International Journal of Strength and Conditioning最新文献

{"title":"Measurement of Absolute and Relative Reliability during the Countermovement and Split-Squat Jump using PUSH Pro Band 2.0.","authors":"K. McCurdy, John Walker, David Pozuc, Jordan Pitts","doi":"10.47206/ijsc.v2i1.133","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.133","url":null,"abstract":"The purpose of this study was to determine the relative and absolute reliability using PUSH Pro Band 2.0 IMU to measure peak velocity and power during the countermovement (CMJ) and split-squat jump (SSJ). Twenty-three resistance trained males and females completed the study.   After a familiarization session, each subject completed 2 identical sessions separated by a minimum of 72 hours that included 4 loads during the CMJ (body weight, body weight plus 20, 40 and 60%) and SSJ (body weight, body weight plus 15, 30 and 45%).  In each session, 3 repetitions were completed at each load in randomized order with 3 minutes rest between sets and 5 minutes rest between jump types.  Dumbbells held to the side were used to add load.  A waist belt was worn that contained the accelerometer. High relative (intra-class coefficient ranging from 0.86-0.99) and absolute (coefficient of variation ranging from 1.7-8.0%) reliability were found for all measures of peak velocity and power during the CMJ and SSJ.  The PUSH device produced highly reliable measures of jump performance across all loads between trials and across sessions.  ","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126893288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Do Acute Bouts of Resistance Training Influence the Psychometric Status and Affective State of Prepubertal Weightlifters?","authors":"Werfelli Hanen, R. Hammami, Walid Selmi, Mohamed Amine Selmi, D. Sekulić, H. Rebai, U. Granacher, J. Moran","doi":"10.47206/ijsc.v2i1.111","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.111","url":null,"abstract":"Resistance training (RT) can represent a challenging and stressful endeavour for those who participate in it. We aimed to investigate the acute effect of four types of RT exercise [i.e., Concentric (CONC), Isometric (ISOM), Dynamic (DYN) and Eccentric (ECC)] on psychological parameters (feeling scale: FS) and perceived internal load (RPE) in young elite weightlifters. The RT protocols were differentiated according to the contractile characteristics of the involved muscles and comprised: (i) CONC: 3 sets of 3 hurdle jumps; (ii) ECC: 3 sets of drop jumps; (iii) ISOM: 3 sets of 3-second maximal isometric back squat; (iv) DYN: 3 sets of 3 repetitions of 10 RM maximal back squats. Thereafter, participants were reported scores for RPE and FS. The execution of different types of RT exercises did not induce changes in FS. On the contrary, differences in RPE were observed with the CONC protocol being the least acutely strenuous, followed by the ECC and DYN methods. Of all four types used in this study, ISOM seemed to induce the highest RPE score , though these remained relatively low across the 10-point scale. Coaches can manipulate training activities based on the condition of the athlete and the potential physical strain that is associated with each exercise type. \u0000Key words: Plyometrics, strenghtening, psychometric status, affective prevalence","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"228 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133144625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Instruction on Isometric Mid-Thigh Pull Force-Time Variables","authors":"Brian T. McCormick, S. Talpey, L. James, C. MacMahon","doi":"10.47206/ijsc.v2i1.134","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.134","url":null,"abstract":"Purpose: The isometric mid-thigh pull (IMTP) is commonly used to assess maximal and rapid (i.e., explosive) strength in athlete populations. The conventional IMTP instruction is to pull “as hard and fast as possible” (CON). However, previous studies using other isometric tests indicate that the use of ‘hard’ and ‘fast’ independently can result in different test outcomes. This investigation assessed the impact of a ‘hard’ only (HARD) and ‘fast’ only (FAST) instruction on IMTP kinetics when compared to the conventional combined instruction. Methods: Over three separate testing sessions, 17 National level, male, youth footballers (age: 16.4±1.3yr, mass: 69.7±8.0kg, height: 1.75±0.07m) completed three trials of the IMTP under each instruction. Peak force (N) and rapid force production, measured as impulse (N.s-1) over 50ms, 75ms, 100ms, 150ms, and 200ms were extracted and brought forward for analysis. To determine the presence of a statistical difference between conditions, a repeated measures ANOVA was employed while Cohen’s d effects sizes were used to quantify the magnitude of practical difference between each condition. Results: There was no significant or practically relevant impact of instruction condition on peak force (P > 0.05, d=0.08-0.27), or impulse over any time frame (P > 0.05, d=0.01-0.16). Conclusion: Practitioners can be confident that the conventional IMTP instruction is suitable for continued use in this athlete population.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134183815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effects of a Peaking Protocol on Heart Rate Variability and its Predictive Associations with Wilks Coefficient in Competitive Powerlifters","authors":"Mitchell C. Cholewinski, Steven B. Machek, T. Cardaci, Dylan T. Wilburn, D. Willoughby, L. Funderburk, Andrew R. Gallucci","doi":"10.47206/ijsc.v2i1.115","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.115","url":null,"abstract":"Powerlifting competition is comprised of three barbell lifts: squat, bench press, and deadlift that are all completed in a single day and summed together, ultimately normalized to the lifter’s body weight via the Wilks Coefficient. This figure is then subsequently employed to determine the “best” athlete in that meet. During the competition preparation, powerlifters often undergo peaking protocols which include physiologically taxing overreach and low-volume, recovery-focused taper phases to collectively induce super-compensatory strength adaptations. Heart rate variability (HRV) has emerged as an easily accessible, user-friendly biomarker for autonomic nervous system-associated fatigue and readiness. Therefore, the purpose of this observational study was to investigate the potential impact of a peaking protocol on fatigue/readiness via HRV measurements and its possible relationship with competitive powerlifting performance. Daily measurements of HRV were taken, each morning, using the HRV4Trainning smartphone application by nineteen competitive powerlifters (26.16±4.56 years) from 14-days prior to a peaking protocol, throughout individual peaking phases, on meet day, and 14-days following competition. A quadratic regression was used to determine the predictability of HRV measurements and powerlifting performance. The change in HRV from competition day to baseline was found to be a significant predictor of Wilks coefficient (p=0.038,","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"45 19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117173397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Acute Effects of Weighted Vest Protocols on 20-Metre Sprint Performance in Youth Soccer Players","authors":"Thomas Bright, J. Hughes, Matthew J. Handford, B. Anniss, Caroline Westwood","doi":"10.47206/ijsc.v2i1.104","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.104","url":null,"abstract":"This investigation examined the effects of a warm-up containing weighted vest (WV) sprints on subsequent 20-metre sprint time relative to a control (C) condition in youth soccer players (n=12, mean ± SD age 16 ± 0.60 years, height 175.17 ± 5.92 cm and body mass 61.85 ± 5.88 kg). The main experimental trials consisted of three WV conditions at 10, 20 and 30% of body mass (WV10, WV20 and WV30) and C. Participants were required to complete one 20-metre sprint with each of WV conditions or without additional mass as part of C prior to a 20-metre sprint at 4-, 8- and 12-minutes. A two-way repeated measures ANOVA revealed no significant difference between any of the conditions and rest periods (p = >0.05). The between condition effect sizes for 20-metre sprint times were moderate at 4- and 12-minutes post WV10 (d = -0.86 and -1.15, respectively) and 12-minutes post WV20 (d = -0.84) and WV30 (d = -0.80). Moderate effect sizes were also observed at 4-minutes post WV10 (d = -1.04) and WV20 (d = -0.67) for 10-metre sprint times. These findings demonstrate that WV loading has no significant effect on 20-metre sprint time in youth soccer players. However, there is an opportunity for S&C coaches to implement WV warm-ups of no more than 30% body mass to improve 20-metre sprint times.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125744069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does Split-Body Resistance Training Routine Performed Two Versus Three Days Per Week Induce Distinct Strength and Morphological Adaptations in Resistance-Trained Men? A Randomized Longitudinal Study","authors":"Felipe Alves Brigatto, Júlio Benvenutti Bueno de Camargo, Yuri Benhur Machado, Moisés Diego Germano, Marcelo Saldanha Aoki, Tiago Volpi Braz, Charles Ricardo Lopes","doi":"10.47206/ijsc.v2i1.96","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.96","url":null,"abstract":"The purpose of this study was to investigate the chronic effects of training muscle groups, through a split-body routine on 2 versus 3 days per week, on neuromuscular performance and morphological adaptations in resistance-trained men with the number of sets per muscle group equated between conditions. Twenty healthy men (28.8 ± 6.1 years [range 19 to 37 years]; 172.8 ± 5.1 cm; total body mass = 70.2 ± 7.4 kg; RT experience = 3.5 ± 0.8 years [range 2 to 5 years]; RT frequency = 4.4 ± 0.5 session·wk-1) volunteered to participate in this study. Subjects were randomly assigned into 2 experimental groups: (1) 2 sessions·wk-1 per muscle (G2x, n = 10), in which every muscle was trained twice a week with 9 sets or (2) 3 sessions·wk-1 per muscle (G3x, n = 10), in which every muscle was trained thrice a week with 6 sets. All other variables were held constant over the 8-week study period. No significant difference between conditions for maximal strength in the back squat and bench press, muscle thickness of the biceps brachii, triceps brachii, vastus lateralis and anterior quadriceps (rectus femoris and vastus intermedius) was detected. In conclusion, both G2x and G3x significantly enhance muscular adaptations, with a similar improvement noted between experimental conditions.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129185639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Different Foam Rolling Protocols on Ankle Range of Motion, Strength, Muscle Activation and Jump Performance","authors":"E. Soares, Vinícius Martins Almeida, Christine Megumi Wakuda de Abreu Vasconcelos, João Henrique Barbosa de Jesus, Charles Ricardo Lopes","doi":"10.47206/ijsc.v2i1.97","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.97","url":null,"abstract":"Background: Foam rolling (FR) has been widely used with the intent to increase range of motion (ROM) before strength and power activities. At the moment, few studies have investigated practical strategies to control FR intensity. Purpose: The aim was to compare the effect (FR) intensity by different combinations of a smooth roller, grid roller, unilateral or bilateral rolling massage on the triceps suralis ROM, strength, muscle activation, and jump performance. Methods: Ten male (28±4 years, 175±5 cm, 81±13 kg) and ten female (29±4 years, 163±5 cm, 66±10 kg) recreationally trained performed two sessions of data collection that compared 4 combinations of rolling surface and technique: unilateral smooth roller (US), bilateral smooth roller (BS), unilateral grid roller (UG), and bilateral grid roller (BG). During all conditions, the triceps suralis was rolled for 2 sets of 60 s with 60 s of rest between sets. Rate of perceived pain (RPP) after the rolling protocol; peak force during a maximal voluntary isometric contraction (MVIC) (PF), muscle activation during a MVIC, and unilateral drop jump (UDJ) performance were measured before and after each condition. Results: The greatest RPP was reported in UG condition and the lowest RPP was reported in BS condition. All conditions increased ankle ROM to the same extent without subsequent effect on PF, muscle activity UDJ height, and UDJ contact time. Our data indicate that FR using different combinations of surface pattern and rolling techniques increased ankle ROM without a subsequent effect on drop jump performance, triceps suralis strength, and activation. Conclusion: In conclusion, practitioners could be encouraged to perform FR with mild discomfort and use a bilateral technique to save time. \u0000Keywords: Flexibility, self-myofascial release, electromyography, force, strength.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121292747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Training Load and Match-Play Performance in Collegiate Division I Basketball","authors":"Adam J Petway","doi":"10.47206/ijsc.v2i1.114","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.114","url":null,"abstract":"Purpose: This study examined the relationship between training load and match-play team performance in the subsequent game. Methods: Training load for a NCAA Division I Basketball team was tracked over a 3-year period; 225 practices were observed and recorded. Training load was classified as total duration of training and duration of full-court 5-versus-5 (5v5) during training. In-game performance was tracked for 92 matches during this period. Training load was organized into 48-hours prior to competition (MD-2), 24-hours prior to competition (MD-1), Total Duration, Average Duration, Totals 5v5, and Average 5v5. Performance was determined on how the team faired against the closing point spread differential (CPSD). If the team performed above the CPSD it was considered an ABOVE performance, whereas if the team performed below the CPSD it was considered BELOW. A linear mixed model was used to assess the differences between ABOVE and BELOW performances. Cohen’s d effect sizes (ES) were calculated to determine the magnitude of the differences. Results: Statistical significance was set at p ≤ 0.05. Both 5v5 MD-1 (p = 0.03; ES = -0.43) and Average 5v5 (p = 0.01; ES = -0.55) leading into matches was significantly greater for BELOW than ABOVE outcomes. Conclusion: 5v5 MD-1 and the Average 5v5 in preparation for competition had a significant impact on ensuing performances, whereas no significant difference was found in training MD-2. These findings could have implications on the sequencing of training sessions leading into competition. \u0000  \u0000Keywords: basketball training; team sports; duration; team performance; points spread \u0000  \u0000 ","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121757217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role of Supervision in Resistance Training; an Exploratory Systematic Review and Meta-Analysis","authors":"J. Fisher, J. Steele, Milo Wolf, Patroklos Androulakis Korakakis, Dave Smith, J. Giessing","doi":"10.47206/ijsc.v2i1.101","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.101","url":null,"abstract":"Background: Since many people choose to perform resistance training unsupervised, and a lack of supervision within strength training is reported to result in inadequate workout quality, we aimed to compare outcomes for resistance training with and without supervision. Methods: A systematic review and meta-analysis were performed for performance/functional outcomes and/or body composition measurements. Results: 12 studies were included in the review; 301 and 276 participants were in supervised and unsupervised groups, respectively. The main model for all performance/function effects revealed a small, standardised point estimate favouring SUP (0.28 [95%CI = 0.02 to 0.55]). For sub-grouped outcome types, there was very poor precision of robust estimates for speed, power, function, and endurance. However, for strength there was a moderate effect favouring SUP (0.40 [95%CI = 0.06 to 0.74]). The main model for all body composition effects revealed a trivial standardised point estimate favouring SUP (0.07 [95%CI = -0.01 to 0.15]). Conclusions: Supervised resistance training, compared to unsupervised training, might produce a small effect on increases in performance/function, most likely in strength, but has little impact on body composition outcomes.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127194232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Agility in Invasion Sports: Position Stand of the IUSCA","authors":"W. Young, Tom Dos'Santos, Damian J. Harper, Ian Jefferys, S. Talpey","doi":"10.47206/ijsc.v2i1.126","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.126","url":null,"abstract":"Agility is a complex skill that is influenced by several physical, technical and cognitive factors. In this position stand, we discuss agility as it relates to invasion sports such as the many football codes. An important concept when conceptualising agility is understanding how it is applied on the field or court. Agility is particularly important in contests between attackers and defenders. For example, an attacker needs to create space or separation from defenders, in order to evade or to maintain possession of the ball. Conversely, defenders may require agility to reduce time and space in relation to the attacker, thereby applying pressure with the intention of achieving a turnover of possession. The movements performed in an agility scenario are diverse, and may involve an isolated deceleration, or a range of actions to produce a lateral displacement of the body at various angles and speeds. To create novel insights into agility, the interactions between predators and prey are explored in the animal world and reveal that successful pursuit (like a defender) or escape (like an attacker) is influenced by the ability to accelerate and attain high speeds, decelerate, and manoeuvre with control at optimum speeds, as well as expressing perceptual and cognitive skills. A plethora of sports literature claiming to discuss agility actually refers to pre-planned change-of-direction (COD) movements, known as COD ability. There are several differences between agility and COD ability, which should be considered when testing and prescribing agility activities. The characteristics of different agility techniques are presented and discussed with consideration to performance and the risk of injury such as anterior cruciate ligament (ACL) rupture, with the aim of creating multiple movement solutions for the athlete. Due to the diversity of agility actions performed in invasion sports, physical development should include tissue strengthening as well as fast and slow stretch-shortening cycle exercises to cater for different speeds and angles of agility movements. The speed and accuracy of decision-making in agility contests (cognitive component) are determined by the athlete’s ability to anticipate opponent’s actions, visually scan the environment, recognise patterns of play, and predict movement strategies based on knowledge of situations. One versus one contests, small-sided games, and video perceptual training can enhance the cognitive component of agility. Finally, there is no single coaching strategy or method that should be used to develop agility. Instead, the appropriate methodology must fit the individual needs of athletes, and therefore a mixed multicomponent approach is needed as part of an agility framework. Training examples to develop agility are presented throughout this position statement.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129170685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}