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This investigation assessed the psycho-physiological and performance effects of hot water immersion (HWI) implemented either before or after a repeated-sprint training in hypoxia (RSH) session conducted in the heat. Ten participants completed three RSH trials (3 × 10 × 5-s sprints), conducted at 40°C and simulated altitude of 3000 m. A 30-min monitoring period preceded and followed all exercise sessions. In PRE, the pre-exercise period was HWI, and the post-exercise period was seated rest in temperate conditions. This combination was reversed in POST. In CON, participants were seated in temperate conditions for both periods. Compared to CON, PRE elicited a reduction in power output during each repeated-sprint set (14.8–16.2%, all p < 0.001), and a significantly higher core temperature (Tc) during the pre-exercise period and throughout the exercise session (p < 0.001 and p = 0.025, respectively). In POST, power output and Tc until the end of exercise were similar to CON, with Tc higher at the conclusion of the post-exercise period (p < 0.001). Time across the entire protocol spent ≥38.5°C Tc was significantly longer in PRE (48.1 ± 22.5 min) than POST (31.0 ± 11.3 min, p = 0.05) and CON (15.8 ± 16.3 min, p < 0.001). Employing HWI following RSH conducted in the heat provides effective outcomes regarding physiological strain and cycling performance when compared to pre-exercise or no HWI.

Performance tracking devices in the form of wrist-worn watches are common in rowing; however, the accuracy of relevant output variables (i.e. stroke rate [SR] and velocity) during on-water training is unknown. To assess the quality of wrist-watch data output, 16 rowing athletes recorded 118 on-water rowing sessions using a Garmin Forerunner 735XT, which was compared to a Catapult Optimeye R4 tracking device. Garmin recording function was set to ‘Every Second’ (N = 68 sessions) or ‘Smart’ (N = 50 sessions). Catapult velocity was calculated as the average velocity per stroke, while a 15 s velocity moving average was determined for Garmin data. Catapult and Garmin were filtered for training-specific data (SR = 14–50 strokes per minute [spm]; velocity = 2.1–7.0 m/s−1). Efficacy and reliability of the Garmin was assessed via the difference between devices (% error), intra-class correlation coefficient (ICC ± 95% confidence interval (CI)) and coefficient of variation (CV%). Error in 15 s smoothed velocity was 3.8% (‘Every Second’) and 8.2% (‘Smart’). Both recording functions demonstrated ‘good’ reliability (ICC = 0.75–0.9, CV < 10%) for SR and velocity; the exception was SR using ‘Smart’ recording. Our data suggests that when using the ‘Every Second’ recording function, data is filtered and velocity is smoothed over 15 s, the Garmin device can be reliable for SR and velocity measurement within 1 spm and <0.20 m/s−1 respectively.

Field hockey is a high-intensity intermittent team sport that has recently undergone a series of rule changes that have resulted in a greater demand for repeated high-intensity movements. Coaches and practitioners now require a reliable assessment of repeated accelerations, decelerations and changes of direction to assess these important match qualities. This investigation assessed the test-retest reliability of a novel 6x40m repeated shuttle sprint test (20m + 20m with a 180° turn) and its association with 40m straight line sprint and YoYo Intermittent Recovery Test performance in 28 International field hockey players (n = 14 females and n = 14 males). The sum of 6 sprint times (SUM) demonstrated ‘excellent’ (ICC = 0.94 and CV = 0.59%) and ‘good’ (ICC = 0.84 and CV = 0.75%) reliability in females and males, respectively. Best sprint time during the repeated shuttle sprint test also demonstrated suitable reliability to evaluate field hockey physical performance (ICC = 0.92 & 0.76, CV = 0.76% & 1.00% in females and males, respectively). SUM was significantly associated with 40 m straight line sprint performance in females (r = 0.90; p<0.001) and males (r = 0.92; p<0.001), but only a weak association was found with YoYo Intermittent Recovery Test performance for either group (r = 0.20; p = 0.495 & r = -0.19; p = 0.525 in females and males, respectively). In summary, field hockey testing batteries that include a repeated shuttle sprint test should consider including a test of intermittent endurance. Further, changes in SUM greater than 1.0% can be confidently interpreted by coaches and practitioners as a real change for both female and male elite field hockey players.

The present study examined (i) the magnitude of the rate of torque development (RTD) and (ii) the between-day reliability of RTD at the start of a cycling sprint when sprint resistance, sprint duration, and the pedal downstroke were altered. Nineteen well-trained cyclists completed one familiarisation and three testing sessions. Each session involved one set of 1-s sprints and one set of 5-s sprints. Each set contained one moderate (0.3 N m kg−1), one heavy (0.6 N m kg−1), and one very heavy (1.0 N m kg−1) resistance sprint. RTD measures (average and peak RTD, RTD 0–100 ms, and RTD 0–200 ms) were calculated for downstroke 1 in the 1-s sprint. For the 5-s sprints, RTD measures were calculated for each of the first three downstrokes, as an average of downstrokes 1 and 2, and as an average of downstrokes 2 and 3. Whilst RTDs were greatest in downstroke 3 at all resistances, the greatest number of reliable RTD measures were obtained using the average of downstrokes 2 and 3 with heavy or very heavy resistances, where average and peak RTD, and RTD 0–200 ms were deemed reliable (ICC ≥ 0.8, CV ≤ 10%). Since only 1–2 downstrokes can be completed within 1 s, the greatest RTD reliability cannot be achieved using a 1-s sprint; therefore, the average of downstrokes 2 and 3 during a >2-s cycling sprint (e.g. 5-s test) with heavy or very heavy resistance is recommended for the assessment of RTD in sprint cyclists.

The aim of this study was to investigate acute performance and physiological responses to the manipulation of exercise-to-rest ratio (E:R) during repeated-sprint hypoxic training (RSH) in hot conditions. Twelve male team-sport players completed two experimental sessions at a simulated altitude of ∼3000 m (FIO2 0.144), air temperature of 40°C and relative humidity of 50%. Exercise involved either 3×5×10-s (E:R1:2) or 3×10×5-s (E:R1:4) maximal cycling sprints interspersed with active recoveries at 120W (20-s between sprints, 2.5 and 5-min between sets for E:R1:2 and E:R1:4 respectively). Sessions were matched for overall sprint and total session duration (47.5-min). Peak and mean power output, and total work were greater in E:R1:4 than E:R1:2 (p < 0.05). Peak core temperature was significantly higher in E:R1:4 than E:R1:2 (38.44 ± 0.33 vs. 38.20 ± 0.35°C, p = 0.028). Muscle deoxygenation magnitude during sprints was greater in E:R1:2 (28.2 ± 1.6 vs. 22.4 ± 4.6%, p < 0.001), while muscle reoxygenation did not differ between conditions (p > 0.05).These results indicate E:R1:4 increased mechanical power output and core temperature compared to E:R1:2. Both protocols had different effects on measures of muscle oxygenation, with E:R1:2 generating greater muscle oxygen extraction and E:R1:4 producing more muscle oxygenation flux, which are both important signals for peripheral adaptation. We conclude that the E:R manipulation during RSH in the heat might be used to target different physiological and performance outcomes, with these findings forming a strong base for future mechanistic investigation.

The present study aims to investigate the acute performance and physiological responses, with specific reference to muscle oxygenation, to ambient air temperature manipulation during repeated-sprint training in hypoxia (RSH). Thirteen male team-sport players completed one familiarisation and three experimental sessions at a simulated altitude of ∼3000 m (FIO2 0.144). Air temperatures utilised across the three experimental sessions were: 20°C, 35°C and 40°C (all 50% relative humidity). Participants performed 3 × 5 × 10-s maximal cycle sprints, with 20-s passive recovery between sprints, and 5 min active recovery between sets. There were no differences between conditions for cycling peak power, mean power, and total work (p>0.05). Peak core temperature (Tc) was not different between conditions (38.11 ± 0.36°C). Vastus lateralis muscle deoxygenation during exercise and reoxygenation during recovery was of greater magnitude in 35°C and 40°C than 20°C (p<0.001 for all). There was no condition × time interaction for Tc, skin temperature, pulse oxygen saturation, heart rate, rating of perceived exertion and thermal sensation (P>0.05). Exercise-induced increases in blood lactate concentration were higher in 35°C and 40°C than 20°C (p=0.010 and p=0.001, respectively). Integrating ambient temperatures up to 40°C into a typical RSH session had no detrimental effect on performance. Additionally, the augmented muscle oxygenation changes experienced during exercise and recovery in temperatures ≥35°C may indicate that the potency of RSH training is increased with additional heat. However, alterations to the training session may be required to generate a sufficient rise in Tc for heat training purposes.

Purpose: This study aimed to assess the influence of graded air temperatures during repeated-sprint training in hypoxia (RSH) on performance and physiological responses. Methods: Ten well-trained athletes completed one familiarization and 4 experimental sessions at a simulated altitude of 3000 m (0.144 FIO2) above sea level. Air temperatures utilized across the 4 experimental sessions were 20°C, 25°C, 30°C, and 35°C (all 50% relative humidity). The participants performed 3 sets of 5 × 10 seconds “all-out” cycle sprints, with 20 seconds of active recovery between sprints and 5 minutes of active recovery between sets (recovery intensity = 120 W). Core temperature, skin temperature, pulse oxygen saturation, heart rate, rating of perceived exertion, and thermal sensation were collected. Results: There were no differences between conditions for peak power, mean power, and total work in each set (P > .05). There were no condition × time interaction effects for any variables tested. The peak core temperature was highest at 30°C (38.06°C [0.31°C]). Overall, the pulse oxygen saturation was higher at 35°C than at 20°C (P < .001; d < 0.8), 25°C (P < .001; d = 1.12 ± 0.54, large), and 30°C (P < .001; d = 0.84 ± 0.53, large). Conclusion: Manipulating air temperature between 20°C and 35°C had no effect on performance or core temperature during a typical RSH session. However, the pulse oxygen saturation was preserved at 35°C, which may not be a desirable outcome for RSH interventions. The application of increased levels of ambient heat may require a different approach if augmenting the RSH stimulus is the desired outcome.

This study aimed to quantify the workload demands, internal stress response and perceptual fatigue experienced by Laser class sailors across multiple days of competition. Eleven elite male Laser Standard athletes (age: 23.2 ± 3.4y, body mass: 82.6 ± 2.3 kg, stature: 182 ± 5 cm) competing at two regattas were recruited. Athletes wore a heart rate (HR) monitor and global positioning system (GPS) unit whilst racing and completed a daily short recovery and stress scale (SRSS). Athletes spent longer sailing upwind (29:08 ± 2:13 min:s) than on a reach (5:19 ± 1:11 min:s), (P < 0.001) and downwind (13:13 ± 3:04 min:s), (P < .001) in each race. Mean HR during upwind sailing (159 ± 11 beats per minute (bpm)) was higher than downwind sailing (147 ± 15 bpm), (P < 0.001) and reaching (156 ± 16 bpm), (P = 0.002). Although regatta schedules are highly governed by environmental conditions, this study confirms that sailing upwind (i.e., hiking) is the most physically demanding aspect of racing. Additionally, perceptual fatigue increases over time in more demanding regatta schedules. These findings provide a framework to prescribe training and recovery regimes for Laser class sailing athletes, to optimise physical performance during sailing regattas.

We conducted a longitudinal (3-month) qualitative study to examine elite military personnel's (N = 32) experiences and perspectives of team resilience emergence following two team-oriented training courses within an 18-month high-stakes training programme where personnel are required to operate in newly formed tactical teams for extended periods. Our thematically informed interpretations of the participants’ subjective experiences of reality were constructed according to five key themes: (i) adversity is an enduring, shared experience of an event; (ii) individuals recognise adversity through physiological and/or behavioural states; (iii) social resources bind together individual self-regulatory capacities when confronted with adversity to support team functioning; (iv) shared experiences of adversity and collective structures strengthen social bonds and mental models needed for resilience emergence; and (v) behavioural processes and shared states are how collectives turn individual and team capacities into performance under adversity. These findings provide novel insights that supplement our current understanding of team resilience emergence, including the varying means by which adversity may be collectively experienced, synergies between specific forms of adversity and resilience processes or protective factors, and the unique influence of performance context (e.g., task type).

There is intuitive and practical appeal to the idea of emergent resilience, that is, sustaining healthy levels of functioning or recovering quickly after some degree of deterioration following exposure to heightened risk or vulnerability. Scholars typically utilize mean levels of functioning indices to identify qualitatively distinct latent subgroups of individuals who share similar patterns of change over time. We propose and showcase an alternative, yet complementary operationalization of emergent resilience via temporal changes in within-person variability. Twenty-nine male personnel (26.25 ± 2.67 years) from the Australian Army who passed a 3-week Special Forces Selection Course provided device-based assessments of sleep functioning for seven nights immediately following course completion. Participants also provided a hair sample for cortisol analysis prior to and immediately after the selection course as an index of accumulated stress, and self-reported their adaptability prior to the 7-day monitoring period. We combined latent growth modeling with an exponential variance function to capture fluctuations around latent means and their change over time. Consistent with our conceptualization of “bounce back” emergent resilience, within-person variability in sleep duration decreased each night by around 10%, which reflects a meaningful small mean decrease over time. We also revealed differential effects of the predictor variables; biological stress primarily influenced the total sleep duration on the first night of the 7-day monitoring period, whereas adaptability largely affected temporal changes in the within-person residual variances. These findings underscore the importance of synergizing concept, operationalization, and method for the science of human resilience. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

Purpose: To assess the efficacy of a topical sodium bicarbonate (0.3 g/kg body weight NaHCO3) application (PR lotion; Amp Human) on blood buffering capacity and performance in recreationally active participants (study A) and moderately trained athletes (study B). Methods: In Study A, 10 participants completed 2 experimental trials: oral NaHCO3 (0.3 g/kg body weight + placebo lotion) or PR lotion (0.9036 g/kg body weight + oral placebo) applied 90 minutes prior to a cycling task to exhaustion (30-s sprints at 120% peak power output with 30-s rest). Capillary blood was collected and analyzed for pH, bicarbonate, and lactate every 10 minutes throughout the 90-minute loading period and postexercise at 5, 10, and 15 minutes. In Study B, 10 cyclists/triathletes completed 2 experimental trials, applying either PR or placebo lotion 30 minutes prior to a cycling performance task (3 × 30-s maximal sprints with 90-s recovery). Capillary blood samples were collected at baseline, preexercise, and postexercise and analyzed as per study A. Results: In Study A, pH and bicarbonate were significantly elevated from baseline after 10 minutes in the oral NaHCO3 condition and throughout recovery compared with no elevation in the PR lotion condition (P < .001). No differences in cycling time occurred between PR lotion (349 [119] s) and oral NaHCO3 (363 [80] s; P = .697). In Study B, no differences in blood parameters, mean power (P = .108), or peak power (P = .448) were observed between conditions. Conclusions: PR lotion was ineffective in altering blood buffering capacity or enhancing performance in either trained or untrained individuals.

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Purpose: To determine the effect of limb selection (upper/lower), cuff width (small (6 cm)/medium (13 cm) upper; medium/large (18 cm) lower) and anthropometry on arterial occlusion pressure (AOP) in ischemic preconditioning (IPC). Methods: Twenty athletes (10 females and 10 males) had surface anthropometry and dual x-ray absorptiometry (DXA) assessments before using Doppler ultrasound to confirm AOP for each limb. Subsequently, 5 min of occlusion occurred, with near-infrared spectroscopy (NIRS) measuring muscle oxygenation changes. Resultant AOP was compared between sexes, limbs and cuff sizes using linear regression models. Results: Mean AOP was higher in the lower limbs than the upper limbs (161 ± 18 vs. 133 ± 12 mm Hg; p < .001), and with smaller cuffs in upper (161 ± 16 vs. 133 ± 12 mm Hg; p < .001), but not lower limbs (161 ± 16 vs. 170 ± 26 mm Hg; p = .222). Sex and resting systolic blood pressure (SBP) accounted for 77% (small cuff) to 83% (medium cuff) of variance in AOP for upper limbs, and 61% (medium cuff) to 63% (large cuff) in lower limbs. Including anthropometry accounted for 82% (small cuff) to 89% (medium cuff) and 78% (medium cuff) to 79% (large cuff) of variance for upper and lower limbs, respectively. Adding DXA variables improved the explained variance up to 83% (small cuff) to 91% (medium cuff) and 79% (medium cuff) to 87% (large cuff) for upper and lower limbs, respectively. NIRS data showed significantly greater tissue oxygenation changes in upper versus lower limbs. Conclusions: The AOP in athletes is dependent on limb occluded, sex, SBP, limb and cuff size, and body composition.

Altitude training is associated with changes in blood markers, which can confound results of the Athlete?s Biological Passport (ABP). This meta-analysis aims to describe the fluctuations during- and post-altitude in key ABP variables; hemoglobin concentration ([Hb]), square-root transformed reticulocyte percentage (sqrt(retic%)) and the OFF-score. Individual de-identified raw data were provided from 17 studies. Separate linear mixed effects analyses were performed for delta values from baseline for [Hb], sqrt(retic%) and OFF-score, by altitude phase (during and post). Mixed models were fitted with the hierarchical structure: study and subject within study as random effects. Delta values as response variables and altitude dose (in kilometer hours; km.hr = altitude (m) / 1000 x hours), sex, age, protocol and baseline values as fixed effects. Allowances were made for potential autocorrelation. Within two days at natural altitude [Hb] rapidly increased. Subsequent delta [Hb] values increased with altitude dose, reaching a plateau of 0.94 g/dL [95%CI (0.69, 1.20)] at ~1000 km.hr. Delta sqrt(retic%) and OFF-score were the first to identify an erythrocyte response, with respective increases and decreases observed within 100 to 200 km.hr. Post-altitude, [Hb] remained elevated for two weeks. Delta sqrt(retic%) declined below baseline, the magnitude of change was dependent on altitude dose. Baseline values were a significant covariate (p<0.05). The response to altitude is complex resulting in a wide range of individual responses, influenced primarily by altitude dose and baseline values. Improved knowledge of the plausible hematological variations during- and post-altitude provides fundamental information for both the ABP expert and sports physician.

Numerous factors contribute to peak athletic performance. Among these, a strong foundation in physical conditioning and sport-specific experience, in addition to a bespoke and periodized training and nutrition program, the latter based predominately from whole food choices, are essential. Once these underpinning factors are accounted for, and the athlete reaches a training maturity and competition level where marginal gains determine success, a role may exist for the use of evidence-based performance supplements. Although an array of supplements are marketed for the enhancement of sports performance, many lack robust evidence of an ergogenic benefit. Furthermore, some may actually impair performance, often due to gastrointestinal (GI) concerns, while others are potentially detrimental to an athlete’s health. Finally, numerous ingredients in commercial supplements, sometimes presenting as contaminants or undeclared ingredients, carry a risk of inadvertent anti-doping rule violations (Baylis et al., 2001). With this in mind, athletes and their associated support teams should only consider performance supplements where a strong body of evidence supports their use as safe, legal, and effective. The following review focuses on the available evidence base for performance supplements that are commonly used in sport, summarizing the type of event/exercise scenario they are suited to, the potential mechanisms of beneficial effects, and the typical dosing schedule/protocols of use. The supplements of interest have been divided into three categories according to the strength of evidence supporting their use for the enhancement of sports performance. These categories include: (1) established, (2) equivocal, and (3) developing performance supplements.

Objectives The purpose of this study was to conduct a conceptual replication of the proposition that mental toughness is associated positively with behavioural perseverance. Design Repeated-measures design. Methods In total, 38 male Australian rules footballers took part in this study (age, 21 ± 3 y; mass, 82.7 ± 11.0 kg; height, 1.84 ± .07 m; football experience, 13 ± 4 y). Participants self-reported mental toughness approximately one week prior to their first testing session where we assessed their aerobic capacity via the measurement of peak oxygen consumption (V˙ O2peak). Approximately one week later, participants completed a 20 m shuttle run test (MST). The final testing session took place approximately one week later, where participants completed a simulated team game circuit (STGC; 60 min) to simulate game-relevant level of fatigue, which was followed immediately by a 20 m MST. Results Mental toughness was a salient determinant of the variation in behavioural perseverance under typical circumstances, when prior knowledge from past research was incorporated directly into the estimation process. However, the positive association between mental toughness and behavioural perseverance did not generalise to a performance context in which participants were fatigued. Conclusions The results of the current study suggest that mental toughness represents a salient psychological correlate of behavioural perseverance in a discrete physical task that taxes the aerobic energy system in some but not all situations. When fatigued, the effect of mental toughness is outweighed by greater underlying fitness.

Purpose: To determine the effect of limb selection (upper/lower), cuff width (small (6 cm)/medium (13 cm) upper; medium/large (18 cm) lower) and anthropometry on arterial occlusion pressure (AOP) in ischemic preconditioning (IPC). Methods: Twenty athletes (10 females and 10 males) had surface anthropometry and dual x-ray absorptiometry (DXA) assessments before using Doppler ultrasound to confirm AOP for each limb. Subsequently, 5 min of occlusion occurred, with near-infrared spectroscopy (NIRS) measuring muscle oxygenation changes. Resultant AOP was compared between sexes, limbs and cuff sizes using linear regression models. Results: Mean AOP was higher in the lower limbs than the upper limbs (161 ± 18 vs. 133 ± 12 mm Hg; p < .001), and with smaller cuffs in upper (161 ± 16 vs. 133 ± 12 mm Hg; p < .001), but not lower limbs (161 ± 16 vs. 170 ± 26 mm Hg; p = .222). Sex and resting systolic blood pressure (SBP) accounted for 77% (small cuff) to 83% (medium cuff) of variance in AOP for upper limbs, and 61% (medium cuff) to 63% (large cuff) in lower limbs. Including anthropometry accounted for 82% (small cuff) to 89% (medium cuff) and 78% (medium cuff) to 79% (large cuff) of variance for upper and lower limbs, respectively. Adding DXA variables improved the explained variance up to 83% (small cuff) to 91% (medium cuff) and 79% (medium cuff) to 87% (large cuff) for upper and lower limbs, respectively. NIRS data showed significantly greater tissue oxygenation changes in upper versus lower limbs. Conclusions: The AOP in athletes is dependent on limb occluded, sex, SBP, limb and cuff size, and body composition.

With empirical research on team resilience on the rise, there is a need for an integrative conceptual model that delineates the essential elements of this concept and offers a heuristic for the integration of findings across studies. To address this need, we propose a multilevel model of team resilience that originates in the resources of individual team members and emerges as a team-level construct through dynamic person–situation interactions that are triggered by adverse events. In so doing, we define team resilience as an emergent outcome characterized by the trajectory of a team's functioning, following adversity exposure, as one that is largely unaffected or returns to normal levels after some degree of deterioration in functioning. This conceptual model offers a departure point for future work on team resilience and reinforces the need to incorporate inputs and process mechanisms inherent within dynamic interactions among individual members of a team. Of particular, importance is the examination of these inputs, process mechanisms and emergent states, and outcomes over time, and in the context of task demands, objectives, and adverse events. Practitioner points: Team resilience as a dynamic, multilevel phenomenon requires clarity on the individual- and team-level factors that foster its emergence within occupational and organizational settings. An understanding of the nature (e.g., timing, chronicity) of adverse events is key to studying and intervening to foster team resilience within occupational and organizational settings.

The present study aimed to investigate pre-sleep behaviours (including evening electronic device use) and sleep quantity in well-trained athletes. Seventy well-trained athletes (44 females, 26 males) aged 21 ± 4 y from a range of team and individual sports were asked to complete an online sleep diary for 7 days. The sleep diary included questions about pre-sleep behaviours (e.g. napping, caffeine intake), electronic device use in the 2 h prior to bedtime (e.g. type of device and duration of use) and sleep (e.g. time in bed, sleep onset latency). On average, athletes spent 8:20 ± 1:21 h in bed each night. Associations between age, time in bed and sleepiness suggested that younger athletes spent more time in bed (B = -0.05, p = 0.001) but felt sleepier (r = -0.32, p < 0.01) than older athletes. On average, athletes mostly used electronic devices for 0–30 min prior to sleep. The use of multiple devices in the evening was associated with more perceived difficulty in falling asleep (B = 0.22, p = 0.03), but no associations existed with other sleep variables. In summary, younger athletes may require later start times or improved sleep quality to resolve excessive sleepiness.

© 2018 Informa UK Limited, trading as Taylor & Francis Group. The purpose of this scoping review was to examine the literature on team resilience to gain insight into current thinking regarding its definition and conceptualisation, and to identify how researchers have operationalised and measured this concept. We conducted a systematic scoping review using the 5-phase approach proposed by Arksey and O’Malley. A total of seven databases were searched, followed by a citation search of eligible papers via Google Scholar. Of the 275 articles identified via the search process, 27 papers were deemed eligible for review. Several key findings regarding the literature on team resilience were observed: (i) definitions varied in terms of content (e.g. input or process), breadth (e.g. unidimensional versus multidimensional), and quality (e.g. essential and necessary attributes of key components); (ii) there was a predominance of single-level conceptualisations of team resilience; and (iii) there has been a reliance on cross-sectional research designs in empirical studies, which is incongruent with the dynamic nature of this concept. Key recommendations from this scoping review focus on definitional, theoretical, and methodological issues.

© 2018 Informa UK Limited, trading as Taylor & Francis Group The 10-min Psychomotor Vigilance Test (PVT-10) is regarded as the gold-standard for assessing vigilant attention following sleep loss; however, other studies have investigated whether shorter versions of the test elicit similar results to the PVT-10. The present study compared the PVT-10 with 3-min (PVT-3) and 5-min (PVT-5) versions of the test in elite female basketball players. Athletes performed all three tests in the morning and evening for seven consecutive days. Response speed (mean reciprocal reaction time; mean 1/RT), number of errors and number of lapses were determined for each test and time point. The PVT-3 elicited significantly faster response speeds than the other two tests (p < 0.01), while the PVT-5 and PVT-10 were not different. The PVT-10 resulted in more lapses than the PVT-5, followed by the PVT-3, with all tests being significantly different to each other (p < 0.01). In conclusion, while the PVT-5 and PVT-10 were generally similar for response speed, the PVT-3 did not produce results comparable with the PVT-10 for response speed, lapses or errors, and should therefore not be used interchangeably. Further research is required to determine whether the shorter tests are a suitable replacement for the PVT-10 in professional basketball players.

© 2017 Sports Medicine Australia. Objectives: The purpose of this study was to conduct a conceptual replication of the proposition that mental toughness is associated positively with behavioural perseverance. Design: Repeated-measures design. Methods: In total, 38 male Australian rules footballers took part in this study (age, 21±3 y; mass, 82.7±11.0kg; height, 1.84±.07m; football experience, 13±4 y). Participants self-reported mental toughness approximately one week prior to their first testing session where we assessed their aerobic capacity via the measurement of peak oxygen consumption (V O 2peak ). Approximately one week later, participants completed a 20m shuttle run test (MST). The final testing session took place approximately one week later, where participants completed a simulated team game circuit (STGC; 60min) to simulate game-relevant level of fatigue, which was followed immediately by a 20m MST. Results: Mental toughness was a salient determinant of the variation in behavioural perseverance under typical circumstances, when prior knowledge from past research was incorporated directly into the estimation process. However, the positive association between mental toughness and behavioural perseverance did not generalise to a performance context in which participants were fatigued. Conclusions: The results of the current study suggest that mental toughness represents a salient psychological correlate of behavioural perseverance in a discrete physical task that taxes the aerobic energy system in some but not all situations. When fatigued, the effect of mental toughness is outweighed by greater underlying fitness.

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The post-exercise hepcidin response during prolonged (>2 weeks) hypoxic exposure is not well understood. We compared plasma hepcidin levels 3 h after exercise [6 × 1000 m at 90% of maximal aerobic running velocity (vVO2max)] performed in normoxia and normobaric hypoxia (3000 m simulate altitude) 1 week before, and during 14 days of normobaric hypoxia [196.2 ± 25.6 h (median: 200.8 h; range: 154.3–234.8 h) at 3000 m simulated altitude] in 10 well-trained distance runners (six males, four females). Venous blood was also analyzed for hepcidin after 2 days of normobaric hypoxia. Hemoglobin mass (Hbmass) was measured via CO rebreathing 1 week before and after 14 days of hypoxia. Hepcidin was suppressed after 2 (Cohen's d = −2.3, 95% confidence interval: [−2.9, −1.6]) and 14 days of normobaric hypoxia (d = −1.6 [−2.6, −0.6]). Hepcidin increased from baseline, 3 h post-exercise in normoxia (d = 0.8 [0.2, 1.3]) and hypoxia (d = 0.6 [0.3, 1.0]), both before and after exposure (normoxia: d = 0.7 [0.3, 1.2]; hypoxia: d = 1.3 [0.4, 2.3]). In conclusion, 2 weeks of normobaric hypoxia suppressed resting hepcidin levels, but did not alter the post-exercise response in either normoxia or hypoxia, compared with the pre-exposure response.

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The post-exercise hepcidin response during prolonged (>2 weeks) hypoxic exposure is not well understood. We compared plasma hepcidin levels 3 h after exercise [6 × 1000 m at 90% of maximal aerobic running velocity (vVO2max)] performed in normoxia and normobaric hypoxia (3000 m simulate altitude) 1 week before, and during 14 days of normobaric hypoxia [196.2 ± 25.6 h (median: 200.8 h; range: 154.3–234.8 h) at 3000 m simulated altitude] in 10 well-trained distance runners (six males, four females). Venous blood was also analyzed for hepcidin after 2 days of normobaric hypoxia. Hemoglobin mass (Hbmass) was measured via CO rebreathing 1 week before and after 14 days of hypoxia. Hepcidin was suppressed after 2 (Cohen's d = −2.3, 95% confidence interval: [−2.9, −1.6]) and 14 days of normobaric hypoxia (d = −1.6 [−2.6, −0.6]). Hepcidin increased from baseline, 3 h post-exercise in normoxia (d = 0.8 [0.2, 1.3]) and hypoxia (d = 0.6 [0.3, 1.0]), both before and after exposure (normoxia: d = 0.7 [0.3, 1.2]; hypoxia: d = 1.3 [0.4, 2.3]). In conclusion, 2 weeks of normobaric hypoxia suppressed resting hepcidin levels, but did not alter the post-exercise response in either normoxia or hypoxia, compared with the pre-exposure response.

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Purpose: To investigate the effect of 3 swim-pacing profiles on subsequent performance during a sprint-distance triathlon (SDT). Methods: Nine competitive/trained male triathletes completed 5 experimental sessions including a graded running exhaustion test, a 750-m swim time trial (STT), and 3 SDTs. The swim times of the 3 SDTs were matched, but pacing was manipulated to induce positive (ie, speed gradually decreasing from 92% to 73% STT), negative (ie, speed gradually increasing from 73% to 92% STT), or even pacing (constant 82.5% STT). The remaining disciplines were completed at a self-selected maximal pace. Speed over the entire triathlon, power output during the cycle discipline, rating of perceived exertion (RPE) for each discipline, and heart rate during the cycle and run were determined. Results: Faster cycle and overall triathlon times were achieved with positive swim pacing (30.5 ± 1.8 and 65.9 ± 4.0 min, respectively), as compared with the even (31.4 ± 1.0 min, P =.018 and 67.7 ± 3.9 min, P =.034, effect size [ES] = 0.46, respectively) and negative (31.8 ± 1.6 min, P =.011 and 67.3 ± 3.7 min, P =.041, ES = 0.36, respectively) pacing. Positive swim pacing elicited a lower RPE (9 ± 2) than negative swim pacing (11 ± 2, P =.014). No differences were observed in the other measured variables. Conclusions: A positive swim pacing may improve overall SDT performance and should be considered by both elite and age-group athletes during racing.

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Purpose: To investigate the effect of 3 swim-pacing profiles on subsequent performance during a sprint-distance triathlon (SDT). Methods: Nine competitive/trained male triathletes completed 5 experimental sessions including a graded running exhaustion test, a 750-m swim time trial (STT), and 3 SDTs. The swim times of the 3 SDTs were matched, but pacing was manipulated to induce positive (ie, speed gradually decreasing from 92% to 73% STT), negative (ie, speed gradually increasing from 73% to 92% STT), or even pacing (constant 82.5% STT). The remaining disciplines were completed at a self-selected maximal pace. Speed over the entire triathlon, power output during the cycle discipline, rating of perceived exertion (RPE) for each discipline, and heart rate during the cycle and run were determined. Results: Faster cycle and overall triathlon times were achieved with positive swim pacing (30.5 ± 1.8 and 65.9 ± 4.0 min, respectively), as compared with the even (31.4 ± 1.0 min, P =.018 and 67.7 ± 3.9 min, P =.034, effect size [ES] = 0.46, respectively) and negative (31.8 ± 1.6 min, P =.011 and 67.3 ± 3.7 min, P =.041, ES = 0.36, respectively) pacing. Positive swim pacing elicited a lower RPE (9 ± 2) than negative swim pacing (11 ± 2, P =.014). No differences were observed in the other measured variables. Conclusions: A positive swim pacing may improve overall SDT performance and should be considered by both elite and age-group athletes during racing.

This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5 s cycling sprints in simulated altitude (3000 m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60 min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855 ± 89 vs. 739 ± 95 W, p = .006; PPO: 1024 ± 114 vs. 895 ± 112 W, p = .010) and third (MPO: 819 ± 105 vs. 686 ± 83 W, p = .008; PPO: 985 ± 125 vs. 834 ± 99 W, p = .008) sets, respectively. IL-6 was significantly increased from pre- to 1 h post-exercise in both hypoxia (0.7 ± 0.2 vs. 2.4 ± 1.4 pg/mL, p = .004) and sea-level conditions (0.7 ± 0.2 vs. 1.6 ± 0.3 pg/mL, p < .001), with a large effect (d = 0.80) suggesting higher IL-6 levels of post-hypoxia. F2-IsoP was significantly lower 1 h post-exercise in both the hypoxic (p = .005) and sea-level (p = .002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response.

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© 2015 Taylor & Francis. This study examined the haemolytic effects of an interval-based running task in fore-foot and rear-foot striking runners. Nineteen male distance runners (10 fore-foot, 9 rear-foot) completed 8 × 3 min repeats at 90% vVO 2peak on a motorised treadmill. Pre-and post-exercise venous blood samples were analysed for serum haptoglobin to quantify the haemolytic response to running. Vertical ground reaction forces were also captured via a force plate beneath the treadmill belt. Haptoglobin levels were significantly decreased following exercise (P = 0.001) in both groups (but not between groups), suggesting that the running task created a haemolytic stress. The ground reaction force data showed strong effect sizes for a greater peak force (d = 1.20) and impulse (d = 1.37) in fore-foot runners, and a greater rate of force development (d = 2.74) in rear-foot runners. The lack of difference in haptoglobin response between groups may be explained by the trend for fore-foot runners to experience greater peak force and impulse during the stance phase of their running gait, potentially negating any impact of the greater rate of force development occurring from the rear-foot runners’ heel strike. Neither type of runner (forefoot or rear-foot) appears more susceptible to technique-related foot-strike haemolysis.

© 2015 Taylor & Francis. This study examined the haemolytic effects of an interval-based running task in fore-foot and rear-foot striking runners. Nineteen male distance runners (10 fore-foot, 9 rear-foot) completed 8 × 3 min repeats at 90% vVO 2peak on a motorised treadmill. Pre-and post-exercise venous blood samples were analysed for serum haptoglobin to quantify the haemolytic response to running. Vertical ground reaction forces were also captured via a force plate beneath the treadmill belt. Haptoglobin levels were significantly decreased following exercise (P = 0.001) in both groups (but not between groups), suggesting that the running task created a haemolytic stress. The ground reaction force data showed strong effect sizes for a greater peak force (d = 1.20) and impulse (d = 1.37) in fore-foot runners, and a greater rate of force development (d = 2.74) in rear-foot runners. The lack of difference in haptoglobin response between groups may be explained by the trend for fore-foot runners to experience greater peak force and impulse during the stance phase of their running gait, potentially negating any impact of the greater rate of force development occurring from the rear-foot runners’ heel strike. Neither type of runner (forefoot or rear-foot) appears more susceptible to technique-related foot-strike haemolysis.

© 2014 Sports Medicine Australia. Objectives: This study examined the association between self-reported mental toughness and behavioural perseverance among a sample of male Australian footballers in a naturalistic context. DesignCross-sectional field study, with the multistage 20 m shuttle run test (MST) employed as a proxy for behavioural perseverance. Methods: 330 male Australian footballers aged between 15 and 18 years (M=16.86; SD=.71) with between 2 and 14 years playing experience (M=9.32; SD=2.51) participated. Initially, footballers completed a mental toughness questionnaire, before having their height and body mass measurements taken. Subsequently, a performance testing session was completed, which included the 20 m sprint, Australian football-specific agility run, vertical jump, and the MST. Bayesian estimation was employed to allow for the simultaneous examination of existing findings with our new data in a way that provides an automatic meta-analysis of evidence in this area. Results: The analysis indicated a 95% probability that the association between mental toughness and behavioural perseverance lies between .14 and .34, even when controlling for other factors known to influence MST performance, including age, height, body mass, and years playing experience. Conclusions: Taken together with previous research, these findings support the theoretical proposition that persistence, effort or perseverance represents a behavioural signature of mental toughness.

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Item does not contain fulltext, OBJECTIVES: The post-exercise interleukin-6 (IL-6) and hepcidin response was investigated during the hormone-deplete and hormone-replete phases of an estradiol and progestogen regulated oral contraceptive cycle (OCC). DESIGN: Counterbalanced, repeated measures cross-over study. METHODS: Ten active female monophasic oral contraceptive pill (OCP) users completed two 40 min treadmill running trials at 75% of their pre-determined peak oxygen uptake velocity (vVO2peak). These trials were randomly performed in two specific phases of the OCC: (a) Day 2-4, representing a hormone-free withdrawal period (D-0); (b) Day 12-14, representing the end of the first week of active hormone therapy (D+7). Venous blood samples were drawn pre-, post- and 3h post-exercise. RESULTS: In both trials, serum IL-6 was significantly elevated (p<0.05) immediately post-exercise, while serum hepcidin was significantly elevated (p<0.05) 3h post-exercise, with no significant differences recorded between trials. CONCLUSIONS: These findings suggest that exercise performed during the different phases (D-0 vs. D+7) of a monophasic OCP regulated cycle does not alter exercise induced IL-6 or hepcidin production. As such, future studies looking to investigate similar variables post-exercise, may not need to 'control' for different phases of the OCC, provided participants are current monophasic OCP users.

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Item does not contain fulltext, OBJECTIVES: The post-exercise interleukin-6 (IL-6) and hepcidin response was investigated during the hormone-deplete and hormone-replete phases of an estradiol and progestogen regulated oral contraceptive cycle (OCC). DESIGN: Counterbalanced, repeated measures cross-over study. METHODS: Ten active female monophasic oral contraceptive pill (OCP) users completed two 40 min treadmill running trials at 75% of their pre-determined peak oxygen uptake velocity (vVO2peak). These trials were randomly performed in two specific phases of the OCC: (a) Day 2-4, representing a hormone-free withdrawal period (D-0); (b) Day 12-14, representing the end of the first week of active hormone therapy (D+7). Venous blood samples were drawn pre-, post- and 3h post-exercise. RESULTS: In both trials, serum IL-6 was significantly elevated (p<0.05) immediately post-exercise, while serum hepcidin was significantly elevated (p<0.05) 3h post-exercise, with no significant differences recorded between trials. CONCLUSIONS: These findings suggest that exercise performed during the different phases (D-0 vs. D+7) of a monophasic OCP regulated cycle does not alter exercise induced IL-6 or hepcidin production. As such, future studies looking to investigate similar variables post-exercise, may not need to 'control' for different phases of the OCC, provided participants are current monophasic OCP users.