著者

Paul Comfort Peter D. Mundy Philip Graham-Smith Paul A. Jones Laura C. Smith Jason P. Lake

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.5, no.1, pp.1-5, 2016-03-01 (Released:2016-05-20)

参考文献数

40

被引用文献数

2 6

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Objectives: The aim of this investigation was to compare peak power between the mid-thigh power clean, squat jump and push press. Design and Methods: Eleven recreationally trained men (age 22.2 ± 3.5 yrs; height 178.6 ± 8.5 cm; body mass 88.7 ± 13.5 kg) performed one set of three repetitions of the mid-thigh power clean, squat jump and push press, with 50, 60 and 70% of respective 1RM, while standing on two force platforms. The effect of load and lift on peak power was analyzed with two-way analysis of variance. Results: Peak power was highest during mid-thigh power clean (4739.2 ± 1015.8 W), but was not significantly higher than the squat jump (4430.4 ± 1140.3 W, Cohen’s d = 0.29) and push press (4071.1 ± 1552.3 W, Cohen’s d = 0.51) performed at equiva lent intensities. Similarly, the load effect on peak power was non-significant and trivial (Cohen’s d < 0.35). Conclusions: The findings of this study show that when training to maximize peak power output the mid-thigh power clean, squat jump and push press performed at 50-70% of 1RM could be incorporated interchangeably without any detriment to peak power output.

著者

Thomas Dos’Santos Christopher Thomas Paul A. Jones Paul Comfort

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.6, no.2, pp.35-41, 2017-06-17 (Released:2017-08-19)

参考文献数

35

被引用文献数

1 60

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Objectives: To determine the impact of between limb asymmetries in hop performance on change of direction speed (CODS). Design and Methods: Twenty-two multisport collegiate athletes (mean ± SD; age: 21.8 ± 3.4 years, height: 178.1 ± 6.7 cm, mass: 73.5 ± 7.1kg) performed three single and triple horizontal hops for distance per limb, followed by three modified 505 and 90˚cut CODS trials each side to establish imbalances between right and left, and dominant (D) and non-dominant (ND) limbs. Limb dominance was defined as the limb that produced the furthest hop or faster CODS performance. Results: Paired sample t-tests revealed no significant differences in hop performance and CODS performance between right and left limbs (p > 0.05, g ≤ 0.11), however, significant differences were observed when comparing D and ND limbs (p < 0.001, g = 0.46-0.61). No significant correlations were observed between hop imbalance and CODS performance (p > 0.05, r ≤ 0.35). Low agreements (32-55%) were demonstrated between like for like identifications of asymmetry for CODS and hop performance. Conclusions: Imbalances in hop and CODS were present; however, greater hop imbalances were not detrimental to CODS. Furthermore, the D limb for hopping did not necessarily correspond to faster performance from that limb during 180˚ turns and 90˚ cuts (plant foot). Collegiate male multi-sport athletes with imbalances within the range reported within this study (≤ 15%) should not experience associated CODS detriments.

著者

Michael B. Zweifel Andrew D. Vigotsky Bret Contreras Wycliffe W. Njororai Simiyu

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.6, no.1, pp.13-17, 2017-02-11 (Released:2017-05-12)

参考文献数

18

被引用文献数

1 6

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Objectives: To compare the ergogenic effects of back squats, deadlifts, and hip thrusts. Design: Pilot randomized-controlled trial Methods: In order to determine the feasibility of such a large training study, a pilot study was carried out with 26 male and female participants (age = 22.15 ± 2.2 years; height = 180.17 ± 8.37 cm; body mass = 87.27 ± 15.72 kg). Subjects performed squats (n = 8), hip thrusts (n = 8), deadlifts (n = 6), or nothing (control) (n = 4) for three training sessions a week, for six weeks; thereafter, measures of sprinting performance, vertical jump, broad jump, strength, and change of direction were compared to baseline. Results: This pilot study was carried out successfully. Effect-sizes, medians, and interquartile ranges for all possible comparisons have been presented for power analyses. Conclusion: Although all of the studied interventions show promise, larger investigations are necessary in order to draw more definitive, applicable conclusions.

著者

Jeremy P Loenneke

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.1, no.2, pp.28-31, 2012-09-05 (Released:2015-05-04)

参考文献数

28

被引用文献数

6 6

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Current recommendations for training protocols aimed at increasing muscle mass are commonly based on a percentage of the concentric one repetition maximum (1RM) for a particular exercise. However, research utilizing lower exercise intensities (20- 30% 1RM) has been observed to result in skeletal muscle hypertrophy similar to that of higher intensity resistance training. These findings appear to question the overall importance of exercise intensity for increasing muscle mass. Objectives: The purpose of this manuscript is to discuss the skeletal muscle hypertrophy exercise intensity recommendations and provide discussion on overall exercise volume, which is likely more important for stimulating skeletal muscle hypertrophy than exercise intensity per se. Design and Methods: Non-systematic review Results: It appears that a large portion of the exercise recommendations for skeletal muscle hypertrophy appear to be based on protocols that elicit short term changes in systemic ‘anabolic' hormones; although little conclusive evidence exists to support that ‘anabolic' hormone hypothesis. Exercise volume may be of much more importance for stimulating and maximizing the duration of the muscle protein synthesis (MPS) response than exercise intensity per se. In addition,chronic training studies confirm the acute findings that volume, not exercise intensity is the mediating factor for skeletal muscle hypertrophy. Conclusion: The data suggests that skeletal muscle hypertrophy recommendations on the basis of exercise intensity are too simplistic and more focus should instead be placed on total exercise volume. The current recommendations for muscle hypertrophy do not reflect current science.

著者

A. Bailey Christopher C. McInnis Timothy J. Batcher Justin

出版者

アクティブ・エイジングリサーチセンター

雑誌

Journal of Trainology

巻号頁・発行日

vol.5, no.2, pp.43-45, 2016

被引用文献数

7

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<p><i><b>Objectives</b></i>: The purpose of this investigation was to evaluate the intra- and intersession reliability of a new inertial measurement unit (ZEPP Sensor (ZS)) for bat swing mechanical analysis. <i><b>Design and Methods</b></i>: This investigation included 16 male collegiate baseball players (89.53 ± 12.5 kg, 180.61 ± 6.5 cm, 20.12 ± 0.8 years). Following a whole body dynamic warm-up and 5 dry swings, 5 swings were recorded where athletes hit balls off of a tee with bats instrumented with a ZS. Data collection took place on 3 days. Intrasession reliability analyzed trial to trial data, while intersession reliability analyzed data from each of the 3 sessions. Both relative and absolute measures of reliability were calculated with intraclass correlation coefficients (ICC), coefficients of variation (CV), and limits of agreement (LOA). <i><b>Results</b></i>: Within and between session acceleration/time related variables produced excellent relative reliability measurements (ICCs 0.882-0.988) as well as acceptable absolute measures of reliability (CVs 1.9%-9.2%). Variables derived from the gyro scope did not display the same consistency (intrasession vertical angle ICC = 0.492, intersession attack angle CV = 108.6%). <i><b>Conclusions</b></i>: Considering acceleration/time data, the ZS appears to be a reliable method of monitoring bat swing mechanics, but not for the angular position variables. Changes in body position have been demonstrated with fatigue in jumping performance. Similarly, bat position changes may occur with fatigue and should be monitored, but coaches and sport scientists should use caution when selecting variables to monitor and only select those that are reliable.</p>

著者

Timothy J. Suchomel George K. Beckham and Glenn A. Wright

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.2, no.2, pp.19-22, 2013-09-25 (Released:2015-05-04)

参考文献数

14

被引用文献数

11 28

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Objectives: To examine the impact of load on lower body kinetics during the jump shrug. Design: Randomized, repeated measures design. Methods: Fourteen men performed randomized sets of the jump shrug at relative loads of 30%, 45%, 65%, and 80% of their one repetition maximum hang clean (1RM-HC). A number of variables were obtained through analysis of the force-time data, which included peak force, peak velocity, peak power, force at peak power, and velocity at peak power. A series of one-way repeated measures ANOVA were used to compare the differences in peak force, peak velocity, peak power, force at peak power, and velocity at peak power between each load. Results: Statistical differences in peak velocity, peak power, force at peak power, and velocity at peak power existed between loads (p<0.001), while peak force trended toward statistical significance (p=0.060). The greatest peak velocity, peak power, and velocity at peak power occurred at 30% 1RM-HC. In addition the greatest peak force and force at peak power occurred at loads of 65% and 80% 1RM-HC, respectively. Conclusions: Velocity is the greatest contributing factor to peak power production during the jump shrug. Practitioners should prescribe specific loading schemes for the jump shrug to provide optimal training stimuli to their athletes based on the training goal: specifically, loads of 65% 1RM-HC or higher, loads of approximately 30-45% 1RM-HC, and loads of 30% 1RM-HC should be prescribed for improvements in peak force and force at peak power, peak power, and velocity and velocity at peak power, respectively.

著者

Kevin M. Carroll Kimitake Sato George K. Beckham Travis Triplett N. Cameron V. Griggs Michael H. Stone

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.6, no.1, pp.9-12, 2017-01-26 (Released:2017-04-25)

参考文献数

16

被引用文献数

6

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Objectives: The purpose of this study was to examine the relationship of velocities in the back squat between one repetition maximum (1RM) and submaximally loaded repetition maximum (RM) conditions, specifically in regard to what has been described as the minimal velocity threshold (MVT). The MVT describes a minimum concentric velocity that an individual must reach or surpass in order to successfully complete a repetition. Design: To test the presence of a MVT, participants were tested for 1RM and RM back squat ability. The mean concentric veloci ties (MCV) of the last successful repetition of each condition were then compared. Methods: Fourteen male participants familiar with the back squat volunteered to participate in the current study (age = 25.0 y ± 2.6, height = 178.9 cm ± 8.1, body mass = 88.2 kg ± 15.8). The mean concentric velocity (MCV) during the last successful repetition from each testing condition was considered for the comparison. Results: Results indicated a non-significant negative relationship of MCV between the 1RM and RM conditions (r = -0.135), no statistical difference between testing conditions (p = 0.266), with a small-to-moderate effect size (d = 0.468). Conclusions: The results of this study suggest that MVT should be further investigated to enhance its use in the practical setting. Additionally, coaches considering using a velocity-based approach for testing athletes should use data from either 1RM or RM conditions, but not both interchangeably. Coaches should be cautious when considering group averages or comparing velocity data between athletes, which may not be appropriate based on our results.

著者

Jeremy A. Gentles William G. Hornsby Howard S. Gray Jonathan A. Miller Andrew R. Dotterweich Charles A. Stuart Michael H. Stone

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.4, no.1, pp.25-31, 2015-06-18 (Released:2015-07-06)

参考文献数

47

被引用文献数

3

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Objectives: This study investigated chronic changes in cell free DNA (cf-DNA) throughout a collegiate soccer season. The relationship between cf-DNA, C-reactive protein (CRP), creatine kinase (CK), testosterone (T), cortisol (C), testoster one-cortisol ratio (T:C), body mass and body composition were also examined. Design: Longitudinal study design with repeated measures and group comparisons. Methods: Twenty three NCAA Division I male soccer players were divided into two groups. Starters were placed in Group 1 (G1) and non-starters were placed in Group 2 (G2). cf-DNA, CRP, CK, T, C, T:C, body mass and body composition were taken three times, corresponding to pre-season, approximately mid-season and immediately after the concluding the season. Results: In G1, cf-DNA, CRP, CK, cf-DNA %∆, CRP %∆ and, CK %∆ were all statistically higher at T2 and T3 than T1. In G2, CRP %∆ was statistically higher at T2 than T1. In G2, cf-DNA %∆, CRP %∆ and CK %∆ were higher at T2 and T3 than T1. Conclusions: This suggests that cf-DNA may be a useful marker that can reflect accumulated soccer training and competi tive stressors.

著者

James Fisher James Steele Matthew Brzycki Bill DeSimone

出版者

Active Aging Research Center

雑誌

Journal of Trainology (ISSN:21865264)

巻号頁・発行日

vol.3, no.1, pp.31-34, 2014-04-25 (Released:2015-05-04)

参考文献数

35

被引用文献数

1 5

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Objectives: Recently attention has been brought to potentially unsafe training methods within the practice of resistance training. Thus purpose of this commentary is to highlight the importance of the moral injunction Primum non nocere, and of weighing risks to rewards of training methods, for those providing resistance training recommendations and practitioners of it as a training approach. Design & Methods: Narrative review Results: It appears that many popular resistance training methods that make use of either explosive movements or unstable platforms with heavy external loading may present an increased risk of injury. In addition they may not offer any greater improvements to measures of health and fitness above safer alternatives that utilise more controlled repetition durations and avoid use of unstable platforms. Indeed, as resistance type and load may not be as important for determining strength or hypertrophic adaptations as previously thought, nor does there appear to be much supporting evidence for the transfer of balance skills developed using unstable platforms to other movement skills, the necessity of such unsafe practices appears further questionable. Conclusions: It is recommended that persons wishing to engage in resistance training for the purposes of health and fitness whilst reducing risk of injury should utilise a controlled repetition duration that maintains muscular tension and avoid use of unstable platforms. Indeed, practices involving use of lower external loads, or even the absence of external loads such as bodyweight training or isometric co-contraction, may also be effective and may pose an even lower risk of injury.