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Purpose:To examine relationships between on-field game movement patterns and changes in markers of neuromuscular fatigue and muscle damage during a 2-d women’s rugby sevens tournament.Methods:Female national (mean ± SD n = 12, 22.3 ± 2.5 y, 1.67 ± 0.04 m, 65.8 ± 4.6 kg) and state (n = 10, 24.4 ± 4.3 y, 1.67 ± 0.03 m, 66.1 ± 7.9 kg) representative players completed baseline testing for lower-body neuromuscular function (countermovement-jump [CMJ] test), muscle damage (capillary creatine kinase [CK]), perceived soreness, and perceived recovery. Testing was repeated after games on days 1 and 2 of the tournament. GPS (5-Hz) data were collected throughout the tournament (4−6 games/player).Results:National players were involved in greater on-field movements for total time, distance, high-speed running (>5 m/s), and impacts >10 g (effect size [ES] = 0.55−0.97) and displayed a smaller decrement in performance from day 1 to day 2. Despite this, state players had a much greater 4-fold increase (ΔCK = 737 U/L) in CK compared with the 2-fold increase (ΔCK = 502 U/L) in national players (ES = 0.73). Both groups had similar perceived soreness and recovery while CMJ performance was unchanged. High-speed running and impacts >10 g were largely correlated (r = .66−.91) with ΔCK for both groups.Conclusion:A 2-day women’s rugby sevens tournament elicits substantial muscle damage; however, there was little change in lower-body neuromuscular function. Modest increases in CK can largely be attributed to high-speed running and impacts >10 g that players typically endure.

Purpose:To characterize relationships between propulsion, anthropometry, and performance in Paralympic swimming.Methods:A cross-sectional study of swimmers (13 male, 15 female) age 20.5 ± 4.4 y was conducted. Subject locomotor categorizations were no physical disability (n = 8, classes S13–S14) and low-severity (n = 11, classes S9–S10) or midseverity disability (n = 9, classes S6–S8). Full anthropometric profiles estimated muscle mass and body fat, a bilateral swim-bench ergometer quantified upper-body power production, and 100-m time trials quantified swimming performance.Results:Correlations between ergometer mean power and swimming performance increased with degree of physical disability (low-severity male r = .65, ±0.56, and female r = .68, ±0.64; midseverity, r = .87, ±0.41, and r = .79, ±0.75). The female midseverity group showed nearperfect (positive) relationships for taller swimmers’ (with a greater muscle mass and longer arm span) swimming faster, while for female no- and low-severity-disability groups, greater muscle mass was associated with slower velocity (r = .78, ±0.43, and r = .65, ±0.66). This was supported with lighter females (with less frontal surface area) in the low-severity group being faster (r = .94, ±0.24). In a gender contrast, low-severity males with less muscle mass (r = -.64, ±0.56), high skinfolds (r = .78, ±0.43), a longer arm span (r = .58, ±0.60) or smaller frontal surface area (r = -.93, ±0.19) were detrimental to swimming-velocity production.Conclusion:Low-severity male and midseverity female Paralympic swimmers should be encouraged to develop muscle mass and upper-body power to enhance swimming performance. The generalized anthropometric measures appear to be a secondary consideration for coaches.

Internal validity refers to the degree of control exerted over potential confounding variables to reduce alternative explanations for the effects of various treatments. In exercise and sports-science research and routine testing, internal validity is commonly achieved by controlling variables such as exercise and warm-up protocols, prior training, nutritional intake before testing, ambient temperature, time of testing, hours of sleep, age, and gender. However, a number of other potential confounding variables often do not receive adequate attention in sports physiology and performance research. These confounding variables include instructions on how to perform the test, volume and frequency of verbal encouragement, knowledge of exercise endpoint, number and gender of observers in the room, influence of music played before and during testing, and the effects of mental fatigue on performance. In this review the authors discuss these variables in relation to common testing environments in exercise and sports science and present some recommendations with the goal of reducing possible threats to internal validity.

This review examines the question of whether exercise can be used as an experimental model to further our understanding of innate antimicrobial peptides and proteins (AMPs) and their role in susceptibility to infection at mucosal surfaces. There is strong evidence to suggest that AMPs, in combination with cellular and physical factors, play an important role in preventing infection. Although AMPs act directly on microorganisms, there is increasing recognition that they also exert their protective effect via immunomodulatory mechanisms, especially in noninflammatory conditions. Further studies that manipulate physiologically relevant concentrations of AMPs are required to shed light on the role they play in reducing susceptibility to infection. Evidence shows that in various form prolonged and/or exhaustive exercise is a potent modulator of the immune system, which can either sharpen or blunt the immune response to pathogens. The intensity and duration of exercise can be readily controlled in experimental settings to manipulate the degree of physical stress. This would allow for an investigation into a potential dose–response effect between exercise and AMPs. In addition, the use of controlled exercise could provide an experimental model by which to examine whether changes in the concentration of AMPs alters susceptibility to illness.

The purpose of this study was to characterize changes and variability in test performance of swimmers within and between seasons over their elite competitive career. Forty elite swimmers (24 male, 16 female) performed a 7×200-m incremental swimming step test several times each 6-month season (10±5 tests, spanning 0.5–6.0 y). Mixed linear modeling provided estimates of percent change in the mean and individual responses (within-athlete variation as a coefficient of variation) for measures based on submaximal performance (fixed 4-mM lactate), maximal performance (the seventh step) and lean mass (from skinfolds and body mass). Submaximal and maximal swim speed increased within each season from pre to taper phase by ∼2.2% for females and ∼1.5% for males (95% confidence limits ±1.0%), with variable contributions from stroke rate and stroke length. Most of the gains in speed were lost in the off-season, leaving a net average annual improvement of ∼1.0% for females and ∼0.6% for males (±1.0%). For subma...

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.

Background: The lean mass index (LMI) is a new empirical measure that tracks within-subject proportional changes in body mass adjusted for changes in skinfold thickness. Objective: To compare the ability of the LMI and other skinfold derived measures of lean mass to monitor changes in lean mass. Methods: 20 elite rugby union players undertook full anthropometric profiles on two occasions 10 weeks apart to calculate the LMI and five skinfold based measures of lean mass. Hydrodensitometry, deuterium dilution, and dual energy x ray absorptiometry provided a criterion choice, four compartment (4C) measure of lean mass for validation purposes. Regression based measures of validity, derived for within-subject proportional changes through log transformation, included correlation coefficients and standard errors of the estimate. Results: The correlation between change scores for the LMI and 4C lean mass was moderate (0.37, 90% confidence interval −0.01 to 0.66) and similar to the correlations for the other practical measures of lean mass (range 0.26 to 0.42). Standard errors of the estimate for the practical measures were in the range of 2.8–2.9%. The LMI correctly identified the direction of change in 4C lean mass for 14 of the 20 athletes, compared with 11 to 13 for the other practical measures of lean mass. Conclusions: The LMI is probably as good as other skinfold based measures for tracking lean mass and is theoretically more appropriate. Given the impracticality of the 4C criterion measure for routine field use, the LMI may offer a convenient alternative for monitoring physique changes, provided its utility is established under various conditions.

We assessed the magnitude of changes in fitness and anthropometric test scores of well-trained basketball players between phases of a year and over several years. Players were 1011 females and 1087...

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.

The aim of this study was to quantify movements of Super 12 rugby players in competition because information on elite rugby players' movements is unavailable. Players were categorized into forwards [front (n = 16) and back row (n = 15)] and backs [inside (n = 9) and outside backs (n = 7)] and their movements analysed by video-based time motion analysis. Movements were classified as rest (standing, walking and jogging) and work (striding, sprinting, static exertion, jumping, lifting or tackling). The total time, number and duration of individual activities were assessed, with differences between groups evaluated using independent sample t-tests (unequal variances), while differences between halves were assessed with paired sample t-tests. Forwards had 7:47 min:s (95% confidence limits: 6:39 to 8:55 min:s, P0.01) more time in static exertion than backs, but backs spent 0:52 (0:34 to 1:09, P = 0.01) min:s more time sprinting than forwards, and had a 0.7 (0.3 to 1.2, P = 0.01) s longer duration of each sprint. Forwards spent 7:31 (5:55 to 9:08) min:s more time in work activities (P = 0.01) and had 2.1 (1.3 to 2.8) s longer work durations (P0.01) than backs. The results indicate frequent short duration (4 s) work efforts followed by moderate duration (20 s) rest for forwards, and extended (100 s) rest duration for backs. High-intensity efforts involved static exertion for forwards (mean +/- standard deviation frequency = 80 +/- 17) and sprinting for backs (27 +/- 9). In conclusion, after nearly a decade since becoming professional, elite rugby union is still characterized by highly intense, intermittent movement patterns and marked differences in the competition demands of forwards and backs.

FRANCIS, J. L., M. GLEESON, D. B. PYNE, R. CALLISTER, and R. L. CLANCY. Variation of Salivary Immunoglobulins in Exercising and Sedentary Populations. Med. Sci. Sports Exerc., Vol. 37, No. 4, pp. 571–578, 2005. Purpose: This study examined the nature of the variability in salivary immunoglobulin and albumin concentrations within an individual, between individuals, and between populations with differing levels of habitual physical activity. Methods: Fourteen elite swimmers, and 21 active and 18 sedentary individuals provided 12 saliva samples over a 30-d period. Group classifications were based on interviews, anthropometric measurements, and physical activity records. Symptoms of illness and physical activity data were recorded daily. Salivary IgA, IgG, and IgM were measured by ELISA, and albumin concentrations were measured by nephelometry. Variability was assessed using ANOVA procedures. Results: Elite swimmers, compared with active and sedentary individuals, had higher concentrations of salivary IgA (geometric mean 65 vs 32 and 40 mg·L 1 , P 0.002) and greater variability in salivary IgA concentrations as individuals (P 0.007) and as a group (P 0.03). Salivary IgG variability in swimmers was also twofold greater than the other two groups (P 0.008). Salivary IgM and albumin variability were not significantly different between groups, but individual variability differed for swimmers and active individuals. The intraclass correlations for salivary IgA and IgG (but not for IgM or albumin) were 50% lower for swimmers than the other two groups (ICC for IgA: 20% swimmers vs 54% active and 46% sedentary individuals; ICC for IgG: 36 vs 59 and 57%). Conclusion: The variability and fluctuation of salivary immunoglobulin concentrations were consistently greater in the elite swimmers, but multiple samples from individual swimmers were less correlated compared with participants with lower physical activity levels. These findings have implications for monitoring mucosal immune status within individuals and when comparing salivary immunoglobulin concentrations between groups with differing levels of physical fitness and activity. Key Words: MUCOSAL IMMUNITY, SECRETORY IGA, EXERCISE, SWIMMERS, VARIABILITY

In this technical note we provide data useful for the clinical application of the target-induced Natural Killer (NK) loss (TINKL) assay. The TINKL assay is a sensitive flow cytometry-based assay for measuring NK cell function. Loss of NK cells from the lymphocyte gate occurs following culture with K562 (the prototypic target cell for natural killing) and antibody-coated target cells (for antibody-dependent killing). By analysis of multiple samples of PBMC from single donors we document the intra-experimental variability and the inter-experimental variability of the assay. The intra-experimental coefficient of variation (CV) was on average 11% for natural killing and 3% for antibody-dependent killing, compared to 14% and 9% respectively for the inter-experimental variation. Analysis of a 123 normal healthy adults shows large variability in the functional capacity of NK cells in the population both for natural killing (CV 33%) and antibody-dependent killing (CV 27%).

To establish the typical error (TE) associated with equipment, testing, and biological variation of a running economy (RE) test in 11 elite male distance runners (VO2max 70.3 +/- 7.3 mL x min(-1) x kg(-1)), and measure the between-athlete variation of 70 highly trained runners (VO2max 69.7 +/- 6.0 mL x min(-1) x kg(-1)) to determine the magnitude of the smallest worthwhile change (SWC) required for RE.Runners performed three 4-min bouts of submaximal treadmill running at speeds of 14, 16, and 18 km x h(-1) (0% grade), on two separate occasions within a 7-d period to determine reliability and once over a 3-yr period to measure the SWC. During all RE tests O2 consumption (VO2), ventilation (VE), respiratory exchange ratio (RER), heart rate (HR), stride rate (SR), and concentration of blood lactate (Lac) were determined.The TE for the pooled data of three running speeds (14, 16, and 18 km x h(-1)) was 2.4% for VO2, 7.3% for VE, 27% for Lac, and ranged between 1 and 4% for RER, HR, and SR.The results demonstrate that although the magnitude of the TE for a submaximal treadmill running protocol of three 4-min work efforts is small (2.4-7.3%) for measures associated with cardiorespiratory parameters, it is three- to fourfold higher for Lac. Given the small TE associated with RE, and a SWC of similar magnitude for this cohort of distance runners, the RE test is useful in detecting changes attributable to training interventions. Changes in RE greater than approximately 2.4% in this cohort of elite distance runners are likely to be "real" and "worthwhile," and not simply related to testing error and typical variation.

Estimates of progression and variability of athletic performance in competitions are useful for researchers and practitioners interested in factors that affect performance. We used repeated-measures mixed modelling to analyse 676 official race times of 26 US and 25 Australian Olympic swimmers in the 12-month period leading up to the 2000 Olympic Games. Progression was expressed as percent changes in mean performance; variability was expressed as the coefficient of variation in performance of an individual swimmer between races. Within competitions, both nations showed similar improvements in mean time from heats through finals (overall 1.2%; 95% confidence limits 1.1 to 1.3%). Mean competition time also improved over 12 months by a similar amount in both nations (0.9%; 95% confidence limits 0.6 to 1.2%). The US swimmers showed a greater improvement between the finals (a difference of 0.5%; 95% confidence limits -0.2 to 1.1%), which paralleled changes in the medal haul of the two nations. The coefficient of variation in performance time for a swimmer between races was 0.60% (95% confidence limits 0.56 to 0.65%) within a competition and 0.80% (95% confidence limits 0.73 to 0.86%) between competitions. Our results show that: (a) to stay in contention for a medal, an Olympic swimmer should improve his or her performance by approximately 1% within a competition and by approximately 1% within the year leading up to the Olympics; (b) an additional enhancement of approximately 0.4% (one-half the between-competition variability) would substantially increase the swimmer's chances of a medal.

COX, A. J., M. GLEESON, D. B. PYNE, P. U. SAUNDERS, R. L. CLANCY, and P. A. FRICKER. Valtrex TM Therapy for Epstein-Barr Virus Reactivation and Upper Respiratory Symptoms in Elite Runners. Med. Sci. Sports Exerc., Vol. 36, No. 7, pp. 1104 –1110, 2004. Purpose: The aim of the study was to examine the effectiveness of prophylactic administration of the antiviral agent Valtrex TM for control of Epstein-Barr virus (EBV) reactivation and upper respiratory symptoms in elite distance runners. Methods: Twenty elite male distance runners were randomized into a 4-month double-blind, placebo-controlled cross-over trial. Saliva samples were collected weekly and mucosal immune status assessed by measurement of secretory IgA (SIgA) using an enzyme-linked immunosorbent assay (ELISA). EBV reactivation was monitored at the same time by detection of EBV in saliva using a quantitative real-time polymerase chain reaction. The initial EBV status of the runners was determined by detecting EBV antibodies in serum using an ELISA. Upper respiratory symptoms were recorded using self-reporting illness logs. Results: There was no evidence of any marked change in maximal oxygen uptake (P 0.86), training volume (P 0.30), or mucosal immunity (P 0.21) over the study period. Valtrex TM treatment resulted in an 82% reduction in the detectable EBV load in saliva for EBV seropositive runners compared with the placebo treatment (P 0.04). The incidence of upper respiratory symptoms was not reduced by Valtrex TM treatment. Conclusions: The prophylactic administration of Valtrex TM reduced EBV reactivation but was not an effective intervention strategy for limiting upper

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.

Coaches believe world-ranking lists are a reliable tool for predicting international swimming performance. To examine the relationship between world-ranking and Olympic performance, we modelled world-ranking time and best time from the 2000 Olympic Games for 407 top-50 world-ranked swimmers. Analysis of log-transformed times yielded within-athlete and between-athlete coefficients of variation (CV) and percent changes in performance from world-rankings to Olympics. Variations and performance progressions were compared across sex, stroke, distance, nation and medal status. The within-athlete coefficient of variation of performance for all swimmers was 0.8% (95% confidence limits: 0.7 to 0.9%). Females were slightly less consistent, although not substantially different to males (ratio of female/male within-athlete CV: 1.1; 95% confidence limits: 1.0 to 1.2) and had a wider range of talent (ratio of female/male between-athlete CV: 1.2; 95% confidence limits: 1.1 to 1.4). Swimmers from Australia (AUS) were more consistent than those from the United States (USA) and other nations (OTHER) (ratio of within-athlete CV, USA/AUS: 1.5; 95% confidence limits: 1.0 to 2.2; OTHER/ AUS: 1.6; 95% confidence limits: 1.2 to 2.1). Most Olympic medallists (87%) had a top-10 world-ranking. Overall performance time at the Olympics was slower than world-ranking time by 0.3% (95% confidence limits: 0.2 to 0.4%), medallists improved by 0.6% (95% confidence limits: 0.4 to 0.9%) and non-medallists swam 0.6% slower (95% confidence limits: 0.5 to 0.7%). We conclude that a top-10 ranked swimmer who can improve performance time by 0.6%, equivalent to 0.13 s in the men's 50-m freestyle, will substantially increase their chance of an Olympic medal (the difference between first and fourth place).

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.

Running economy (RE) is typically defined as the energy demand for a given velocity of submaximal running, and is determined by measuring the steady-state consumption of oxygen (VO2) and the respiratory exchange ratio. Taking body mass (BM) into consideration, runners with good RE use less energy and therefore less oxygen than runners with poor RE at the same velocity. There is a strong association between RE and distance running performance, with RE being a better predictor of performance than maximal oxygen uptake (VO2max) in elite runners who have a similar VO2max). RE is traditionally measured by running on a treadmill in standard laboratory conditions, and, although this is not the same as overground running, it gives a good indication of how economical a runner is and how RE changes over time. In order to determine whether changes in RE are real or not, careful standardisation of footwear, time of test and nutritional status are required to limit typical error of measurement. Under controlled conditions, RE is a stable test capable of detecting relatively small changes elicited by training or other interventions. When tracking RE between or within groups it is important to account for BM. As VO2 during submaximal exercise does not, in general, increase linearly with BM, reporting RE with respect to the 0.75 power of BM has been recommended. A number of physiological and biomechanical factors appear to influence RE in highly trained or elite runners. These include metabolic adaptations within the muscle such as increased mitochondria and oxidative enzymes, the ability of the muscles to store and release elastic energy by increasing the stiffness of the muscles, and more efficient mechanics leading to less energy wasted on braking forces and excessive vertical oscillation. Interventions to improve RE are constantly sought after by athletes, coaches and sport scientists. Two interventions that have received recent widespread attention are strength training and altitude training. Strength training allows the muscles to utilise more elastic energy and reduce the amount of energy wasted in braking forces. Altitude exposure enhances discrete metabolic aspects of skeletal muscle, which facilitate more efficient use of oxygen. The importance of RE to successful distance running is well established, and future research should focus on identifying methods to improve RE. Interventions that are easily incorporated into an athlete's training are desirable.

Increased professionalism in rugby has elicited rapid changes in the fitness profile of elite players. Recent research, focusing on the physiological and anthropometrical characteristics of rugby players, and the demands of competition are reviewed. The paucity of research on contemporary elite rugby players is highlighted, along with the need for standardised testing protocols. Recent data reinforce the pronounced differences in the anthropometric and physical characteristics of the forwards and backs. Forwards are typically heavier, taller, and have a greater proportion of body fat than backs. These characteristics are changing, with forwards developing greater total mass and higher muscularity. The forwards demonstrate superior absolute aerobic and anaerobic power, and muscular strength. Results favour the backs when body mass is taken into account. The scaling of results to body mass can be problematic and future investigations should present results using power function ratios. Recommended tests for elite players include body mass and skinfolds, vertical jump, speed, and the multi-stage shuttle run. Repeat sprint testing is a possible avenue for more specific evaluation of players. During competition, high-intensity efforts are often followed by periods of incomplete recovery. The total work over the duration of a game is lower in the backs compared with the forwards; forwards spend greater time in physical contact with the opposition while the backs spend more time in free running, allowing them to cover greater distances. The intense efforts undertaken by rugby players place considerable stress on anaerobic energy sources, while the aerobic system provides energy during repeated efforts and for recovery. Training should focus on repeated brief high-intensity efforts with short rest intervals to condition players to the demands of the game. Training for the forwards should emphasise the higher work rates of the game, while extended rest periods can be provided to the backs. Players should not only be prepared for the demands of competition, but also the stress of travel and extreme environmental conditions. The greater professionalism of rugby union has increased scientific research in the sport; however, there is scope for significant refinement of investigations on the physiological demands of the game, and sports-specific testing procedures.

The warm-up procedure in traditional rowing usually involves continuous low-intensity rowing and short bouts of intense exercise, lasting about 60 min.Purpose:To compare the effects of a traditional and an experimental 30-min warm-up of lower intensity on indoor rowing time-trial performance.Methods:Fourteen highly trained male rowers (age 25.9 ± 5.3 y, height 1.86 ± 0.06 m, mass 80.4 ± 5.2 kg, peak aerobic power 352.0 ± 24.4 W; mean ± SD) performed 2 indoor rowing trials 12 d apart. Rowers were randomly assigned to either LONG or SHORT warm-ups using a crossover design, each followed by a 10-min all-out fixed-seat rowing-ergometer time trial.Results:Mean power output during the time trial was substantially higher after SHORT (322 ± 18 vs 316 ± 17 W), with rowers generating substantially more power in the initial 7.5 min of the time trial after SHORT. LONG elicited substantially higher mean warm-up heart rate than SHORT (134 ± 11 vs 121 ± 13 beats/min), higher pre–time-trial rating of perceived exertion (10.2 ± 1.4 vs 7.6 ± 1.7) and blood lactate (1.7 ± 0.4 mM vs 1.2 ± 0.2 mM), but similar heart rate (100 ± 14 vs 102 ± 9 beats/min). No substantial differences were observed between LONG and SHORT in stroke rate (39.4 ± 2.0 vs 39.4 ± 2.2 strokes/min) or mean heart rate (171 ± 6 vs 171 ± 8 beats/min) during the time trial, nor in blood lactate after it (11.8 ± 2.5 vs 12.1 ± 2.0 mM).Conclusion:A warm-up characterized by lower intensity and shorter duration should elicit less physiological strain and promote substantially higher power production in the initial stages of a rowing time trial.

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.

An editorial under the title Statistics: all together now, one step at a time appeared in this and other physiological journals earlier this year (Drummond et al., 2011) to announce a forthcoming series of 14 perspective articles on statistics. Two of the articles have now been published in six journals (Drummond and Vowler, 2011a; Drummond and Vowler, 2011b) and the third has started to appear (Drummond and Tom, 2011). The purpose of this letter is to identify what we consider to be substantial errors and omissions.

An editorial under the title All together now: one step at a time appeared in this and other physiological journals earlier this year (e.g. Drummond et al. 2011) to announce a forthcoming series of 14 perspective articles on statistics. Two of the articles have now been published in six journals (e.g. Drummond & Vowler, 2011a,b;) and the third has started to appear (Drummond & Tom, 2011). The purpose of this letter is to identify what we consider to be substantial errors and omissions.

High-speed running (5 m · s⁻¹) is commonly reported in men's rugby union and sevens; however, the appropriateness of using the same speed threshold for Women's Rugby Sevens players is unclear, and likely underestimates the degree of high-intensity exercise completed by female players. The aim of this study was to establish, for international Women's Rugby Sevens players, a physiologically defined threshold - speed at the second ventilatory threshold (VT(2peed)) - for the analysis of high-intensity running, using mean and individualised thresholds. Game movement patterns (using 5 Hz GPS) of 12 international Women's Rugby Sevens players (23.5 ± 4.9 ears, 1.68 ± 0.04 m, 68.2 ± 7.7 kg; mean ± s) were collected at an international tournament. Seven of these players also completed a treadmill VO(2max) test to estimate VT(2speed). Compared to the mean VT(2speed) threshold (3.5 m · s⁻¹), the industry-used threshold of 5 m · s⁻¹ underestimated the absolute amount of high-intensity running completed by individual players by up to 30%. Using an individualised threshold, high-intensity running could over- or underestimating high-intensity running by up to 14% compared to the mean VT(2peed) threshold. The use of individualised thresholds provides an accurate individualised assessment of game demands to inform the prescription of training.

Talent identification and development typically involve allocation of resources toward athletes selected on the basis of early-career performance.Purpose:To compare 4 methods for early-career selection of Australia’s 2012 Olympic-qualifying swimmers.Methods:Performance times from 5738 Australian swimmers in individual Olympic events at 101 competitions from 2000 to 2012 were analyzed as percentages of world-record times using 4 methods that retrospectively simulated early selection of swimmers into a talent-development squad. For all methods, squad-selection thresholds were set to include 90% of Olympic qualifiers. One method used each swimmer’s given-year performance for selection, while the others predicted each swimmer’s 2012 performance. The predictive methods were regression and neural-network modeling using given-year performance and age and quadratic trajectories derived using mixed modeling of each swimmer’s annual best career performances up to the given year. All methods were applied to swimmers in 2007 and repeated for each subsequent year through 2011.Results:The regression model produced squad sizes of 562, 552, 188, 140, and 93 for the years 2007 through 2011. Corresponding proportions of the squads consisting of Olympic qualifiers were 11%, 11%, 32%, 43%, and 66%. Neural-network modeling produced similar outcomes, but the other methods were less effective. Swimming Australia’s actual squads ranged from 91 to 67 swimmers but included only 50−74% of Olympic qualifiers.Conclusions:Large talent-development squads are required to include most eventual Olympic qualifiers. Criteria additional to age and performance are needed to improve early selection of swimmers to talent-development squads.

Endurance athletes and coaches often pose these questions: How do we maintain good health and optimise performance? Are there nutritional strategies that promote good health during periods of heavy exercise training and preparation for competition? Are diet or supplement intakes of antioxidants beneficial, and if so, which is the best strategy? Researchers and practitioners are also interested in these issues and there has been concerted effort in laboratory and field-based studies to identify the clinical and performance effects of supplementation, and the underlying physiological mechanisms.This review examines some of the important aspects of antioxidant supplementation in endurance athletes including increases in free radical production and subsequent oxidative stress created by high endurance training loads, the impact of endurance training and oxidative stress on immune function, the impact of improving antioxidant status on factors affecting performance, recovery and adaptation, and whether the source of supplementation is best obtained directly from dietary sources or nutraceutical supplements. Two special circumstances, ultra-endurance events and altitude training, which may invoke specific oxidative stress, are also examined.

This study evaluated the effectiveness of a dry-land resistance training program in Paralympic swimmers to increase swimming power and strength measures, and how these changes affect swimming performance. Seven elite-level Paralympic swimmers (1 man and 6 women; age: 19.4 ± 6.5 years; body mass: 57 ± 12 kg; height: 1.66 ± 0.21 m) performed a 6-week coach-prescribed strength training intervention program designed to improve power, flexibility, and postural control. Exercises targeted the main swimming movements: the start and turn, postural control in the water, and the pull and kick focusing on the gluteals, upper body, and trunk. Swimming-specific tests, involving a 50-m time trial, and timed dive starts were conducted at baseline and after the 6-week program. A bilateral swim-bench ergometer and jump tests were conducted to quantify arm and leg strength and power. After the 6-week intervention, 50-m time trials improved by 1.2%, ± 1.5% (mean, ± 90% confidence limits). Increases in both mean power (6.1%, ± 5.9%) and acceleration (3.7%, ± 3.7%) generated during the dive start enabled swimmers to substantially improve start times to the 5-m (5.5%, ± 3.2) and 15-m (1.8%, ± 1.1%) marks. The resistance training intervention resulted in a very large (r = 0.78, ± 0.37) correlation between dive start velocity and the counter movement jump mean velocity. The 6-week resistance training program for Paralympic swimmers yielded substantial improvements in dry-land measures that corresponded with improvements in both timed dive starts and 50-m time trial performance, thus highlighting the usefulness of dry-land training for enhancing swimming performance in Paralympic swimming.

The aquatic sports competitions held during the summer Olympic Games include diving, open-water swimming, pool swimming, synchronized swimming, and water polo. Elite-level performance in each of these sports requires rigorous training and practice to develop the appropriate physiological, biomechanical, artistic, and strategic capabilities specific to each sport. Consequently, the daily training plans of these athletes are quite varied both between and within the sports. Common to all aquatic athletes, however, is that daily training and preparation consumes several hours and involves frequent periods of high-intensity exertion. Nutritional support for this high-level training is a critical element of the preparation of these athletes to ensure the energy and nutrient demands of the training and competition are met. In this article, we introduce the fundamental physical requirements of these sports and specifically explore the energetics of human locomotion in water. Subsequent articles in this issue explore the specific nutritional requirements of each aquatic sport. We hope that such exploration will provide a foundation for future investigation of the roles of optimal nutrition in optimizing performance in the aquatic sports.

Disabilities in Paralympic swimming could impact a swimmer’s ability to execute an effective swim-start. We examined how swim-start performance differed between severity and type of physical disability. Swim-starts were measured in 55 elite Paralympic swimmers from eight different Paralympic classes; S14, S13, S10-S6, S3 grouped as no- (classes S13 & S14), low- (S9 & S10), mid- (S7 & S8) or high- (≤ S6) severity of physical disability and also by type of physical disability (upper, lower, and palsy) to provide meaningful comparisons. The swimmer’s competitive level was determined by the international point score (IPS). Swimmers with no physical disability were significantly faster in most swim-start phases compared with those with physical disabilities, as were swimmers with low-severity disabilities compared with the mid- and high-severity groups. Block velocity was highly negatively correlated (r = –0.57 to –0.86) with 15-m swimming time for all groups except high-severity disabilities. Free-swim velocity is a priority area for improving swim-starts for swimmers regardless of disability, given large correlations between this measure and IPS. Swimmers with lower body or high-severity disabilities spent a smaller percentage of time overall in the underwater phase. Assessment of four specific phases of the swim-start highlight distinctive priorities for coaches working with Paralympic swimmers in an applied biomechanical manner.

Heat and immune stress can affect athletes in a wide range of sports and environmental conditions. The classical thermoregulatory model of heat stress has been well characterized, as has a wide range of practical strategies largely centered on cooling and heat-acclimation training. In the last decade evidence has emerged of an inflammatory pathway that can also contribute to heat stress. Studies are now addressing the complex and dynamic interplay between hyperthermia, the coagulation cascade, and a systemic inflammatory response occurring after transient damage to the gastrointestinal tract. Damage to the intestinal mucosal membrane increases permeability, resulting in leakage of endotoxins into the circulation. Practical strategies that target both thermoregulatory and inflammatory causes of heat stress include precooling; short-term heat-acclimation training; nutritional countermeasures including hydration, energy replacement, and probiotic supplementation; pacing strategies during events; and postevent cooling measures. Cooperation between international, national, and local sporting organizations is required to ensure that heat-management policies and strategies are implemented effectively to promote athletes’ well-being and performance.

To expand our understanding of the overall anti-inflammatory nature of routine exercise; we compared resting blood values from adults who habitually undertake frequent, moderate levels of exercise to reference interval values assumed to reflect values largely from non-exercisers. This information would be useful for clinicians interpreting blood tests assessing inflammatory, immune and acute phase responses. Blood samples were collected from 119 community adult self-reported routine exercisers (61 males and 58 females aged 18–60 years). Samples were analysed for 20 cellular and non-cellular biomarkers which included 11 immunological and 9 acute phase reactants. These data were compared to reference intervals from the same hospital laboratory that performed the analyses on our participants’ samples. Individual analyte values were also compared with participants’ self-reported 150 day exercise patterns which included exercise frequency, intensity and duration. In general, mean values for routine exercise participants fell at the lower end of laboratory reference interval for most inflammatory analytes. More than 10 % of participants had numbers of CD19+, CD8+ and 16/56+ NK cells below the low end of the respective reference interval. More than 10 % of observed acute phase reactant values (for C3, haptoglobin and ferritin) were also below the low end of the reference interval. At rest IgM (r = −0.22) and IgG (r = −0.31) values correlated negatively (p

Use of probiotic-containing foods and probiotic supplements is increasing; however, few studies document safety and tolerability in conjunction with defined clinical end points. This paper reports the effects of 150 days of supplementation with either a single- (Bifidobacterium animalis subsp. lactis Bl-04) or a double-strain (Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07) probiotic on routine haematology and clinical chemistry measures in healthy active adults. Pre- to post-intervention changes in laboratory measures were determined and compared between supplement and placebo groups. Overall there were few differences in routine haematology and clinical chemistry measures between supplement and placebo groups post-intervention. Exceptions included plasma calcium (P=0.03) and urea (P=0.015); however, observed changes were small and within assay-specific laboratory reference ranges. These data provide evidence supporting the use of these probiotic supplements over a period of 5 months in healthy active adults without obvious safety or tolerability issues.

PURPOSE Exercise and training are known to elicit changes in mucosal humoral immunity, but whether these alterations have any impact on competitive performance remains unclear. This investigation examined relationships between salivary immunoglobulin (Ig) concentration, the incidence of respiratory tract illness (RTI), and competitive performance in elite swimmers. METHODS Forty-one members of the Australian Swimming Team (21 males and 20 females) aged 15-27 yr were monitored during preparations for the 1998 Commonwealth Games. Twenty-five coaches and staff (19 males and 6 females) aged 32-65 yr, serving as "environmental controls," were also monitored. Salivary IgA, IgM, and IgG and albumin concentration (mg.L-1) were measured in both groups in May 1998 and again in August 1998, 17 d before competition. Subjects were categorized as "ill" (at least one RTI) or "healthy". RESULTS There were no significant changes in salivary IgA, IgM, or IgG concentration in the swimmers between May and August, nor were there any differences between healthy (N = 23) and ill (N = 18) swimmers. There was a significant positive relationship between IgM and performance in the male swimmers (r = 0.85, P < 0.001) but not for any other parameter. There was no significant difference in performance between ill and healthy swimmers (P = 0.11). Gold medal winners (N = 9) had higher IgM levels than other swimmers (N = 32) in May (P = 0.02) and higher IgG in August (P = 0.02). CONCLUSION These data indicate that a season of training by elite swimmers did not alter salivary immunoglobulin concentrations, and the presence of RTI had no significant impact on competitive performance.

To determine whether lactate profiling could detect changes in discrete aspects of endurance fitness in world-ranked swimmers during a season.Eight male and four female Australian National Team swimmers aged 20--27 yr undertook a 7 x 200-m incremental swimming step test on four occasions over an 8-month period before the 1998 Commonwealth Games (CG): January (10 d before the World Championships), May (early-season camp), July (midseason), and August (16 d before the CG). The lactate threshold (LT) was determined by a mathematical formula that calculated the threshold as a function of the slope and y-intercept of the lactate-velocity curve.Maximal 200-m test time declined initially from 127.7 +/- 4.2 s (January 1998) to 130.2 +/- 4.5 s (May 1998) and 129.1 +/- 4.3 s (July 1998) before improving to 126.8 +/- 4.2 s (August 1998) (P0.005). The swimming velocity at LT (s.100 m(-)1) also declined midseason before improving before the CG (P0.02) (January 1998: 70.5 +/- 2.1; May 1998: 72.0 +/- 2.2; July 1998: 72.2 +/- 2.2; and August 1998: 70.8 +/- 2.1). The blood lactate concentration at the LT decreased (P0.02) from 3.6 +/- 0.2 mM to 3.2 +/- 0.1 mM and 2.9 +/- 0.2 mM before returning to 3.4 +/- 0.2 mM for January, May, July, and August, respectively. The lactate tolerance rating (LT(5--10)), defined as the differential velocity between lactate concentrations of 5.0 and 10.0 mM, declined midway through the season (P0.015): 6.6 +/- 0.5 s.100 m(-1), 7.7 +/- 0.5 s.100 m(-1), 8.5 +/- 0.5 s.100 m(-1), and 6.9 +/- 0.4 s.100 m(-1), for January, May, July, and August, respectively. Despite these improvements in indicators of fitness, there was no significant improvement in competition performance across the season.Maximal effort 200-m time, lactate tolerance rating, and swimming velocity at LT (s.100 m(-1)) all improved in world-ranked swimmers with training, but these changes were not directly associated with competition performance.

This study investigated using reticulocyte (retic) parameters as indirect markers of human recombinant erythropoietin (r-HuEPO) abuse in elite athletes. Absolute reticulocyte count (# retic), the per cell haemoglobin content of reticulocytes (CHr), reticulocyte haemoglobin mass per litre of blood (RetHb) and red blood cell:reticulocyte haemoglobin (RBCHb:RetHb) ratio were assessed using flow cytometry. Venous blood was drawn from 155 elite athletes from six sports during regular training to establish reference ranges (95% confidence interval) for these parameters. The reference ranges were compared with those of a non-athletic population (n = 23), four groups of athletes (n = 24) before and after exposure to simulated altitudes (2,500-3,000 m for 11-23 nights), two groups of elite cyclists (n = 13) before and after four weeks of training at natural altitude (1,780 and 2,690 m), and with those of non-athletic subjects from a separate study (n =24) before and 1-2 days after they were injected with 1,200 U x kg(-1) r-HuEPO over a 9-10 day period. Generally the changes induced by r-HuEPO injection exceeded by approximately 100% the magnitude of the changes associated with natural altitude exposure. Simulated altitude exposure did not significantly alter the reticulocyte parameters. From the sample of 155 non-users and 24 r-HuEPO users, the population mean and variance, as well as the 95% confidence limits for the population mean and population variance, were estimated. Relative to arbitrarily chosen cut-off levels, the confidence limits for the rate of true positives and rate of true negatives were also calculated. Based on the lowest rate of false positives and highest rate of true positives, the best discriminator between r-HuEPO users and non-users was # retic, marginally superior to RBCHb: RetHb ratio and RetHb. At a cut-off for # retic of 221 x 10(9)x L(-1) we could be 95% sure that we would find no more than 7 false positives in every 100,000 tests. We would expect to pick up 51.8% of users, and could be 95% sure of picking up at least 38% of current or recent users. This result highlights the potential power of retic parameters for detecting r-HuEPO abuse among athletes. However, the efficacy of these cut-offs for detecting r-HuEPO abuse is unknown if an athlete is a chronic user or stops using r-HuEPO several weeks before being tested.

The present review examines the effects of exercise on mucosal immunity in recreational and elite athletes and the role of mucosal immunity in respiratory illness. Habitual exercise at an intense level can cause suppression of mucosal immune parameters, while moderate exercise may have positive effects. Saliva is the most commonly used secretion for measurement of secretory antibodies in the assessment of mucosal immune status. Salivary IgA and IgM concentrations decline immediately after a bout of intense exercise, but usually recover within 24 h. Training at an intense level over many years can result in a chronic suppression of salivary immunoglobulin levels. The degree of immune suppression and the recovery rates after exercise are associated with the intensity of exercise and the duration or volume of the training. Low levels of salivary IgM and IgA, particularly the IgA1 subclass, are associated with an increased risk of respiratory illness in athletes. Monitoring mucosal immune parameters during critical periods of training provides an assessment of the upper respiratory tract illness risk status of an individual athlete. The mechanisms underlying the mucosal immune suppression are unknown.

The impact of a 12-week training program by elite swimmers on systemic and mucosal immunity was studied prospectively to examine the relationship between changes in immune parameters and the incidence of respiratory illness. Saliva was collected before and after selected training sessions at 2 weekly intervals. There were significant decreases in salivary IgA (p=0.05) and salivary IgM (p < 0.0001) concentrations after individual training sessions, but no significant changes in salivary IgG or albumin concentrations. Over the 12-week training program there were small but statistically significant increases in pre-exercise concentrations of salivary IgA (p

To determine the immunologic consequences of athletic training at altitude, blood samples were taken at rest from 10 swimmers and 8 control nontraining but altitude-exposed members of the 1996 Australian Olympic Swimming Team, near the start and completion of a 21-day training camp at 2102 m. Blood leukocyte numbers dropped in both groups (p0.05), with the decrease greater in the swimmers (-38% swimmers, -3% controls). Concanavalin A (ConA)-induced blastogenesis decreased in both groups (p0.01), but the drop was greater in the control group (-32% swimmers, -56% controls, p0.05). Lipopolysaccharide (LPS)-induced blastogenesis more than doubled in both groups (281% swimmers, 249% controls, p0.01). Increases in mitogen-induced interleukin-1beta (IL-1beta), IL-4, and interferon-gamma (IFN-gamma) production and a decrease in IL-2 levels were observed in both groups after altitude exposure (all p0.05). The percentage of cells expressing HLA-DR fell (-33% swimmers, -20% controls, p0.01), whereas those expressing CD-4 expression increased (16% swimmers only, p0.01). Although training at medium-level altitude alters some immunologic parameters, the training-induced changes may be secondary to those induced by altitude alone.

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.

The effects of exercise on the immune system has been shown to be dependent on the level of fitness of the subjects, the degree of intensity, and the duration of the exercise. A reduction in salivary IgA levels occurs after individual sessions of exercise. Purpose: The purpose of this study was to assess the relationship between changes in salivary IgA and training volume, psychological stress, and infection rates in a cohort of 26 elite swimmers over a 7-month training period and to compare the changes with a group of 12 moderately exercising controls. Methods: Salivary IgA concentrations were measured by an electroimmunodiffusion. Exercise gradings were assessed by a standardized aerobic-anaerobic rating system. Psychological stress/anxiety was evaluated by the Spielberger State-Trait Anxiety Inventory. Infections were physician-verified. Results: Salivary IgA levels showed an inverse correlation with the number of infections in both elite swimmers and moderately exercising control subjects. The pretraining salivary IgA levels in swimmers were 4.1% lower for each additional month of training and 5.8% lower for each additional infection. The posttraining salivary IgA levels in swimmers were not significantly correlated with infection rates but were 8.5% lower for each additional I km swum in a training session and 7.0% lower for each additional month of training. The number of infections observed in the elite swimmers was predicted from regression models by the preseason (P = 0.05) and the mean pretraining salivary IgA levels (P = 0.006). The trends in pretraining salivary IgA levels over the 7-month season, calculated as individual slopes of pretraining IgA levels over time, were also predictive of the number of infections (P = 0.03) in the swimmers. Conclusions: These results indicate that measurement of salivary IgA levels over a training season may be predictive for athletes at risk of infection.

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.

Elite athletes who compete in aquatic sports face the constant challenge of arduous training and competition schedules in difficult and changing environmental conditions. The huge range of water temperatures to which swimmers and other aquatic athletes are often exposed (16–31 °C for open-water swimming), coupled with altered aquatic thermoregulatory responses as compared with terrestrial athletes, can challenge the health, safety, and performance of these athletes. Other environmental concerns include air and water pollution, altitude, and jetlag and travel fatigue. However, these challenging environments provide the potential for several nutritional interventions that can mitigate the negative effects and enhance adaptation and performance. These interventions include providing adequate hydration and carbohydrate and iron intake while at altitude; optimizing body composition and fluid and carbohydrate intake when training or competing in varying water temperatures; and maximizing fluid and food hygiene when traveling. There is also emerging information on nutritional interventions to manage jetlag and travel fatigue, such as the timing of food intake and the strategic use of caffeine or melatonin. Aquatic athletes often undertake their major global competitions where accommodations feature cafeteria-style buffet eating. These environments can often lead to inappropriate choices in the type and quantity of food intake, which is of particular concern to divers and synchronized swimmers who compete in physique-specific sports, as well as swimmers who have a vastly reduced energy expenditure during their taper. Taken together, planned nutrition and hydration interventions can have a favorable impact on aquatic athletes facing varying environmental challenges.

Objectives: Identifying performance indicators related to rugby sevens competition outcomes will inform development of team tactics that increase the likelihood of success. This study characterized 16 team performance indicators and quantified the effect of changes and differences in performance indicators within and between teams on team ranking in international tournaments.

In this review, we outline key principles for prevention of injury and illness in aquatic sports, detail the epidemiology of injury and illness in aquatic athletes at major international competitions and in training, and examine the relevant scientific evidence on nutrients for reducing the risk of illness and injury. Aquatic athletes are encouraged to consume a well-planned diet with sufficient calories, macronutrients (particularly carbohydrate and protein), and micronutrients (particularly iron, zinc, and vitamins A, D, E, B6, and B12) to maintain health and performance. Ingesting carbohydrate via sports drinks, gels, or sports foods during prolonged training sessions is beneficial in maintaining energy availability. Studies of foods or supplements containing plant polyphenols and selected strains of probiotic species are promising, but further research is required. In terms of injury, intake of vitamin D, protein, and total caloric intake, in combination with treatment and resistance training, promotes recovery back to full health and training.

One of the challenges for sports scientists working in football is to balance the needs for routine fitness testing with daily fatigue and well-being monitoring to best manage the physical preparation of players. In this commentary, the authors examine contemporary issues of fitness testing in football to identify ways of improving the value of routine testing and monitoring. A testing program must be well planned and organized to ensure that the results are useful. Different tests can be employed for younger and older players. A rigorous approach to analysis and interpretation of results is desirable, and database management must address both short- and long-term requirements of players, staff, and programs.

Effective cycle training for triathlon is a challenge for coaches. We compared the effects of two variants of cycle high-intensity interval training (HIT) on triathlon-specific cycling and running. Fourteen moderately-trained male triathletes ([Formula: see text]O2peak 58.7 ± 8.1 mL kg(-1) min(-1); mean ± SD) completed on separate occasions a maximal incremental test ([Formula: see text]O2peak and maximal aerobic power), 16 × 20 s cycle sprints and a 1-h triathlon-specific cycle followed immediately by a 5 km run time trial. Participants were then pair-matched and assigned randomly to either a long high-intensity interval training (LONG) (6-8 × 5 min efforts) or short high-intensity interval training (SHORT) (9-11 × 10, 20 and 40 s efforts) HIT cycle training intervention. Six training sessions were completed over 3 weeks before participants repeated the baseline testing. Both groups had an ∼7% increase in [Formula: see text]O2peak (SHORT 7.3%, ±4.6%; mean, ±90% confidence limits; LONG 7.5%, ±1.7%). There was a moderate improvement in mean power for both the SHORT (10.3%, ±4.4%) and LONG (10.7%, ±6.8%) groups during the last eight 20-s sprints. There was a small to moderate decrease in heart rate, blood lactate and perceived exertion in both groups during the 1-h triathlon-specific cycling but only the LONG group had a substantial decrease in the subsequent 5-km run time (64, ±59 s). Moderately-trained triathletes should use both short and long high-intensity intervals to improve cycling physiology and performance. Longer 5-min intervals on the bike are more likely to benefit 5 km running performance.