International Journal of Strength and Conditioning最新文献

{"title":"Periodisation of Eccentrically-Integrated Resistance Training during a National Rugby League Pre-Season","authors":"Ryan Whitley, Patrick M. Holmberg, David Jenkins, V. Kelly","doi":"10.47206/ijsc.v2i1.151","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.151","url":null,"abstract":"Successful performances in rugby league require the ability to engage in repeated contact efforts with minimal recovery while maintaining a high running intensity. The capacity to express high levels of time-limited force appears to underlie many important physical attributes required to meet the repeated-effort demands of rugby league play. If appropriately periodised and integrated into the training plan, resistance exercise that sufficiently loads the eccentric phase of movement may provide a beneficial stimulus to improve players’ force-generating capacity. Comprehensive reviews relating to the adaptive effects of eccentric training and the methods most commonly prescribed in practical environments are available and may provide context for applying these strategies. However, no literature to date has specifically discussed the planning and programming of eccentric resistance exercise to enhance force production characteristics in elite athletes. Therefore, this narrative review focuses on the periodisation of eccentrically-integrated resistance training during a 17-week National Rugby League pre-season phase. To help guide programming during the pre-season period, the 17-week timeline is divided into several phases (i.e., general preparation, special preparation, active rest, and pre-competition). Within the periodised model, eccentric exercise parameters (i.e., volume, load [% 1RM]) are manipulated to progressively increase the rate of muscle lengthening velocity over the pre-season phase and sequentially elicit changes in muscle-tendon properties and neural function that culminate in improving muscular strength expression.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"27 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130715535","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":"Development of the Strength and Conditioning Coach Student-Athlete Satisfaction Survey (SCC-SASS)","authors":"Megan Lynn Cottet, Michael G. Miller, Thomas A. Cappaert, Mitchel Schwartzman","doi":"10.47206/ijsc.v2i1.143","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.143","url":null,"abstract":"The purpose of this study was to develop a valid and reliable survey for student-athletes to assess their satisfaction with their strength and conditioning coach (SCC) and the services they provide. This three-round Delphi Method study utilized experts to establish group consensus on survey items. Round one was completed by 28 experts, round two by 24 experts and round three by 22 experts. The Delphi Method resulted in the 32 item Strength and Conditioning Coach Student-Athlete Satisfaction Survey (SCC-SASS). Next, test-retest reliability was established by a sample (n=25) of student-athletes who were asked to complete the SCC-SASS twice, one to six days apart. The mean pre-test score was 126.62, and the post-test score was 126.04. A Two-Way Mixed Intra Class Correlation was run, resulting in an ICC of .956. Finally, Cronbach's alpha was calculated at an alpha value of .98. The results of these tests established the reliability of the SCC-SASS. This study led to the development of a valid and reliable survey to assess student-athlete satisfaction with their SCC and the services they provide. Knowing student-athlete satisfaction is important because student-athletes spend significant time with their SCC and higher athlete satisfaction is commonly associated with increased athletic performance. The development of this tool was vital to aid in assessing SCCs in hopes to further enhance the quality of the profession and the services and quality of care SCCs provide. \u0000Keywords: strength coach, college-age, quality improvement tool, group consensus, Delphi Method","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115803994","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":"Influence of Takeoff and Landing Displacement Strategies on Standing Long Jump Performance","authors":"D. Scherrer, L. Barker, J. Harry","doi":"10.47206/ijsc.v2i1.159","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.159","url":null,"abstract":"We evaluated the influence of takeoff and landing distance contributions to measured jump distance during the standing long jump (SLJ). Twenty male soccer players performed three SLJs while ground reaction force data (GRF) were obtained. The horizontal distances created by lower body position (DBODY) prior to takeoff (DTO) and landing (DLA) were calculated. Ratios for DTO (RTO) and DLA (RLA) were calculated relative to standing height, quantifying the proportion of measured jump distance (DJUMP) created during each phase. Variables were compared using dependent t-tests (α=0.05) and effect sizes (ES; large>1.2). Pearson correlations determined the relationships among variables. RLA was greater than RTO (p<0.001). DLA was greater than DTO (p<0.001). Very large ES were detected between RTO and RLA and DTO and DLA (ES≥2.53). Near perfect correlations were identified between DTO and RTO (r=0.96; p<0.001) and DLA and RLA (r=0.99; p<0.001). Strong correlations were identified between DJUMP and RLA (r=0.63; p=0.003) and DBODY and DJUMP (r=0.70; p<0.001). It is concluded that DLA more greatly influences the total distance measured during the SLJ versus DTO. These results highlight athletes’ strategy to maximize jump distance (flight distance plus the distances prior to takeoff and landing) during SLJ tests.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"288 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121488715","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 Unilateral Resistance Training on Muscular Strength, Power, and Measures of Core Stability in Resistance Trained Individuals","authors":"Anthony Duong, T. Wójcicki, Andrew J. Carnes","doi":"10.47206/ijsc.v2i1.145","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.145","url":null,"abstract":"Purpose: To examine the effects of unilateral resistance training on lower body power, muscular strength, and measures of core stability in resistance-trained college students. Methods: Participants (N=22; mean age= 19.86 ± 0.9 years) underwent 10 sessions of either unilateral (UL) or bilateral (BL) resistance training on three non-consecutive days per week for three weeks. Pre and post training outcome measures included one repetition maximum (1-RM) leg press for lower body strength, standing vertical jump (VJ) for lower body power, and double leg lowering (DLL), hip abduction isometric strength (HAIS), and Sorensen (SOR) tests for core stability. Results: There was a significant (p≤ 0.05) main effect of time across all variables, such that both groups improved scores on 1-RM leg press, VJ, DLL, HAIS, and SOR. Additionally, the magnitude of improvement (Cohen’s d) was larger in UL for all variables except VJ, which was larger in the BL group. Conclusion: This study adds to the growing body of literature investigating the effects of UL resistance training in athletic populations. Similar improvements following UL or BL resistance training suggest that both methods can effectively enhance strength, power, and core stability. UL training may potentially yield greater improvement of core stability variables.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123962796","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":"A Qualitative Review Of Annual Progress In Powerlifting Disciplines And Total Score","authors":"José Alfredo Hernández Ugalde","doi":"10.47206/ijsc.v2i1.139","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.139","url":null,"abstract":"This study drew on data mining from Powerlifting Championships recognized by the International Powerlifting Federation and compiled by the Openpowerlifting project. Analysis was made of the records of the best total score for each athlete by year from 2012 to 2021, evaluating the squat, bench press and deadlift disciplines. The annual progress (AP) of the athletes was then qualitatively codified using the difference between the results of consecutive years for each discipline and total. A positive difference was codified as 1 and a negative or equal result as 0, so obtaining 6 categories. AP was thus calculated for 32,539 men’s and 15,700 women’s samples from Classic powerlifting, and 14,181 men’s and 6,518 women’s samples from Equipped powerlifting. In order to evaluate these APs, decision tree analysis was generated using the CHAID growing method (Chi2 p<0.05), with AP as the dependent variable and Event, Age and Gender as factors. The most robust category was “Improvement of all disciplines and total” (IA), representing 46.1% of the global results. Age was the most relevant classification factor on the tree, with the youngest groups presenting the highest percentages of IA. Event was the next most significant factor, with Classic powerlifters showing higher percentages of IA than Equipped ones. Likewise, IA results within most weight classes were higher for Classic events than Equipped ones. The third important factor was Gender, with women attaining higher IAs than men, except for the 14–18-year-old group. Notably, the “No Improvements” category reflected a considerable percentage (11.7% of global results). The study suggests a sequence of annual outcomes in order of likelihood as follows: 1-Improvement of all disciplines and total, 2-Improvement of two disciplines and total, 3-No improvements, 4-Improvement of one discipline but not total, 5-Improvement of one discipline and total, and 6-Improvement of two disciplines but not total.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132362935","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 Menstrual Cycle Phases on Running Repeated Sprint Ability","authors":"Samuele Di Nicola, Brendon Ferrier, G. Florida-James, Mykolas Kavaliauskas","doi":"10.47206/ijsc.v2i1.137","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.137","url":null,"abstract":"Female participation in regular sport activities has increased in recent years, yet their representation in sports and exercise science literature remains low. This can be partly attributed to the complexities associated with the menstrual cycle (MC). Despite these challenges, sport and exercise science studies should not ignore the effects of the MC and its hormonal fluctuations on performance and physiological measures. The aim of this study was to compare performance, physiological and perceptual differences when performing a running repeated sprint ability (RSA) exercise during the early-follicular, and mid-luteal sub-phases of the MC. Five healthy, physically active participants (25.4 ± 3.0 years; 1.65 ± 0.1 m; 64.5 ± 18.6 kg; 43.2 ± 5.2 ml O2·kg-1) took part in this study. The participants completed two familiarization and four intervention sessions (twice during each MC sub-phase) of the RSA exercise. The RSA protocol consisted of five ‘all-out’ sprints of six seconds on a non-motorized treadmill with 24 seconds of walking between the sprints. Results indicated no significant differences (p > 0.05) between MC sub-phases in body mass index, fat mass, mean and peak power output, fatigue index for peak power output, distance, peak acceleration, pre-exercise lactate, oxygen uptake, and heart rate. However, significant differences were found in post-exercise lactate (p = 0.04) and rating of perceived exertion (p = 0.001). In conclusion, MC phases do not appear to influence most of the chosen RSA performance indicators thus suggesting that practitioners should not tailor repeated sprint exercises and tests based on the MC phases.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128953266","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":"Workload Management Strategies to Optimize Athlete Performance in Collegiate Men’s and Women’s Basketball","authors":"Jacob Hurwitz, Darby Rich, Connor Agnew, J. Harry","doi":"10.47206/ijsc.v2i1.136","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.136","url":null,"abstract":"Monitoring workload provides information about the physical demands in which athletes are competing in the sport of basketball. Sports scientists, strength and conditioning coaches and athletic trainers need to utilize this information to periodize and make decisions on practices and training program to optimize performance and prevent injuries. External workload was determined as impact workload asymmetry: low-intensity, medium-intensity, and high-intensity and overall inertial movement analysis. The internal workload was determined by a modified rating of perceived exertion (RPE) scale to mimic the three different intensity levels of the internal workload. The following narrative review presents knowledge on monitoring internal and external workload utilizing 95% confidence intervals during training sessions (practices), competition (games), and testing sessions (return to play protocols) while employing the use of inertial measurement units (IMUs) in basketball athletes. ","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"199 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114120616","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 Relationship between Acute: Chronic Workload Ratio of High-Speed Running and Hamstring Injuries in Professional Footballers","authors":"T. Gee","doi":"10.47206/ijsc.v2i1.105","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.105","url":null,"abstract":"Hamstring strain injuries are common within professional footballers with high-speed running (HSR) being known to increase the likelihood of sustaining a hamstring injury. This study aimed to assess the acute: chronic workload ratio (ACWR) of HSR that preceded hamstring injuries in professional footballers. Global positioning system (GPS)-derived HSR distances and weekly ACWR were obtained from 18 footballers from one English Football League (EFL) club during the 2018-2019 season. Hamstring injuries were documented by the club’s medical team and the ACWR data of the four weeks preceding each hamstring injury were analysed. The mean ACWR of injured players was calculated for each season along with the ACWR of the squad. Ten hamstring injuries were recorded in total, across eight of the 18 players (44%). The most common site of injury was the medial part of the hamstring (70%). At the time of injury the mean ACWR for injured players was 0.90, while the squad mean ACWR for the season was 1.04. In conclusion, this study evidenced a high prevalence of non-contact hamstring injuries over a competitive season within an EFL club. The majority of hamstring injuries occurred when the mean ACWR was below the squad mean ACWR for the season. The loading pattern of ‘moderate to high’ followed by ‘low to moderate’ ACWR was commonly observed in the four weeks prior to injury.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132384386","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 Optimal Time Window for Complex Training in Order to Increase Repeated Sprint Ability in Professional Ice Hockey Players","authors":"Sébstien Lagrange","doi":"10.47206/ijsc.v2i1.106","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.106","url":null,"abstract":"ABSTRACT \u0000The goal of this study was to investigate the post-activation performance enhancement (PAPE) and optimal time window following complex training (CT) to increase ice-hockey player skating speed and endurance. Ten professional ice-hockey players (age= 19.8±1.23 years, height= 1.8± 0.06 m, weight= 83.37±4.79 Kg,) from the American Hockey League (AHL, n=7) and the National Hockey League (NHL, n=3) were assigned randomly into two groups. Both groups completedthe same CT training protocol, designed to induce post-activation potentiation (PAP). One group completed the training 8 hours prior to testing (8HPT), and the other 4 hours (4HPT) before testing. The CT PAP training protocol consisted of 3 sets of 5 repetitions of trap high bar deadlifts superset with 6 box jumps on a 20-inch plyometric box. The effect of CT PAP training on performance was assessed using the following testing: the countermovement jump (CMJ), the static squat jump (SSJ), the stationary broad jump (BJ), reactive strength index (RSI), eccentric utilization ratio (EUR), the double leg incremental drop jump tests (DJ), and on ice 40 meter sprint time during the Peterson On-Ice repeated shift Test (POIT). Results showed significant improvements for both groups for the after CT PAP training for the SJ (4HPT: p= 0.04), BJ (8HPT: p= 0.02; 4HPT: p=0.03), POIT (8HPT: Sprint 4, 5, 6, 8: p<0.05; 4HPT: Sprint 2, 3: p<0.05), POIT total sprint time (8HPT: p= 0. 01), mean 40-meter sprint time (8HPT: Sprint 1, 2, 3, 4, 5, 6 and 8: p<0.05; 4HPT: Sprint 2, 3, 4, 5, 6 and 7: p<0.05), and total 40 meter sprint time (8HPT and 4HPT: Sprint 2 p= 0.03). However, no significant difference (p≥0.05) was found following CT PAP training for the CMJ, DJ, and RPE. Thus, the present study suggests that PAP has a greater effect on jumping and on ice-hockey repeated sprint performance when completed 8 hours before. Nonetheless, CT PAP training appears to be beneficial to improve the rate of force development and performance when performed more than 4 hours before the competition in professional North-American ice-hockey players. The present protocol and timing window can be utilized by strength and conditioning specialists to improve on-ice repeated sprint performance of professional ice-hockey players.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130262685","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":"Effects of Relative Inertial Load on Quadriceps Electromyography during Maximal Effort Flywheel-based Iso-Inertial Training (FIT) Squats","authors":"Bollinger Lance","doi":"10.47206/ijsc.v2i1.123","DOIUrl":"https://doi.org/10.47206/ijsc.v2i1.123","url":null,"abstract":"The effects of inertial load on quadriceps electromyography (EMG) during flywheel-based iso-inertial training (FIT) squats is unclear. Healthy, resistance-trained males (n=8) and females (n=8) completed five sets of five maximal-effort squats with varying inertial loads in a randomized order.  Sagittal plane knee joint angles and surface EMG activity of the vastus lateralis (VL) were measured. Average knee angular velocity, but not peak knee flexion or total excursion, decreased during both the concentric and eccentric phases with increasing inertial load (p<0.001) in both sexes.  Integrated EMG (iEMG) activity increased with increasing inertial load for all muscles (p<0.001).  VL iEMG and peak amplitude were significantly greater in females.  However, peak EMG amplitude was not significantly different among inertial loads for either sex. Mean EMG amplitude during the concentric phase and eccentric phases of the VL tended to be greater in females.  Increasing relative inertial load increases quadriceps iEMG activity due to greater exercise duration, but has minimal effects on EMG amplitude.","PeriodicalId":170948,"journal":{"name":"International Journal of Strength and Conditioning","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127704615","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}