The Provision and Experience of Variety in Physical Activity Settings: A Systematic Review of Quantitative and Qualitative Studies.

BACKGROUND: Emerging evidence indicates that the provision or experience of "variety" may be an important determinant of physical activity behavior. Variety refers to diverse endeavors, opportunities, or tasks and, in the context of physical activity, has been examined as a feature of an activity or environment (i.e., variety support) and an experience (i.e., one's felt experience or perceived variety). OBJECTIVE: The primary aim of our review was to synthesize studies investigating the provision or experience of variety in physical activity settings on health and well-being, behaviors, and motivation. Our secondary aim was to examine quantitative data reporting on different facets of variety in physical activity settings. METHODS: We conducted a systematic search of five electronic databases (Scopus, SPORTDiscus, Science Direct, MEDLINE, and the Human Kinetics Library) to identify studies providing a quantitative or qualitative assessment of variety in physical activity settings. RESULTS: We identified 5,576 potentially relevant articles to examine. After title and abstract screening (and removal of duplicates), 74 articles remained for full-text screening, from which 28 studies were deemed eligible. Our findings from qualitative and quantitative (experimental and cross-sectional) studies demonstrate that the provision and experience of variety relates to participation and engagement in physical activity, motivation for exercise and physical activity, and well-being outcomes. Our results also indicate that the provision of variety can increase enjoyment, interest (i.e., motivation), and adherence to a physical activity program. CONCLUSION: Our findings support the assertion that variety should be considered during planning, implementation, and evaluation of physical activity programs. Additional experimental studies are needed to gain a better understanding of how elements of physical activity and exercise programs, delivery, and environment can be manipulated to increase variety and foster participation in physical activity.

The role of anthropometric, performance and psychological attributes in predicting selection into an elite development programme in older adolescent rugby league players.

This study aimed to identify attributes that discriminate selected from non-selected players and predict selection into a rugby league development programme in older adolescent players. Anthropometric, performance and psychological attributes were measured in under-16 (N = 100) and under-18 (N = 60) rugby league players trialling for selection into a development programme with a professional Australian club. Sprint times (P < 0.001), predicted VO2max (P = 0.002) and push-ups1 min (P = 0.004) were superior in selected under-16 players, and sprint times (P ≤ 0.045), push-ups1 min (P < 0.001) and chin-ups1 min (P = 0.013) were superior in selected under-18 players. Further, 10-m sprint (ß = -7.706, standard error [SE] = 2.412), VO2max (ß = 0.168, SE = 0.052) and body mass (ß = 0.071, SE = 0.023) significantly predicted selection (R2 = 0.339) in under-16 players, while push-ups1 min (ß = 0.564, SE = 0.250), 10-m sprint (ß = -68.477, SE = 28.107), body mass (ß = 0.360, SE = 0.155) and chronological age (ß = -3.577, SE = 1.720) significantly predicted selection (R2 = 0.894) in under-18 players. These findings emphasise the importance of performance attributes in junior rugby league and indicate talent identification test batteries should be age-specific in older adolescent players.

The Validity and Contributing Physiological Factors to 30-15 Intermittent Fitness Test Performance in Rugby League.

Scott, TJ, Duthie, GM, Delaney, JA, Sanctuary, CE, Ballard, DA, Hickmans, JA, and Dascombe, BJ. The validity and contributing physiological factors to 30-15 intermittent fitness test performance in rugby league. J Strength Cond Res 31(9): 2409-2416, 2017-This study examined the validity of the 30-15 Intermittent Fitness Test (30-15IFT) within rugby league. Sixty-three Australian elite and junior-elite rugby league players (22.5 ± 4.5 years, 96.1 ± 9.5 kg, Σ7 skinfolds: 71.0 ± 18.7 mm) from a professional club participated in this study. Players were assessed for anthropometry (body mass, Σ7 skinfolds, lean mass index), prolonged high-intensity intermittent running (PHIR; measured by 30-15IFT), predicted aerobic capacity (MSFT) and power (AAS), speed (40 m sprint), repeated sprint, and change of direction (COD-505 agility test) ability before and after an 11-week preseason training period. Validity of the 30-15IFT was established using Pearson's coefficient correlations. Forward stepwise regression model identified the fewest variables that could predict individual final velocity (VIFT) and change within 30-15IFT performance. Significant correlations between VIFT and Σ7 skinfolds, repeated sprint decrement, V[Combining Dot Above]O2maxMSFT, and average aerobic speed were observed. A total of 71.8% of the adjusted variance in 30-15IFT performance was explained using a 4-step best fit model (V[Combining Dot Above]O2maxMSFT, 61.4%; average aerobic speed, 4.7%; maximal velocity, 4.1%; lean mass index, 1.6%). Across the training period, 25% of the variance was accounted by ΔV[Combining Dot Above]O2maxMSFT (R = 0.25). These relationships suggest that the 30-15IFT is a valid test of PHIR within rugby league. Poor correlations were observed with measures of acceleration, speed, and COD. These findings demonstrate that although the 30-15IFT is a valid measure of PHIR, it also simultaneously examines various physiological capacities that differ between sporting cohorts.

Positional group significantly influences the offensive and defensive skill involvements of junior representative rugby league players during match play.

This study examined the skill involvements of three positional groups across a junior representative rugby league season. Data were collected from 45 rugby league players (mean ± SD; age = 16.5 ± 1.0 years) currently participating in the Harold Matthews and SG Ball Cup. Players were subdivided into hit-up forwards, adjustables and outside backs. The frequency (n · min(-1)) of offensive, defensive and overall involvements was coded for each group using a notation system and a practical coach skill analysis tool. Multivariate analysis of variance (MANOVA) revealed a significant effect of playing position on skill involvements (F = 9.06; P < 0.001; ES = 0.41). Hit-up forwards performed a significantly greater frequency of offensive (0.31 ± 0.10), defensive (0.42 ± 0.15) and overall involvements (0.74 ± 0.19) when compared to adjustables (0.20 ± 0.08, 0.28 ± 0.08 and 0.52 ± 0.15, respectively) and outside backs (0.20 ± 0.12, 0.11 ± 0.07 and ± 0.31 ± 0.17, respectively). Further, adjustables performed a significantly greater number of defensive (0.28 ± 0.08) and overall involvements (0.52 ± 0.15) when compared to outside backs (0.11 ± 0.07 and 0.31 ± 0.17, respectively). The findings of this study suggest that it is important to consider a junior player's positional group when analysing their skill involvements. Information gained from this study could assist in the design of specific training methodologies for junior rugby league players in high-level talent development programmes.

Reliability and Usefulness of the 30-15 Intermittent Fitness Test in Rugby League.

This study examined the reliability and usefulness of the 30-15 Intermittent Fitness Test (30-15(IFT)) within rugby league. Fifty-five young rugby league players participated in the study. These included representative players from Under 16s (n = 19; 15.6 ± 0.3 years; 78.1 ± 10.9 kg), Under 18s (n = 21; 17.4 ± 0.5 years; 86.9 ± 11.2 kg), and Under 20s (n = 15; 19.4 ± 0.5 years; 95.9 ± 8.7 kg) squads within a professional rugby league club. Players performed the 30-15(IFT) twice within 9 days of each other. Maximal intermittent running velocity (V(IFT)) and heart rate at exhaustion (HR(peak)) were collected for both tests. Intraclass correlation coefficients (ICCs) for the "Combined" and Under 20s were very large (r > 0.7), whereas the ICCs for Under 16s and Under 18s were almost perfect (r > 0.9). Coefficients of variation were 1.9% (95% confidence interval, 1.6-2.4) for the combined test-retest of the 30-15(IFT) and 0.6% (0.5-1.0) for HR(peak). As the typical error of measurement (TE) (0.36 km·h⁻¹) was greater than the smallest worthwhile change (SWC) (0.21 km·h⁻¹) value, the usefulness of the V(IFT) was rated as "marginal." The TE for HR(peak) was similar to the SWC, rating the usefulness of this variable as "OK." Despite the usefulness of the 30-15(IFT) being deemed Marginal, a change as small as 0.5 km·h⁻¹ (1 stage) in V(IFT) could be considered substantial or "real." As a consequence, the 30-15(IFT) presents as both a reliable and useful field test in the assessment of intermittent fitness for rugby league players.

The workout responses of salivary-free testosterone and cortisol concentrations and their association with the subsequent competition outcomes in professional rugby league.

This study assessed the responses of salivary-free testosterone (T) and cortisol (C) concentrations across selected training workouts and their association with the subsequent competition outcomes in professional rugby league. Thirteen rugby league players were assessed for salivary-free T and C concentrations across 5 training workouts performed 3-4 days before a competitive game. The game outcomes included wins and losses and game-ranked performance (1-5) based on the number of points scored, the points differential, and a coach rating. Data were pooled across the winning (n = 3) and losing (n = 2) outcomes. Pooled free T concentrations (absolute and relative changes) were significantly (p < 0.01) elevated across those workouts that preceded winning games, but not the losses, and the relative (percent) T changes were significantly (p < 0.05) higher before winning (30.9%) than before losing (3.4%). Both outcomes were associated with workout decreases in pooled free C concentrations and the relative C changes were not significantly different between wins (-22.9%) and losses (-25.6%). In conclusion, the free T responses to selected training workouts showed some association with subsequent winning (being elevated) and losing (no change) during a limited number of competitive games in professional rugby league. Speculatively, the free T responses to a midweek workout might provide an early sign of team readiness to compete or to recovery state, thereby providing a novel format for implementing training or management strategies to improve the competition outcomes.

Conceptualising Rugby League Performance Within an Ecological Dynamics Framework: Providing Direction for Player Preparation and Development.

Across team sports, it is critically important to appropriately define, evaluate and then aptly describe individual and team performance. This is of particular significance when we consider that performance models govern the direction of player preparation (short term) and development (long term) frameworks. Within the context of rugby league, this has traditionally been undertaken through hierarchical and linear processes. Such approaches have resulted in research and performance analysis techniques which aim to support these operational outcomes. Yet, these methods may deliver limited application on how or why match-play unfolds and therefore might be sub-optimal in providing insights to truly support coaches. In this paper, we propose the conceptualisation of rugby league performance through the lens of ecological dynamics, which may offer a different view to this traditional approach. We propose that this approach eliminates the silos of disciplinary information (e.g. technical, physical and medical) that may currently exist, allowing for a holistic approach to performance, preparation and development. Specifically, we consider that through the implementation of this ecological approach, all performance coaches (technical, physical and medical) may (co-)design learning environments that more collaboratively develop players for rugby league match-play. As a result, we put forward a new rugby league performance model from which preparation and development programs can be anchored toward. We conclude the paper by offering practical examples where these concepts are contextualised within the landscape familiar to practitioners working within rugby league.

The Susceptibles, Chancers, Pragmatists, and Fair Players: An Examination of the Sport Drug Control Model for Adolescent Athletes, Cluster Effects, and Norm Values Among Adolescent Athletes.

Although there are few high-profile cases of adolescent athletes being caught doping, up to a third of young athletes may dope. In order to generate a more accurate understanding of why adolescent athletes dope, it is important to validate models that help to explain this behavior. The aims of this study were 3-fold: firstly, to test the Sport Drug Control Model for Adolescent Athletes (SDCM-AA); secondly, to generate athlete profiles that would help quantify the proportion of athletes who are at risk of doping; and thirdly, to create norm values for the Adolescent Sport Doping Inventory (ASDI), which would allow national doping organizations, sporting organizations, and clubs to benchmark the scores of their athletes for key psycho-social variables linked to doping. A total of 2208 adolescent athletes from the United Kingdom, Australia, Hong Kong, and the United States completed the ASDI. The data presented an appropriate fit to the SDCM-AA model, in which 54% of the variance in susceptibility to doping was explained in the model, and 44.8% of attitudes toward doping was accounted for. Four distinct clusters of athletes emerged: the Susceptibles (i.e., identified with the benefits of doping, were willing to cheat, and viewed little threat), the Chancers (i.e., identified with the benefits of doping, scored high on willingness to cheat, and were highly influenced by their reference group, but had an average score for threat, self-esteem, and legitimacy), the Pragmatists (i.e., did not engage with any aspects of doping, but were more susceptible than the fair players), and Fair Players (i.e., high levels of sportspersonship, unwilling to cheat, and viewed doping as a threat). The revised SDCM-AA appears a valid model that helps explain the factors associated with doping attitudes and doping susceptibility. Adolescent athletes can be classified into one of four clusters, in relation to doping. Their cluster group could influence the content of the anti-doping education they receive.

The development and validation of the Adolescent Sport Drug Inventory (ASDI) among athletes from four continents.

A significant barrier to understanding the psychosocial antecedents of doping use among adolescent athletes is the lack of valid measures. In order to address this issue, the first aim of this paper was to develop and validate the Adolescent Sport Drug Inventory (ASDI) among adolescent athletes from Asia, Europe, North America, and Oceania. The second aim was to assess the construct validity of the ASDI. As such, this paper is divided into two parts. Part 1 relates to the development of the ASDI and contains two studies: item development (Study 1) and factorial validity (Study 2). Part 2 contains information on how the psychosocial variables measured in the ASDI are associated with situational temptation, and honesty (Study 3), maturation (Study 4), stress and coping (Study 5), and coaching (Study 6). In devising the ASDI, 19 different models were examined, which culminated in a 9-factor, 43-item ASDI. Coping, mastery-approach goals, and cognitive-social maturity were associated with doping attitudes. Caring motivational climates, strong coach-athlete relationships, and positive coach behaviors were associated with athletes being less susceptible toward doping, which provides construct validity for the ASDI. The ASDI is a valid tool to assess the psychosocial factors associated with doping among adolescent athletes. This questionnaire can be used to identify athletes who are the most at risk of doping, assess how the psychosocial factors associated with doping change over time, and to monitor the impact of antidoping interventions for adolescent athletes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Predicting Self-Reported Illness for Professional Team-Sport Athletes.

PURPOSE: To identify contributing factors to the incidence of illness for professional team-sport athletes, using training load (TL), self-reported illness, and well-being data. METHODS: Thirty-two professional rugby league players (26.0 ± 4.8 y, 99.1 ± 9.6 kg, 1.84 ± 0.06 m) were recruited from the same club. Players participated in prescribed training and responded to a series of questionnaires to determine the presence of self-reported illness and markers of well-being. Internal TL was determined using the session rating of perceived exertion. These data were collected over 29 wk, across the preparatory and competition macrocycles. RESULTS: The predictive models developed recognized increases in internal TL (strain values of >2282 AU, weekly TL >2786 AU, and monotony >0.78 AU) to best predict when athletes are at increased risk of self-reported illness. In addition, a reduction in overall well-being (<7.25 AU) in the presence of increased internal TL, as previously stated, was highlighted as a contributor to self-reported-illness occurrence. CONCLUSIONS: These results indicate that self-report data can be successfully used to provide a novel understanding of the interactions between competition-associated stressors experienced by professional team-sport athletes and their susceptibility to illness. This may help coaching staff more effectively monitor players during the season and potentially implement preventive measures to reduce the likelihood of illnesses occurring.

In vitro time-dependent response of periodontal ligament to mechanical loading.

This study examined the time-dependent response of bovine periodontal ligament (PDL). Applying linear viscoelastic theory, the objective was 1) to examine the linearity of the PDL's response in terms of its scaling and superposition property and 2) to generate the phase lag-vs.-frequency spectrum graph. PDL specimens were tested under three separate straining conditions: 1) tension ramp tests conducted at different strain rates, 2) pulling step-straining to 0.3 in discrete tests and to 0.3 and 0.6 in one continuous run, and 3) tension-compression sinusoidal oscillations. To this effect, bar-shaped specimens of bovine roots that comprised portions of dentin, PDL tissue, and alveolar bone were produced and strained in a microtensile machine. The experimental data demonstrated that neither the scaling nor the superposition properties were verified and that the viscoelastic response of the PDL was nonlinear. The PDL's elastic response was essentially stiffening, and its viscous component was pseudoplastic. The tangent of the PDL's strain-stress phase lag was in the 0-0.1 range in the tensile direction and in the 0.35-0.45 range in the compressive direction. In line with other biological tissues, the phase lag was largely independent of frequency. By use of the data generated, a mathematical model is outlined that reproduces both the elastic stiffening and viscous thinning of the PDL's response.

Oscillatory shear loading of bovine periodontal ligament--a methodological study.

This study examined the stress response of bovine periodontal ligament (PDL) under sinusoidal straining. The principle of the test consisted in subjecting transverse tooth, PDL and bone sections of known geometries to controlled oscillatory force application. The samples were secured to the actuator by support plates fabricated using a laser sintering technique to fit their contours to the tooth and the alveolar bone. The actuator was attached to the root slices located in the specimen's center. Hence the machine was able to push or pull the root relative to its surrounding alveolar bone. After determining an optimal distraction amplitude, the samples were cyclically loaded first in ramps and then in sinusoidal oscillations at frequencies ranging from 0.2 to 5 Hz. In the present study the following observations were made: (1) Imaging and the laser sintering technique can be used successfully to fabricate custom-made support plates for cross-sectional root-PDL-bone sections using a laser sintering technique, (2) the load-response curves were symmetric in the apical and the coronal directions, (3) both the stress response versus phase angle and the stress response versus. strain curves tended to "straighten" with increasing frequency, and (4) the phase lag between applied strain and resulting stress was small and did not differ in the intrusive and the extrusive directions. As no mechanical or time-dependent anisotropy was demonstrable in the intrusive and extrusive directions, such results may considerably simplify the development of constitutive laws for the PDL.