Can we predict the landing performance of simulated aerials in surfing?

This study explored which technical and physical attributes could predict superior and/or safe landing performance when surfers performed variations of a simulated aerial task. Fourteen surfers (age 20.6 ± 5.7 years, height 178.1 ± 9.50 cm, mass 70.6 ± 10.8 kg) had their lower limb mobility, squat jump, countermovement jump, and drop-and-stick landing performance assessed. Performance of two aerial variations (Frontside Air (FA) and Frontside Air Reverse (FAR)) was also measured, with variables relating to technical performance (critical feature and subjective ratings) and potential injury risk (relative total peak landing force and loading rates) collected. Multiple linear regressions were used to predict performance of both aerial variations based on a subset of independent variables. Four models could predict performance. Predicted technical capability in the FAR was mostly influenced by lead limb hip extension and lead limb knee flexion range of motion. Potential injury risk when surfers perform an FA and FAR was predicted to be mitigated by increasing lead ankle dorsiflexion range of motion, as well as trail hip extensor mobility to reduce the relative total peak force experienced when landing the FA. These simple outcome measures could be routinely assessed to ensure successful and safe aerial landings in surfing.

Rate of loading, but not lower limb kinematics or muscle activity, is moderated by limb and aerial variation when surfers land aerials.

We aimed to determine whether there were any differences in how surfers used their lead and trail limbs when landing two variations of a simulated aerial manoeuvre, and whether technique affected the forces generated at landing. Fifteen competitive surfers (age 20.3 ± 5.6 years, height 178.2 ± 9.16 cm, mass 71.0 ± 10.5 kg) performed a Frontside Air (FA) and Frontside Air Reverse (FAR), while we collected the impact forces, ankle and knee muscle activity, and kinematic data. A principal component analysis (PCA) was used to reduce 41 dependent variables into 10 components. A two-way MANOVA revealed that although there were no limb x aerial variation interactions, surfers generated significantly higher relative loading rates at landing for the trail limb compared to the lead limb (+28.8 BW/s; F(1,303) = 20.660, p < 0.0001, η2 = 0.064). This was likely due to the surfers "slapping" the trail limb down when landing, rather than controlling placement of the limb. Similarly, higher relative loading rates were generated when landing the FA compared to the FAR (+23.6 BW/s; F(1,303) = 31.655, p < 0.0001, η2 = 0.095), due to less time over which the forces could be dissipated. No relationships between aerial variation or limb were found for any of the kinematic or muscle activity data. Practitioners should consider the higher relative loading rates generated by a surfer's trail limb and when surfers perform a FA when designing dry-land training to improve the aerial performance of surfing athletes.

Training for success: Do simulated aerial landings replicate successful aerial landings performed in the ocean?

PURPOSE: Physical preparation of competitive surfers includes substantial dry-land training. It is currently unknown, however, how closely these exercises replicate surfing maneuvers performed in the ocean. This study compared the technique features displayed by surfers when landing simulated aerial maneuvers on land to critical features previously established as necessary for surfers to successfully land aerials in the ocean during competition. METHODS: Fourteen competitive surfers (age 20.6 ± 5.7 years, height 178.1 ± 9.50 cm, mass 70.6 ± 10.8 kg) were recruited to perform two variations of a simulated aerial task, a Frontside Air (FA) and Frontside Air Reverse (FAR). Joint ranges of motion (ROM), center of pressure, and apparent gaze data were collected during the landing event. Paired t tests or Wilcoxon signed-rank tests were used to identify any significant differences in the outcome variables between the two aerial tasks. RESULTS: Participants displayed 100% and 60% of the critical features associated with successfully landing a FA and FAR, respectively. In both the simulated FA and FAR, participants landed in 1.0-3.7° of dorsiflexion, moving through significantly less ankle joint ROM in the lead limb during the FAR (P < .01). Participants also displayed significantly less knee and hip ROM (P = .002-.048) while landing the FAR compared to the FA. CONCLUSION: The simulated FA and FAR tasks are appropriate training tools for surfers to replicate most of the critical features that a surfer should display to successfully land aerial maneuvers in the ocean. These tasks therefore enable surfers to practice these complex movements in a controlled environment.

Upper-Body Strength Measures and Pop-Up Performance of Stronger and Weaker Surfers.

Parsonage, J, Secomb, JL, Sheppard, JM, Ferrier, BK, Dowse, RA, and Nimphius, S. Upper-body strength measures and pop-up performance of stronger and weaker surfers. J Strength Cond Res 34(10): 2982-2989, 2020-The primary purpose of this study was to investigate the reliability of the isometric push-up (IPU), dynamic push-up (DPU), and force plate pop-up (FP POP) as measures of upper-body isometric and dynamic strength qualities in surfing athletes. Furthermore, the study aimed to compare pop-up performance between stronger and weaker surfers. Eighteen female (n = 9) and male (n = 9) surfers (age = 28.1 ± 6.4 years, mass = 69.6 ± 10.4 kg, and height = 172.5 ± 6.7 cm) completed a battery of upper-body strength assessments, of which exhibited high between-day reliability: IPU, (coefficient of variation [CV%] = 4.7, intraclass correlation coefficient [ICC] = 0.96), DPU (CV% = 5.0, ICC = 0.90), and FP POP (CV% = 4.4, ICC = 0.90). Participants were subsequently split into stronger (n = 9) and weaker (n = 9) surfers based on normalized peak force (PF) attained in the IPU. Pop-up performance was measured both in the water and during the FP POP and was referred to as time to pop-up (TTP). Significant between-group differences were observed for normalized PF during IPU (d = 1.59, p < 0.01) and DPU (d = 0.94 p = 0.04). Although not significant, there was a large magnitude difference in FP POP (d = 0.80, p = 0.08) and FP TTP (d = 0.85, p = 0.07). Significant correlations were identified between normalized IPU PF and normalized DPU FP (r = 0.69, p = 0.03) and FP TTP (r = 0.73, p = 0.02) in the stronger group. The weaker group exhibited a significant inverse correlation between normalized IPU PF and in-water TTP (r = -0.77, p < 0.01). The results suggest improvements in pop-up performance may be elicited by improving dynamic strength for stronger surfers, whereas pop-up performance in weaker surfers may be elicited by improving maximum strength. The upper-body strength assessments provided a novel insight into strength qualities that are associated with in-water performance of surfers (TTP).

Essential Skills for Superior Wave-Riding Performance: A Systematic Review.

Forsyth, JR, Riddiford-Harland, DL, Whitting, JW, Sheppard, JM, and Steele, JR. Essential skills for superior wave-riding performance: A systematic review. J Strength Cond Res 34(10): 3003-3011, 2020-To successfully and safely perform surfing maneuvers, surfers and their coaches need to know how to perform each maneuver correctly. Although some components of the sport are well understood, evidence-based recommendations in the scientific literature on how to perform surfing skills are sparse. The aim of this article was to systematically review the body of literature pertaining to discrete wave-riding skills and characteristics that are associated with the ability of surfers to successfully perform them. Searches of PubMed, SCOPUS, SPORTDiscus with Full-text, and Web of Science were undertaken in January 2019, to identify the most appropriate literature, with secondary searches of reference lists used to create a greater pool of possible articles. The review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P). Ten studies deemed appropriate for review captured data from 299 surfers, who were predominantly competitive (78.3%) and male (58.2%). The average Down and Black Quality Index of the articles was 76.3 ± 8.4%, with these articles focusing on the "pop-up" and landing skills. Performance indicators, such as isometric push-up peak forces, force-plate derived and in-water time to pop-up, relative peak forces generated when landing and time-to-stabilization, were all shown to be related to the physical characteristics of surfers and could affect the ability of surfers to successfully ride a wave. Findings from the studies included in this review suggest that the pop-up and landing exhibit trainable qualities that coaches and athletes can use to improve surfing performance.

Physiological Profile of Male Competitive and Recreational Surfers.

Furness, J, Hing, W, Sheppard, JM, Newcomer, S, Schram, B, and Climstein, M. Physiological profile of male competitive and recreational surfers. J Strength Cond Res 32(2): 372-378, 2018-Surfing consists of both high- and low-intensity paddling of varying durations, using both the aerobic and anaerobic systems. Surf-specific physiological studies lack adequate group sample sizes, and V[Combining Dot Above]O2peak values are yet to determine the differences between competitive and recreational surfers. The purpose of this study was therefore to provide a comprehensive physiological profile of both recreational and competitive surfers. This multisite study involved 62 male surfers, recreational (n = 47) and competitive (n = 15). Anthropometric measurements were conducted followed by dual-energy x-ray absorptiometry, anaerobic testing and finally aerobic testing. V[Combining Dot Above]O2peak was significantly greater in competitive surfers than in recreational surfers (M = 40.71 ± 3.28 vs. 31.25 ± 6.31 ml·kg·min, p < 0.001). This was also paralleled for anaerobic power (M = 303.93 vs. 264.58 W) for competitive surfers. Arm span and lean total muscle mass was significantly (p ≤ 0.01) correlated with key performance variables (V[Combining Dot Above]O2peak and anaerobic power). No significant (p ≥ 0.05) correlations were revealed between season rank and each of the variables of interest (V[Combining Dot Above]O2peak and anaerobic power). Key performance variables (V[Combining Dot Above]O2peak and anaerobic power) are significantly higher in competitive surfers, indicating that this is both an adaptation and requirement in this cohort. This battery of physiological tests could be used as a screening tool to identify an athlete's weaknesses or strengths. Coaches and clinicians could then select appropriate training regimes to address weaknesses.

Workloads of Competitive Surfing: Work-to-Relief Ratios, Surf-Break Demands, and Updated Analysis.

Farley, ORL, Secomb, JL, Raymond, ER, Lundgren, LE, Ferrier, BK, Abbiss, CR, and Sheppard, JM. Workloads of competitive surfing: work-to-relief ratios, surf-break demands, and updated analysis. J Strength Cond Res 32(10): 2939-2948, 2018-The study provides an in-depth descriptive and quantitative time-motion analysis of competitive surfing, using Global Positioning System (GPS) units and video synchronization, which serves to extend upon the results of Farley, Harris, and Kilding (Journal of Strength and Conditioning Research, 26, 7 [2012]). In addition, comparisons between locations and surfers competing in the same heats were performed. Global Positioning System and video data were collected from 41 male competitive surfers (23.2 ± 6.1 years, 71 ± 10.3 kg, 177.2 ± 6.4 cm) participating in 3 professional domestic surfing events, with competitive heats of 20-minute duration. Fifty data sets were analyzed across the 3 competitions, with velocities and distances covered, proportion of time spent performing various surfing activities, and total work-to-relief ratio determined. Results revealed surfers paddled 44% of the total time, followed by stationary periods (42%). Surfers performed at a significantly (p ≤ 0.05) higher work-to-relief ratio (1.7:1) at the beach-break (an exposed beach) compared with point-break 1 and 2 (waves breaking around a rocky point). Point-breaks 1 and 2 had longer continuous durations of paddling, with significantly longer rides at point-break 1 over the beach-break (p ≤ 0.01) and point-break 2 (p ≤ 0.01). The average maximal speed (24.8 km·h) from point-break 2 was significantly faster than point-break 1 (p ≤ 0.01) and beach-break (p ≤ 0.05). This information should influence surfing drills and conditioning methods to prepare these athletes for the disparate demands, such as training for a point-break competition involving longer durations of continuous paddling and short, high-intensity workloads for a beach-break.

Performance Analysis of Surfing: A Review.

Farley, ORL, Abbiss, CR, and Sheppard, JM. Performance Analysis of Surfing: A Review. J Strength Cond Res 31(1): 260-271, 2017-Despite the increased professionalism and substantial growth of surfing worldwide, there is limited information available to practitioners and coaches in terms of key performance analytics that are common in other field-based sports. Indeed, research analyzing surfing performance is limited to a few studies examining male surfers' heart rates, surfing activities through time-motion analysis (TMA) using video recordings and Global Positioning Satellite (GPS) data during competition and recreational surfing. These studies have indicated that specific activities undertaken during surfing are unique with a variety of activities (i.e., paddling, resting, wave riding, breath holding, and recovery of surfboard in the surf). Furthermore, environmental and wave conditions also seem to influence the physical demands of competition surfing. It is due to these demands that surfers are required to have a high cardiorespiratory fitness, high muscular endurance, and considerable strength and anaerobic power, particular within the upper torso. By exploring various methods of performance analysis used within other sports, it is possible to improve our understanding of surfing demands. In so doing this will assist in the development of protocols and strategies to assess physiological characteristics of surfers, monitor athlete performance, improve training prescription, and identify talent. Therefore, this review explores the current literature to provide insights into methodological protocols, delimitations of research into athlete analysis and an overview of surfing dynamics. Specifically, this review will describe and review the use of TMA, GPS, and other technologies (i.e., HR) that are used in external and internal load monitoring as they pertain to surfing.

Changes in Rugby League Tackling Ability During a Competitive Season: The Relationship With Strength and Power Qualities.

Speranza, MJA, Gabbett, TJ, Greene, DA, Johnston, RD, and Sheppard, JM. Changes in rugby league tackling ability during a competitive season: the relationship with strength and power qualities. J Strength Cond Res 31(12): 3311-3318, 2017-This study examined the relationship between changes in tackling ability, and muscular strength and power during a semiprofessional rugby league competitive season. Twelve semiprofessional rugby league players (mean ± SD age, 23.3 ± 2.0 years) underwent tests of upper- and lower-body strength and power during the preseason period. Tackling ability was tested using video analysis of a standardized one-on-one tackling drill. Players repeated these tests after round 15 of a 25-match competitive season. Changes in 1 repetition maximum (1RM) squat (rs = 0.70; p < 0.02) and squat relative to body mass (rs = 0.73; p < 0.01) were significantly related to changes in tackling ability. Players with the greatest improvements in tackling ability (i.e., "responders") retained 1RM squat (effect size, ES = 0.85, p = 0.09) and squat relative to body mass (ES = 0.82, p = 0.15) to a greater extent than the "nonresponders." The results of this study suggest that players who retained lower-body strength were able to improve tackling ability during the competitive season, whereas reductions in lower-body strength were associated with decrements in tackling ability. This study highlights the importance of the development and maintenance of lower-body muscular strength for effective tackling performance throughout the rugby league season.

Gender Differences in Physical Performance Characteristics of Elite Surfers.

Parsonage, JR, Secomb, JL, Tran, TT, Farley, ORL, Nimphius, S, Lundgren, L, and Sheppard, JM. Gender differences in physical performance characteristics of elite surfers. J Strength Cond Res 31(9): 2417-2422, 2017-The purpose of this study was to describe and compare the gender differences in physical performance characteristics of elite surfers. Twenty competitive female surfers (CFS) and 20 competitive male surfers (CMS) performed a battery of physical performance tests: squat jump (SJ), isometric midthigh pull (IMTP), 15-m sprint paddle, and 400-m endurance paddle during a single testing session. All performance measures were significantly different between CFS and CMS (p < 0.01). Specifically, CMS produced greater peak force production (28.5%) and jumped higher (27.7%) in the SJ and produced greater normalized peak force during the IMTP (18.9%) compared with CFS. For paddling performance, CMS were faster over 5, 10, and 15 m (12.4%, 9.7%, and 10.9%), possessed a higher peak paddling velocity (11.3%), and recorded faster paddle times over 400 m (11.8%). The results of this study suggest that CMS exhibit superior physical performance characteristics than CFS, in relation to both the lower and upper body. Strength and conditioning practitioners should therefore implement a structured and periodized program to facilitate strength qualities that underpin surfing performance for all participants, but as highlighted in the current investigation, female surfers may have a greater window for adaptation and therefore vast benefit of targeting their underdeveloped physical qualities.

Maximal Strength Training Improves Surfboard Sprint and Endurance Paddling Performance in Competitive and Recreational Surfers.

Coyne, JOC, Tran, TT, Secomb, JL, Lundgren, LE, Farley, ORL, Newton, RU, and Sheppard, JM. Maximal strength training improves surfboard sprint and endurance paddling performance in competitive and recreational surfers. J Strength Cond Res 31(1): 244-253, 2017-Upper-body (UB) strength has very high correlations with faster surfboard paddling speeds. However, there is no research examining the effects of improving UB strength has on surfboard paddling ability. This study aimed to determine the influence that improvements in UB closed-kinetic chain maximal strength have on surfboard paddling in both competitive and recreational surfers. Seventeen competitive and recreational male surfers (29.7 ± 7.7 years, 177.4 ± 7.4 cm, 76.7 ± 9.9 kg) participated in a repeated-measures, parallel control study design. Anthropometry; 5-, 10-, and 15-m sprint; and 400-m endurance surfboard paddling tests along with pull-up and dip 1 repetition maximum strength tests were assessed pre- and postintervention. Subjects in the training group performed 5 weeks of maximal strength training in the pull-up and dip. Differences between the training and control groups were examined postintervention. The training group increased their speed over the 5-, 10-, and 15-m sprint, whereas the control group became slower (d = 0.71, 0.51, and 0.4, respectively). The training group also displayed faster endurance paddling performance compared with the control group (d = 0.72). Short-term exposure to maximal strength training elicits improvements in paddling performance measures. However, the magnitude of performance increases seems to be dependent on initial strength levels with differential responses between strong and weaker athletes. Although a longer maximal strength training period may have produced more significant paddling improvements in stronger subjects, practitioners are unlikely to have any more than 5 weeks in an uninterrupted block with competitive surfing athletes. This study reveals that a "threshold" level of maximal strength that if possessed, short-term maximal strength training may only provide little improvement in paddling performance.

Comparison of impact forces, accelerations and ankle range of motion in surfing-related landing tasks.

This study aimed to describe the impact forces, accelerations and ankle range of motion in five different landing tasks that are used in training and testing for competitive surfing athletes, to assist coaches in the prescription of landing task progression and monitoring training load. Eleven competitive surfing athletes aged 24 ± 7 years participated, and inertial motion sensors were fixed to the anterior aspect of the feet, mid-tibial shafts, sacrum and eighth thoracic vertebrae on these athletes. Three tasks were performed landing on force plates and two tasks in a modified gymnastics set-up used for land-based aerial training. Peak landing force, resultant peak acceleration and front and rear side ankle dorsiflexion ranges of motion during landing were determined. The peak acceleration was approximately 50% higher when performing aerial training using a mini-trampoline and landing on a soft-density foam board, compared to a similar landing off a 50 cm box. Furthermore, the ankle ranges of motion during the gymnastic type landings were significantly lower than the other landing types (P ≤ 0.05 and P ≤ 0.001), for front and rear sides, respectively. Conclusively, increased task complexity and specificity of the sport increased the tibial peak acceleration, indicating greater training load.

Effect of Strength and Power Training on Tackling Ability in Semiprofessional Rugby League Players.

This study examined the influence of a strength and power program on tackling ability in rugby league players. Twenty-four semiprofessional rugby league players (mean ± SD age, 23.4 ± 3.1 years) underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up), and lower-body power (countermovement jump [CMJ]). Muscular strength relative to body mass was also calculated. Tackling ability of the players was assessed using video analysis of a standardized one-on-one tackling drill. The players then underwent 8 weeks of strength and power training as part of their preseason training before being retested. Training resulted in significant (p ≤ 0.01) improvements in absolute and relative measures of squat, bench press, CMJ peak power, and plyometric push-up peak power. The strongest correlates of change in tackling ability were changes in 3RM squat (r = 0.60; p < 0.01) and squat relative to body mass (r = 0.54; p < 0.01). The players with the greatest improvements in 3RM squat and squat relative to body mass (i.e., responders) had significantly greater improvements in tackling ability than nonresponding players (p = 0.04; effect size [ES] ≥ 0.85). A small, nonsignificant difference (p = 0.20; ES = 0.56) in tackling ability was found between responders and nonresponders for lower-body power. The findings of this study demonstrate that the enhancement of lower-body muscular strength, and to a lesser extent muscular power, contribute to improvements in tackling ability in semiprofessional rugby league players.

Five Weeks of Sprint and High-Intensity Interval Training Improves Paddling Performance in Adolescent Surfers.

Farley, ORL, Secomb, JL, Parsonage, JR, Lundgren, LE, Abbiss, CR, and Sheppard, JM. Five weeks of sprint and high-intensity interval training improves paddling performance in adolescent surfers. J Strength Cond Res 30(9): 2446-2452, 2016-The purpose of our study was to examine the effects of sprint interval training (SIT; 10 seconds) and high-intensity interval training (HIT; 30 seconds) on surfing athletes paddling performance (400-m time trial and repeat-sprint paddle performance). Twenty-four competitive adolescent surfers (19 male, 5 female; age = 14.4 ± 1.3 years, mass: 50.1 ± 10.7 kg, and stature: 159.9 ± 10.3 cm) were assigned to perform either 5 weeks of SIT and HIT. Participants completed a repeated-sprint paddle ability test (RSPT, 15-m surfboard sprint paddle initiated every 40 seconds × 10 bouts) and 400-m endurance surfboard paddle time trial before and after training. High-intensity interval training decreased the total time to complete the 400 m by 15.8 ± 16.1 seconds (p = 0.03), and SIT decreased the total time to complete the RSPT by 6.5 ± 4.3 seconds (p = 0.02). Fatigue index during the RSPT (first-slowest effort) was lower after HIT and SIT (p ≤ 0.001 and p = 0.02, respectively). There were no significant differences in performance changes in the 400 m (total time) and RSPT (total time, fastest 15 m time, and peak velocity) between HIT and SIT. Our study indicates that HIT and SIT may be implemented to the training program of surfers to improve aerobic and repeat-sprint paddle ability, both of which are identified as key aspects of the sport. In addition, these findings indicate that 400-m paddle and RSPT can discriminate between aerobic and anaerobic training adaptations, with aerobic gains likely from HIT and anaerobic gains from SIT.

Reductions in Sprint Paddling Ability and Countermovement Jump Performance After Surfing Training.

The present study aimed to determine whether any meaningful change in a surfer's sprint paddling ability and countermovement jump (CMJ) performance developed after a 2-hour surfing training session and also whether any physical demands of the surfing session were related to the resultant changes in the capacities. Fifteen competitive male surfing athletes (age, 22.1 ± 3.9 years; height, 175.4 ± 6.4 cm; body mass, 72.5 ± 7.7 kg) performed a 2-hour surfing training session, with 15-m sprint paddle and CMJ trials performed both before and after the surfing session. Pre- to posttesting measures were analyzed using magnitude-based inferences. Likely declines were observed in the velocity achieved at the 5-, 10-, and 15-m splits of the 15-m sprint paddle, as well as peak velocity. Similarly, likely declines were calculated for CMJ peak force, relative peak force, and jump height. Furthermore, large correlations were calculated between presurfing session peak velocity and the change in 5, 10, 15 m, and peak velocity of the 15-m sprint paddle and total distance covered, wave riding bouts, and success rate. Surfing athletes and coaches may need to consider implementing shorter duration training sessions to reduce the decline in sprint paddling ability and CMJ performance. Furthermore, surfing athletes should possess highly developed sprint paddling ability because this may allow them to undertake a greater workload and catch more waves, which will increase the opportunity for technical refinement of maneuvers and skill acquisition.

Effect of 8 days of a hypergravity condition on the sprinting speed and lower-body power of elite rugby players.

-Sprinting speed and lower-body power are considered to be key physical abilities for rugby players. A method of improving the lower-body power of athletes is simulated hypergravity. This method involves wearing a weighted vest at all times during the day for an extended period of time. There are no studies that have examined the effect of hypergravity on speed or the benefit for rugby players. An experimental group (n = 8) and a control group (n = 7) of national team rugby players took part in the study, which consisted of rugby, conditioning, speed, and strength sessions. The experimental group wore a weighted vest equating to 12% of their body mass for 8 days. All players were tested for speed and lower-body power before, 2 days after, and 9 days after the intervention. Speed testing involved the athletes completing 40-m sprints with timing lights and high-speed video cameras assessing acceleration and maximal velocity sprinting kinematics. Lower-body power was assessed using weighted countermovement jumps (CMJs). No group differences were found for sprinting speed at any point. The experimental group displayed a large decrease in acceleration ground contact time (-0.01 ± 0.005 s, d = 1.07) and a moderate increase in 15-kg CMJ velocity (0.07 ± 0.11 m·s, d = 0.71). Individual responses showed that players in the experimental group had both negative and positive speed and power responses to the training intervention. Simulated hypergravity for 8 days is likely ineffective at improving sprinting speed while undergoing standard rugby training.

Muscular Strength and Power Correlates of Tackling Ability in Semiprofessional Rugby League Players.

This study investigated the relationship between muscular strength and power and tackling ability in semiprofessional rugby league players. Thirty-six semiprofessional (mean ± SD age, 23.1 ± 3.6 years) rugby league players, from 3 distinct playing divisions (first grade, second grade, and under 20s), underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up [PPU]), and lower-body power (countermovement jump). Muscular strength relative to body mass was also calculated. Tackling ability of the players was tested using video analysis of a standardized one-on-one tackling drill. For all players, the strongest correlates of tackling ability were squat (r = 0.67), bench press (r = 0.58), relative squat (r = 0.41), and PPU (r = 0.56). The strongest correlates of tackling ability in first grade players were squat (r = 0.72), bench press (r = 0.72), relative squat (r = 0.86), and PPU (r = 0.70). For second grade players, only relative squat (r = 0.60) and PPU (r = 0.67) were associated with tackling ability. The strongest correlates of tackling ability in under 20s players were squat (r = 0.77), bench press (r = 0.70), and PPU (r = 0.65). The findings of this study demonstrate that muscular strength and upper-body power contribute to tackling ability in semiprofessional rugby league players. Therefore, as long as the technical aspects of tackling technique are adequately coached and practiced, then enhancements in muscular strength and power may serve as foundational components to underpin improvement in tackling ability.

Relationships Between Lower-Body Muscle Structure and Lower-Body Strength, Power, and Muscle-Tendon Complex Stiffness.

The purpose of this study was to determine whether any relationships were present between lower-body muscle structure and strength and power qualities. Fifteen elite male surfing athletes performed a battery of lower-body strength and power tests, including countermovement jump (CMJ), squat jump (SJ), isometric midthigh pull (IMTP), and had their lower-body muscle structure assessed with ultrasonography. In addition, lower-body muscle-tendon complex (MTC) stiffness and dynamic strength deficit (DSD) ratio were calculated from the CMJ and IMTP. Significant relationships of large to very large strength were observed between the vastus lateralis (VL) thickness of the left (LVL) and right (RVL) leg and peak force (PF) (r = 0.54-0.77, p < 0.01-0.04), peak velocity (PV) (r = 0.66-0.83, p < 0.01), and peak jump height (r = 0.62-0.80, p < 0.01) in the CMJ and SJ, as well as IMTP PF (r = 0.53-0.60, p = 0.02-0.04). Furthermore, large relationships were found between left lateral gastrocnemius (LG) pennation angle and SJ and IMTP PF (r = 0.53, p = 0.04, and r = 0.70, p < 0.01, respectively) and between LG and IMTP relative PF (r = 0.63, p = 0.01). Additionally, large relationships were identified between lower-body MTC stiffness and DSD ratio (r = 0.68, p < 0.01), right (LG) pennation angle (r = 0.51, p = 0.05), CMJ PF (r = 0.60, p = 0.02), and jump height (r = 0.53, p = 0.04). These results indicate that greater VL thickness and increased LG pennation angle are related to improved performance in the CMJ, SJ, and IMTP. Furthermore, these results suggest that lower-body MTC stiffness explains a large amount of variance in determining an athlete's ability to rapidly apply force during a dynamic movement.

Mechanical Determinants of Faster Change of Direction and Agility Performance in Female Basketball Athletes.

Change of direction (COD) and agility require the integration of multiple components to produce a faster performance. However, the mechanisms contributing to a faster performance without the confounding factor of athlete expertise or gender is currently unknown. Therefore, the purpose of this study was to assess body composition, strength, and kinetic profile required for a faster COD and agility performance across multiple directional changes. Six faster and 6 slower (n = 12) elite female basketball athletes completed a maximal dynamic back squat; eccentric and concentric only back squat; isometric midthigh pull; whole-body scan to determine lean, fat, and total mass; 505 COD test; T-test; and a multidirectional agility test over in-ground force plates to obtain relevant kinetic measures. Group (faster and slower) by test (2 × 3) multivariate analyses of variance with follow-up analyses of variance were conducted to examine differences between faster and slower groups and each COD and agility test (p ≤ 0.05). Faster athletes during the 505 COD test produced significantly greater vertical force (p = 0.002) and eccentric and isometric strength capacity (p = 0.001). Faster agility and T-test athletes demonstrated significantly shorter contact times (p = 0.001), greater propulsive impulse (p = 0.02), isometric strength, and relative lean mass compared with slower athletes. Differences between faster athletes across each test seem to be attributed to the mechanical demands of the directional change, increasing force and impulse application as the degree of directional change increased. These findings indicate that different mechanical properties are required to produce a faster COD and agility performances, and the importance of a greater strength capacity to enable greater mechanical adjustment through force production and body control, during different directional changes.

Relationships Between Lower-Body Muscle Structure and, Lower-Body Strength, Explosiveness and Eccentric Leg Stiffness in Adolescent Athletes.

The purpose of the present study was to determine whether any relationships were present between lower-body muscle structure and, lower-body strength, variables measured during a countermovement jump (CMJ) and squat jump (SJ), and eccentric leg stiffness, in adolescent athletes. Thirty junior male (n = 23) and female (n = 7) surfing athletes (14.8 ± 1.7 y; 1.63 ± 0.09 m; 54.8 ± 12.1 kg) undertook lower-body muscle structure assessment with ultrasonography and performed a; CMJ, SJ and an isometric mid-thigh pull (IMTP). In addition, eccentric leg stiffness was calculated from variables of the CMJ and IMTP. Moderate to very large relationships (r = 0.46-0.73) were identified between the thickness of the vastus lateralis (VL) and lateral gastrocnemius (LG) muscles, and VL pennation angle and; peak force (PF) in the CMJ, SJ and IMTP. Additionally, moderate to large relationships (r = 0.37-0.59) were found between eccentric leg stiffness and; VL and LG thickness, VL pennation angle, and LG fascicle length, with a large relationship (r = 0.59) also present with IMTP PF. These results suggest that greater thickness of the VL and LG were related to improved maximal dynamic and isometric strength, likely due to increased hypertrophy of the extensor muscles. Furthermore, this increased thickness was related to greater eccentric leg stiffness, as the associated enhanced lower-body strength likely allowed for greater neuromuscular activation, and hence less compliance, during a stretch-shortening cycle. Key pointsGreater thickness of the VL and LG muscles were significantly related to an enhanced ability to express higher levels of isometric and dynamic strength, and explosiveness in adolescent athletes.Isometric strength underpinned performance in the CMJ and SJ in these athletes.Greater lower-body isometric strength was significantly related to eccentric leg stiffness, which is potentially the result of greater neuromuscular activation in the muscle-tendon unit.