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This study examined the test re-test, intrarater and interrater reliability of joint kinematics from the Coach’s Eye smartphone application. Twenty-two males completed a 1-repetition maximum (1-RM) assessment followed by 2 identical sessions using 5 incremental loads (20%-40%-60%-80%-90% 1-RM). Peak flexion angles at the hip, knee, and ankle joints were assessed using 1 experienced practitioner and 1 inexperienced practitioner. The acceptable reliability thresholds were defined as intraclass correlation coefficient (ICC) (r) > 0.70 and coefficient of variation (CV) ≤ 10%. The test re-test reliability of peak hip and knee flexion were reliable across 20-90% 1-RM (r > 0.64; CV < 4.2%), whereas peak ankle flexion was not reliable at any loaded condition (r > 0.70; CV < 20.4%). No significant differences were detected between trials (p > 0.11). The intrarater reliability was near perfect (r > 0.90) except for peak ankle flexion (r > 0.85). The interrater reliability was nearly perfect (r > 0.91) except for hip flexion at 80% 1-RM and ankle flexion at 20% (r > 0.77). Concludingly, the Coach’s Eye application can produce repeatable assessments of joint kinematics using either a single examiner or 2 examiners, regardless of experience level. The Coach’s Eye can accurately monitor squat depth.

The purpose of this study was to examine the reliability of load-velocity profiles (LVPs) and validity of 1-repetition maximum (1-RM) prediction methods in the back-squat using the novel Vitruve linear position transducer (LPT). Twenty-five men completed a back-squat 1-RM assessment followed by 2 LVP trials using five incremental loads\ud (20%–40%–60%–80%–90% 1-RM). Mean propulsive velocity (MPV), mean velocity (MV) and peak velocity (PV) were measured via a (LPT). Linear and polynomial regression models were applied to the data. The reliability and validity criteria were defined a priori as intraclass correlation coefficient (ICC) or Pearson correlation coefficient (r) . 0.70,\ud coefficient of variation (CV) 410%, and effect size (ES) \0.60. Bland Altman analysis and heteroscedasticity of errors (r2) were also assessed. The main findings indicated MPV, MV and PV were reliable across 20%–90% 1-RM\ud (CV \ 8.8%). The secondary findings inferred all prediction models had acceptable reliability (CV \ 8.0%). While\ud the MPV linear and MV linear models demonstrated the best estimation of 1-RM (CV \ 5.9%), all prediction models\ud displayed unacceptable validity and a tendency to overestimate or underestimate 1-RM. Mean systematic bias (27.29\ud to 2.83 kg) was detected for all prediction models, along with little to no heteroscedasticity of errors for linear\ud (r2 \ 0.04) and polynomial models (r2 \ 0.08). Furthermore, all 1-RM estimations were significantly different from\ud each other (p \ 0.03). Concludingly, MPV, MV and PV can provide reliable LVPs and repeatable 1-RM predictions.\ud However, prediction methods may not be sensitive enough to replace direct assessment of 1-RM. Polynomial regression\ud is not suitable for 1-RM prediction.

The corticospinal responses to high-intensity and low-intensity strength-training of the upper limb are modulated in an intensity-dependent manner. Whether an intensity-dependent threshold occurs following acute strength training of the knee extensors (KE) remains unclear. We assessed the corticospinal responses following high-intensity (85% of maximal strength) or low-intensity (30% of maximal strength) KE strength-training with measures taken during an isometric KE task at baseline, post-5, 30 and 60-min. Twenty-eight volunteers (23 ± 3 years) were randomized to high-intensity (n = 11), low-intensity (n = 10) or to a control group (n = 7). Corticospinal responses were evoked with transcranial magnetic stimulation at intracortical and corticospinal levels. High- or low-intensity KE strength-training had no effect on maximum voluntary contraction force post-exercise (P > 0.05). High-intensity training increased corticospinal excitability (range 130–180%) from 5 to 60 min post-exercise compared to low-intensity training (17–30% increase). Large effect sizes (ES) showed that short-interval cortical inhibition (SICI) was reduced only for the high-intensity training group from 5–60 min post-exercise (24–44% decrease) compared to low-intensity (ES ranges 1–1.3). These findings show a training-intensity threshold is required to adjust CSE and SICI following strength training in the lower limb. peerReviewed

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.

Periodizing rehearsal and performance schedules in professional ballet is difficult given a lack of published longitudinal data. We aimed to describe the structure of a professional ballet season, and identify factors associated with inter-dancer and inter-production variation in dance hours. Scheduling data were collected from 123 dancers over five seasons at The Royal Ballet. Linear mixed effects models were used to evaluate differences in weekly dance hours and performance counts across sexes, company ranks, and months. Random forest regressions were used to investigate factors associated with the variation in rehearsal hours across different productions. Performance congestion was observed in December, whereas total dance hours peaked between January and April. Differences in weekly dance hours were observed between company ranks (p < .001, range in means: 19.1–27.5 h·week-1). Seasonal performance counts varied across company ranks (p < .001), ranging from 28, 95% CI [22, 35] in principals, to 113, 95% CI [108, 118] in artists. Rehearsal durations were greatest in preparation for newly choreographed and longer ballets. Dancers creating roles in new ballets completed considerably more rehearsal hours than for existing ballet. These results provide a basis for the implementation of rehearsal and repertoireperiodization in professional ballet.

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.]

The effectiveness of 8-week force-velocity optimised training was assessed in highly trained professional rugby league (RL) athletes. Players (age 24 ± 3 years; body mass 94.9 ± 21.6 kg; height 181.3 ± 6.0 cm) were strength-matched and assigned to a force-velocity optimised group (OP; n=15) or a general strength-power group (GP; n=14). Tests conducted pre-and post-training included 10-m, 20-m sprints, 3 repetition-maximum (3RM) squat and squat jumps (SJ) over five load conditions to ascertain vertical force-velocity relationship. ANCOVA revealed there was a group effect for force-velocity deficit (P

Purpose: To determine whether corticospinal excitability (CSE) and inhibition aredifferentially modulated following high-volume light-load strength training compared to low-volume heavy-load strength training. We hypothesised high-volume light-load strengthtraining would increase CSE and low-volume heavy-load strength training would reduceintracortical inhibition.\ud \ud Methods: Transcranial magnetic stimulation (TMS) was used to assess CSE, short-intervalintracortical inhibition (SICI), and silent period duration (SP) following high-volume light-loadstrength training (n = 9), low-volume heavy-load strength training (n = 8) compared to acontrol group (n = 10). Twenty-seven participants completed either (1) low-volume heavy-loadstrength training (80% one-repetition maximum [1RM]); (2) high-volume light-load strengthtraining (20% 1RM) or (3) a control condition. CSE, SICI and SP were measured using TMS atbaseline and four time-points over a 60 min post-exercise period.\ud \ud Results: CSE increased rapidly (within 5 min post-exercise) for high-volume light-loadstrength training and remained elevated for 60 min compared to low-volume heavy-loadstrength training and control groups. There were no differences following any training forreduced SICI or SP.\ud \ud Conclusion: These results suggest that high-volume light-load strength training increases theexcitability of corticospinal neurons and this increase is likely to be the predominantmechanism for increasing CSE for up to 60 min post training. It may be possible that agreater number of ST sessions are required to observe any differences in the excitability ofthe intrinsic inhibitory motor-network following high-volume light-load strength training andlow-volume heavy-load strength training

The aim of this study was to determine the effect of five days dietary nitrate (NO3-) consumption on exercise tolerance and thermoregulation during cycling in hot, dry conditions. In a double-blind, randomised crossover design, 11 healthy males participated in an exercise tolerance test (Tlim) in the heat (35°C, 28% relative humidity), cycling above the thermoneutral gas exchange threshold, after five days of dietary supplementation, with either NO3--rich beetroot juice (BR; ~ 9.2 mmol NO3-) or placebo (PLA). Changes in plasma [NO3-] and nitrite [NO2-], core and mean skin temperatures, mean local and whole-body sweat rates, heart rate, perceptual ratings and pulmonary gas exchange were measured during exercise, alongside calorimetric estimations of thermal balance. Mean arterial pressures (MAP) were recorded pre-Tlim. There were no differences in Tlim between conditions (BR = 22.8 ± 8.1 min; Placebo = 20.7 ± 7.9 min) (P = 0.184), despite increases in plasma [NO3-] and [NO2-] (P < 0.001) and a 3.8% reduction in resting MAP (P = 0.004) in the BR condition. There were no other differences in thermoregulatory, cardio-metabolic, perceptual or calorimetric responses to the Tlim between conditions (P > 0.05). Dietary NO3- supplementation had no effect on exercise tolerance or thermoregulation in hot, dry conditions, despite reductions in resting MAP and increases in plasma [NO3-] and [NO2-]. Healthy, yet physically inactive individuals with no known impairments in vasodilatory and sudomotor function do not appear to require BR for ergogenic or thermolytic effects during exercise in the heat.

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.

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

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.

Mixed marital arts (MMA) is a hybrid of a number of fighting styles. Time motion analysis demonstrates that the high and low intensity work ratio of 1:4 appears to be similar to other martial arts such as taekwondo and kick boxing. The intermittent nature of such repeated high intensity work periods suggests that energy is produced by predominantly anaerobic means. This is evidenced with findings of high intensity exchanges lasting no more than 6-14 seconds. However, the aerobic energy system remains important for recovery in aiding removal of lactate, improved oxygen extraction and additional supplementation of anaerobic energy production. Injuries to the head and face are most prevalent, with lacerations and contusions being the leading diagnoses, followed by concussion. Evidence would indicate that more skilled fighters, who are able to end bouts swiftly, as less likely to sustain injury. Musculoskeletal structures need to be accustomed to the high forces and velocities that occur during combat. Practitioners need to ensure that athletes have an efficient aerobic system to last up to 25 mins of competitions. Athletes with higher levels of anaerobic power have demonstrated a greater success in ground-based activities. Consequently, the physical preparation of MMA athletes should be multifaceted with the development of a large aerobic base and the ability to react explosively essential to success. Athletes also need to train in numerous different individual martial arts leading to a high training load, strength and conditioning sessions consequently need to be efficient and often minimise training volume.

This study investigated the effects of leucine or leucine + glutamine supplementation on recovery from eccentric exercise. In a double-blind independent groups design, 23 men were randomly assigned to a leucine (0.087 g/kg; n = 8), leucine + glutamine (0.087 g/kg + glutamine 0.3 g/kg; n = 8) or placebo (0.3 g/kg maltodextrin; n = 7) group. Participants performed 5 sets of drop jumps, with each set comprising 20 repetitions. Isometric knee-extensor strength, counter-movement jump (CMJ) height, delayed onset muscle soreness (DOMS) and creatine kinase (CK) were measured at baseline, 1 h, 24 h, 48 h and 72 h post-exercise. There was a time × group interaction for isometric strength, CMJ and CK (P < 0.05), with differences between the leucine + glutamine and placebo group at 48 h and 72 h for strength (P = 0.013; d = 1.43 and P < 0.001; d = 2.06), CMJ (P = 0.008; d = 0.87 and P = 0.019; d = 1.17) and CK at 24 h (P = 0.012; d = 0.54) and 48 h (P = 0.010; d = 1.37). The leucine group produced higher strength at 72 h compared to placebo (P = 0.007; d = 1.65) and lower CK at 24 h (P = 0.039; d = 0.63) and 48 h (P = 0.022; d = 1.03). Oral leucine or leucine + glutamine increased the rate of recovery compared to placebo after eccentric exercise. These findings highlight potential benefits of co-ingesting these amino acids to ameliorate recovery.

This study investigated the effects of taurine on repeated sprint exercise, performed after fixed incremental ramp exercise to exhaustion at isokinetic high (90 r/min) or low (50 r/min) cadences. In a double-blind, repeated measures design, nine females completed an incremental ramp test to volitional exhaustion, followed by 2-min active recovery and 6 x 10-s sprints on a cycle ergometer, in one of four conditions: high cadence (90 r/min) + taurine (50 mg/kg body mass); high cadence + placebo (3 mg/kg body mass maltodextrin); low cadence (50 r/min) + taurine; low cadence + placebo. Heart rate (HR) and blood lactate concentration B[La] were measured before and after the ramp test and after the sprints. Taurine lowered HR vs. placebo prior to the ramp test (P = 0.004; d = 2.1). There was an effect of condition on ramp performance (P < 0.001), with higher end-test power (d = 3.7) in taurine conditions. During repeated sprints, there was a condition × time interaction (P = 0.002), with higher peak sprint power in the placebo conditions compared to taurine (sprint 2-6; P < 0.05). B[La] was higher in taurine compared to placebo post-ramp (P = 0.004; d = 4.7). Taurine lowered pre-exercise HR and improved incremental end-test power output, with subsequent detrimental effects on sprint performance, independent of cadence. Short endurance performance can be acutely enhanced after taurine ingestion but this effect might not be maintained across longer periods of exercise or induce the need for longer recovery periods.

Background\ud \ud Taurine is central to many physiological processes, some of which are augmented by exogenous supply and have the potential to facilitate endurance performance; however, its independent effects on performance have not been systematically analysed.\ud Objective\ud \ud To evaluate the effects of isolated oral taurine ingestion on endurance performance and to assess the contribution of (1) the dose and (2) the supplementation period to the ergogenic effect.\ud Methods\ud \ud A search was performed using various databases in September 2017. The studies were screened using search criteria for eligibility. Ten peer-reviewed articles were identified for inclusion. A sub-analysis of time-to-exhaustion (TTE) trials (n = 7) was also performed. The effects of (1) dose and (2) the acute (single dose) or chronic (> 1 day) supplementation periods were assessed using meta-regression. The doses of taurine ranged from 1 to 6 g/day and were provided in single doses and for up to 2 weeks among a range of subjects.\ud Results\ud \ud Taurine ingestion improved overall endurance performance (Hedges’ g = 0.40, 95% CI 0.12–0.67, P = 0.004), which was similar in TTE trials (Hedges’ g = 0.43, 95% CI 0.12–0.75, P = 0.007). There were no differences between acute or chronic supplementation for the full sample (P = 0.897) or the TTE group (P = 0.896). The dose of taurine did not moderate its effect on endurance performance (P > 0.05).\ud Conclusion\ud \ud Human endurance performance can be improved by orally ingesting a single dose of taurine in varying amounts (1–6 g).

There is a limited understanding of the neurological adaptations responsible for changes in strength following shortening and lengthening resistance training and subsequent detraining. The aim of the study was to investigate differences in corticospinal and spinal responses to resistance training of the tibialis anterior muscle between shortening or lengthening muscle contractions for 4 weeks and after 2 weeks of detraining. Thirty-one untrained individuals were assigned to either shortening or lengthening isokinetic resistance training (4 weeks, 3 days/weeks) or a non-training control group. Transcranial magnetic stimulation and peripheral nerve stimulation (PNS) were used to assess corticospinal and spinal changes, respectively, at pre-, mid-, post-resistance training and post detraining. Greater increases changes (P < 0.01) in MVC were found from the respective muscle contraction training. Motor evoked potentials (expressed relative to background EMG) significantly increased in lengthening resistance training group under contraction intensities ranging from 25 to 80% of the shortening and lengthening contraction intensity (P < 0.01). In the shortening resistance training group increases were only seen at 50 and 80% of both contraction type. Volitional drive (V-wave) showed a greater increase following lengthening resistance training (57%) during maximal lengthening contractions compared to maximal shortening contractions following shortening resistance training (23%; P < 0.001). During the detraining period MVC and V-wave did not change (P > 0.05), although MEP amplitude decreased during the detraining period (P < 0.01). No changes in H-reflex were found pre to post resistance training or post detraining. Modulation in V-wave appeared to be contraction specific, whereby greatest increases occurred following lengthening resistance training. Strength and volitional drive is maintained following 2 weeks detraining, however corticospinal excitability appears to decrease when the training stimulus is withdrawn.

Maximising strength and neurological adaptations to resistance training has long been sought to improve athletic performance and enhance clinical rehabilitation functional outcomes. In recent years, transcranial magnetic stimulation (TMS) and peripheral nerve stimulation (PNS) have been applied to investigate changes in the central nervous system (CNS). Conventional resistance training programmes consist of shortening and lengthening muscle contractions and have been shown to have uniquely different motor control strategies; how this neurological control is modified during specific muscle contraction resistance training is unknown. Additionally, understanding the detraining process will assist in designing tapers for elite athletes and improve our knowledge of detraining and inactivity in other populations. The overall aim of the thesis was to determine the TMS and PNS responses to, and following, shortening and lengthening resistance exercise and subsequent detraining.

Warm-ups utilising post-activation performance enhancement (PAPE) strategies have been shown to increase clubhead speed (CHS) in golfers. However, the effectiveness of overspeed training using weighted clubs to elicit PAPE in CHS is unknown. The purpose of this investigation was to compare traditional, field-based warm-up activities with no potentiation activity (CON), against a field-based potentiated warm-up using high rate of force development bodyweight movements (BWP), and an overspeed warm-up using speed sticks (SSP) as the potentiation method. Thirteen skilled adult male golfers (handicap 1.0 ± 2.1) completed three testing sessions, separated by seven days. The CON, BWP and SSP warm-ups were identical, except for the potentiation method. After each warm-up condition, ten shots, separated by one minute, were recorded using a doppler rader launch monitor (Trackman 4) with CHS, ball speed (BS), carry distance (CD) and total distance (TD) recorded. A repeated measures one-way ANOVA with Bonferroni post hoc pairwise comparisons revealed increases in CHS in the BWP (p= 0.004) and SSP (p= 0.003) groups against CON, with no difference between BWP and SSP. Increased CD was observed for BWP (p= 0.034) and SWP (p= 0.030) against CON with no differences between BWP and SSP. No differences for BS or TD were observed. Warm-ups with BWP or SSP activities should be considered if players are attempting to increase CHS or CD of drives, although utilising overspeed potentiation methods appear to confer no additional benefit to bodyweight PAPE exercises in skilled collegiate golfers.

This study aimed to investigate the within- and between-session reliability, variability, and minimal detectable change (MDC) of vertical ground reaction force (vGRF) during bilateral and unilateral lower extremity maximal isometric force tests. Eighteen participants (men: n = 9, age: 27.9 ± 6.3 y, height: 1.82 ± 0.06 m, mass: 82.4 ± 10.4 kg, strength training experience: 10.4 ± 7.7 y; women: n = 9, age: 29.3 ± 8.6 y, height: 1.68 ± 0.01 m, mass: 58.0 ± 5.8 kg, strength training experience: 5.5 ± 3.6 y) attended two data collection sessions separated by 48 h. The absolute, net, and relative vGRF were calculated across bilateral and unilateral variations of the squat, standing plantarflexion, and seated plantarflexion positions. All measures of vGRF demonstrated excellent reliability and low variability within (intraclass correlation coefficients (ICC): 0.92–0.99; coefficient of variation (CV): 2.9–6.5%) and between sessions (ICC: 0.95–1.00; CV: 2.0–6.0%), across all positions. The MDC ranged between 135–276 N (5.1–14.5%), with the seated plantarflexion positions demonstrating the highest values as a percentage of the group mean (13.3–14.5%). Maximal isometric force testing during bilateral and unilateral variations of the squat, standing plantarflexion, and seated plantarflexion positions provide reliable measures of vGRF in men and women.