Countermovement jump variables not tensiomyography can distinguish between sprint and endurance focused track cyclists
- Authors: Lewis, Mitchell , Young, Warren , Knapstein, Luke , Lavender, Andrew , Talpey, Scott
- Date: 2022
- Type: Text , Journal article
- Relation: Biology of Sport Vol. 39, no. 1 (2022), p. 67-72
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- Description: This study investigated the reliability and discriminative ability of tensiomyography and countermovement jump variables as measures of a muscles contractile properties in a cohort of elite endurance and sprint track cyclists. Tensiomyography was performed on the vastus lateralis (VL) and rectus femoris (RF) muscles in sprint track cyclists (N = 8) and endurance track cyclists (N = 8). Additionally, the participants completed a countermovement jump on a force plate. Tensiomyography measurements obtained from the RF displayed greater reliability (ICC = 0.879–0.997) than VL (ICC = 0.746–0.970). Radial muscle belly displacement (Dm), contraction time (Tc) and delay time (Td) demonstrated the most reliable TMG measurements. Only two variables displayed acceptable coefficient of variation (RF Td = 8.89, VL Td = 6.88), other variables presented as unacceptable. The TMG variables were unable to discriminate between endurance and sprint track cyclists whilst the CMJ variables could. Due to the high variability in measurements and its inability to distinguish between sprint and endurance based track cyclists TMG should be used cautiously in this athlete population and if available the CMJ is a more appropriate assessment of leg muscle function. © 2022 Institute of Sport. All rights reserved.
The occurrence of different vertical jump types in basketball competition and their relationship with lower-body speed-strength qualities
- Authors: Talpey, Scott , Smyth, Andrew , O'Grady, Mathew , Morrison, Matthew , Young, Warren
- Date: 2021
- Type: Text , Journal article
- Relation: International Journal of Strength and Conditioning Vol. 1, no. 1 (2021), p.
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- Description: Jumps occur frequently in basketball and can be executed from a single-leg take-off following a run-up or bilaterally from a standing start. Understanding the type of jumps performed in competition and how different muscular qualities influence their performance, informs training prescription. Firstly, to quantify the occurrence of different jump types performed in competition an analysis of 15 semi-professional basketball games was undertaken. Secondly, to understand the influence of muscular qualities on performance of different jump types, Semi-professional male basketball players (N=17) performed jump tests standing vertical jump, running vertical jumps with a double leg take-off (RVJ2) and a single leg take-off (RVJ1) and tests of lower-body speed-strength reactive strength index (RSI) from a drop jump, counter movement jump (CMJ) and squat jump. A stationary approach was employed for 69%, a running approach for 26% and a one-step approach for 5%. RVJ1 displayed non-significant (P=0.07) moderate correlation with jump height attained from the CMJ (r=0.439) and a very large (r =.806) significant (P<0.01) correlation with RSI. Most jumps were executed from a stationary start with a bilateral take-off while a run-up occurred prior to a substantial proportion of jumps. Jumps with a single-leg take-off from a run-up strongly correlate with RSI.
Relationship between selected physical qualities, bowling kinematics, and pace bowling skill in club-standard cricketers
- Authors: Feros, Simon , Young, Warren , O'Brien, Brendan
- Date: 2019
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 33, no. 10 (Oct 2019), p. 2812-2825
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- Description: Although strength and conditioning of cricket pace bowlers has become more specialized in recent times, little is understood about the interplay between physical capacities, pace bowling kinematics, and pace bowling skill measures. This study sought to determine these interrelationships. Thirty-one male club-standard pace bowlers completed 3 test sessions on separate occasions 4-7 days apart. The first testing session comprised an 8-over pace bowling assessment, where bowling skill and selected bowling kinematics were measured. A physical test battery was completed over the remaining 2 sessions. Peak and mean ball release (BR) speed were related with 1 repetition maximum pull-up strength (r(s) = 0.56, p = 0.005) and correlated with 20-m sprint time (r(s) = -0.42, p = 0.022; r(s) = -0.37, p = 0.044, respectively). Mean radial error was associated with 10-m and 20-m sprint times (r(s) = 0.41, p = 0.030; r(s) = 0.38, p = 0.037, respectively), and correlated with height and peak power from 3 countermovement jumps (CMJs) (r(s) = -0.39, p = 0.036; r(s) = -0.41, p = 0.031, respectively), and mean peak power from 20 CMJs (r(s) = -0.45, p = 0.020). Bivariate variable error was correlated with front-leg extension angle at BR (r(s) = 0.41, p = 0.036), and also with approach speed (r(s) = -0.36, p = 0.050). These relationships may assist strength and conditioning coaches in designing more effective training programs to enhance bowling speed and accuracy. Training interventions are warranted, however, to validate these associations.
Is nine weeks of complex training effective for improving lower body strength, explosive muscle function, sprint and jumping performance?
- Authors: Talpey, Scott , Young, Warren , Saunders, Natalie
- Date: 2016
- Type: Text , Journal article
- Relation: International Journal of Sports Science & Coaching Vol. 11, no. 5 (2016), p. 736-745
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- Description: There is currently minimal evidence from training studies that document the effectiveness of complex training to elicit gains in explosive muscle function that are greater than those obtained from a more conventional approach. Over nine weeks of training, 20 recreationally trained athletes with a minimum of one year of resistance training experience were randomly assigned to either a complex training group (n=9) or a conventional training group (n=11). In an attempt to capitalise on muscles post-activation potentiation response, the complex training group performed all sets of 1/2 back squats prior to sets of jumps squats, while the conventional training group performed jump squats prior to sets of 1/2 back squats. Lower body explosive muscle function and jump performance improved significantly in both groups. The complex training group's improvement in running vertical jump performance was significantly greater than in the conventional groups. Sprint performance was not significantly improved in either training group.
The effect of including a series of isometric conditioning contractions to the rowing warm-up on 1,000-m rowing ergometer time trial performance
- Authors: Feros, Simon , Young, Warren , Rice, Anthony , Talpey, Scott
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Strength and Conditioning Research Vol. 26, no. 12 (2012), p. 3326-3334
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- Description: The effect of including a series of isometric conditioning contractions to the rowing warm-up on 1,000-m rowing ergometer time trial performance. J Strength Cond Res 26(12): 3326-3334, 2012- Rowing requires strength, power, and strength-endurance for optimal performance. A rowing-based warm-up could be enhanced by exploiting the postactivation potentiation (PAP) phenomenon, acutely enhancing power output at the beginning of a race where it is needed most. Minimal research has investigated the effects of PAP on events of longer duration (i.e. 1,000-m rowing). The purpose of this research was to investigate the effects of PAP on 1,000-m rowing ergometer performance through the use of 2 different warm-up procedures: (a) a rowing warm-up combined with a series of isometric conditioning contractions, known as the potentiated warm-up (PW), and (b) a rowing warm-up only (NW). The isometric conditioning contractions in the PW were performed by "pulling" an immovable handle on the rowing ergometer, consisting of 5 sets of 5 seconds (2 seconds at submaximal intensity, and 3 seconds at maximal intensity), with a 15-second recovery between sets. The 1,000-m rowing ergometer time trial was performed after each warm-up condition, whereby mean power output, mean stroke rate, and split time were assessed every 100 m. Ten Australian national level rowers served as the subjects and performed both conditions in a counterbalanced order on separate days. The PW reduced 1,000-m time by 0.8% (p > 0.05). The PW improved mean power output by 6.6% (p < 0.01) and mean stroke rate by 5.2% (p < 0.01) over the first 500 m; resulting in a reduction of 500-m time by 1.9% (p < 0.01), compared with the NW. It appears that the inclusion of isometric conditioning contractions to the rowing warm-up enhance short-term rowing ergometer performance (especially at the start of a race) to a greater extent than a rowing warm-up alone. © 2012 National Strength and Conditioning Association.
- Description: 2003010579
Which jump variables should be used to assess explosive leg muscle function?
- Authors: Young, Warren , Cormack, Stuart , Crichton, Michael
- Date: 2011
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 6, no. 1 (2011), p. 51-57
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- Description: Purpose: The main purpose of this study was to determine the relationships between countermovement jump (CMJ) variables and acceleration and maximum speed performance. Methods: Twenty-three elite Australian football players were tested on a CMJ, which yielded several kinematic and kinetic variables describing leg muscle function. A 40 m sprint was also conducted to assess acceleration (10 m time) and an estimate of maximum speed (flying 20 m time). Players from one Australian Football League (AFL) club were tested and Pearson correlations for CMJ variables and sprint performance were calculated. Results: Jump height, peak velocity, peak force, and peak power had less than 50% common variance, and therefore represented independent expressions of CMJ performance. Generally, the correlations between CMJ variables and sprinting performance were stronger for maximum speed (small to large effect sizes) than for acceleration (trivial to moderate sizes). The variable that produced the strongest correlation with acceleration was jump height (r = -0.430, P = .041) and with maximum speed was peak power/weight (r = -0.649, P = .001). Conclusions: The results indicate that if an integrated system comprising a position transducer and a force platform is available for CMJ assessment, jump height and peak power/weight are useful variables to describe leg muscle explosive function for athletes who perform sprints.
The use of static stretching in warm-up for training and competition
- Authors: Young, Warren
- Date: 2007
- Type: Text , Journal article
- Relation: International journal of sports physiology and performance Vol. 2, no. 2 (2007), p. 212-216
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- Description: Static stretching (SS) is widely used in warm-ups before training and competition. A growing amount of research, however, has demonstrated that SS can impair muscle performance, leading to a reevaluation of optimal warm-up protocols. This commentary discusses many of the methodological issues that can influence conclusions about the acute effects of SS on performance. One difficulty in interpreting the literature is the lack of control or communication about the volume and intensity of the various stretching treatments used. Another major issue is the failure of many researchers to evaluate SS as it is used in practice, particularly the interaction with the other general and sport-specific components of the warm-up. Acute warm-up effects on performance should be considered in conjunction with potential effects on injury prevention. Future directions in research include optimizing general and sport-specific warm-ups, time course of physiological and performance effects, and individualization of warm-ups according to fitness and skill level.
- Description: 2003005660
Physiological and anthropometric characteristics of starters and non-starters and playing positions in elite Australian Rules football : A case study
- Authors: Young, Warren , Newton, Robert , Doyle, Tim , Chapman, Dale , Cormack, Stuart , Stewart, Glenn , Dawson, Brian
- Date: 2005
- Type: Text , Journal article
- Relation: Journal of Science and Medicine in Sport Vol. 8, no. 3 (Sep 2005), p. 333-345
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- Description: A purpose of this study was to determine if pre-season anthropometric and physiological measures were significantly different for the players from one Australian Football League (AFL) club selected to play in the first game of the season compared to the players not selected. Another purpose was to compare fitness test results for defenders, forwards and mid-fielders in the same AFL club. Thirty-four players were tested for isolated quadriceps and hamstrings strength, leg extensor muscle strength and power, upper body strength, sprinting speed, vertical jump (VJ), endurance, skinfolds and hamstring flexibility. The starters who were selected to play the first game were a significantly older and more experienced playing group, and were significantly better (p < 0.05) in measures of leg power, sprinting speed and the distance covered in the Yo Yo intermittent recovery test compared to the non-starters. Although there were trends for the superiority of the starters, the differences in lower and upper body strength, VJ and predicted VO(2)max were nonsignificant. The forwards generally produced the worst fitness scores of the playing positions with the midfielders having significantly lower skinfolds and the defenders possessing better hamstring strength and VJ compared to the forwards. It was concluded that some fitness qualities can differentiate between starters and non-starters, at least in one AFL club. Comparisons of playing positions and the development of fitness norms for AFL players require further research.
- Description: C1
- Description: 2003001187
An acute bout of static stretching : Effects on force and jumping performance
- Authors: Power, Kevin , Behm, David , Cahill, Farrell , Carroll, Michael , Young, Warren
- Date: 2004
- Type: Text , Journal article
- Relation: Medicine and Science in Sports and Exercise Vol. 36, no. 8 (2004), p. 1389-1396
- Full Text: false
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- Description: Introduction/Purpose: The objectives of this study were to examine whether a static stretching (SS) routine decreased isometric force, muscle activation, and jump power while improving range of motion (ROM). Second, the study attempted to compare the duration of the dependent variable changes with the duration of the change in ROM. Methods: Twelve participants were tested pre- and post- (POST, 30, 60, 90, and 120 min) SS of the quadriceps and plantar flexors (PF) or a similar period of no stretch (control). Measurements during isometric contractions included maximal voluntary force (MVC), evoked contractile properties (peak twitch and tetanus), surface integrated electromyographic (iEMG) activity of the agonist and antagonistic muscle groups, and muscle inactivation as measured by the interpolated twitch technique (ITT). Vertical jump (VJ) measurements included unilateral concentric-only (no countermovement) jump height as well as drop jump height and contact time. ROM associated with seated hip flexion, prone hip extension, and plantar flexion-dorsiflexion was also recorded. Results: After SS, there were significant overall 9.5% and 5.4% decrements in the torque or force of the quadriceps for MVC and ITT, respectively. Force remained significantly decreased for 120 min (10.4%), paralleling significant percentage increases (6%) in sit and reach ROM (120 min). After SS, there were no significant changes in jump performance or PF measures. Conclusion: The parallel duration of changes in ROM and quadriceps isometric force might suggest an association between stretch-induced changes in muscle compliance and isometric force output.
- Description: C1
- Description: 2003001185
The effect of a resistance training programme on the grab, track and swing starts in swimming
- Authors: Breed, Ray , Young, Warren
- Date: 2003
- Type: Text , Journal article
- Relation: Journal of Sports Sciences Vol. 21, no. 3 (2003), p. 213-220
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- Description: The aim of this study was to establish the effectiveness of a resistance training programme, designed to improve vertical jumping ability, on the grab, swing and rear-weighted track starts in swimming. Twenty-three female non-competitive swimmers participated (age 19.9±2.4 years; mean±s). The diving techniques were practised weekly for 8 weeks. The participants were randomly assigned to a control group (n = 11) or a resistance-training group (n = 12), which trained three times a week for 9 weeks. The tests before and after the training programme involved performing each dive technique and six dry-land tests: two countermovement jumps (with and without arms), two isokinetic squats (bar speeds of 0.44 and 0.70 rad.s-1) and two overhead throws (with and without back extension). A repeated-measures multivariate analysis of variance was used to show that resistance training improved performance in the dry-land tests (P < 0.0001). No significant improvements due to training were found for any temporal, kinematic or kinetic variables within the grab or swing starts. Significant improvements (P < 0.05) were found for the track start for take-off velocity, take-off angle and horizontal impulse. The results suggest that the improved skill of vertical jumping was not transferred directly to the start, particularly in the grab technique. Non-significant trends towards improvement were observed within all starts for vertical force components, suggesting the need to practise the dives to retrain the changed neuromuscular properties.
- Description: C1
- Description: 2003000554