Pub Date : 2024-08-01Epub Date: 2024-06-18DOI: 10.1519/JSC.0000000000004803
Wissem Dhahbi, Johnny Padulo, Luca Russo, Ghazi Racil, Mohamed-Amine Ltifi, Pietro Picerno, Enzo Iuliano, Gian Mario Migliaccio
Abstract: Dhahbi, W, Padulo, J, Russo, L, Racil, G, Ltifi, M-A, Picerno, P, Iuliano, E, and Migliaccio, GM. Four- to 6-repetition maximum and 1-repetition maximum estimation in free-weight bench press and smith machine squat based on body mass in male athletes. J Strength Cond Res 38(8): 1366-1371, 2024-This study aimed to explore the feasibility and face validity of predicting maximum strength 1 repetition maximum (1-RM) and 4-6 RM in athletes across different sports specialties, based on the relationship between muscle strength and BM. One hundred fifteen male athletes, aged 23.63 ± 6.77 years and participating in diverse sports specialties, were included in this study. Muscle strength was assessed using the 4-6 RM and 1-RM tests in free-weight bench press (BP) and Smith machine squat (SQ) exercises, whereas BM was measured using a portable digital scale. A linear regression equation based on muscle strength and BM was performed. The 4-6 RM and 1-RM scores showed excellent intersession relative reliability (intraclass correlation coefficient (2,1) : 0.946-0.989) and absolute reliability (CV: 3.4-4.7%) in both BP and SQ exercises. In addition, the magnitude of the relationship and the coefficients used to estimate the 4-6 RM and 1RM, based on BM, differed among the subjects when they are grouped according to their sports specialties ( R2 ranged from non-significant to 0.998). Overall, the 4-6 RM test showed a stronger correlation with BM ( R : 0.655 for SQ and R : 0.683 for BP) than the 1RM ( R : 0.552 for SQ and R : 0.629 for BP), and the general (i.e., not sport-specific) 4 to 6-RM prediction equations should be preferred over sport-specific ones because they are statistically more robust due to the larger sample size. In conclusion, the 4-6 RM can be predicted from BM with high reliability, a moderate association, and a prediction error that, when considering the 4-6 RM as a starting point for estimating of the 1RM, can be considered entirely acceptable in practical settings.
{"title":"4-6 Repetition Maximum (RM) and 1-RM Prediction in Free-Weight Bench Press and Smith Machine Squat Based on Body Mass in Male Athletes.","authors":"Wissem Dhahbi, Johnny Padulo, Luca Russo, Ghazi Racil, Mohamed-Amine Ltifi, Pietro Picerno, Enzo Iuliano, Gian Mario Migliaccio","doi":"10.1519/JSC.0000000000004803","DOIUrl":"10.1519/JSC.0000000000004803","url":null,"abstract":"<p><strong>Abstract: </strong>Dhahbi, W, Padulo, J, Russo, L, Racil, G, Ltifi, M-A, Picerno, P, Iuliano, E, and Migliaccio, GM. Four- to 6-repetition maximum and 1-repetition maximum estimation in free-weight bench press and smith machine squat based on body mass in male athletes. J Strength Cond Res 38(8): 1366-1371, 2024-This study aimed to explore the feasibility and face validity of predicting maximum strength 1 repetition maximum (1-RM) and 4-6 RM in athletes across different sports specialties, based on the relationship between muscle strength and BM. One hundred fifteen male athletes, aged 23.63 ± 6.77 years and participating in diverse sports specialties, were included in this study. Muscle strength was assessed using the 4-6 RM and 1-RM tests in free-weight bench press (BP) and Smith machine squat (SQ) exercises, whereas BM was measured using a portable digital scale. A linear regression equation based on muscle strength and BM was performed. The 4-6 RM and 1-RM scores showed excellent intersession relative reliability (intraclass correlation coefficient (2,1) : 0.946-0.989) and absolute reliability (CV: 3.4-4.7%) in both BP and SQ exercises. In addition, the magnitude of the relationship and the coefficients used to estimate the 4-6 RM and 1RM, based on BM, differed among the subjects when they are grouped according to their sports specialties ( R2 ranged from non-significant to 0.998). Overall, the 4-6 RM test showed a stronger correlation with BM ( R : 0.655 for SQ and R : 0.683 for BP) than the 1RM ( R : 0.552 for SQ and R : 0.629 for BP), and the general (i.e., not sport-specific) 4 to 6-RM prediction equations should be preferred over sport-specific ones because they are statistically more robust due to the larger sample size. In conclusion, the 4-6 RM can be predicted from BM with high reliability, a moderate association, and a prediction error that, when considering the 4-6 RM as a starting point for estimating of the 1RM, can be considered entirely acceptable in practical settings.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141419631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-06-25DOI: 10.1519/JSC.0000000000004811
Théo Bouzigues, Olivier Maurelli, Frank Imbach, Jacques Prioux, Robin Candau
Abstract: Bouzigues, T, Maurelli, O, Imbach, F, Prioux, J, and Candau, R. A new training load quantification method at supramaximal intensity and its application in injuries among members of an international volleyball team. J Strength Cond Res 38(8): 1453-1463, 2024-The quantification of training loads (TLs) is essential for optimizing jump performance and reducing the occurrence of injuries. This study aimed to (a) propose a new method for quantifying TLs in explosive exercises, (b) determine the nature of the relationship between TLs dynamics and injury occurrence, and (c) assess a TL critical for training schedule purposes, above which the risk of injury occurrence becomes unacceptable. This study was conducted with 11 male volleyball players on a national team during a 5-month international competitive period. The proposed new method for quantifying TLs is based on a weighting factor applied to relative jumping intensities, determined by the number of sustainable jumps and their intensities measured by G-Vert accelerometer. The relationship between TLs dynamics and injury occurrence was assessed using a variable dose-response model. A high coefficient of determination was found between the maximum number of jumps possible and their intensities ( r2 = 0.94 ± 0.14, p < 0.001), indicating a strong physiological relationship between jumping intensities and the constraints imposed. The occurrence of injury was dependent on TLs dynamics for 2 players ( r2 = 0.26 ± 0.01; p < 0.001). The TL critical corresponded to 11 jumps over 80% of maximum jump height during games and approximately 130 jumps at <80% of maximal jump height. The present study proposes a new approach for quantifying supramaximal exercises and provides tools for training schedules and the prevention of volleyball injuries.
{"title":"A New Training Load Quantification Method at Supramaximal Intensity and Its Application in Injuries Among Members of an International Volleyball Team.","authors":"Théo Bouzigues, Olivier Maurelli, Frank Imbach, Jacques Prioux, Robin Candau","doi":"10.1519/JSC.0000000000004811","DOIUrl":"10.1519/JSC.0000000000004811","url":null,"abstract":"<p><strong>Abstract: </strong>Bouzigues, T, Maurelli, O, Imbach, F, Prioux, J, and Candau, R. A new training load quantification method at supramaximal intensity and its application in injuries among members of an international volleyball team. J Strength Cond Res 38(8): 1453-1463, 2024-The quantification of training loads (TLs) is essential for optimizing jump performance and reducing the occurrence of injuries. This study aimed to (a) propose a new method for quantifying TLs in explosive exercises, (b) determine the nature of the relationship between TLs dynamics and injury occurrence, and (c) assess a TL critical for training schedule purposes, above which the risk of injury occurrence becomes unacceptable. This study was conducted with 11 male volleyball players on a national team during a 5-month international competitive period. The proposed new method for quantifying TLs is based on a weighting factor applied to relative jumping intensities, determined by the number of sustainable jumps and their intensities measured by G-Vert accelerometer. The relationship between TLs dynamics and injury occurrence was assessed using a variable dose-response model. A high coefficient of determination was found between the maximum number of jumps possible and their intensities ( r2 = 0.94 ± 0.14, p < 0.001), indicating a strong physiological relationship between jumping intensities and the constraints imposed. The occurrence of injury was dependent on TLs dynamics for 2 players ( r2 = 0.26 ± 0.01; p < 0.001). The TL critical corresponded to 11 jumps over 80% of maximum jump height during games and approximately 130 jumps at <80% of maximal jump height. The present study proposes a new approach for quantifying supramaximal exercises and provides tools for training schedules and the prevention of volleyball injuries.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141450751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1519/JSC.0000000000004807
Jun Seob Song, William B Hammert, Ryo Kataoka, Yujiro Yamada, Anna Kang, Jeremy P Loenneke
Abstract: Song, JS, Hammert, WB, Kataoka, R, Yamada, Y, Kang, A, and Loenneke, JP. Individuals can be taught to sense the degree of vascular occlusion: Implications for practical blood flow restriction. J Strength Cond Res 38(8): 1413-1418, 2024-It is currently unknown if individuals can be conditioned to a relative arterial occlusion pressure (AOP) and replicate that pressure at a later time point. The purpose of this study was to determine whether individuals can be taught to sense a certain relative pressure (i.e., target pressure) by comparing a conditioning method with a time-matched non-conditioning control. Fifty-eight subjects completed 2 visits in a randomized order: (a) conditioning condition and (b) time-matched control condition. The conditioning involved 11 series of inflations to 40% AOP for 12 seconds followed by cuff deflation for 22 seconds. The pressure estimations were taken at 5 and 30 minutes after each condition. Data are presented as mean differences (95% credible interval). The absolute error at 5 minutes was greater for the control compared with conditioning condition (7.1 [2.0-12.1] mm Hg). However, this difference in absolute error between conditioning and control was reduced at 30 minutes (2.9 [-1.3 to 7.1] mm Hg). The mean difference and 95% limits of agreement for the control were 8.2 (-42.4 to 58.5) mm Hg at 5 minutes and 0.02 (-43.5 to 43.5) at 30 minutes. The agreements for the conditioning were -6.2 (-32.4 to 20.0) mm Hg at 5 minutes and -11.2 (-36.6 to 14.3) mm Hg at 30 minutes. The results suggest that the individuals can be taught to sense the target pressure, but this effect only lasts a short amount of time. Future work is necessary to refine the conditioning method to extend the duration of this conditioning effect.
{"title":"Individuals Can be Taught to Sense the Degree of Vascular Occlusion: Implications for Practical Blood Flow Restriction.","authors":"Jun Seob Song, William B Hammert, Ryo Kataoka, Yujiro Yamada, Anna Kang, Jeremy P Loenneke","doi":"10.1519/JSC.0000000000004807","DOIUrl":"10.1519/JSC.0000000000004807","url":null,"abstract":"<p><strong>Abstract: </strong>Song, JS, Hammert, WB, Kataoka, R, Yamada, Y, Kang, A, and Loenneke, JP. Individuals can be taught to sense the degree of vascular occlusion: Implications for practical blood flow restriction. J Strength Cond Res 38(8): 1413-1418, 2024-It is currently unknown if individuals can be conditioned to a relative arterial occlusion pressure (AOP) and replicate that pressure at a later time point. The purpose of this study was to determine whether individuals can be taught to sense a certain relative pressure (i.e., target pressure) by comparing a conditioning method with a time-matched non-conditioning control. Fifty-eight subjects completed 2 visits in a randomized order: (a) conditioning condition and (b) time-matched control condition. The conditioning involved 11 series of inflations to 40% AOP for 12 seconds followed by cuff deflation for 22 seconds. The pressure estimations were taken at 5 and 30 minutes after each condition. Data are presented as mean differences (95% credible interval). The absolute error at 5 minutes was greater for the control compared with conditioning condition (7.1 [2.0-12.1] mm Hg). However, this difference in absolute error between conditioning and control was reduced at 30 minutes (2.9 [-1.3 to 7.1] mm Hg). The mean difference and 95% limits of agreement for the control were 8.2 (-42.4 to 58.5) mm Hg at 5 minutes and 0.02 (-43.5 to 43.5) at 30 minutes. The agreements for the conditioning were -6.2 (-32.4 to 20.0) mm Hg at 5 minutes and -11.2 (-36.6 to 14.3) mm Hg at 30 minutes. The results suggest that the individuals can be taught to sense the target pressure, but this effect only lasts a short amount of time. Future work is necessary to refine the conditioning method to extend the duration of this conditioning effect.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788391","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers. J Strength Cond Res 38(8): 1479-1485, 2024-In occupations with high physical demands, strength relative to bodymass is an important measure as it signifies an individual's ability to control and move their body mass through space. The purpose of this investigation was to examine physical characteristics, training, and performance based on different magnitudes of relative strength. Subjects were 1,806 male and 319 female US Army soldiers. Sex, age, height, body mass, and physical training data were obtained by an electronic survey. Physical performance was measured by the Army Combat Fitness Test (ACFT), which includes a three-repetition maximum deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck, and two-mile run. The relative body mass deadlifted was calculated and categorized into 4 groups for men and 3 groups for women. An analysis of variance and post hoc least significant difference test were used to evaluate the differences in relative strength and physical performance. Overall, 33% of men deadlifted ≥1.5 times their body mass, while 30% of women deadlifted ≥1.25 times their body mass. Men and women deadlifting the highest percentage of their body mass (≥1.5 times for men and ≥1.25 times for women) outperformed those with lower relative strength within their own sex in all 6 ACFT events. In 4 of the 6 ACFT events, women who deadlifted ≥1.25 times their body mass had similar performance compared with men deadlifting 1 to 1.24 times their body mass and outperformed men deadlifting <1 times their body mass. Greater strength relative to body mass was associated with higher physical performance.
Abstract: Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers.J Strength Cond Res 38(8):1479-1485, 2024-在体能要求较高的职业中,相对于体重的力量是一项重要的衡量指标,因为它标志着一个人在空间中控制和移动体重的能力。这项调查的目的是根据相对力量的不同大小来研究身体特征、训练和表现。研究对象为 1806 名男性和 319 名女性美国陆军士兵。通过电子调查获得了性别、年龄、身高、体重和体能训练数据。体能表现通过陆军战斗体能测试(ACFT)进行测量,其中包括三次最大举重、立定投掷、徒手俯卧撑、冲刺-拖拽-搬运、收腿和两英里跑。计算举起的相对体重并将男子分为 4 组,女子分为 3 组。采用方差分析和事后最小显著差异检验来评估相对力量和体能表现的差异。总体而言,33% 的男性负重≥1.5 倍体重,而 30% 的女性负重≥1.25 倍体重。在所有 6 个 ACFT 项目中,负重占体重百分比最高的男性和女性(男性≥1.5 倍,女性≥1.25 倍)的成绩均优于相对力量较低的性别。在 6 个 ACFT 项目中的 4 个项目中,负重≥1.25 倍体重的女性与负重 1 至 1.24 倍体重的男性相比,成绩相近,而负重≥1.25 倍体重的女性则优于负重≥1.24 倍体重的男性。
{"title":"Relative Strength and Physical Performance in US Army Male and Female Soldiers.","authors":"Tyson Grier, Timothy Benedict, Olivia Mahlmann, Michelle Canham-Chervak","doi":"10.1519/JSC.0000000000004823","DOIUrl":"10.1519/JSC.0000000000004823","url":null,"abstract":"<p><strong>Abstract: </strong>Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers. J Strength Cond Res 38(8): 1479-1485, 2024-In occupations with high physical demands, strength relative to bodymass is an important measure as it signifies an individual's ability to control and move their body mass through space. The purpose of this investigation was to examine physical characteristics, training, and performance based on different magnitudes of relative strength. Subjects were 1,806 male and 319 female US Army soldiers. Sex, age, height, body mass, and physical training data were obtained by an electronic survey. Physical performance was measured by the Army Combat Fitness Test (ACFT), which includes a three-repetition maximum deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck, and two-mile run. The relative body mass deadlifted was calculated and categorized into 4 groups for men and 3 groups for women. An analysis of variance and post hoc least significant difference test were used to evaluate the differences in relative strength and physical performance. Overall, 33% of men deadlifted ≥1.5 times their body mass, while 30% of women deadlifted ≥1.25 times their body mass. Men and women deadlifting the highest percentage of their body mass (≥1.5 times for men and ≥1.25 times for women) outperformed those with lower relative strength within their own sex in all 6 ACFT events. In 4 of the 6 ACFT events, women who deadlifted ≥1.25 times their body mass had similar performance compared with men deadlifting 1 to 1.24 times their body mass and outperformed men deadlifting <1 times their body mass. Greater strength relative to body mass was associated with higher physical performance.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1519/JSC.0000000000004821
Stefano Amatori, Werner F Helsen, Carlo Baldari, Tommaso Serra, Annalisa Belli, Laura Guidetti, Marco B L Rocchi, Davide Sisti, Fabrizio Perroni
Abstract: Amatori, S, Helsen, WF, Baldari, C, Serra, T, Belli, A, Guidetti, L, Rocchi, MBL, Sisti, D, and Perroni, F. High-speed efforts of elite association football referees in national and international matches. J Strength Cond Res 38(8): e417-e422, 2024-Field referees (FRs) need to move throughout the pitch to identify any infringements of the game's laws. Their performance depends on technical, tactical, physical, physiological, and mental factors. This retrospective study aimed to examine and assess the physical and physiological parameters as a function of time in elite association football referees during official matches. Global positioning system (match time, distance in different intensity ranges [low-intensity, high-speed, very high-speed running, and sprinting], average and peak speed, distance in accelerations or decelerations) and heart rate (average and peak) data from 212 national and international football matches were analyzed. A linear mixed-model analysis was performed to assess the differences between halves and between the three 15-minute sections of each half-time for all the physical and physiological variables collected. A significant effect of match half was found for the game time (p < 0.001) and the standing time (p = 0.005), both higher in the second half, and for the average speed (p = 0.017), which was lower in the second half. Total distance (p < 0.001), low-intensity distance (p = 0.004), and average speed (p = 0.007) all showed a reduction as a function of time. More than 7.800 high-speed intervals were detected. Accelerative actions within 3 seconds characterized most of the high-speed efforts of an FR during a match. Significant differences emerged in the way the match intensity is distributed across the match, analyzed both in halves (first vs. second) and 15-minute intervals within each half. It is important to emphasize the importance of high-speed training with a focus on a faster transition from low- to high-speed running to keep up with the play to get into an appropriate position and subsequently make the correct decisions.
{"title":"High-Speed Efforts of Elite Association Football Referees in National and International Matches.","authors":"Stefano Amatori, Werner F Helsen, Carlo Baldari, Tommaso Serra, Annalisa Belli, Laura Guidetti, Marco B L Rocchi, Davide Sisti, Fabrizio Perroni","doi":"10.1519/JSC.0000000000004821","DOIUrl":"10.1519/JSC.0000000000004821","url":null,"abstract":"<p><strong>Abstract: </strong>Amatori, S, Helsen, WF, Baldari, C, Serra, T, Belli, A, Guidetti, L, Rocchi, MBL, Sisti, D, and Perroni, F. High-speed efforts of elite association football referees in national and international matches. J Strength Cond Res 38(8): e417-e422, 2024-Field referees (FRs) need to move throughout the pitch to identify any infringements of the game's laws. Their performance depends on technical, tactical, physical, physiological, and mental factors. This retrospective study aimed to examine and assess the physical and physiological parameters as a function of time in elite association football referees during official matches. Global positioning system (match time, distance in different intensity ranges [low-intensity, high-speed, very high-speed running, and sprinting], average and peak speed, distance in accelerations or decelerations) and heart rate (average and peak) data from 212 national and international football matches were analyzed. A linear mixed-model analysis was performed to assess the differences between halves and between the three 15-minute sections of each half-time for all the physical and physiological variables collected. A significant effect of match half was found for the game time (p < 0.001) and the standing time (p = 0.005), both higher in the second half, and for the average speed (p = 0.017), which was lower in the second half. Total distance (p < 0.001), low-intensity distance (p = 0.004), and average speed (p = 0.007) all showed a reduction as a function of time. More than 7.800 high-speed intervals were detected. Accelerative actions within 3 seconds characterized most of the high-speed efforts of an FR during a match. Significant differences emerged in the way the match intensity is distributed across the match, analyzed both in halves (first vs. second) and 15-minute intervals within each half. It is important to emphasize the importance of high-speed training with a focus on a faster transition from low- to high-speed running to keep up with the play to get into an appropriate position and subsequently make the correct decisions.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1519/JSC.0000000000004813
Darragh R Connolly, Sean Stolp, Antonio Gualtieri, Duccio Ferrari Bravo, Roberto Sassi, Ermanno Rampinini, Aaron J Coutts
Abstract: Connolly, DR, Stolp, S, Gualtieri, A, Ferrari Bravo, D, Sassi, R, Rampinini, E, and Coutts, AJ. How do young soccer players train? A 5-year analysis of weekly training load and its variability between age groups in an elite youth academy. J Strength Cond Res 38(8): e423-e429, 2024-The aim of this study was to quantify the session rating of perceived exertion (sRPE), duration, and training load accrued across typical training weeks undertaken by youth soccer players. Differences between starters, nonstarters, and variations in training load variables were also investigated. Data were collected from 230 elite youth players in 4 age groups (U15, U16, U17, and U19) during 5 competitive seasons. Mixed models were used to describe variation between age groups and compare starters with nonstarters, with season as a fixed covariate effect. Week-to-week variation in training load was expressed as the percentage coefficient of variation. The main findings may be used to highlight a significant effect of age and playing status on training intensity, duration, and internal training load. Weekly training load increased progressively from the U15 to U17, with significant differences between each age group (p < 0.03). Lower mean weekly perceived intensity (sRPE) was noted in U15 when compared with the older age groups (4.2 vs. 4.6-4.9 arbitrary unit for U16 to U19, p < 0.001). Low weekly training load variation was observed across the different phases of the season in each age group, with the preseason exhibiting the greatest variance (3.6-6.2%). Differences in the training load are likely more attributable to changes in training duration rather than sRPE. Control of session duration seems to play an important role when aiming to control load in the academy environment, and practitioners should closely monitor the differences in duration and load being recorded between starters and nonstarters.
Abstract: Connolly, DR, Stolp, S, Gualtieri, A, Ferrari Bravo, D, Sassi, R, Rampinini, E, and Coutts, AJ.年轻足球运动员如何训练?对精英青训学院各年龄组每周训练负荷及其可变性的 5 年分析。J Strength Cond Res 38(8): e423-e429, 2024-这项研究的目的是量化青少年足球运动员在典型训练周内的感知消耗量(session rating of perceived exertion, sRPE)、持续时间和训练负荷。研究还调查了首发球员和非首发球员之间的差异以及训练负荷变量的变化。数据收集自 5 个赛季中 4 个年龄组(U15、U16、U17 和 U19)的 230 名精英青少年球员。研究人员使用混合模型来描述不同年龄组之间的差异,并对首发球员和非首发球员进行比较,将季节作为一个固定的协变量效应。训练负荷的周间变化以变异系数百分比表示。主要研究结果可用于强调年龄和比赛状态对训练强度、持续时间和内部训练负荷的显著影响。从 15 岁到 17 岁,每周训练量逐渐增加,各年龄组之间存在显著差异(p < 0.03)。与年龄较大的年龄组相比,15 岁以下年龄组的平均每周感知强度(sRPE)较低(16 至 19 岁年龄组为 4.2 对 4.6-4.9 任意单位,p < 0.001)。各年龄组在赛季不同阶段的每周训练量差异较小,季前赛的差异最大(3.6-6.2%)。训练负荷的差异可能更多地归因于训练时间的变化,而非 sRPE。在学院环境中,控制训练时间似乎对控制训练负荷起着重要作用,从业人员应密切关注首发球员和非首发球员在训练时间和训练负荷上的差异。
{"title":"How Do Young Soccer Players Train? A 5-Year Analysis of Weekly Training Load and its Variability Between Age Groups in an Elite Youth Academy.","authors":"Darragh R Connolly, Sean Stolp, Antonio Gualtieri, Duccio Ferrari Bravo, Roberto Sassi, Ermanno Rampinini, Aaron J Coutts","doi":"10.1519/JSC.0000000000004813","DOIUrl":"10.1519/JSC.0000000000004813","url":null,"abstract":"<p><strong>Abstract: </strong>Connolly, DR, Stolp, S, Gualtieri, A, Ferrari Bravo, D, Sassi, R, Rampinini, E, and Coutts, AJ. How do young soccer players train? A 5-year analysis of weekly training load and its variability between age groups in an elite youth academy. J Strength Cond Res 38(8): e423-e429, 2024-The aim of this study was to quantify the session rating of perceived exertion (sRPE), duration, and training load accrued across typical training weeks undertaken by youth soccer players. Differences between starters, nonstarters, and variations in training load variables were also investigated. Data were collected from 230 elite youth players in 4 age groups (U15, U16, U17, and U19) during 5 competitive seasons. Mixed models were used to describe variation between age groups and compare starters with nonstarters, with season as a fixed covariate effect. Week-to-week variation in training load was expressed as the percentage coefficient of variation. The main findings may be used to highlight a significant effect of age and playing status on training intensity, duration, and internal training load. Weekly training load increased progressively from the U15 to U17, with significant differences between each age group (p < 0.03). Lower mean weekly perceived intensity (sRPE) was noted in U15 when compared with the older age groups (4.2 vs. 4.6-4.9 arbitrary unit for U16 to U19, p < 0.001). Low weekly training load variation was observed across the different phases of the season in each age group, with the preseason exhibiting the greatest variance (3.6-6.2%). Differences in the training load are likely more attributable to changes in training duration rather than sRPE. Control of session duration seems to play an important role when aiming to control load in the academy environment, and practitioners should closely monitor the differences in duration and load being recorded between starters and nonstarters.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1519/JSC.0000000000004809
Andrew R Jagim, Joel Luedke, Jacob L Erickson, Jennifer B Fields, Margaret T Jones
Abstract: Jagim, AR, Luedke, J, Erickson, JL, Fields, JB, and Jones, MT. Validation of bioelectrical impedance devices for the determination of body fat percentage in firefighters. J Strength Cond Res 38(8): e448-e453, 2024-To cross-validate bioelectrical impedance devices for the determination of body fat percentage (BF%) in firefighters. Twenty-eight structural firefighters were evaluated (female, n = 2; male, n = 26 [mean ± SD] age: 38.2 ± 8.3 years; height: 180.2 ± 7.5 cm; body mass: 86.7 ± 20.8 kg; body mass index: 25.8 ± 7.8 kg·m-2) using multifrequency bioelectrical impedance analysis (MFBIA) hand-to-foot device, and single-frequency BIA foot scale (F2FBIA), and a single-frequency handheld BIA device (HHBIA). Dual X-ray absorptiometry served as the criterion. Validity metrics were examined to establish each method's performance. Body fat % values produced by MFBIA (r = 0.913), F2FBIA (r = 0.695), and HHBIA (r = 0.876) were strongly associated (p < 0.001) with criterion BF% measures. However, MFBIA, F2FBIA, and HHBIA all significantly (p < 0.001) underestimated BF% when compared with the criterion measure. Constant error ranged between 4.0 and 5.5% across all BIA devices. Despite strong associations between the BIA devices included in the current study and the criterion measure, all BIA devices underestimated BF%, which resulted in an overestimation of fat-free mass. In addition, proportional bias was observed in which BF% was overestimated at lower values and underestimated at higher values.
{"title":"Validation of Bioelectrical Impedance Devices for the Determination of Body Fat Percentage in Firefighters.","authors":"Andrew R Jagim, Joel Luedke, Jacob L Erickson, Jennifer B Fields, Margaret T Jones","doi":"10.1519/JSC.0000000000004809","DOIUrl":"10.1519/JSC.0000000000004809","url":null,"abstract":"<p><strong>Abstract: </strong>Jagim, AR, Luedke, J, Erickson, JL, Fields, JB, and Jones, MT. Validation of bioelectrical impedance devices for the determination of body fat percentage in firefighters. J Strength Cond Res 38(8): e448-e453, 2024-To cross-validate bioelectrical impedance devices for the determination of body fat percentage (BF%) in firefighters. Twenty-eight structural firefighters were evaluated (female, n = 2; male, n = 26 [mean ± SD] age: 38.2 ± 8.3 years; height: 180.2 ± 7.5 cm; body mass: 86.7 ± 20.8 kg; body mass index: 25.8 ± 7.8 kg·m-2) using multifrequency bioelectrical impedance analysis (MFBIA) hand-to-foot device, and single-frequency BIA foot scale (F2FBIA), and a single-frequency handheld BIA device (HHBIA). Dual X-ray absorptiometry served as the criterion. Validity metrics were examined to establish each method's performance. Body fat % values produced by MFBIA (r = 0.913), F2FBIA (r = 0.695), and HHBIA (r = 0.876) were strongly associated (p < 0.001) with criterion BF% measures. However, MFBIA, F2FBIA, and HHBIA all significantly (p < 0.001) underestimated BF% when compared with the criterion measure. Constant error ranged between 4.0 and 5.5% across all BIA devices. Despite strong associations between the BIA devices included in the current study and the criterion measure, all BIA devices underestimated BF%, which resulted in an overestimation of fat-free mass. In addition, proportional bias was observed in which BF% was overestimated at lower values and underestimated at higher values.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01Epub Date: 2024-05-21DOI: 10.1519/JSC.0000000000004820
Pedro J Cornejo-Daza, Juan Sánchez-Valdepeñas, Jose Páez-Maldonado, Luis Rodiles-Guerrero, Daniel Boullosa, Juan A León-Prados, Mathias Wernbom, Fernando Pareja-Blanco
Abstract: Cornejo-Daza, PJ, Sánchez-Valdepeñas, J, Páez-Maldonado, J, Rodiles-Guerrero, L, Boullosa, D, León-Prados, JA, Wernbom, M, and Pareja-Blanco, F. Acute responses to traditional and cluster-set squat training with and without blood flow restriction. J Strength Cond Res 38(8): 1401-1412, 2024-To compare the acute responses to different set configurations (cluster [CLU] vs. traditional [TRA]) under distinct blood flow conditions (free vs. restricted) in full-squat (SQ). Twenty resistance-trained males performed 4 protocols that differed in the set configuration (TRA: continuous repetitions; vs. CLU: 30 seconds of rest every 2 repetitions) and in the blood flow condition (FF: free-flow; vs. blood flow restriction [BFR]: 50% of arterial occlusion pressure). The relative intensity (60% 1RM), volume (3 sets of 8 repetitions), and resting time (2 minutes) were equated. Mean propulsive force (MPF), velocity (MPV) and power (MPP), and electromyography (EMG) parameters were recorded during each repetition. Tensiomyography (TMG), blood lactate, countermovement jump (CMJ) height, maximal voluntary isometric contraction, in SQ, and movement velocity against the load that elicited a 1 m·s -1 velocity at baseline (V1-load) in SQ were assessed at pre- and post-exercise. The CLU protocols allowed a better maintenance of MPF, MPV, MPP, and EMG median frequency during the exercise compared to TRA (clu-time interaction, p < 0.05). The TRA protocols experienced greater impairments post-exercise in TMG- and EMG-derived variables (clu-time interaction, p < 0.05) and SQ and CMJ performance (clu-time interaction, p = 0.08 and p < 0.05, respectively), as well as higher blood lactate concentrations (clu-time interaction, p < 0.001) than CLU. Moreover, BFR displayed decreases in TMG variables (bfr-time interaction, p < 0.01), but BFR-CLU resulted in the greatest reduction in twitch contraction time ( p < 0.001). Cluster sets reduced fatigue during and after the training session and BFR exacerbated impairments in muscle mechanical properties; however, the combination of both could improve contraction speed after exercise.
{"title":"Acute Responses to Traditional and Cluster-Set Squat Training With and Without Blood Flow Restriction.","authors":"Pedro J Cornejo-Daza, Juan Sánchez-Valdepeñas, Jose Páez-Maldonado, Luis Rodiles-Guerrero, Daniel Boullosa, Juan A León-Prados, Mathias Wernbom, Fernando Pareja-Blanco","doi":"10.1519/JSC.0000000000004820","DOIUrl":"10.1519/JSC.0000000000004820","url":null,"abstract":"<p><strong>Abstract: </strong>Cornejo-Daza, PJ, Sánchez-Valdepeñas, J, Páez-Maldonado, J, Rodiles-Guerrero, L, Boullosa, D, León-Prados, JA, Wernbom, M, and Pareja-Blanco, F. Acute responses to traditional and cluster-set squat training with and without blood flow restriction. J Strength Cond Res 38(8): 1401-1412, 2024-To compare the acute responses to different set configurations (cluster [CLU] vs. traditional [TRA]) under distinct blood flow conditions (free vs. restricted) in full-squat (SQ). Twenty resistance-trained males performed 4 protocols that differed in the set configuration (TRA: continuous repetitions; vs. CLU: 30 seconds of rest every 2 repetitions) and in the blood flow condition (FF: free-flow; vs. blood flow restriction [BFR]: 50% of arterial occlusion pressure). The relative intensity (60% 1RM), volume (3 sets of 8 repetitions), and resting time (2 minutes) were equated. Mean propulsive force (MPF), velocity (MPV) and power (MPP), and electromyography (EMG) parameters were recorded during each repetition. Tensiomyography (TMG), blood lactate, countermovement jump (CMJ) height, maximal voluntary isometric contraction, in SQ, and movement velocity against the load that elicited a 1 m·s -1 velocity at baseline (V1-load) in SQ were assessed at pre- and post-exercise. The CLU protocols allowed a better maintenance of MPF, MPV, MPP, and EMG median frequency during the exercise compared to TRA (clu-time interaction, p < 0.05). The TRA protocols experienced greater impairments post-exercise in TMG- and EMG-derived variables (clu-time interaction, p < 0.05) and SQ and CMJ performance (clu-time interaction, p = 0.08 and p < 0.05, respectively), as well as higher blood lactate concentrations (clu-time interaction, p < 0.001) than CLU. Moreover, BFR displayed decreases in TMG variables (bfr-time interaction, p < 0.01), but BFR-CLU resulted in the greatest reduction in twitch contraction time ( p < 0.001). Cluster sets reduced fatigue during and after the training session and BFR exacerbated impairments in muscle mechanical properties; however, the combination of both could improve contraction speed after exercise.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11286160/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141080881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-01DOI: 10.1519/JSC.0000000000004810
Marcos A Soriano, Ester Jiménez-Ormeño, Jason P Lake, John J McMahon, César Gallo-Salazar, Peter Mundy, Paul Comfort
{"title":"Kinetics and Kinematics of the Push Press, Push Jerk, and Split Jerk.","authors":"Marcos A Soriano, Ester Jiménez-Ormeño, Jason P Lake, John J McMahon, César Gallo-Salazar, Peter Mundy, Paul Comfort","doi":"10.1519/JSC.0000000000004810","DOIUrl":"10.1519/JSC.0000000000004810","url":null,"abstract":"","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Chen, P-T, Lin, Y-C, Chang, H-Y, Chiu, C-H, Chen, C-Y, Chen, P, and Lin, Y-H. Effects of shoulder corrective training program on pitching loads and sonographic morphology in elbow joint in youth baseball players. J Strength Cond Res 38(8): e440-e447, 2024-We assessed the effects of a 12-week shoulder corrective training program for shoulder flexibility and strengthening on pitching loads and sonographic morphology of the elbow joints in youth baseball players. Seventeen subjects were recruited and underwent evaluations before and after the training program. We found that following training, subjects demonstrated significantly increased ranges of shoulder internal rotation (38.9 ± 12.9° vs. 69.2 ± 10.8°, p < 0.001), external rotation (91.2 ± 14.6° vs. 107.3 ± 9.5°, p = 0.004), and horizontal adduction (21.5 ± 8.0° vs. 32.7 ± 7.3°, p = 0.002); improved strength in the shoulder internal rotators (8.7 ± 1.6 kg vs. 9.8 ± 2.1 kg, p = 0.04), external rotators (6.5 ± 1.9 kg vs. 7.5 ± 2.8 kg, p = 0.04), middle trapezius (12.7 ± 2.1 kg vs. 14.3 ± 2.4 kg, p = 0.04), and middle deltoid muscles (10.8 ± 3.3 kg vs. 14.8 ± 3.2 kg, p = 0.001); and decreased thickness of the ulnar collateral ligament (6.1 ± 0.6 mm vs. 4.8 ± 0.7 mm, p = 0.002). Although there was no substantial change in elbow torque and arm speed, significantly increased ball speed (51.2 ± 4.6 mph vs. 54.1 ± 4.5 mph, p < 0.001) and decreased arm slot (63.8 ± 11.9° vs. 53.0 ± 12.7°, p = 0.02) were observed. We suggest that adequate corrective training should be performed regularly to minimize or mitigate adverse soft tissue changes at the elbow in youth baseball players. Balanced shoulder strength and flexibility may decrease medial elbow stress during pitching. Future studies should consider the kinetic and kinematic effects of other corrective training programs on the shoulder or elbow joint during pitching.
摘要: Chen, P-T, Lin, Y-C, Chang, H-Y, Chiu, C-H, Chen, C-Y, Chen, P, and Lin, Y-H.肩关节矫正训练计划对青少年棒球运动员投球负荷和肘关节声像图形态的影响J Strength Cond Res 38(8): e440-e447, 2024-我们评估了为期12周的肩关节柔韧性和强化纠正训练计划对青少年棒球运动员投球负荷和肘关节声像图形态的影响。我们招募了 17 名受试者,并在训练前后对他们进行了评估。我们发现,在训练后,受试者的肩关节内旋(38.9 ± 12.9° vs. 69.2 ± 10.8°,p < 0.001)、外旋(91.2 ± 14.6° vs. 107.3 ± 9.5°,p = 0.004)和水平内收(21.5 ± 8.0° vs. 32.7 ± 7.3°,p = 0.002)的范围明显增加;肩关节内旋肌的力量得到改善(8.7 ± 1.6 kg vs. 9.8 ± 2.1 kg,p = 0.04)、外旋肌(6.5 ± 1.9 kg vs. 7.5 ± 2.8 kg,p = 0.04)、斜方肌中部(12.7 ± 2.1 kg vs. 14.3 ± 2.4 kg,p = 0.04)、三角肌中部(10.8 ± 3.3 kg vs. 14.8 ± 3.2 kg,p = 0.001);尺侧副韧带厚度减少(6.1 ± 0.6 mm vs. 4.8 ± 0.7 mm,p = 0.002)。虽然肘部扭矩和臂速没有发生实质性变化,但观察到球速明显增加(51.2 ± 4.6 mph vs. 54.1 ± 4.5 mph,p < 0.001),臂槽减少(63.8 ± 11.9° vs. 53.0 ± 12.7°,p = 0.02)。我们建议,应定期进行适当的矫正训练,以尽量减少或减轻青少年棒球运动员肘部软组织的不良变化。均衡的肩部力量和柔韧性可减少投球时肘部内侧的压力。未来的研究应考虑其他矫正训练计划对投球时肩关节或肘关节的运动学和动力学影响。
{"title":"Effects of Shoulder Corrective Training Program on Pitching Loads and Sonographic Morphology in Elbow Joint in Youth Baseball Players.","authors":"Po-Tsun Chen, Yu-Chun Lin, Hsiao-Yun Chang, Chih-Hao Chiu, Cheng-Yu Chen, Poyu Chen, Yang-Hua Lin","doi":"10.1519/JSC.0000000000004804","DOIUrl":"10.1519/JSC.0000000000004804","url":null,"abstract":"<p><strong>Abstract: </strong>Chen, P-T, Lin, Y-C, Chang, H-Y, Chiu, C-H, Chen, C-Y, Chen, P, and Lin, Y-H. Effects of shoulder corrective training program on pitching loads and sonographic morphology in elbow joint in youth baseball players. J Strength Cond Res 38(8): e440-e447, 2024-We assessed the effects of a 12-week shoulder corrective training program for shoulder flexibility and strengthening on pitching loads and sonographic morphology of the elbow joints in youth baseball players. Seventeen subjects were recruited and underwent evaluations before and after the training program. We found that following training, subjects demonstrated significantly increased ranges of shoulder internal rotation (38.9 ± 12.9° vs. 69.2 ± 10.8°, p < 0.001), external rotation (91.2 ± 14.6° vs. 107.3 ± 9.5°, p = 0.004), and horizontal adduction (21.5 ± 8.0° vs. 32.7 ± 7.3°, p = 0.002); improved strength in the shoulder internal rotators (8.7 ± 1.6 kg vs. 9.8 ± 2.1 kg, p = 0.04), external rotators (6.5 ± 1.9 kg vs. 7.5 ± 2.8 kg, p = 0.04), middle trapezius (12.7 ± 2.1 kg vs. 14.3 ± 2.4 kg, p = 0.04), and middle deltoid muscles (10.8 ± 3.3 kg vs. 14.8 ± 3.2 kg, p = 0.001); and decreased thickness of the ulnar collateral ligament (6.1 ± 0.6 mm vs. 4.8 ± 0.7 mm, p = 0.002). Although there was no substantial change in elbow torque and arm speed, significantly increased ball speed (51.2 ± 4.6 mph vs. 54.1 ± 4.5 mph, p < 0.001) and decreased arm slot (63.8 ± 11.9° vs. 53.0 ± 12.7°, p = 0.02) were observed. We suggest that adequate corrective training should be performed regularly to minimize or mitigate adverse soft tissue changes at the elbow in youth baseball players. Balanced shoulder strength and flexibility may decrease medial elbow stress during pitching. Future studies should consider the kinetic and kinematic effects of other corrective training programs on the shoulder or elbow joint during pitching.</p>","PeriodicalId":17129,"journal":{"name":"Journal of Strength and Conditioning Research","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}