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Longitudinal changes in anthropometric and physical performance characteristics of International female rugby union players were evaluated across 5-seasons, according to field position. Sixty-eight international female rugby union players from a top 2 ranked international team, undertook anthropometric and physical performance measurements across five seasons. Anthropometric and physical performance changes occurred, with skinfolds decreasing between 2015 and 2017 and body mass increasing between 2017 and 2019. Single-leg isometric squat (SL ISO), 0-10 m momentum (0-10 Mom) and 20-30 m momentum (20-30Mom) were higher in 2018 and 2019 than all years. Front-row players were characterised by greater SL ISO and 1-RM bench press than inside and outside backs, with higher skinfolds and lower endurance levels than all positions. Between 2017 and 2019, front-row players had larger decreases and increases in endurance and one repetition maximum (1-RM) bench press, respectively, compared to all other positions. Forwards had the highest 0-10Mom and 20-30Mom, and scrum-half the lowest, while outside backs had faster 0-10, 30-40, and 40 m (TT40 m) times, and greater peak velocity (Vmax) compared to forward positions. These longitudinal findings show that physical performance has increased, with anthropometric and performance characteristics becoming more distinctive between positions, among elite female rugby union players.

This study aimed to evaluate changes in rugby union physical match characteristics across five seasons of International female competition, according to position and opposition quality. Global positional systems and performance analysis data from 78 female rugby union players (minimum of five international appearances) were analysed between 2015 and 2019. Mixed-linear-modelling was used to investigate the effects of season, opposition and position during 969 individual match performances from 53 International matches. Running demands increased between 2015 and 2017 (World Cup year) and plateaued thereafter, except for sprints among the outside backs, which declined between 2017 and 2019, and accelerations and decelerations >3 m s which increased between 2017 and 2019. Collisions were higher in forwards than backs, and highest against stronger opposition. Running demands were greater against weaker opposition, but the 'most intense periods' of running were greater against stronger opposition in 2017. Match demands increased between 2015 and the 2017 World Cup year, which was underpinned by increased sprinting and greater running during maximum intensity periods against top 5 opposition. The increase in accelerations and decelerations in the latter years, alongside the maintenance of average running demands and collision counts, is consistent with the reported continuous playing style of female rugby, thus placing specific demands on players and requiring tailored training methods. Some positions (Forwards and Scrum-halves) appear to be important for this adopted style, demonstrating concomitantly high relative collision and running intensities. [Abstract copyright: Copyright © 2021 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.]

Context: Neuromuscular electrical stimulation (NMES) combined with blood flow restriction (BFR) has been shown to improve muscular strength and size greater than NMES alone. However, the previous studies use varied methodologies not recommended by previous NMES or BFR research. Objective: The present study investigated the acute effects of NMES combined with varying degrees of BFR, using research recommended procedures to enhance understanding and the clinical applicability of this combination. Design: Randomised crossover. Setting: Physiology laboratory. Participants: 20 healthy adults (age: 27 ± 4; height: 177 ± 8 cm; body mass: 77 ± 13 kg). Interventions: Six sessions separated by at least seven days. The first two visits served as familiarisation, with the experimental conditions performed in the final four sessions; NMES alone, NMES 40% BFR, NMES 60% BFR and NMES 80% BFR. Main outcome measures: Maximal voluntary isometric contraction (MVIC), muscle thickness, blood pressure, heart rate, rating of perceived exertion (RPE) and pain were all recorded before and after each condition. Results: NMES 80% BFR caused greater MVIC decline than any other condition (-38.9 ± 22.3 Nm, p < 0.01). Vastus medialis and VL muscle thickness acutely increased after all experimental conditions (p < 0.05). Pain and RPE ratings were higher after NMES 80% BFR, compared with all other experimental conditions (p < 0.05). No cardiovascular effects were observed between conditions. Conclusion: NMES combined with 80% BFR caused greater acute force decrement than the other conditions. Although, greater perceptual ratings of pain and RPE were observed with NMES 80% BFR. These acute observations must be investigated during chronic interventions to corroborate any relationship to changes in muscle strength and size in clinical populations.

This study investigated the reliability of repetitions in reserve (RIR) as a method for prescribing resistance training load for the deadlift and bench press exercises. Fifteen novice trained men (age: 17.3 ± 0.9 years, height: 176.0 ± 8.8 cm, body mass: 71.3 ± 10.7 kg) were assessed for 1 repetition maximum (1RM) for deadlift (118.1 ± 27.3 kg) and bench press (58.2 ± 18.6 kg). Subsequently, they completed 3 identical sessions (one familiarization session and 2 testing sessions) comprising sets of 3, 5, and 8 repetitions. For each repetition scheme, the load was progressively increased in successive sets until subjects felt they reached 1-RIR at the end of the set. Test-retest reliability of load prescription between the 2 testing sessions was determined using intraclass correlation coefficient (ICC) and coefficient of variation (CV). A 2-way analysis of variance with repeated measures was used for each exercise to assess differences in the load corresponding to 1-RIR within each repetition scheme. All test-retest comparisons demonstrated a high level of reliability (deadlift: ICC = 0.95–0.99, CV = 2.7–5.7% and bench press: ICC = 0.97–0.99, CV = 3.8–6.2%). Although there were no differences between time points, there was a difference for load corresponding to 1-RIR across the 3 repetition schemes (deadlift: 88.2, 84.3, and 79.2% 1RM; bench press: 93.0, 87.3, and 79.6% 1RM for the 3-, 5-, and 8-repetition sets, respectively). These results suggest that RIR is a reliable tool for load prescription in a young novice population. Furthermore, the between-repetition scheme differences highlight that practitioners can effectively manipulate load and volume (repetitions in a set) throughout a training program to target specific resistance training adaptations.

Explosive actions are integral to soccer performance and highly influenced by the ability to generate maximal power. The purpose of this study was to investigate the relationship between force-velocity profile, jump performance, acceleration and maximal sprint speed in elite female soccer players. Thirty-nine international female soccer players (24.3 ± 4.7 years) performed 40-m sprints, maximal countermovement jumps and five loaded squat jumps at increasing loads to determine individual force-velocity profiles. Theoretical maximal velocity, theoretical maximal force, maximal power output, one repetition maximal back squat and one repetition maximal back squat relative to body mass were determined using the force-velocity profile. Counter movement jump, squat jump and maximal power output demonstrated moderate to large correlation with acceleration and maximal sprint speed (r= -0.32 to -0.44 and -0.32 to -0.67 respectively, p < 0.05). Theoretical maximal velocity and force, one repetition maximal and relative back squat demonstrated a trivial to small relationship to acceleration and maximal sprint speed (p > 0.05). Vertical force-velocity profiling and maximal strength can provide valuable insight into the neuromuscular qualities of an athlete to individualize training, but the ability to produce force, maximal power, and further transference into sprint performance, must be central to program design.

Achieving adequate sleep is considered important for athletic performance and recovery from exercise, yet the sleep monitoring methods applied amongst practitioners within high- performance sport are not well documented. This study aimed to identify the athlete sleep monitoring practices currently being implemented by practitioners working with full-time, junior (competing at the highest level), and semi-professional athletes. An online survey was developed and disseminated via email and social media to practitioners working with high-performance athletes. A sample of 145 practitioners completed the survey. Most (88%) practitioners rated sleep as ‘extremely important’ for recovery and performance (79%) and 84% of practitioners had advised athletes on improving sleep. The practitioners who reported monitoring sleep used several methods, including a questionnaire (37%), diary (26%) and actigraphy (19%). The most cited barrier to monitoring sleep was lack of time/resources. Most (79%) practitioners had not determined athletes’ chronotypes. Over half (54%) of the practitioners suggested their athletes did not get enough sleep outside of competition periods; the highest ranked suggested reason for this was screen time (i.e., using electronic devices). Practitioners recognise the importance of sleep for athletes and sleep education/monitoring was common amongst the practitioners; however, chronotype analysis was not widely used. Most practitioners used questionnaires and diaries to monitor athletes’ sleep and suggested that their athletes often experience insufficient sleep outside of competition periods.

The validity of the TritonWear® device to measure swimming performance was investigated, with a pre-determined analytical goal of 6%. Twenty youth swimmers completed a 100 m swim in a 25 m pool, swimming breaststroke or freestyle wearing the TritonWear® device, whilst being filmed above and below water with three cameras. 95% Limits of Agreement (95% LoA) and coefficient of variation (CV%) were used to calculate error. Systematic biases (P < 0.05) were found between the two systems only for distance per stroke during breaststroke. Freestyle metrics agreement ranged between 1.06 % and 10.40 % CV, except for distance per stroke (CV = 14.64 %), and time underwater (CV = 18.15 %). Breaststroke metrics ranged between 0.95 % and 13.74 % CV, except for time underwater (CV = 25.76 %). The smallest errors were found for split-times, speed, stroke-count and stroke-rate, across both strokes (all < 5% CV). The TritonWear® can be used for basic metrics of performance, such as split-time and speed but the error of more complex measurements, such as time underwater or turn-times, renders them unable to identify typical performance changes.

Purpose: This study investigated the effects of a 10-day heat acclimation (HA) programme on the time-course of changes in thermoneutral maximal oxygen uptake (V ̇O2max) during and up to 10 days post-HA. Methods: Twenty-two male cyclists were assigned to a HA or control (Con) training group following baseline ramp tests of thermoneutral V ̇O2max. Ten days of fixed-intensity (50% baseline V ̇O2max) indoor cycling was performed in either ~ 38.0 °C (HA) or ~ 20 °C (Con). V ̇O2max was re-tested on HA days 5, 10 and post-HA days 1, 2, 3, 4, 5 and 10. Results: V ̇O2max initially declined across time in both groups during training (P < 0.05), before increasing in the post-HA period in both groups (P < 0.05). However, V ̇O2max was higher than control by post-HA day 4 in the HA group (P = 0.046). Conclusions: The non-linear time-course of V ̇O2max adaptation suggests that post-testing should be performed 96-h post training to identify the maximal change for most individuals. In preparation for training or testing, athletes can augment their aerobic power in thermoneutral environments by performing 10 days HA but the full effects will manifest at varying stages of the post-HA period.

Purpose: The purpose of this study was to determine the primary cues regulating perceived effort and exercise performance using a fixed-RPE protocol in severe and moderate hypoxia. \ud \ud Methods: Eight male participants (26 6 y, 76.3 8.6 kg, 178.5 3.6 cm, 51.4 8.0 mL·kg-1·min-1 V ̇O2max) completed three exercise trials in environmental conditions of severe hypoxia (FIO2 0.114), moderate hypoxia (FIO2 0.152) and normoxia (FIO2 0.202). They were instructed to continually adjust their power output to maintain a perceived effort (RPE) of 16, exercising until power output declined to 80 % of the peak 30-s power output achieved.\ud \ud Results: Exercise time was reduced (severe hypoxia 428 210 s; moderate hypoxia 1044 384 s; normoxia 1550 590 s) according to a reduction in FIO2 (P < 0.05). The rate of oxygen desaturation during the first 3-min of exercise was accelerated in severe hypoxia (-5.3 ± 2.8 %·min-1) relative to moderate hypoxia (-2.5 ± 1.0 %·min-1) and normoxia (-0.7 ± 0.3 %·min-1). Muscle tissue oxygenation did not differ between conditions (P > 0.05). Minute ventilation increased at a faster rate according to a decrease in FIO2 (severe hypoxia 27.6 ± 6.6; moderate hypoxia 21.8 ± 3.9; normoxia 17.3 ± 3.9 L∙min-1). Moderate to strong correlations were identified between breathing frequency (r = -0.718, P < 0.001), blood oxygen saturation (r = 0.611, P = 0.002) and exercise performance.\ud \ud Conclusions: The primary cues for determining perceived effort relate to progressive arterial hypoxemia and increases in ventilation.