Haemoglobin mass responses and performance outcomes among high-performance swimmers following a 3-week live-high, train-high camp at 2320 m.

AIM: Greater quantification and characterisation of training load (TL) throughout Live-high, train-high (LHTH) altitude (ALT) training is required to identify periodisation strategies that may lead to physiological and performance improvements in swimmers. PURPOSE: This study aimed to examine the physiological responses and performance outcomes of 14 high-performance swimmers (FINA points: 836.0 ± 35.1) following 3 weeks of LHTH at 2320 m, while characterising the training load periodisation strategy adopted during the intervention. METHODS: Haemoglobin (Hb) mass was measured pre-, 7 and 14 days post-ALT via CO rebreathing. Performance in each athlete's primary event at national standard meets were converted to FINA points and compared from pre-to-post-ALT. TL was quantified at sea level (SL) and ALT through session rating of perceived exertion (RPE), where duration of each session was multiplied by its RPE for each athlete, with all sessions totalled to give a weekly TL. Pre-to-post-ALT changes were evaluated using repeated-measures ANOVA. RESULTS: Hb mass increased significantly from 798 ± 182 g pre-ALT to 828 ± 187 g at 7 days post (p = 0.013) and 833 ± 205 g 14 days post-ALT (p = 0.026). Weekly TL increased from SL (3179 ± 638 au) during week one (4797 ± 1349 au, p < 0.001) and week two (4373 ± 967 au, p < 0.001), but not week three (3511 ± 730 au, p = 0.149). No evidence of improved SL swimming performance was identified. CONCLUSION: A periodisation strategy characterised by a sharp spike in TL followed by a slight de-load towards the end of a LHTH intervention led to improved physiological characteristics but no change in the competitive performance of high-performance swimmers.

Practices and perceptions of strength and conditioning training in female golf: A cross-sectional survey study of high-level amateur players.

This study aims to ascertain an in-depth understanding of current practices and perceptions of S&C training in high-level amateur female golfers. A cross-sectional, explorative survey study was constructed which asked questions relating to four key areas: i) general participant information, ii) current strength and conditioning (S&C) practices, iii) the perceived influence of S&C training on golf performance, and iv) knowledge and awareness of S&C. Results showed that the majority of female players had participated in some form of S&C training in the past, with the majority believing that clubhead speed and carry distance were the primary golfing metrics which could be positively impacted. More specifically, 91-97% of the players "Strongly agreed" or "Agreed" that the key physical characteristics for golf were strength and power for the lower and upper body, and flexibility. Interestingly, 58% of the players believed that S&C training should mimic the movement of the golf swing, which based off current evidence, is not how drive metrics and ultimately shots gained, can be maximised. This survey study provides useful information relating to the practices and perceptions of S&C training in high-level female amateur players and areas where education may be able to further advance player understanding of physical preparation.

The Countermovement Rebound Jump: Between-Session Reliability and a Comparison With the Countermovement and Drop Jump Tests.

ABSTRACT: Xu, J, Turner, A, Comyns, TM, Chavda, S, and Bishop, C. The countermovement rebound jump: Between-session reliability and a comparison with the countermovement and drop jump tests. J Strength Cond Res 38(4): e150-e159, 2024-The countermovement jump (CMJ) and drop jump (DJ) are widely used jump tests to evaluate an athlete's neuromuscular performance. Nevertheless, conducting both the CMJ and the DJ assessments during one testing session can demand a considerable time investment that practitioners or coaches might not always have available. This study investigated whether the countermovement rebound jump (CMRJ) could be considered a viable alternative to the CMJ and DJ tests, respectively. Thirty-three physically active students volunteered as subjects (age: 27.2 ± 5.9 years, height: 1.78 ± 0.8 cm, body mass: 77.5 ± 11.5 kg), with 18 jumps completed for each subject across 2 testing sessions. The jump height (JH) and strategy-based metrics (time to take-off [TTTO], countermovement depth [CM depth], and reactive strength index [RSI] modified for CMJ and the first jump of the CMRJ; leg stiffness [ Kleg ], ground contact time [GCT], and RSI for DJ and the second jump for the CMRJ) were calculated simultaneously via the impulse-momentum, flight time, double integration, and motion capture methods. All variables were examined by repeated-measures analysis of variance, 2-way random effects model intraclass correlation coefficient (ICC), coefficient of variation (CV), and standard error of measurement, with the significance set at p ≤ 0.05. All 3 jump tests showed good-to-excellent relative reliability (ICC = 0.79-0.98) and good-to-moderate CV (≤9.83), with the only exception being Kleg measured during the DJ and in the second jump of the CMRJ assessment (CV ≤ 16.01%). Of all measured metrics, significant differences were only observed regarding TTTO between jumps ( p ≤ 0.027, effect size [ES] ≤ 0.49). The comparison of calculation methods indicated that the JH calculated by 4 methods were not significantly different between jump actions ( p ≥ 0.254). These findings support the use of the CMRJ as a reliable alternative to the CMJ and DJ tests. However, practitioners should be mindful of using Kleg as a metric, whereas practitioners are also advised to allocate sufficient familiarization trials before implementing the CMRJ into their routine test batteries.

Seasonal Variation and Positional Differences in Anthropometry, Strength, and Power Characteristics in English Premiership Women's Rugby Union Players.

ABSTRACT: Yao, X, Austerberry, A, Bishop, C, Wilson, L, Chiang, C-Y, and Turner, A. Seasonal variation and positional differences in anthropometry, strength, and power characteristics in English premiership women's rugby union players. J Strength Cond Res 38(5): 924-931, 2024-Women's rugby is a collision sport that relies heavily on body composition and physical characteristics of strength and power to achieve competitive success. Furthermore, the seasonal nature presents a variety of physical challenges that can cause fluctuations in a player's physical development. Therefore, the purpose of this study was to determine the differences in anthropometry, strength, and power characteristics between forwards and backs in women's rugby union athletes in England and to identify changes throughout a season. Forty-seven players were recruited from the English premiership women's rugby during the 2020-2021 season. Players were split into forwards and backs and underwent body composition testing by dual-energy X-ray absorptiometry and strength and power tests (countermovement jump, drop jump [DJ], and isometric midthigh pull) on 3 separate occasions (preseason, midseason, postseason). Overall, forwards had significantly ( p < 0.01) higher body mass, fat mass, lean mass [LM], bone mineral content, and take off momentum, and backs had significantly higher ( p < 0.01, d > 0.5) jump height, reactive strength, and shorter DJ contact time. When observing seasonal changes, there were statistically significant differences ( p < 0.01) or moderate-to-large practical differences ( d > 0.5) in LM, reactive strength index modified, time to take-off, and DJ flight time [FT] among forwards when comparing 3 testing time frames. For backs, statistically significant differences ( p < 0.01) or moderate-to-large practical differences ( d > 0.5) were reported in LM and DJ FT throughout the season. In conclusion, the strength and power testing and characteristics shown in this study could support coaches and junior women's rugby athletes to have a basic understanding of English premiership physical standards.

Effects of Physical Training and Associations Between Physical Performance Characteristics and Golf Performance in Female Players: A Systematic Review With Meta-Analysis.

ABSTRACT: Robinson, L, Murray, A, Ehlert, A, Wells, J, Jarvis, P, Turner, A, Glover, D, Coughlan, D, Hembrough, R, and Bishop, C. Effects of physical training and associations between physical performance characteristics and golf performance in female players: A systematic review with meta-analysis. J Strength Cond Res 37(12): e646-e655, 2023-The aims of this systematic review were to assess the association between physical performance and measures of golf performance, and the effects of physical training on measures of golf performance, in female golfers. A systematic literature search was conducted in PubMed, SPORTDiscus, Medline, and CINAHL. Inclusion criteria required studies to (a) have conducted a physical training intervention of any duration in female players and determine the effects on measures of golf performance, (b) determine the association between physical performance in at least one test and golf performance in female players, and (c) be peer-reviewed and published in English language. Methodological quality was assessed using a modified version of the Downs and Black Quality Index tool, and heterogeneity was examined through the Q statistic and I2 . Pooled effect sizes were calculated using standardized mean differences (SMDs) (with 95% confidence interval [CI]s) within a random-effects model, with Egger's regression test used to assess small study bias (inclusive of publication bias). Of the 2,378 articles screened, only 9 were included in the final review, with 3 of these being associative by design and 6 being training interventions. From an associative standpoint, clubhead speed (CHS) was reported in all 3 studies and was associated with measures of strength ( r = 0.54), lower-body power ( r = 0.60), upper-body power ( r = 0.56-0.57), and flexibility ( r = 0.52-0.71). When assessing the effects of physical training interventions, CHS was again the most commonly reported golf outcome measure ( n = 5). The random-effect model indicated that CHS significantly improves within each training group following training interventions (SMD = 0.73 [95% CIs: 0.32-1.14], Z = 3.50, p < 0.001), with trivial heterogeneity ( I2 = 0.00%, Q = 0.18; p = 0.9963) and no prevalence of small study bias depicted through the Egger's regression test ( z = -0.28, p = 0.78). From the available research, it seems that CHS can be positively affected from strength, power, and flexibility training interventions. From an associative standpoint, only 3 studies have been conducted solely in female players, with one showcasing questionable methodology. Future research should aim to carefully select test measures which better represent the physical capacities needed for the sport when determining the effects of and relationships with golf performance.

Validity and Reliability of the FlightScope Mevo+ Launch Monitor for Assessing Golf Performance.

ABSTRACT: Brennan, A, Murray, A, Coughlan, D, Mountjoy, M, Wells, J, Ehlert, A, Xu, J, Broadie, M, Turner, A, and Bishop, C. Validity and reliability of the FlightScope Mevo+ launch monitor for assessing golf performance. J Strength Cond Res 38(4): e174-e181, 2024-The purpose of this study was to (a) assess the validity of the FlightScope Mevo+ against the TrackMan 4 and (b) determine the within-session reliability of both launch monitor systems when using a driver and a 6-iron. Twenty-nine youth golfers, with a minimum of 3 years of playing experience, volunteered for this study. All golfers completed 10 shots with a 6-iron and a driver, with 8 metrics concurrently monitored from both launch monitor systems in an indoor biomechanics laboratory. For both clubs, Pearson's r values ranged from small to near perfect ( r range = 0.254-0.985), with the strongest relationships evident for clubhead speed (CHS) and ball speed ( r ≥ 0.92). Bland-Altman plots showed almost perfect levels of agreement between devices for smash factor (mean bias ≤-0.016; 95% CI: -0.112, 0.079), whereas the poorest levels of agreement was for spin rate (mean bias ≤1,238; 95% CI: -2,628, 5,103). From a reliability standpoint, the TrackMan showed intraclass correlation coefficients (ICCs) ranging from moderate to excellent (ICC = 0.60-0.99) and coefficient of variation (CV) values ranged from good to poor (CV = 1.31-230.22%). For the Mevo+ device, ICC data ranged from poor to excellent (ICC = -0.22 to 0.99) and CV values ranged from good to poor (CV = 1.46-72.70%). Importantly, both devices showed similar trends, with the strongest reliability consistently evident for CHS, ball speed, carry distance, and smash factor. Finally, statistically significant differences ( p < 0.05) were evident between devices for spin rate (driver: d = 1.27; 6-iron: d = 0.90), launch angle (driver: d = 0.54), and attack angle (driver: d = -0.51). Collectively, these findings suggest that the FlightScope Mevo+ launch monitor is both valid and reliable when monitoring CHS, ball speed, carry distance, and smash factor. However, additional variables such as spin rate, launch angle, attack angle, and spin axis exhibit substantially greater variation compared with the TrackMan 4, suggesting that practitioners may wish to be cautious when providing golfers with feedback relating to these metrics.

Book Review: Alzheimer's Disease Research: What has guided research so far and why it is high time for a paradigm shift (Christian Behl. Springer Nature, Switzerland, 2023) 661 pp.

This is a review of a recently published book entitled 'Alzheimer's Disease Research: What has guided research so far and why it is high time for a paradigm shift' by Christian Behl, a leading contributor to the field of Alzheimer disease over the last three decades. It presents a personal viewpoint on the historical developments in dementia research and therapeutics from its early beginnings through to the current day. The conflicting hypotheses, the therapeutic trials, the successes and the failures of the vast research infrastructure devoted to dissecting the aberrant pathways underlying the inexorable progression of this ultimately fatal neurodegenerative disease are discussed. It is based, among others, on numerous personal discussions of the author with other leading researchers in the field, and thus gives this (hi)story of Alzheimer research a personal touch and spotlight on controversies that distinguishes it from other books in the field.

Do people with musculoskeletal pain differ from healthy cohorts in terms of global measures of strength? A systematic review and meta-analysis.

OBJECTIVE: It is currently unknown if people with musculoskeletal pain display different multi-joint strength capacities than healthy cohorts. The aim was to investigate whether people with musculoskeletal pain show differences in global measures of strength in comparison to healthy cohorts. DATA SOURCES: A systematic review was conducted using three databases (Medline, CINAHL and SPORTDiscus) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. REVIEW METHODS: Studies involving participants with painful musculoskeletal conditions and multi-joint strength assessment measured at baseline were included. A meta-analysis was also performed to compute standardized mean differences (± 95% confidence intervals), using Hedge's g, and examined the differences in multi-joint strength at baseline between participants with painful musculoskeletal conditions and healthy participants. RESULTS: In total, 5043 articles were identified, of which 20 articles met the inclusion criteria and were included in the qualitative analysis. The available evidence revealed that multi-joint strength values were limited to knee osteoarthritis, fibromyalgia, chronic low back pain, and rheumatoid arthritis. Only four studies were included in the quantitative synthesis and revealed that only small differences in both chest press (g = -0.34, 95% CI [-0.64, -0.03]) and leg press (g = -0.25, 95% CI [-0.49, -0.02]) existed between adult women with fibromyalgia and active community women. CONCLUSION: There is a paucity of multi-joint strength values in participants with musculoskeletal pain. Quantitative comparison with healthy cohorts was limited, except for those with fibromyalgia. Adult women with fibromyalgia displayed reduced multi-joint strength values in comparison to active community women.

The impact of sprint, middle-distance, and long-distance orienteering races on perceived mental fatigue in national level orienteers.

Experiencing mental fatigue (MF) before an orienteering race can lead to a slower completion time. This study aimed to explore the changes in perceived MF, mood and other psychological responses during an orienteering competition. Sixteen national level orienteering athletes (20.8 ± 4.9 years) provided informed consent and completed the online surveys, before and immediately after each race, and 24- and 48-hours post competition (48POST). This study measured MF, physical fatigue, stress, tiredness and motivation using 0-100 Visual Analogue Scale, and the mood was assessed using The Brunel Mood Scale (BRUMS). A moderate to large increase in MF (ES = 0.93 [0.54 to 1.31]), BRUMS fatigue (ES = 0.61 [0.3 to 0.92]), and PF (ES = 1.21 [0.81 to 1.61]) was reported following orienteering races. A small increase in tiredness and BRUMS confusion, and a small decrease in motivation, stress and BRUMS vigour was also reported. There was a delay in recovering from the MF elicited by competition, with a small increase in MF (ES = 0.54 [0.08 to 1.15]) at 48POST compared to the pre-competition value. This study found that orienteers experience MF during competition and have a delayed recovery that can last up to two days after the competition.

Assessment of contact involvements and scrums in international rugby union match-play using video analysis and microsensor technology methods.

This study sought to assess the validity of contact involvement (CI) detection using microsensor technology (MST, Catapult Vector) within the context of a Tier One national rugby union (RU) squad, consisting of 44 players. Sensitivity of MST units to detect CI and scrums was assessed in eight test matches, by comparison with match data obtained by video analysis. This paper is the first to assess the sensitivity of MST to the full range of skilled CI which occur in RU, including evaluating "non-performance" collisions, such as incidental collisions or foul play. Sensitivity to tackles made (52.9-84.9%) and ruck hits (53.3-87.2%) was lower than previous research, although ball carries (71.9-93.5%) showed broadly similar sensitivity to established results. The sensitivity of the MST to detect scrums was substantially lower than previous findings, with large positional variation evident (51.4-91.5%). Further refinement of MST software should be considered in order to facilitate valid monitoring of RU performance and injury risk. An additional finding was that video analysis generally demonstrated satisfactory intrarater reliability. This result supports the use of video analysis as a reliable method of assessing RU performance, including CI.

Trackman 4: Within and between-session reliability and inter-relationships of launch monitor metrics during indoor testing in high-level golfers.

The aims of the present study were to: 1) investigate the within and between-session reliability of the Trackman 4 launch monitor system, and 2) determine the inter-relationships of some of these commonly used metrics. Golfers attended two test sessions at an indoor golf academy and performed 10 shots using their own driver. Results showed excellent within and between-session reliability for CHS (ICC = 0.99; SEM = 1.64-1.67 mph), ball speed (ICC = 0.97-0.99; SEM = 2.46-4.42 mph) and carry distance (ICC = 0.91-0.97; SEM = 7.80-14.21 mph). In contrast, spin rate showed the worst reliability (ICC = 0.02-0.60; SEM = 240.93-454.62 º/s) and also exhibited significant differences between test sessions (g = -0.41; p < 0.05), as did smash factor (g = 0.47; p < 0.05) and dynamic loft (g = -0.21; p < 0.05). Near perfect associations were evident in both test sessions between CHS and ball speed (r = 0.98-0.99), CHS and carry distance (r = 0.94-0.95), ball speed and carry distance (r = 0.97-0.98), and launch angle and dynamic loft (r = 0.98-0.99). Collectively, CHS, ball speed and carry distance serve as the most consistently reliable metrics making them excellent choices for practitioners working with golfers.

Seasonal Variation of Physical Performance, Bilateral Deficit, and Interlimb Asymmetry in Elite Academy Soccer Players: Which Metrics Are Sensitive to Change?

ABSTRACT: Bishop, C, Abbott, W, Brashill, C, Loturco, I, Beato, M, and Turner, A. Seasonal variation of physical performance, bilateral deficit, and interlimb asymmetry in elite academy soccer players: Which metrics are sensitive to change? J Strength Cond Res 37(2): 358-365, 2023-This study aimed to report seasonal variations for (a) physical performance, (b) interlimb asymmetry, and (c) bilateral deficit (BLD) data over the course of a competitive soccer season and determine which metrics are sensitive to change. This study used a repeated-measures observational design for 19 under-20, elite, academy, soccer players (age: 17.58 ± 0.61 years; height: 1.81 ± 0.09 m; body mass: 74.36 ± 7.58 kg), who conducted bilateral and single-leg countermovement jumps (CMJ and SLCMJ), linear speed (5, 10, 20, and 30-m) and 505 change of direction (COD) speed tests, at pre, mid, and end of season time points. For jump tests, jump height, reactive strength index modified, time to takeoff, and countermovement depth metrics were monitored, with interlimb asymmetry and the BLD also calculated for each. Significant improvements ( p < 0.05) in performance were evident in all fitness tests: CMJ (effect size [ES]: 0.61 to 1.03), SLCMJ (ES: 0.60 to 2.25), linear speed (ES: -0.54 to -1.96), and COD speed (ES: -0.68 to -1.14). Significant reductions in asymmetry (ES: -0.68 to -1.07) and significant increases in the BLD (ES: 1.15 to 1.57) were also evident throughout the season. Additionally, kappa coefficients were used to determine consistency in limb dominance throughout the season, but only poor to fair levels of agreement (kappa: -0.17 to 0.37) were evident, highlighting the fluctuating nature of limb dominance throughout the season. Despite all tests exhibiting meaningful change, the SLCMJ and linear speed showed the most frequent and largest differences in performance, highlighting their usefulness in the ongoing monitoring process of physical capacities in elite male academy players across a competitive soccer season.

Contemporary Practices of Strength and Conditioning Coaches in High-Level Male Ice Hockey: A Survey-Based Investigation.

ABSTRACT: Galati, D, Turner, AN, Bishop, C, and Maloney, SJ. Contemporary practices of strength and conditioning coaches in high-level male ice hockey: a survey-based investigation. J Strength Cond Res 37(11): 2241-2250, 2023-The aim of this study was to provide an updated view of the common practices, ideologies, education level, and professional environment of strength and conditioning (S&C) coaches in elite male ice hockey. Nineteen S&C coaches from professional, semiprofessional, and top-tier collegiate hockey teams in North America completed an anonymous online survey. This was composed of 10 sections: (a) background information; (b) technology use, (c) testing and periodization, (d) strength and power, (e) flexibility/mobility, (f) speed, (g) plyometrics, (h) aerobic and anaerobic conditioning, (i) rehabilitation, and (j) challenges and areas of improvement. Fixed-response questions were analyzed through frequency analyses. Thematic analyses were used to identify common themes from open-response questions. Strength and conditioning coaches had an average of 8 (±6.5) years of experience when they accepted their current role. The majority held a master's degree and S&C certification. Muscular power, linear speed, and body composition were the most frequently tested qualities. Neuromuscular fatigue was the most important consideration during the season and least important consideration during the off-season. Training frequencies for all physical capacities were lower during the season compared with the off-season. All S&Cs had access to technology, with wearables, with force plates identified as the most used devices. This information may be used by S&C coaches to compare working practices with those used by their peers and inform them of the likely requirements and skill sets needed for job applications. Educational institutions may use this information to align teaching to current practice and to inform future research.

A Survey Into the Use of Priming Techniques Implemented by Athletes and Coaches to Improve Athletic Performance.

ABSTRACT: Collins, J, Bishop, C, Hills, F, Spiegelhalter, A, Cohen, R, and Turner, A. A survey into the use of priming techniques implemented by athletes and coaches to improve athletic performance. J Strength Cond Res 37(1): 107-113, 2023-This study aimed to examine the frequency and modes of psychological priming techniques and strategies being implemented by athletes of a variety of performance levels. A 15-question, anonymous questionnaire was developed and shared via social media sites. The survey implemented a quantitative method approach to collect background information (e.g., demographics, competition, and training history), the prevalence of priming, and the methods used. Ninety subjects met the inclusion criteria (71 men, 18 women, and 1 subject did not identify their sex), with a median age of 28 ± 7.47 years (range, 24-33 years) and training experience of 11 ± 7.57 years (range, 8-18 years). Self-selected participation level accounted for 11 professional, 17 semiprofessional, and 54 amateur-level athletes. Priming strategies were implemented by 79% of subjects without the use of a coach, 10% used strategies with their coach, and 11% did not prime. For athletes, music was the preferred choice (27%), followed by instructional self-talk (24%), motivational self-talk (23%), applied physical actions (20%), and watching videos clips (6.3%). Coaches preferred motivational statements with 55% implementing this technique, followed by 27% using inspiring team talks, and only 18% playing music. Of those who implemented a priming strategy, 66% found them to be either "very" or "extremely" effective," With 38% of subjects feeling that priming accomplished this through increased motivation, 22% felt that it reduced their fear and anxiety, 21% thought that it improved their intensity, 15% felt that it increased strength and power, and 2% felt that it improved endurance. The chi-square test also found a significant (φc = 0.27; p = 0.011) relationship with the use of priming to increase motivation. These results demonstrate that priming strategies are being used irrespective of coach intervention; therefore, educating coaches and athletes on the implementation of priming techniques has its place when aiming to improve athlete performance.

The Effects of a 6-Week Unilateral Strength and Ballistic Jump Training Program on the Force-Velocity Profiles of Sprinting.

ABSTRACT: Bettariga, F, Maestroni, L, Martorelli, L, Turner, A, and Bishop, C. The effects of a 6-week unilateral strength and ballistic jump training program on the force-velocity profiles of sprinting. J Strength Cond Res 37(7): 1390-1396, 2023-The aims of this study were (a) to investigate the effects of a unilateral training program, compared with a control group, on a force-velocity (F-V) profile in soccer players and (b) to explore such effects on linear speed. Twenty-four soccer players, randomly assigned to a 6-week unilateral strength and ballistic jump training (UNI) ( n = 12) or a control group (CON) ( n = 12), performed 30-meter linear sprint test. Findings showed small-to-moderate improvements ( p < 0.05) in linear speed time ( g = 0.66-0.81) and in most F-V variables: maximal running velocity ( V0 ) ( g = 0 .81), maximal power output ( Pmax ) ( g = 0.49), maximal ratio of force ( RFmax ) ( g = 0.55), optimal velocity ( Vopt ) ( g = 0.83), and maximal speed ( g = 0.84) from pre- to post-intervention in the UNI group, whereas no meaningful changes were found in the CON group. The between-group comparison indicated small to large significant changes in V0 ( g = 0.95), RFmax ( g = 0.48), Vopt ( g = 0.95), maximal speed ( g = 0.98), and linear speed time performance ( g = 0.42-1.02), with the exception of the 0-5 meter distance, in favor of the UNI group. Thus, a unilateral strength and ballistic jump training program can be used to improve the F-V profile and linear speed performance of amateur soccer players.

Measuring Interlimb Asymmetry for Strength and Power: A Brief Review of Assessment Methods, Data Analysis, Current Evidence, and Practical Recommendations.

ABSTRACT: Bishop, C, de Keijzer, KL, Turner, AN, and Beato, M. Measuring interlimb asymmetry for strength and power: A brief review of assessment methods, data analysis, current evidence, and practical recommendations. J Strength Cond Res 37(3): 745-750, 2023-The aim of this brief narrative review is to summarize the present evidence, provide recommendations for data analysis, and provide appropriate training methods to reduce strength and power asymmetries within athlete populations. Present evidence shows that a strong interest in the assessment of asymmetry exists. Despite the perceived associated relationship between asymmetry and injury and performance, a clear link is still missing. Practitioners need to be aware of this when they decide to assess asymmetries and later design training interventions. Several bilateral and unilateral tests could be used to assess asymmetries, such as isokinetic dynamometry, the isometric mid-thigh pull, squat, and Nordic hamstring exercise. Based on the current evidence, future investigations require further standardization of methodology and analysis to optimize interpretation (e.g., within session and between session), adoption, and implementation of interlimb asymmetry testing and appropriate interventions. In this review, 3 training interventions have been proposed to reduce existing lower limb asymmetries in sport populations: traditional resistance training, flywheel resistance training, and combined training interventions, with some evidence suggesting that such interventions can reduce lower limb asymmetries. Nonetheless, the number and quality of articles currently available are too limited to draw firm conclusions; therefore, further research is needed to verify whether training interventions can achieve these aims. To develop an understanding and application of interventions addressing interlimb asymmetries within the sport, greater methodological rigor should be applied toward study design, data analysis, and interpretation of future investigations and when appraising the current literature.

Predicting Weight Category-Specific Performance Zones for Olympic, World, and European Weightlifting Competitions.

ABSTRACT: Chavda, S, Comfort, P, Lake, JP, Bishop, C, and Turner, AN. Predicting weight category-specific performance zones for Olympic, World, and European weightlifting competitions. J Strength Cond Res 37(10): 2038-2045, 2023-Understanding the total likely required weight category to achieve a specific rank within a specific competition can aid in the long-term and short-term preparation and tactics for performance teams. The primary objective of this investigation was to develop a set of predictive models for new weight categories across 5 performance zones for 3 major weightlifting competitions. Performance total (Ptot) data for top 15 male athletes were obtained from the International Weightlifting Federation website from 1998 to 2020 across the Olympics, and World and European Championships. A second-order polynomial regression was conducted with 95% confidence, and predictive intervals were calculated. The average of the newly contested body mass was then used as the intercept. Predictions were compared against current performances of the new weight categories up to the 2020 Olympics. Results revealed that the models for all competition types varied in their predictive ability for each performance zone, across each new weight category. On average, predicted Ptot displayed a difference from actual Ptot of 3.65 ± 2.51% (12.46 ± 9.16 kg), 0.78 ± 3.29% (2.26 ± 10.08 kg), and -1.13 ± 3.46% (-4.32 ± 11.10 kg) for the Olympics, and World and European Championships, respectively. The results suggest that the predictive models may be a good indicator of future performances; however, the models may have greater efficacy in some weight categories and performance zones than others.

Alternate Leg Bounding Acutely Improves Change of Direction Performance in Women's Team Sports Players Irrespective of Ground Type.

ABSTRACT: Dann, E, Quinn, S, Russell, M, Kilduff, LP, Turner, AN, and Hills, SP. Alternate leg bounding acutely improves change-of-direction performance in women's team sports players irrespective of ground type. J Strength Cond Res 37(6): 1199-1203, 2023-This study aimed to assess whether body mass only alternate leg bounding performed post-warm-up on grass or a hard surface acutely improves preplanned change-of-direction performance in women's team sports players relative to a control condition and, if so, profile the time course of such changes. On 3 occasions, 14 amateur women's team sports players performed 20 m preplanned change-of-direction ("Pro-Agility") tests at 4, 8, and 12 minutes after interventions. Interventions were implemented immediately after a standardized warm-up and consisted of 3 sets of 10 repetitions of alternate leg bounding (5 ground contacts per limb) on a hard indoor surface (HARD) or natural grass (GRASS), or a control condition involving approximately 75 seconds of continuous walking with no bounding (CON). Performance was similar between conditions at 4-minutes postintervention. Performance at 8 minutes was greater in HARD (2.9%, p = 0.015) and GRASS (3.8%, p = 0.029) relative to CON, whereas GRASS also exceeded CON at 12 minute post-bounding (5.2%, p = 0.004). All effects were large. No differences existed between HARD and GRASS at any time. Irrespective of the ground surface, alternate leg bounding performed with body mass only can acutely improve indices of change-of-direction performance in women's team sports players when an appropriate post-stimulus recovery period is provided. Bounding on grass or a hard surface represents a feasible match-day practice that enhances subsequent change-of-direction performance and could therefore be used as part of practically applicable pre-match, half-time, and pitch-side (re)warm-up activities.

Acute effects of combined cycling and plyometrics on vertical jump performance in active males.

The aim of this study was to analyze the acute effects of high vs low-intensity cycling efforts, combined with plyometrics, on vertical jump performance. Twenty-four physically active men (mean ± SD: 23 ± 2 years, 72.1 ± 10.1 kg, 1.73 ± 0.07 m) were randomly divided into two groups: experimental group (EXP, n = 16) and control group (CON, n = 8). EXP competed 2 experimental trials in a random order: (a) short high-intensity interval exercise (HI + Plyo) [5 × 10 s of cycling ("all-out")/50 s active rest] or (b) low-intensity continuous exercise (LO + Plyo) [5 min of cycling at 75% of the HRmax)], along with 3 × 10 plyometric bounds (drop jumps)/1 min rest between sets. CON used a preconditioning activity of 13 min of low intensity cycling at ~60% of HRmax. Both EXP interventions significantly increased (p ≤ 0.05) the countermovement jump (CMJ) height at 1 min, 3 min, 6 min and 9 min compared to baseline, while the CON remained unchanged. There were no significant differences in CMJ performance enhancement between HI + Plyo (largest 11.2% at 9 min) and LO + Plyo (largest 15.0% at 3 min) at any time-point, suggesting that the plyometric component may be most important, with HR recovery taking slightly longer following HI + Plyo. The findings suggest that CMJ performance can be enhanced following high or low-intensity cycling combined with plyometric preconditioning activities in active males, the optimum recovery period likely to be individual-specific.

Carotid stenosis patients with a remote history of cerebrovascular events have increased risk of major adverse events over asymptomatic patients.

INTRODUCTION: Asymptomatic patients with a remote history of transient ischemic attack (TIA) or stroke are not well studied as a separate population from asymptomatic patients with no prior history of TIA or stroke. We compared in-hospital outcomes after transcarotid artery revascularization (TCAR) and transfemoral carotid artery stenting (TFCAS) among symptomatic patients, patients with a remote history of neurologic symptoms, and asymptomatic patients. METHODS: Data from patients in the Vascular Quality Initiative database who underwent TCAR (January 2017 to April 2020) or TFCAS (May 2005 to April 2020) were analyzed. Symptomatic status was defined as TIA and/or stroke occurring within 180 days before the procedure. Asymptomatic status was divided into patients with no history of TIA/stroke (asymptomatic) and patients with a history of TIA/stroke occurring more than 180 days before the procedure (remote history of neurologic symptoms). The Student t-test and Pearson χ2 test were used to compare baseline patient characteristics and outcomes. Multivariate logistic regression was used to adjust for significant between-group differences in baseline characteristics. RESULTS: There were 7158 patients who underwent TCAR (symptomatic: 2574, asymptomatic: 3689, and asymptomatic with a remote history of neurologic symptoms: 895) and 18,023 patients who underwent TFCAS (symptomatic: 6195, asymptomatic: 10,333, and asymptomatic with a remote history of neurologic symptoms: 1495). Regardless of symptom status, the mean patient age was 73 years for TCAR and 69 years for TFCAS. A total of 64% of patients in the study were male and 36% of patients were female. The mean long-term follow-up data ranged between 208 and 331 days within the three patient groups. Carotid stenosis patients with a remote history of neurologic symptoms had higher rates of TIA, stroke, TIA/stroke, stroke/death, and stroke/death/myocardial infarction than asymptomatic patients, and these rates were similar to those of symptomatic patients. Comparing TCAR and TFCAS among patients with a remote history of neurologic symptoms, there were statistically significant reductions in the odds of stroke/death (odds ratio: 0.46, 95% confidence interval: 0.27-0.84, P = .011) and stroke/death/myocardial infarction (odds ratio: 0.51, 95% confidence interval: 0.30-0.87, P = .013) after TCAR. This was likely driven by the increased rate of death after TFCAS in patients with a remote history of neurologic symptoms (0.9%) compared with asymptomatic patients (0.6%). CONCLUSIONS: Asymptomatic patients with a remote history of TIA/stroke do not have the same outcomes as asymptomatic patients without a history of TIA/stroke and are at higher risk of adverse in-hospital events. Patients with a remote history of TIA/stroke have increased risk of in-hospital death after TFCAS and may benefit from TCAR.