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The effect of repeated exposures to natural and simulated moderate altitude on physiology and competitive performance of elite athletes warrants further investigation. This study quantified changes in hemoglobin mass, performance tests, and competitive performance of elite swimmers undertaking a coach-prescribed program of natural and simulated altitude training. Nine swimmers (age 21.1 [+ or -] 1.4 years, mean + SD) completed up to four 2-week blocks of combined living and training at moderate natural altitude (1,360 m) and simulated live high-train low (2,600-600 m) altitude exposure between 2 National Championships. Changes in hemoglobin mass ([Hb.sub.mass]), 4-mM lactate threshold velocity, and 2,000 m time trial were measured. Competition performance of these swimmers was compared with that of 9 similarly trained swimmers (21.1 [+ or -] 4.1 years) who undertook no altitude training. Each 2-week altitude block on average produced the following improvements: [Hb.sub.mass] 0.90/0 (90% confidence limits, [+ or -] 0.8%); 4-mM lactate threshold velocity, 0.9% ([+ or -]0.8%); and 2,000 m time trial performance, 1.2% ([+ or -] 1.6%). The increases in [Hb.sub.mass] had a moderate correlation with time trial performance (r = 0.47; [+ or -] 0.41) but an unclear correlation with lactate threshold velocity (r = -0.23; [+ or -] 0.48). The altitude group did not swim faster at National Championships compared with swimmers who did not receive any altitude exposure, the difference between the groups was not substantial ( 0.5%; [+ or -] 1.0%). A coach-prescribed program of repeated altitude training and exposure elicited modest changes in physiology but did not substantially improve competition performance of elite swimmers. Sports should investigate the efficacy of their altitude training program to justify the investment. KEY WORDS swimming, live high-train low, hemoglobin mass, performance

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. [ABSTRACT FROM AUTHOR]

Although the characteristics of 15-a-side rugby union players have been well defined, there is little information on rugby sevens players. Purpose: The authors profiled the anthropometric, physiological, and performance qualities of elite-level rugby sevens players and quantified relationships between these characteristics. Methods: Eighteen male international rugby sevens players undertook anthropometric (body mass, height, sum of 7 skinfolds, lean-mass index), acceleration and speed (40-m sprint), muscle-power (vertical jump), repeated- sprint-ability (6 x 30-m sprint), and endurance (Yo-Yo Intermittent Recovery test and treadmill VO2max) testing. Associations between measurements were assessed by correlation analysis. Results: Rugby sevens players had anthropometric characteristics (body mass 89.7 ± 7.6 kg, height 1.83 ± 0.06 m, sum of 7 skinfolds 52.2 ± 11.5 mm; mean ± SD) similar to those of backs in international 15-player rugby union. Acceleration and speed (40-m sprint 5.11 ±0.15 s), muscle-power (vertical jump 66 ± 7 cm), and endurance (VO2max 53.8 ± 3.4 mL ¦ kg^1 ¦ min"1) qualities were similar to, or better than, those of professional 15-a-side players. Coefficients of variation ranged from 2.5% to 22%. Relative VO2max was largely correlated with Yo-Yo distance (r = .60, .21-.82; 90% confidence interval) and moderately correlated with 40-m sprint time (r = -.46, -.75 to-.02) and repeated-sprint ability (r - -.38, -.72 to .09). Conclusions: International rugby sevens players require highly developed speed, power, and endurance to tolerate the demands of competition. The small between-athletes variability of characteristics in rugby sevens players highlights the need for relatively uniform physical and performance standards in contrast with 15-a-side players. [ABSTRACT FROM AUTHOR]

Purpose: The patterns of power output in the ~l-h cycle section of Olympic-distance triathlon races are not well documented. Here the authors establish a typical cycling-race profile derived from several International Triathlon Union elite-level drafting-legal triathlon races. Methods: The authors collated 12 different race power profiles from elite male triathletes (N = 5, age 25 ± 5 y, body mass 65.5 ± 5.6 kg; mean ± SD) during 7 international races. Power output was recorded using SRM cranks and analyzed with proprietary software. Results: The mean power output was 252 ± 33 W, or 3.9 ± 0.5 W/kg in relative terms, with a coefficient of variation of 71% ± 13%. Normalized power (power output an athlete could sustain if intensity were maintained constant without any variability) for the entire cycle section was 291 ± 29 W, or 40 ± 13 W higher than the actual mean power output. There were 34 ± 1 4 peaks of power output above 600 W and -18% time spent at >100% of maximal aerobic power. Conclusion: Cycling during Olympic-distance triathlon, characterized by frequent and large power variations including repeat supramaximal efforts, equates to a higher workload than cycling at constant power. [ABSTRACT FROM AUTHOR]

To inform recruitment, selection, training and testing of male and female rugby sevens players game running movement patterns and physical characteristics were quantified across junior, senior, and elite playing levels. Anthropometric and physical testing (40 m sprint, vertical jump, Yo-Yo IR1) occurred prior to players’ national championships or international tournaments (n = 110 players), while game movements were obtained via GPS (n = 499 game files). The game movements of male players were similar across playing levels except for number of impacts >10 g which were 2 to 4-fold higher in elite (25.0 ± 11.2 impacts · game−1; mean ± SD), than junior (6.3 ± 3.5) and senior (11.8 ± 6.6) players. In men, there were fewer substantial correlations between on- and off-field measures which may reflect similar physical attributes across playing levels, and that other (strength, technical or tactical) factors may better differentiate these players. In females, elite players had more favourable on- and off-field performance measures than juniors and seniors, with moderate to strong correlations between on- and off-field variables. Female players should benefit from additional fitness training, while male players need to balance fitness with other technical and tactical factors. [ABSTRACT FROM PUBLISHER]

We sought to explore the relationship between two subjective falls-risk assessment tools (Falls Efficacy Scale-International [FES-I] and Activities- Specific Balance Confidence [ABC] Scale) and functional, health-related, and body composition characteristics. A total of 245 community-dwelling people aged 60 to 88 years underwent assessments for subjective falls risk (using the FES-I and ABC Scale), health-related (cognitive; Short-Form Health Survey [SF-12]), functional (physical activity and physical function), and body composition characteristics (measured by dual X-ray absorptiometry). The FES-I and ABC Scale are strongly correlated with each other for females and males (r = -.70, p < .001; r = -.65, p < .001), respectively. There are substantial differences between males and females when they self-assess their risk of falling as well as what characteristics contribute to explaining these self-assessments. Females are potentially more self-aware of their functional, body composition and health-related characteristics to better estimate their own risk of falling. FES-I correlates better with functional, body composition, and health-related characteristics, and thus may be more appropriate for use than the ABC in community-dwelling older adults. [ABSTRACT FROM AUTHOR]

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 (O2peak 58.7 ± 8.1 mL kg−1 min−1; mean ± SD) completed on separate occasions a maximal incremental test (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 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. [ABSTRACT FROM AUTHOR]

Live High:Train Low (LHTL) altitude training is a popular ergogenic aid amongst athletes. An alternative hypoxia protocol, acute (60-90 min daily) Intermittent Hypoxic Exposure (IHE), has shown potential for improving athletic performance. The aim of this study was to compare directly the effects of LHTL and IHE on the running and blood characteristics of elite triathletes. Changes in total haemoglobin mass (Hbmass), maximal oxygen consumption (VO2max), velocity at VO2max (vVO2max), time to exhaustion (TTE), running economy, maximal blood lactate concentration ([La]) and 3 mM [La] running speed were compared following 17 days of LHTL (240 h of hypoxia), IHE (10.2 h of hypoxia) or Placebo treatment in 24 Australian National Team triathletes (7 female, 17 male). There was a clear 3.2 ± 4.8% (mean ± 90% confidence limits) increase in Hbmass following LHTL compared with Placebo, whereas the corresponding change of -1.4 ± 4.5% in IHE was unclear. Following LHTL, running economy was 2.8 ± 4.4% improved compared to IHE and 3mM [La] running speed was 4.4 ± 4.5% improved compared to Placebo. After IHE, there were no beneficial changes in running economy or 3mM [La] running speed compared to Placebo. There were no clear changes in VO2max, vVO2max and TTE following either method of hypoxia. The clear difference in Hbmass response between LHTL and IHE indicated that the dose of hypoxia in IHE was insufficient to induce accelerated erythropoiesis. Improved running economy and 3mM [La] running speed following LHTL suggested that this method of hypoxic exposure may enhance performance at submaximal running speeds. Overall, there was no evidence to support the use of IHE in elite triathletes. [ABSTRACT FROM AUTHOR]

Identification of performance indicators related to scoring points and winning is needed to inform tactical approaches to international rugby sevens competition. The aim of this study was to characterize team performance indicators in international rugby sevens and quantify their relationship with a team's points scored and probability of winning. Performance indicators of each team during 196 matches of the 2011/2012 International Rugby Board Sevens World Series were modeled for their linear relationships with points scored and likelihood of winning within (changes in team values from match to match) and between (differences between team values averaged over all matches) teams. Relationships were evaluated as the change and difference in points and probability of winning associated with a two within- and between-team standard deviations increase in performance indicator values. Inferences about relationships were assessed using a smallest meaningful difference of one point and a 10% probability of a team changing the outcome of a close match. All indicators exhibited high within-team match-to-match variability (intraclass correlation coefficients ranged from 0.00 to 0.23). Excluding indicators representing points-scoring actions or events occurring on average less than once per match, 13 of 17 indicators had substantial clear within-team relationships with points scored and/or likelihood of victory. Relationships between teams were generally similar in magnitude but unclear. Tactics that increase points scoring and likelihood of winning should be based on greater ball possession, fewer rucks, mauls, turnovers, penalties and free kicks, and limited passing. Key pointsSuccessful international rugby sevens teams tend to maintain ball possession; more frequently avoid taking the ball into contact; concede fewer turnovers, penalties and free kicks; retain possession in scrums, rucks and mauls; and limit passing the ball.Selected performance indicators may be used to evaluate team performances and plan more effective tactical approaches to competition.There is greater match-to-match variability in performance indicator values within than between international rugby sevens teams.The priorities for a rugby sevens team's technical and tactical preparation should reflect the magnitudes of the relationships between performance indicators, points scoring and the likelihood of winning.