROGER, NEWTON, ROBERT U., SHARMAN, MATTHEW J., GRAHAM, JOHN C., CODY, DAVID V., and KRAEMER, WILLIAM J.
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- 2001
25. 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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Loturco, Irineu, primary, Suchomel, Timothy, additional, James, Lachlan P., additional, Bishop, Chris, additional, Abad, César C. C., additional, Pereira, Lucas A., additional, and McGuigan, Michael R., additional
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- 2018
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26. Factors influencing overweight children's commencement of and continuation in a resistance training program
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McGuigan Michael R, Pettigrew Simone, Pescud Melanie, and Newton Robert U
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Public aspects of medicine ,RA1-1270 - Abstract
Abstract 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.
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- 2010
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27. 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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Loturco, Irineu, Suchome, Timothy, James, Lachlan P., Bishop, Chris, Abad, César C. C., Pereira, Lucas A., McGuigan, Michael R., Loturco, Irineu, Suchome, Timothy, James, Lachlan P., Bishop, Chris, Abad, César C. C., Pereira, Lucas A., and McGuigan, Michael R.
- Abstract
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.
- Published
- 2018
28. 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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Dent, Jessica R., Fletcher, Deborah K., and McGuigan, Michael R.
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power ,lcsh:Sports ,rapid ,lcsh:GV557-1198.995 ,female ,Calcium ,fatigue ,Review Article ,androgen ,lcsh:Sports medicine ,lcsh:RC1200-1245 - Abstract
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. Key pointsNon-genomic calcium mediated events activated by testosterone have been identified in skeletal muscle cells.The non-genomic action originates at the cell membrane, is rapid in onset and is directed by second messengers' calcium and IP3.A possible action of non-genomic testosterone may be the initiation of a more efficient contraction through the mobilisation of calcium from the SR resulting in greater force production or velocity of contraction in fast twitch fibres.Physiologically, females with menstrual disorders that cause hyperandrogenism may have a performance advantage in events that require great force or power production.
- Published
- 2012
29. CIRCADIAN RHYTHMS IN EXERCISE PERFORMANCE: IMPLICATIONS FOR HORMONAL AND MUSCULAR ADAPTATION
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Teo, Weipeng, Newton, Michael J., and McGuigan, Michael R.
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Diurnal variation ,lcsh:Sports ,lcsh:GV557-1198.995 ,neuromuscular adaptation ,steroidal hormones ,Review Article ,lcsh:Sports medicine ,lcsh:RC1200-1245 - Abstract
Almost all physiological and biochemical processes within the human body follow a circadian rhythm (CR). In humans, the suprachiasmatic nucleus regulates sleep- wake cycle and other daily biorhythms in line with solar time. Due to such daily physiological fluctuations, several investigations on neuromuscular performance have reported a distinct CR during exercise. Generally, peak performances have been found to occur in the early evening, at approximately the peak of core body temperature. The increase in core body temperature has been found to increase energy metabolism, improve muscle compliance and facilitate actin-myosin crossbridging. In addition, steroidal hormones such as testosterone (T) and cortisol (C) also display a clear CR. The role of T within the body is to maintain anabolism through the process of protein synthesis. By contrast, C plays a catabolic function and is involved in the response of stress. Due to the anabolic and catabolic nature of both T and C, it has been postulated that a causal relationship may exist between the CR of T and C and muscular performance. This review will therefore discuss the effects of CR on physical performance and its implications for training. Furthermore, this review will examine the impact of muscular performance on CR in hormonal responses and whether could variations in T and C be potentially beneficial for muscular adaptation. Key pointsA distinct CR can be observed in physical performance.CR of exercise performance is highly associated with CR in core body temperatureBoth T and C display a clear CR, however, the current evidence does not show a clear relationship with neuromuscular adaptations.TST is able to induce changes in physical performance variables at the particular time point, but not for the circadian profile of T and C.
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- 2011
30. Eight Weeks of Resistance Training Can Significantly Alter Body Composition in Children Who Are Overweight or Obese
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Mcguigan, Michael R, Mcguigan, Michael R, Tatasciore, Melissa, Newton, Robert U, Pettigrew, Simone, Mcguigan, Michael R, Mcguigan, Michael R, Tatasciore, Melissa, Newton, Robert U, and Pettigrew, Simone
- Abstract
The purpose of this study was to investigate the effect of an 8-week resistance training program on children who were overweight or obese. Forty-eight children (n = 26 girls and 22 boys; mean age = 9.7 years) participated in an 8-week undulating periodized resistance training program for 3 d*wk^sup -1^. Measures of body composition via dual-energy X-ray absorptiometry, anthropometry, strength, and power were made before and after the training intervention. There was a significant decrease in absolute percent body fat of 2.6% (p = 0.003) and a significant increase in lean body mass of 5.3% (p = 0.07). There were no significant changes in height, weight, body mass index, total fat mass, or bone mineral content. There were significant increases in 1-repetition maximum squat (74%), number of push-ups (85%), countermovement jump height (8%), static jump height (4%), and power (16%). These results demonstrate that the resistance training program implemented produces significant changes in body composition and strength and power measures, as well as being well tolerated by the participants. An undulating periodized program provides variation and significantly increases lean body mass, decreases percent body fat, and increases strength and power in children who are overweight and obese.
- Published
- 2009
31. The relationship between isometric and dynamic strength in college football players
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Mcguigan, Michael R., Mcguigan, Michael R., Winchester, Jason, Mcguigan, Michael R., Mcguigan, Michael R., and Winchester, Jason
- Abstract
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 < 0.05). The correlations were very strong between the power clean 1RM and squat 1RM (r = 0.90, p < 0.05). There were very strong correlations between 2RM split jerk and clean 1RM (r = 0.71, p < 0.05), squat 1RM (r = 0.71, p < 0.05), bench 1RM (r = 0.70, p < 0.05) and PF (r = 0.72, p < 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.
- Published
- 2008
32. Use of Session Rating of Perceived Exertion for Monitoring Resistance Exercise in Children Who Are Overweight or Obese
- Author
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McGuigan, Michael R, McGuigan, Michael R, Al Dayel, Abdulaziz, Tod, David, Foster, Carl, Newton, Robert U, Pettigrew, Simone, McGuigan, Michael R, McGuigan, Michael R, Al Dayel, Abdulaziz, Tod, David, Foster, Carl, Newton, Robert U, and Pettigrew, Simone
- Abstract
The purpose of this study was to investigate the use of the OMNI Resistance Exercise scale (OMNI-RES) for monitoring the intensity of different modes of resistance training in children who are overweight or obese. Sixty-one children (mean age = 9.7 ± 1.4 years) performed three resistance training sessions every week for 4 weeks. Each session consisted of three sets of 3-15 repetitions of eight different resistance exercises. OMNI-RES RPE measures (0-10) were obtained following each set and following the end of the exercise session. There was a significant difference between average RPE (1.68 ± 0.61) and Session RPE (3.10 ± 1.18) during the 4 weeks of training (p < .05). There was no significant change in session RPE over the 4 weeks of training. The correlation coefficient between average and session RPE values was significant (r = .88, p < .05). The findings of the current study indicate that the RPE values are higher when OMNI-RES measures are obtained following the whole training session than when obtained following every single set of exercise. This suggests that in children the session RPE provides different information to the average RPE across the entire session.
- Published
- 2008
33. Eccentric utilization ratio: Effect of sport and phase of training
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McGuigan, Michael R, McGuigan, Michael R, Doyle, Timothy, Newton, Michael, Edwards, Dylan J, Nimphius, Sophia, Newton, Robert U, McGuigan, Michael R, McGuigan, Michael R, Doyle, Timothy, Newton, Michael, Edwards, Dylan J, Nimphius, Sophia, and Newton, Robert U
- Abstract
The eccentric utilization ratio (EUR), which is the ratio of countermovement jump (CMJ) to static jump (SJ) performance, has been suggested as a useful indicator of power performance in athletes. The purpose of the study was to compare the EUR of athletes from a variety of different sports and during different phases of training. A total of 142 athletes from rugby union, Australian Rules Football, soccer, softball, and field hockey were tested. Subjects performed both CMJ and SJ on a force plate integrated with a position transducer. The EUR was measured as the ratio of CMJ to SJ for jump height and peak power. The rugby union, Australian Rules Football, and hockey athletes were tested during off-season and preseason to provide EUR data during different phases of training. For men, EUR for soccer, Australian Rules Football, and rugby was greater than softball (effect size range, 0.83-0.92). For women, EUR for soccer was greater than field hockey and softball (0.86-1.0). There was a significant difference between the jump height and peak power method for the Australian Rules Football, rugby, and field hockey tests conducted preseason (p < 0.05). Fear field hockey, there was a significant increase in EUR from off-season to preseason. Athletes in sports such as soccer, rugby union, and Australian Rules Football appear to have higher EUR values, which reflects the greater reliance on stretch shortening activities in these sports. It does appear that EUR can be used to track changes in training with the values significantly increasing from off-season to preseason. The EUR provides the practitioner with information about the performance of athletes and appears to be sensitive to changes in the type of training being undertaken.
- Published
- 2006
34. Resistance Training for Better Health in Older Adults
- Author
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McGuigan, Michael R, McGuigan, Michael R, Newton, Robert U, Kraemer, William J, McGuigan, Michael R, McGuigan, Michael R, Newton, Robert U, and Kraemer, William J
- Abstract
There is increasing research evidence for the efficacy of resistance training programs for improving health and functional status in older adults. Resistance training has been shown to be an effective method to avoid age related losses in skeletal muscle tissue. Resistance training appears to be a potential solution for prevention purposes by inducing increases in strength, power and muscle cross sectional area, in addition to moderately improving endurance. There are also improvements in some aspects of functional status such as walking speed. Further research is required to determine the efficacy of resistance exercise for fall prevention. It does appear that muscular power and rate of force development are important indicators of health and functional status in older adults. Therefore resistance training programs should incorporate some of these aspects into the program design. Resistance training also provides an alternative method of rehabilitation for various disease states such as cardiovascular disease and type II diabetes. It now appears that resistance training is a critical component of exercise programs designed to improve health in older populations and should receive similar emphasis to aerobic activities such as walking.
- Published
- 2006
35. Strength and power assessment protocols
- Author
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McGuigan, Michael R., Sheppard, Jeremy M, Cormack, Stuart J, Taylor, Kristie-Lee, McGuigan, Michael R., Sheppard, Jeremy M, Cormack, Stuart J, and Taylor, Kristie-Lee
- Abstract
Both strength and power are critical components of athletic performance. Strength andpower can represent specific or independent qualitiesof neuromuscular performance and therefore can be assessed and trained independently. Strength and power diagnosis is the process of determiningan athlete's level of development of each of these distinct qualities. A variety of tests are used by practitioners to test their athletes and to describe the physical qualities of athletes. The information obtained from strength and power assessment can be used to monitor training, measure the response to training interventions, identity strengths and weaknesses, individualize training loads and programs, and compare the athlete with other athletes and withnormative data. Practitioners and researchers must consider thereliability and validity of the variables obtainedfrom strength and power assessment. This chapter discusses the various strength and power qualities and the methods that are used to assess them.
- Published
- 2013
36. Strength tests for elite rowers: low- or high-repetition?
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Lawton, Trent, Cronin, John B, Mcguigan, Michael R, Lawton, Trent, Cronin, John B, and Mcguigan, Michael R
- Abstract
The purpose of this project was to evaluate the utility of low- and high-repetition maximum (RM) strength tests used to assess rowers. Twenty elite heavyweight males (age 23.7 ± 4.0 years) performed four tests (5 RM, 30 RM, 60 RM and 120 RM) using leg press and seated arm pulling exercise on a dynamometer. Each test was repeated on two further occasions; 3 and 7 days from the initial trial. Per cent typical error (within-participant variation) and intraclass correlation coefficients (ICCs) were calculated using log-transformed repeated-measures data. High-repetition tests (30 RM, 60 RM and 120 RM), involving seated arm pulling exercise are not recommended to be included in an assessment battery, as they had unsatisfactory measurement precision (per cent typical error > 5% or ICC < 0.9). Conversely, low-repetition tests (5 RM) involving leg press and seated arm pulling exercises could be used to assess elite rowers (per cent typical error ≤ 5% and ICC ≥ 0.9); however, only 5 RM leg pressing met criteria (per cent typical error = 2.7%, ICC = 0.98) for research involving small samples (n = 20). In summary, low-repetition 5 RM strength testing offers greater utility as assessments of rowers, as they can be used to measure upper- and lower-body strength; however, only the leg press exercise is recommended for research involving small squads of elite rowers.
- Published
- 2013
37. Does on-water resisted rowing increase or maintain lower-body strength?
- Author
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Lawton, Trent, Cronin, John B, Mcguigan, Michael R, Lawton, Trent, Cronin, John B, and Mcguigan, Michael R
- Abstract
Over the past 30 years, endurance volumes have increased by .20% among the rowing elite; therefore, informed decisions about the value of weight training over other possible activities in periodized training plans for rowing need to be made. The purpose of this study was to quantify the changes in lower-body strength development after two 14-week phases of intensive resisted on-water rowing, either incorporating weight training or rowing alone. Ten elite women performed 2 resisted rowing ("towing ropes," e.g., 83 3 minutes) plus 6 endurance (e.g., 16-28 km at 70-80% maximum heart rate) and 2 rate-regulated races (e.g., 8,000 m at 24 strokes per minute) on-water each week. After a 4-week washout phase, the 14-week phase was repeated with the addition of 2 weighttraining sessions (e.g., 3-4 sets × 6-15 reps). Percent (6SD) and standardized differences in effects (effect size [ES] 6 90% confidence limit) for 5-repetition leg pressing and isometric pulling strength were calculated from data ratio scaled for body mass, log transformed and adjusted for pretest scores. Resisted rowing alone did not increase leg pressing (21.0 ± 5.3%, p = 0.51) or isometric pulling (5.3 ± 13.4%, p = 0.28) strength. In contrast, after weight training, a moderately greater increase in leg pressing strength was observed (ES = 0.72 ± 0.49, p = 0.03), although differences in isometric pulling strength were unclear (ES = 0.56 ± 1.69, p = 0.52). In conclusion, intensive on-water training including resisted rowing maintained but did not increase lower-body strength. Elite rowers or coaches might consider the incorporation of high-intensity nonfatiguing weight training concurrent to endurance exercise if increases in lowerbody strength without changes in body mass are desired.
- Published
- 2013
38. Strength, power, and muscular endurance exercise and elite rowing ergometer performance
- Author
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Lawton, Trent, Cronin, John B, Mcguigan, Michael R, Lawton, Trent, Cronin, John B, and Mcguigan, Michael R
- Abstract
Knowledge of the relationship between weight room exercises and various rowing performance measures is limited; this information would prove useful for sport-specific assessment of individual needs and exercise prescription. The purpose of this study was to establish strength, power, and muscular endurance exercises for weight room training, which are strong determinants of success in specific performance measures used to assess elite rowers. Nineteen heavyweight elite males determined their repetition maximum (RM) loads for exercises using a Concept 2 DYNO [5, 30, 60 and 120RM leg pressing and seated arm pulling (in Joules)] and free weights [1RM power clean (in kilograms) and 6RM bench pull (in kilograms and watts)]. Rowing performance measures included a 7-stage blood lactate response ergometer test (aerobic condition), time trials (500, 2000, and 5000 m), a peak stroke power test, and a 60-minute distance trial. Pearson correlation moments (r + 0.7) and stepwise multiple linear regression calculations (R2 + 50%) were used to establish strong common variances between weight room exercises and rowing ergometer performance (p # 0.05). Weight room exercises were strong predictors of 2000-m, 500-m time (in seconds), and peak stroke power performance measures only. Bench pull power (in watts) and 1RM power clean (in kilograms) were the best 2-factor predictors of peak stroke power (R2 = 73%; standard error of the estimates [SEE] = 59.6 W) and 500 m (R2 = 70%; SEE = 1.75 seconds); while 5RM leg pressing (in Joules) and either 6RM bench pull (kg) or 60RM seated arm pulling (in Joules) the best predictors of 2000 m (R2 = 59%; SEE = 6.3 seconds and R2 = 57%; SEE = 6.4 seconds, respectively). Recommended exercises for weight room training include a 1RM power clean, 6RM bench pull, 5RM leg press, and 60RM seated arm pulling.
- Published
- 2013
39. The Development, Retention and Decay Rates of Strength and Power in Elite Rugby Union, Rugby League and American Football
- Author
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McMaster, Daniel, Gill, Nicholas, Cronin, John B, Mcguigan, Michael R, McMaster, Daniel, Gill, Nicholas, Cronin, John B, and Mcguigan, Michael R
- Abstract
Background and aim: Strength and power are crucial components to excelling in all contact sports; and understanding how a player’s strength and power levels fluctuate in response to various resistance training loads is of great interest, as it will inevitably dictate the loading parameters throughout a competitive season. This is a systematic review of training, maintenance and detraining studies, focusing on the development, retention and decay rates of strength and power measures in elite rugby union, rugby league and American football players. Search strategies: A literature search using MEDLINE, EBSCO Host, Google Scholar, IngentaConnect, OvidLWW, ProQuest Central, ScienceDirect Journals, SPORTDiscusTM and Wiley InterScience was conducted. References were also identified from other review articles and relevant textbooks. From 300 articles, 27 met the inclusion criteria and were retained for further analysis. Study quality: Study quality was assessed via a modified 20-point scale created to evaluate research conducted in athletic-based training environments. The mean ± standard deviation (SD) quality rating of the included studies was 16.2 ± 1.9; the rating system revealed that the quality of future studies can be improved by randomly allocating subjects to training groups, providing greater description and detail of the interventions, and including control groups where possible. Data analysis: Percent change, effect size (ES = [Post-Xmean - Pre-Xmean)/Pre-SD) calculations and SDs were used to assess the magnitude and spread of strength and power changes in the included studies. The studies were grouped according to (1) mean intensity relative volume (IRV = sets 9 repetitions 9 intensity; (2) weekly training frequency per muscle group; and (3) detraining duration. IRV is the product of the number of sets, repetitions and intensity performed during a training set and session. The effects of weekly training frequencies were assessed by normalizing the percent chang
- Published
- 2013
40. Is wireless accelerometry a viable measurement system for assessing vertical jump performance?
- Author
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McMaster, Tim, Gill, Nicholas, Cronin, John B, Mcguigan, Michael R, McMaster, Tim, Gill, Nicholas, Cronin, John B, and Mcguigan, Michael R
- Abstract
The aim of this study was to assess the mechanical differences calculated from hip acceleration (accelerometer attached to the hip), bar acceleration (accelerometer attached to barbell) and centre-of-mass acceleration (force plate) during vertical countermovement jumps (CMJs) and the reliability of each system. Eighteen elite male rugby players served as participants. In relation to the force plate, the bar accelerometer revealed similar peak velocity (PV [2%]) and peak power (PP [2%]), but predicted greater peak force (PF [24%]) during the concentric phase, whereas the hip accelerometer predicted similar PF (2%) but underpredicted PV (21%) and PP (24%) during the concentric phase. Both accelerometer attachments were deemed reliable for assessing PF (correlation coefficient, ICC = 0.80-0.83 and standard error of measurement, SEM = 3-13%), but were low/moderately reliable for monitoring PV and PP (ICC = 0.35-0.77 and SEM = 11-23%). The eccentric phase variables were unreliable across all devices and attachment sites. The kinematics and kinetics measured by the three systems (hip accelerometer, bar accelerometer and force plate) varied significantly (p < 0.05). Based on the outcomes, it is recommended that the force plate be used as the primary means of assessing CMJ performance until the stability of wireless accelerometry set-ups and protocols are improved.
- Published
- 2013
41. Factors influencing overweight children's commencement of and continuation in a resistance training program
- Author
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Pescud, Melanie, Pescud, Melanie, Pettigrew, Simone, McGuigan, Michael R., Newton, Robert, Pescud, Melanie, Pescud, Melanie, Pettigrew, Simone, McGuigan, Michael R., and Newton, Robert
- Abstract
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.
- Published
- 2010
42. The Effect of Duration of Resistance Training Interventions in Children Who are Overweight or Obese
- Author
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Sgro, Melissa, Sgro, Melissa, McGuigan, Michael R, Pettigrew, Simone, Newton, Robert U, Sgro, Melissa, Sgro, Melissa, McGuigan, Michael R, Pettigrew, Simone, and Newton, Robert U
- Abstract
The effect of duration of resistance training interventions in children who are overweight or obese. J Strength Cond Res 23(4): 1263-1270, 2009-The purpose of this study was to investigate the effects of different durations of resistance training on body composition and power in children. The study was a 24-week longitudinal design involving 31 preadolescent children who were overweight or obese (ages 7-12 years), divided into 3 groups and resistance trained 3 times per week. Group 8 (G8) trained for 8 weeks, group 16 (G16) trained for 16 weeks, and group 24 (G24) trained for 24 weeks. All participants were measured at weeks 0, 8, 16, and 24 for body composition and power. Subjects in G8 and G16 continued to be tested during the testing weeks after cessation of their training programs. Body composition and bone mineral content were measured by dual-energy X-ray absorptiometry. Significant improvements in body composition were seen in the initial 8-week training phase, and these improvements were maintained for the subsequent 16 weeks. Significant changes in percent body fat (~5-7%) were observed at 8 weeks in all 3 groups. Total fat mass decreased significantly at week 8 in G16 and G24 (5.9%). By week 24, total fat mass was significantly reduced by 8.1% in G24. Significant improvements were observed in static jump power, which improved by 10.5% at week 16 in G24. These results suggest that an 8-week resistance training program is sufficient time to significantly change body composition, strength, and power measures in children who are overweight or obese. However, further improvements are realized with longer-duration resistance training programs. On cessation of the training programs, the G8 and G16 groups maintained the benefits of the exercise program until the end of the study period.
- Published
- 2009
43. Reliability of performance measurements derived from ground reaction force data during countermovement jump and the influence of sampling frequency
- Author
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Hori, Naruhiro, Hori, Naruhiro, Newton, Robert U, Kawamori, Naoki, McGuigan, Michael R, Kraemer, William J, Nosaka, Kazunori, Hori, Naruhiro, Hori, Naruhiro, Newton, Robert U, Kawamori, Naoki, McGuigan, Michael R, Kraemer, William J, and Nosaka, Kazunori
- Published
- 2009
44. Assessing the Force-Velocity Characteristics of the Leg Extensors in Well-Trained Athletes: the Incremental Load Power Profile
- Author
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Sheppard, Jeremy M, Sheppard, Jeremy M, Cormack, Stuart, Taylor, Kristie-Lee, McGuigan, Michael R, Newton, Robert U, Sheppard, Jeremy M, Sheppard, Jeremy M, Cormack, Stuart, Taylor, Kristie-Lee, McGuigan, Michael R, and Newton, Robert U
- Abstract
Assessing the force-velocity characteristics of the leg extensors in well-trained jumping athletes: the incremental load power profile. J Strength Cond Res 22: 1320-1326, 2008-The purpose of this research project was to evaluate the methodology of an iso-inertial force-velocity assessment utilizing a range of loads and a group of high-performance athletes. A total of 26 subjects (19.8 ± 2.6 years, 196.3 ± 9.6 cm, 88.6 ± 8.9 kg) participated in this study. Interday reliability of various force-time measures obtained during the performance of countermovement jumps with a range of loads was examined, followed by a validity assessment of the various measures' ability to discriminate among performance levels, while the ability of the test protocol to detect training-induced changes was assessed by comparing results before and after an intensive 12-week training period. Force and velocity variables were observed to be reliable (intraclass correlation coefficient 0.74-0.99). Large effect size statistic (ES > 0.50) differences among player groups were observed for peak power (1.36-2.25), relative peak power (1.57-2.42), and peak force (0.74-0.95). Significant (p < 0.05) and large (ES > 0.50) improvements were observed in the kinetic values after the intensive training period. The results of this study indicate that the incremental load power profile is an acceptably reliable, valid, and sensitive method of assessing force and power capabilities of the leg extensors in high-performance and elite volleyball players.
- Published
- 2008
45. Reliability of power output during dynamic cycling
- Author
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Abbiss, Chris, Abbiss, Chris, Levin, Gregory, McGuigan, Michael R., Laursen, Paul B., Abbiss, Chris, Abbiss, Chris, Levin, Gregory, McGuigan, Michael R., and Laursen, Paul B.
- Abstract
The aims of the present study were to determine the influence of familiarization on the reliability of power output during a dynamic 30-km cycling trial and to determine the test-retest reliability following a 6-week period. Nine trained male cyclists performed five self-paced 30-km cycling trials, which contained three 250-m sprints and three 1-km sprints. The first three of these trials were performed in consecutive weeks (Week 1, Week 2 and Week 3), while the latter two trials were consecutively conducted 6 wk following (Week 9 and Week 10). Subjects were instructed to complete each sprint, as well as the entire trial in the least time possible. Reproducibility in average power output over the entire 30-km trial for Week 2 and 3 alone (coefficient of variation, CV = 2.4 %, intra-class correlation coefficient, ICC = 0.93) was better than for Week 1 and 2 (CV = 5.5 %, ICC = 0.77) and Week 9 and 10 alone (CV = 5.3 %, ICC = 0.57). These results indicate that high reliability during a dynamic 30-km cycling trial may be obtained after a single familiarization trial when subsequent trials are performed within 7 days. However, if cyclists do not perform trials for six weeks, the same level of reliability is not maintained.
- Published
- 2008
46. Relationships between sprinting, agility, and jump ability in female athletes
- Author
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Vescovi, Jason, Vescovi, Jason, Mcguigan, Michael R., Vescovi, Jason, Vescovi, Jason, and Mcguigan, Michael R.
- Abstract
The aim of this study was to assess the relationships between various field tests in female athletes. Altogether, 83 high school soccer, 51 college soccer, and 79 college lacrosse athletes completed tests for linear sprinting, countermovement jump, and agility in a single session. Linear sprints (9.1, 18.3, 27.4, and 36.6 m) and agility tests (Illinois and pro-agility) were evaluated using infrared timing gates, while countermovement jump height was assessed using an electronic timing mat. Pearson's product – moment correlation coefficients (r) were used to determine the strength and directionality of the relationship between tests and coefficients of determination (r 2) were used to examine the amount of explained variance between tests. All of the performance scores were statistically correlated with each other; however, the coefficients of determination were low, moderate, and high depending on the test pairing. Linear sprint split times were strongly correlated with each other (r = 0.775 to 0.991). The relationship between countermovement jump height and linear sprinting was stronger with the longer distances (27.4 and 36.6 m) than with the shorter distances (9.1 and 18.3 m), and showed a stronger relationship within the college athletes (r = −0.658 to −0.788) than high school soccer players (r = −0.491 to −0.580). The Illinois and pro-agility tests were correlated (r ≥ 0.600) with each other as well as with linear sprint times. The results of this study indicate that linear sprinting, agility, and vertical jumping are independent locomotor skills and suggest a variety of tests ought to be included in an assessment protocol for high school and college female athletes.
- Published
- 2008
47. Does performance of hang power clean differentiate performance of jumping, sprinting and changing of direction?
- Author
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Hori, Naruhiro, Hori, Naruhiro, Newton, Robert U, Andrews, Warren A, Kawamori, Naoki, McGuigan, Michael R, Nosaka, Kazunori, Hori, Naruhiro, Hori, Naruhiro, Newton, Robert U, Andrews, Warren A, Kawamori, Naoki, McGuigan, Michael R, and Nosaka, Kazunori
- Published
- 2008
48. Neuromuscular and Endocrine Responses of Elite Players During an Australian Rules Football Season
- Author
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Cormack, Stuart J, Cormack, Stuart J, Newton, Robert U, McGuigan, Michael R, Cormie, Prue, Cormack, Stuart J, Cormack, Stuart J, Newton, Robert U, McGuigan, Michael R, and Cormie, Prue
- Abstract
Purpose: To examine variations in neuromuscular and hormonal status and their relationship to performance throughout a season of elite Australian Rules Football (ARF). Methods: Fifteen elite ARF players performed a single jump (CMJ1) and 5 repeated countermovement jumps (CMJ5), and provided saliva samples for the analysis of cortisol (C) and testosterone (T) before the season commenced (Pre) and during the 22-match season. Magnitudes of effects were reported with the effect size (ES) statistic. Correlations were performed to analyze relationships between assessment variables and match time, training load, and performance. Results: CMJ1Flight time:Contraction time was substantially reduced on 60% of measurement occasions. Magnitudes of change compared with Pre ranged from 1.0 ± 7.4% (ES 0.04 ± 0.29) to -17.1 ± 21.8% (ES -0.77 ± 0.81). Cortisol was substantially lower (up to -40 ± 14.1%, ES of -2.17 ± 0.56) than Pre in all but one comparison. Testosterone response was varied, whereas T:C increased substantially on 70% of occasions, with increases to 92.7 ± 27.8% (ES 2.03 ± 0.76). CMJ1Flight time:Contraction time (r = .24 ± 0.13) and C displayed (r = -0.16 ± 0.1) small correlations with performance. Conclusion: The response of CMJ1Flight time:Contraction time suggests periods of neuromuscular fatigue. Change in T:C indicates subjects were unlikely to have been in a catabolic state during the season. Increase in C compared with Pre had a small negative correlation with performance. Both CMJ1Flight time:Contraction time and C may be useful variables for monitoring responses to training and competition in elite ARF athletes.
- Published
- 2008
49. Comparison of weighted jump squat training with and without eccentric braking
- Author
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Hori, Naruhiro, Hori, Naruhiro, Newton, Robert U, Kawamori, Naoki, McGuigan, Michael R, Andrews, Warren A, Chapman, Dale W, Nosaka, Kazunori, Hori, Naruhiro, Hori, Naruhiro, Newton, Robert U, Kawamori, Naoki, McGuigan, Michael R, Andrews, Warren A, Chapman, Dale W, and Nosaka, Kazunori
- Published
- 2008
50. Comparison between old and young men for responses to fast velocity maximal lengthening contractions of the elbow flexors
- Author
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Chapman, Dale W, Chapman, Dale W, Newton, Michael, McGuigan, Michael R, Nosaka, Kazunori, Chapman, Dale W, Chapman, Dale W, Newton, Michael, McGuigan, Michael R, and Nosaka, Kazunori
- Published
- 2008
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