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Muscle contraction velocity (Vc) assessed by tensiomyography is a promising measure for athlete profiling. Multiple formulas are used to estimate Vc, but the most suitable method is yet to be established. Fifteen adults (2 female subjects) underwent tensiomyography assessment of biceps brachii muscle at 10, 45 and 90° of elbow flexion on 2 separate days. Vc was calculated using 6 formulas. Formulas 1 and 2 are measures of the early phase of the twitch; Formulas 3-5 are measures over a wider time-window, with Formula 5 normalizing Vc to maximal displacement (Dm); and we proposed Formula 6 as a measure of peak Vc. Test-retest reliability, the required minimum number of trials, proportional bias, and effects of joint angle were investigated. Higher reliability (coefficient of variation: 2.8-6.9%) was found for Formula 1 (0-2mmof displacement) and Formula 5 (normalized 10-90% of Dm). Overall, a minimum of 6-7 trials was required to obtain reliable estimates. For 10° only, significant positive proportional bias (r = 0.563-0.670) was found for all formulas except Formula 5. Vc was faster (p < 0.001) at shorter muscle lengths for all formulas except Formula 5 (p = 0.06). Vc in the early phase of the twitch was more reliable when calculated using absolute displacement (Formula 1) than a relative threshold (Formula 2). Over a larger time-window, Formulas 3 and 4 were similarly reliable. Because they are derived from different components of the twitch and different parameters, the different formulas should not be used interchangeably. Additionally, more precise nomenclature is required to describe the information obtained from each formula. [ABSTRACT FROM AUTHOR]

Despite being a global sport, there is a paucity of research investigating competition-related factors contributing to World Championship powerlifting success. Therefore, the aim of this study was to determine competition strategies that underpin gold medalists' (GMs) and silver or bronze medalists' (SBMs) performances. Data collected from open-age International Powerlifting Federation (IPF) World Championship events 2013-2019 were analyzed (1,312 competitors [males n = 734, females n = 578]). Attempt weight and success for the squat (SQ), bench press (BP), and deadlift (DL); 'total' competition scores; category (age, weight class, and sex); and placing were categorized into 3 groups: GMs, SBMs, and nonwinners (fourth place or lower). One-way analysis of variances determined between group differences. Odds ratios (ORs) for the likelihood of winning and placing (i.e., GMs or SBMs) were also calculated. The odds of winning a competition were increased 5.9 times for men and by 1.5 times for women, when successfully completing 8 or 9 of 9 lift attempts. These findings provide comprehensive insight into intracompetition-related factors that contribute to World Championship powerlifting success to directly inform coach and athlete strategies. This information may also hold relevance for competitive state or national competitions and extend to other similarly structured strength-based sports. [ABSTRACT FROM AUTHOR]

Soccer physical preparation has been extensively researched with previous emphasis on high-intensity interval running and small-sided games. However, neither approach considers positional differences. The purpose of this study was to investigate the feasibility and short-term effects of a novel position-specific conditioning training (PSCT) paradigm on physical and technical abilities of young soccer players. Fifteen male Vietnamese professional youth soccer players (16.1 ± 0.4 years, 171.7 ± 4.8 cm, 63.9 ± 3.8 kg) undertook a 3-week control period followed by a 3-week intervention with PSCT drills performed twice per week. Position-specific conditioning training comprised purposely designed drills for attackers, defenders, and wingers, respectively. The intensity and duration were the same for all drills (4 × 4 minutes at ∼90% heart rate maximum [HRmax], separated by a 4-minute recovery at 70% HRmax) but differed in the technical and tactical actions performed. Outcome measures included Yo-Yo intermittent recovery test level 1, repeated sprint ability, 10-m and 30-m sprint time, and the Loughborough Soccer Passing Test for technical skills in a fatigued and nonfatigued state. Position-specific conditioning training drills induced a desirable intensity for effective conditioning purpose (89.0 ± 2.1% HRmax) with low interplayer variability (coefficient of variation = 2.4%). Yo-Yo intermittent recovery test level 1 performance improved (p < 0.05) after the control (Δ178.7 ± 203.3 m) and intervention (Δ176.0 ± 225.7 m) periods without a difference between. These results confirmed the feasibility of PSCT as a novel high-intensity training approach for soccer players. Improvements in aerobic capacity were noted, despite no effect on other physical and technical measures. PSCT may be suitable for individual training, return-to-play stages of rehabilitation, during off-season, or in academy settings when time is not a constraint. [ABSTRACT FROM AUTHOR]

Strength is a fundamental component of athletic performance and development. This investigation examined the long-term strength development of powerlifting (PL) athletes. The rate of strength gain/day was assessed in 1897 PL athletes (F = 626, M = 1,271) over a 15-year period (2003-2018). Independent T-tests explored sex differences in baseline absolute (kg) and relative strength (kg⋅body mass-1 [bm]) recorded from the first competition, and strength gain/day (kg⋅d-1). Analyses based on initial strength quartiles were conducted using one-way analysis of variances with significance set at p < 0.05. Bivariate correlational analysis tested for relationships between strength gain/day and baseline strength, the number of competitions, and mean days between competitions. Males had greater absolute (M: 513.3 ± 99.8 kg, F: 289.4 ± 55.7 kg, p < 0.001) and relative (M: 5.89 ± 1.04 kg⋅bm-1, F: 4.27 ± 0.85 kg⋅bm-1, p < 0.001) strength at baseline. Overall, strength gain/day (F: 0.12 ± 0.69 kg⋅d-1, M: 0.15 ± 0.44 kg⋅d-1, p = 0.318) was similar between sexes. However, the strongest males showed a lower rate of strength improvement (0.102 kg⋅d-1) compared with least strong males (0.211 kg⋅d-1), p = 0.010. No differences were observed across quartiles for females. Correlational analyses revealed significant but weak negative relationships between strength gain/day and the mean days between competitions for females (² = -0.120, p = 0.003) and males (² = -0.190, p < 0.001). Similar relationships were observed for baseline strength (² = -0.073, p = 0.009) and the number of competitions (² = -0.111, p < 0.001) for males. The results suggest similar strength adaptation between sexes. The strongest males improve more slowly, possibly due to a ceiling effect. Collectively, the findings provide novel evidence of real-world long-term strength adaptations that may be particularly useful to understand athlete development, to aid periodized programming, and to benchmark strength over time. [ABSTRACT FROM AUTHOR]

Pearson, J, Spathis, JG, van den Hoek, DJ, Owen, PJ, Weakley, J, and Latella, C. Effect of competition frequency on strength performance of powerlifting athletes. J Strength Cond Res 34(5): 1213-1219, 2020-Powerlifting (PL) requires athletes to achieve the highest possible total weight lifted across squat, bench press, and deadlift. Athletes compete multiple times per year; however, it is not well understood how often PL athletes should compete to facilitate maximal strength performance. This study investigated the effect of competition frequency on strength (relative and absolute) in PL athletes over a 12-month period. Results across all male (n = 563, mean ± SD; age; 28 ± 10 years, body mass; 89.3 ± 19.3 kg) and female (n = 437, age; 31 ± 11 years, body mass; 70.1 ± 15.8 kg) PL athletes were collated. Total competition scores were used to calculate absolute and relative strength for each competition. Linear mixed models with random effects, and effect sizes ± 95%% confidence intervals compared competition frequency and total score for (a) all, (b) male, and (c) female competition entries, respectively. The association between total score at each competition was assessed with Pearsons correlation coefficient for the same independent variables. Results demonstrate greater absolute strength at competition 2 for all athletes (5.1%: p=0.043: d=0.16) and males (2.9%: p=0.049: d= 0.15). For females, absolute strength was greater at competition 5 compared to 1 (12.0%: p = 0.001: d = 0.65) and 2 (9.6%: p = 0.007: d = 0.50). Weak positive correlations for relative strength and number of times competed for males were evident between competitions 1 to 4 (r2 = 0.070-0.085, p =0.003-0.043). For females, 3 competitions weakly correlated with absolute strength (r2 = 0.106, p = 0.016). PL athletes who compete multiple times per year are more likely to achieve higher totals; however, there is an upper limit to the number of competitions (4 per year) that seem to allow a performance increase [ABSTRACT FROM AUTHOR]

Latella, C, Grgic, J, and Van der Westhuizen, D. Effect of interset strategies on acute resistance training performance and physiological responses: a systematic review. J Strength Cond Res XX(X): 000-000, 2019-The purpose of this systematic review was to evaluate the evidence surrounding the implementation of interset strategies to optimize acute resistance training performance. Searches of PubMed/MEDLINE, Scopus, and SPORTDiscus electronic databases were conducted. Studies that met the following criteria were included: (a) compared an interset strategy with a traditional passive rest interval in resistance training, (b) the assessed outcomes included performance or physiological responses, (c) resistance training was performed in a traditional dynamic fashion, (d) the study had an acute design, and (e) was published in English and in a peer-reviewed journal. A total of 26 studies were included in the review. When a given interset strategy was used, several studies reported improvements in the number of performed repetitions (i.e. greater total volume load), attenuation of the loss in velocity and power, reduced lactate levels, and in some cases, a decrease in perceived exertion. Dynamic agonist/static antagonist stretching, cooling, aerobic exercise, vibration, and individualized heart rate-based intervals seem to be the most effective strategies. However, the heterogeneity between study designs and methodologies suggests that careful consideration should be given to the type and specific application of the interset method being used. Given the acute nature of studies, extrapolation to any long-term benefits of using a given interset strategy remains limited. Collectively, coaches and sports scientists may consider using the most effective strategies based on practicality and equipment availability to optimize performance during the resistance training component of strength and conditioning programs. [ABSTRACT FROM AUTHOR]

Latella, C, van den Hoek, D, and Teo, WP. Differences in strength performance between novice and elite athletes: Evidence from powerlifters. J Strength Cond Res 33(7S): S103-S112, 2019-Strength forms an integral part of many sports. In particular, powerlifting success is determined solely by maximal strength, providing a unique opportunity to investigate the differences and potential factors influencing novice and elite competitors. We evaluated performance from 2,137 competitors between local (LOC), national (NAT), and international (INT) competitions. Results were analyzed by using the total (TOT) competition score within weight classes and age categories. Cohen's d effect sizes and 95% confidence intervals were used to detect differences within categories between LOC, NAT, and INT competitions. The coefficient of variation (CV) was used to determine the absolute variability. A moderate to large increase in performance was observed for all weight classes between LOC and NAT (men; d = 0.76, women; d = 1.09). No meaningful differences were observed between LOC and NAT, and NAT and INT when compared using age. No meaningful differences were observed between NAT to INT competitions when compared using weight classes. The CV was not different across competition level (CV = 17.4-22.9%) categories. Several internal (athlete) and external (environmental) factors are likely to explain these findings. Therefore, factors such as training experience, performance variability, body composition, anthropometric characteristics, and competition pressure that may influence strength performance should also be considered in both training phases and during competition. Collectively, the results offer novel information regarding the difference in strength performance between novice, subelite, and elite strength athletes. Strength and conditioning professionals should consider these factors when working with various athletes where maximal strength is an important determinant of success. [ABSTRACT FROM AUTHOR]