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Probiotic supplementation may offer team sport athletes a range of benefits beyond the immune and gastrointestinal systems.To examine the effects of a probiotic formulation on perceptual markers of sleep quality and quantity, and muscle soreness, leg heaviness and motivation in elite rugby union athletes.A double-blind randomised controlled trial involving 19 elite male rugby athletes was conducted over 17 weeks encompassing both domestic and international competition. Psychometric variables and salivary biomarkers were assessed twice a week. Athletes were assigned either a daily probiotic (Ultrabiotic 60™) and Saccharomyces boulardii (during international competition) or a placebo. Associations between psychometric scores for perceptual and salivary biomarkers of sleep (melatonin) and inflammation C-reactive protein (CRP) were investigated.Muscle soreness was ∼0.5 units lower (F(1, 343)=42.646, p0.0001) and leg heaviness scores ∼0.7 units lower (F(1, 334)=28.990, p0.0001) in the probiotic group compared to the placebo group. Across both groups, as self-reported muscle soreness scores and salivary CRP concentrations increased, sleep quantity, quality and motivation scores decreased. Conversely as muscle soreness scores and CRP decreased, sleep quantity and quality, and motivation scores improved.A long-term programme of probiotic supplementation in international-level rugby union players may yield favourable effects on self-reported muscle soreness and sleep quality associated with muscle soreness during training and competitions.

Objectives In elite age-group swimming it is unclear to what degree common assessments of anthropometric, jump performance and front-crawl critical speed (CS) correlate with competition performance. Design Cross-sectional field study. Methods Forty eight elite national-level junior swimmers (22 males, age 16.5 ± 1.2 y, 26 females, age 15.5 ± 1.1 y; mean ± SD) completed anthropometry tests, loaded and unloaded countermovement jumps and a series of front-crawl time-trials to determine CS and supra-CS distance capacity (D’). Years from peak height velocity (PHV) predicted from anthropometric data was used as a maturity indicator. Race performances within 3 months of testing were standardised to compare across distances and strokes. Multiple linear regression models were formulated using these data. Results Loaded jump height, mass, D’, PHV and humerus breadth best predicted 100 m performance in males (R2Adj = 0.88, p Conclusions Common assessments of power and aerobic capacity in elite junior swimmers explain more variance in competition performance for male than female swimmers, as well as for 100 m rather than 200 m events. These findings highlight the need to empirically assess testing regimens and suggest new tests in this population may be required.

Objectives To identify the influence of age-policy changes on the relative age effect (RAE) across the Australian Football League (AFL) talent pathway. Design Retrospective cross-sectional analysis of junior AFL players attending the National Draft (National), State, and State Under 16s (U16) combines between 1999–2016. Methods Birth-date data was obtained for players attending the AFL State U16 (n = 663, age: 15.9 ± 0.4 years), State (n = 803, age: 19.1 ± 1.7 years), National (n = 1111, age: 18.3 ± 0.8 years) combines. Corresponding aged-matched Australian general population birth rate data was also collected. Results A chi-squared analysis comparing birth month distributions found all combine groups differed significantly from the general population (Under 16s: χ2 = 62.61, State: χ2 = 38.83, National: χ2 = 129.13, p Conclusions Selection bias exists towards older players is present at the AFL’s State U16, and is maintained at State and National level combines. Age-policy changes are only partially successful at addressing the RAE at the National level, with alternative strategies also recommended in order to address the RAE across the AFL talent pathways.

Objectives Adhering to a low carbohydrate (CHO) high fat (LCHF) diet can alter markers of iron metabolism in endurance athletes. This investigation examined the re-introduction of CHO prior to, and during exercise on the iron-regulatory response to exercise in a homogenous (in regard to serum ferritin concentration) group of athletes adapted to a LCHF diet. Design Parallel groups design. Methods Three weeks prior to the exercise trials, twenty-three elite race walkers adhered to either a CHO-rich (n = 14) or LCHF diet (n = 9). A standardised 19–25 km race walk was performed while athletes were still adhering to their allocated dietary intervention (Adapt). A second test was performed three days later, where all athletes were placed on a high CHO diet (CHO Restoration). Venous blood samples were collected pre-, post- and 3 h post-exercise and measured for interleukin-6 (IL-6) and hepcidin-25. Results The post-exercise IL-6 increase was greater in LCHF (p < 0.001) during both the Adapt (LCHF: 13.1-fold increase; 95% CI: 5.6–23.0, CHO: 8.0-fold increase; 5.1–11.1) and CHO Restoration trials (LCHF: 18.5-fold increase; 10.9–28.9, CHO: 6.3-fold increase; 3.9–9.5); outcomes were not different between trials (p = 0.84). Hepcidin-25 concentrations increased 3 h post-exercise (p < 0.001), however, they did not differ between trials (p = 0.46) or diets (p = 0.84). Conclusions The elevated IL-6 response in athletes adapted to a LCHF diet was not attenuated by an acute increase in exogenous CHO availability. Despite diet-induced differences in IL-6 response to exercise, post-exercise hepcidin levels were similar between diets and trials, indicating CHO availability has minimal influence on post-exercise iron metabolism.

Objectives To compare a field-based critical velocity running test to routine laboratory (treadmill VO 2 max test) and field-based (Yo-Yo intermittent recovery test, Yo-Yo IR1) aerobic fitness tests in women's rugby sevens (7's) players. To quantify the degree of association between field-based fitness test scores and GPS-derived analysis of performance data in competition. Design Single cohort, cross-sectional study involving 22 female Australian Rugby 7's National team players. Methods Players underwent fitness testing comparing the critical velocity test (100 m, 400 m, 1500 m runs) to the Yo-Yo IR1 and a treadmill VO 2 max test. GPS data was obtained during the National Championships using a subgroup of 12 players and compared with each player's fitness test scores. Results The critical velocity test was highly correlated with the Yo-Yo IR1 test ( r = 0.86, 0.69–0.94; 90% confidence interval) and all variables of the VO 2 max test, however mean values were substantially different between tests (Yo-Yo IR1: 4.3 ± 0.1 m s −1 , vVO 2 max: 3.7 ± 0.3 m s −1 , critical velocity: 3.2 ± 0.3 m s −1 ). Average speed, obtained from GPS data, was largely correlated with both the Yo-Yo IR1 ( r = 0.62, 0.10–0.87) and critical velocity ( r = 0.51, −0.06–0.83) tests. Total game distance correlated moderately with the Yo-Yo IR1 ( r = 0.49, −0.09–0.82) and critical velocity ( r = 0.36, −0.25–0.76). Conclusions The critical velocity test is an appropriate aerobic fitness test, yields results similar to the Yo-Yo IR1, and correlates moderately with rugby 7's game data. However the Yo-Yo IR1 and critical velocity test scores cannot be used interchangeably.

There is conflicting evidence whether hypoxia improves running economy (RE), maximal O(2) uptake (V(O)(2max)), haemoglobin mass (Hb(mass)) and performance, and what total accumulated dose is necessary for effective adaptation. The aim of this study was to determine the effect of an extended hypoxic exposure on these physiological and performance measures. Nine elite middle distance runners were randomly assigned to a live high-train low simulated altitude group (ALT) and spent 46+/-8 nights (mean+/-S.D.) at 2860+/-41m. A matched control group (CON, n=9) lived and trained near sea level ( approximately 600m). ALT decreased submaximal V(O)(2) (Lmin(-1)) (-3.2%, 90% confidence intervals, -1.0% to -5.2%, p=0.02), increased Hb(mass) (4.9%, 2.3-7.6%, p=0.01), decreased submaximal heart rate (-3.1%, -1.8% to -4.4%, p=0.00) and had a trivial increase in V(O)(2max) (1.5%, -1.6 to 4.8; p=0.41) compared with CON. There was a trivial correlation between change in Hb(mass) and change in V(O)(2max) (r=0.04, p=0.93). Hypoxic exposure of approximately 400h was sufficient to improve Hb(mass), a response not observed with shorter exposures. Although total O(2) carrying capacity was improved, the mechanism(s) to explain the lack of proportionate increase in V(O)(2max) were not identified.

To evaluate the utility of fitness assessment and trends in drafting of players in the Australian Football League, we analysed height, mass, skinfolds, 20-m sprint, vertical jump, agility run and endurance assessed in the 495 players attending the annual national draft camps between 1999 and 2004. Effects of player position and assessment year were expressed as standardised mean differences (Cohen effect sizes) and interpreted qualitatively. Effect of birth month on chance of being drafted, which may be important in team sports, was also analysed. Compared with midfield players, ruckmen, tall forwards and tall defenders were decisively taller (effect-size range 1.33-1.95, large) and heavier (1.30-1.63, large), but had poorer sprint speed (0.23-0.57, small), aerobic ability (0.66-1.18, moderate) and agility (0.64-1.11, moderate). The only substantial changes in fitness scores over the 5-year period were an increase in height (0.76, moderate) and an increase in 20-m sprint time (0.39, small). A majority (65%) of players attending the camps were born in the first half of a given year, but their chance of being drafted (70%) was similar to that of players born in the second half (64%). We conclude that fitness assessment is useful for differentiating between player positions and identifying some annual trends in recruitment in Australian football, and that players with a second half birth month have been disadvantaged with lower representation at the national draft camp.

Relationships between fitness testing and career progression in the Australian Football League (AFL) are under-explored. This study investigated relationships between anthropometric and fitness tests conducted at the annual AFL National Draft Camp and subsequent career progression of players. A total of 283 players was tested over three consecutive camps (1999-2001). The anthropometric and fitness measures were: height, mass, sum of skinfolds, 20-m sprint test, vertical jump (standing and bilateral running), agility run and a multi-stage incremental shuttle run. The five outcome variables were: drafted (yes/no), AFL debut (yes/no), number of AFL games played to the end of 2003, and subjective ratings of career potential and career value (5-point scale). Of 205 players (72%) subsequently drafted, 166 (59%) eventually made their AFL debut. Players drafted to AFL clubs were faster over 5 m, 10 m and 20 m, ran further in the shuttle run and ran marginally faster in the agility test than players not drafted. Multi-regression analysis showed small to moderate correlations (r = 0.27-0.31) between the designated outcome variables and selected fitness tests: 20-m sprint time (faster), agility run test (faster), and running vertical jump (higher absolute height and smaller difference between left and ride sides). Regression analysis for the standing vertical jump relative to standing reach height showed a counterintuitive negative correlation with positive outcomes, possibly reflecting non-compliance with testing procedures by the less successful athletes. We conclude that the 20-m sprint, jump, agility and shuttle run tests have a small but important association with career progression of AFL footballers.

This study examined the effects of acute exercise on natural killer (NK) cell numbers, their expression of CD94 and cytotoxic capacity in triathletes over a 10-week training period. Nine highly trained male triathletes (age 25.9+/-4.1 yrs, VO2max 5.14+/-0.33 L.min(-1)) attended the laboratory on weeks 0, 2, 5 and 10 for incremental submaximal and maximal cycle ergometry. Peripheral blood was analysed for white blood cell counts, lymphocyte phenotype and cytolytic activity (51Cr release from K562 cells). Maximum oxygen consumption increased from week 2 (5.14+/-0.33 L.min(-1)) to week 10 (5.28+/-0.32 L.min(-1)). Resting NK cell numbers and their expression of CD94 were not altered over the 10-week study period. Natural killer cells expressing CD94+ were not differentially recruited into the circulation and cytolytic activity of exercise-recruited NKs did not differ from those present at rest. There was longitudinal stability (over the 10 weeks of the study) in CD94 expression on NK cells, exercise recruitment of CD94+ NK cells and cytolytic capacity of NK cells. The distribution and functional activity of NK cells are not markedly influenced by 10 weeks of training in competitive triathletes. Natural killer cytotoxic activity after exercise reflects numbers of NK cells and not a changed activation state of these cells per se.

This study investigated in-vivo cell-mediated immune (CMI) responses in elite swimmers over a 5-month training season, to assess the impact of intense training on changes in T-lymphocyte function. The CMI Multitest was performed early in the season after a period of rest, during peak high-intensity training, and late in the season during the precompetition taper period. The CMI tests were performed at rest prior to a morning training session. There were no significant differences between the swimmers and a control group for any of the seven CMI antigen responses at any of the test points during the season. In the swimmers, there were no significant differences in the number of positive responses to the CMI antigens between the three test points (Friedman's test = 9.6364, p = 0.47) and no significant differences for the CMI cumulative scores (Friedman's test = 11.98, p = 0.29) at each test point. There was no consistent pattern for changes in CMI cumulative scores for individual swimmers over the training season. The findings of this study indicate that, despite reported transient T-lymphocyte immunosuppression immediately after intense exercise, probably associated with acute redistribution and temporary pooling of blood T cell subsets in extremities, the T-lymphocyte function involved in CMI responses is not compromised by extended periods of training at an elite level.

Objectives The lengthy competition transition phases commonly experienced by competitive swimmers may mitigate the benefits of the pool warm-up. To combat this, we examined the impact of additional passive and active warm-up strategies on sprint swimming performance. Design Counterbalanced, repeated-measures cross-over study. Methods Sixteen junior competitive swimmers completed a standardised pool warm-up followed by a 30min transition and 100m freestyle time-trial. Swimmers completed four different warm-up strategies during transition: remained seated wearing a conventional tracksuit top and pants (Control), wore an insulated top with integrated heating elements (Passive), performed a 5min dryland-based exercise circuit (Dryland), or a combination of Passive and Dryland (Combo). Swimming time-trial performance, core and skin temperature and perceptual variables were monitored. Time variables were normalised relative to Control. Results Both Combo (−1.05±0.26%; mean±90% confidence limits, p =0.00) and Dryland (−0.68±0.34%; p =0.02) yielded faster overall time-trial performances, with start times also faster for Combo (−0.37±0.07%; p =0.00) compared to Control. Core temperature declined less during transition with Combo (−0.13±0.25°C; p =0.01) and possibly with Dryland (−0.24±0.13°C; p =0.09) compared to Control (−0.64±0.16°C), with a smaller reduction in core temperature related to better time-trial performance ( R 2 =0.91; p =0.04). Conclusions Dryland-based exercise circuits completed alone and in combination with the application of heated tracksuit jackets during transition can significantly improve sprint swimming performance. Attenuation in the decline of core temperature and a reduction in start time appear as likely mechanisms.

The differential effects of exercise intensity and type on neutrophil activation were assessed in eight well-trained male runners. Each subject undertook, on different days, three separate 40 min interval (8 x 5 min) treadmill bouts: an intense uphill run (90% VO2 max), a moderate-intensity near-level run and an eccentrically-biased downhill run (both at 52% VO2 max). Blood granulocyte count increased (p0.05) after all three treadmill bouts (range 25-108%). Chemiluminescence activity of isolated neutrophils decreased (p0.05) immediately after (-58%) and 1-h after (-72%) uphill running, but became significantly elevated (p0.05) at 6-h after the near-level (+71%) and downhill (+84%) runs. The ability of neutrophils to release the superoxide anion radical was reduced (p0.05) immediately after near-level (-29%) and uphill (-21%) running in cells stimulated with opsonized zymosan. Epinephrine concentration increased by 430% (p=0.01) after uphill but not with near-level or downhill running. The plasma concentration of elastase increased (p0.05) immediately after uphill and near-level running, and one hour after uphill running. These results suggest that a population of neutrophils mobilised into the circulation became directly activated in response to exercise, and that neutrophil oxidative activity is affected differentially by both the intensity and type of exercise undertaken.

Haemoglobin mass (Hb mass), maximum oxygen consumption (VO 2max ), simulated 4000 m individual pursuit cycling performance (IP 4000 ), and haematological markers of red blood cell (RBC) turnover were measured in 8 male cyclists before and after (A) 31 d of altitude training at 2690 m. The dependent variables were measured serially after altitude on d A3-4, A8-9 and A20-21. There was no significant change in Hb mass over the course of the study and VO 2max at d A9 was significantly lower than the baseline value (79.3 ± 0.7 versus 81.4 ± 0.6 ml.kg −1 .min −1 , respectively). No increase in Hb mass or VO 2max was probably due to initial values being close to the natural physiological limit with little scope for further change. When the IP 4000 was analysed as a function of the best score on any of the three test days after altitude training there was a 4% improvement that was not reflected in a corresponding change in VO 2max or Hb mass. RBC creatine concentration was significantly reduced after altitude training, suggesting a decrease in the average age of the RBC population. However, measurement of reticulocyte number and serum concentrations of erythropoietin, haptoglobin and bilirubin before and after altitude provided no evidence of increased RBC turnover. The data suggest that for these elite cyclists any benefit of altitude training was not from changes in VO 2max or Hb mass, although this does not exclude the possibility of improved anaerobic capacity.

Objectives Understanding of the physical demands and the effects of fatigue and substitute players in rugby sevens is limited. This study quantified the differences in movement patterns between domestic and international rugby sevens tournaments, the effects of fatigue within and between matches during tournaments, and movement patterns of second half substitute players. Design Movement patterns of 19 international-level male rugby sevens players were recorded using a Global Positioning System (GPS) device during 11 international and 16 domestic matches ( n = 174 files). Methods Maximum velocity, total distance covered, distance covered in velocity zones and number of moderate and high accelerations and decelerations are reported per min of match time. Movement patterns were compared between international and domestic matches, first and second half, first and last tournament match and substitute and full-match players. Results Substantially greater distance was covered at high velocity (∼27% at ≥6 m s −1 ) and 4–39% more accelerations and decelerations were performed in international than domestic matches. The relative distance covered by players at velocities >2 m s −1 and the number of changes in velocity were reduced by 1–16% from first to second half. Small differences were observed in activity at −1 (−8–8%) and moderate accelerations (−18%) from first to last tournament match. All movement variables were higher (2–123%) for substitute players. Conclusions International rugby sevens competition is more intense than domestic matches. Despite reductions in work-rate within individual matches, there is little indication of accumulated fatigue over a multi-day tournament.

This methods paper outlines the overall design of a community-based multidisciplinary longitudinal study with the intent to stimulate interest and communication from scientists and practitioners studying the role of physical activity in preventive medicine. In adults, lack of regular exercise is a major risk factor in the development of chronic degenerative diseases and is a major contributor to obesity, and now we have evidence that many of our children are not sufficiently active to prevent early symptoms of chronic disease. The lifestyle of our kids (LOOK) study investigates how early physical activity contributes to health and development, utilizing a longitudinal design and a cohort of eight hundred and thirty 7–8-year-old (grade 2) school children followed to age 11–12 years (grade 6), their average family income being very close to that of Australia. We will test two hypotheses, that (a) the quantity and quality of physical activity undertaken by primary school children will influence their psychological and physical health and development; (b) compared with existing practices in primary schools, a physical education program administered by visiting specialists will enhance health and development, and lead to a more positive perception of physical activity. To test the first hypothesis we will monitor all children longitudinally over the 4 years. To test the second we will involve an intervention group of 430 children who receive two 50 min physical education classes every week from visiting specialists and a control group of 400 who continue with their usual primary school physical education with their class-room teachers. At the end of grades 2, 4, and 6 we will measure several areas of health and development including blood risk factors for chronic disease, cardiovascular structure and function, physical fitness, psychological characteristics and perceptions of physical activity, bone structure and strength, motor control, body composition, nutritional intake, influence of teachers and family, and academic performance.

Background: Only limited scientific evidence is available on the "best practices" for competition warm-up design in elite swimming. Given the recent occurrence of several major technical and technological changes in elite swimming competitions, coaches are left to draw upon outdated guidelines when designing athlete’s warm-up strategies. The aim of the present study was to describe current warm-up practices and identify contemporary issues faced by elite swimming coaches within the competition environment. Methods: A total of 46 state- to international-level swimming coaches from Australia, Britain and Canada completed a questionnaire consisting of 18 questions (9 multiple choice and 9 short answer) relating to their views on the value of competition warmups, the volume, intensity and recovery used in their pool and out of pool warm-ups and other related issues. Results: The coaches identified three main aims of the competition warm-up: physiological (to elevate body temperature and increase muscle activation), physical (to increase "feel" of the water) and mental (to improve focus and relax nerves). Total warm-up volume employed ranged from 800 to 2400 m, beginning with 300–900m of continuous, low intensity (typically 30–70% of perceived exertion) swimming, followed by 200–600mof increasing intensity (60–90%) with efforts lasting 100–300min length and concluding with several 25–50mrace or near race pace (90–100%) efforts totalling 100–300 m. Some land-based warm-up strategies are encouraged but are typically limited to static stretching and core activation exercises. The preferred time frame between pool warmup end and race start (transition phase) was 20 min. Extended marshalling periods (>15 min), delayed competition schedules and the lengthy time required to change into racing suits (>10 min) were all identified as issues faced during competition. These issues extend the transition phase beyond the preferred time frame. Discussion: Although pool warm-ups are thoroughly prescribed they do not appear to address issues relating to the extended duration of the marshalling periods and the time required to don racing suits. Elevated body temperatures in addition to increased muscle activation are two of the main purported benefits of warming-up but have a limited effect beyond ∼15–20 min following exercise cessation, a scenario common in the contemporary swimming environment. Given these constraints, sport scientists should investigate methods for improving body temperature maintenance such as passive heating techniques and muscle reactivation strategies like postactivation potentiation during the transition phase. These approaches may lead to the optimisation of competition performance in the contemporary swimming environment.

Purpose: To evaluate the utility of an incremental swimming test for monitoring seasonal changes in performance of elite swimmers. Methods: 40 elite swimmers (24 M, 16 F) performed a 7 x 200-m incremental swimming test several times throughout each 6-month season during 1998-2003. Each season concluded with a major competition. Log transformation and repeated measures mixed linear modeling were used to derive estimates of percent change in mean and within swimmercoefficient of variation for swim times between seasons and for the following test measures between phases and seasons: speed, stroke rate, stroke count, and HR at lactate threshold; time for the maximal (last) 200-m step; and maximal lactate. Ability to predict competition time changes was estimated as a within-subject correlation between each measure and performance. A reliability study of 12 swimmers also provided 3-d retest typical error of test measures. Results: Test measures directly related to swimming performance showed cyclical improvement (mean ~2%) from early to taper phases within each season. Within-swimmer variation had similar magnitude. These changes can be monitored confidently in individuals, because the typical error of the test measures was substantially smaller (e.g., lactate-threshold speed, 0.7%; 200-m time, 0.6%). Competition times improved slightly each season (0.7%) against a 1.1% within-swimmer variation between competitions. Only threshold speed, stroke rate and maximal lactate in the taper were moderately correlated (~0.4) with improvements in competition time. Conclusion: The swimming test tracks changes in training performance during a season, but is at best a moderate predictor of competitive performance only during the taper.