bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variation in Performance Times of Elite Flat-Water Canoeists From Race to Race
Authors: Bonetti Darrell L. , Hopkins Will G. 
Published: August 2016

Purpose:To estimate variability in performance time and smallest worthwhile changes for elite fat-water canoeists competing in 200-, 500- or 1000-m events at international regattas.Methods:The data came from A and B finals held at 7 to 13 regattas in 2003 to 2007. A linear mixed-model analysis of log-transformed official race times provided estimates of variability as coefficients of variation and included terms to account for changes in performance between years, venues, and A and B finals.Results:For men, the within-athlete variation in A finals was similar in canoeing and kayaking events, with the 200-m men’s events demonstrating probably less variability than the longer events (by an overall factor of 0.75, ×/÷1.33) that may reflect differences in pacing strategies. In contrast, the within-athlete variation for women kayakers in A finals of the 500-m event was only half that of the other distances (ratio 0.54, ×/÷1.29), possibly because of differences in competitive experience or depth of competition. Predictability of performance in A finals was moderate to very high (interclass correlations 0.40 to 0.89). Within-athlete variation in the B finals was generally greater than in the A finals for the three distances for men, but there was no clear pattern for women.Conclusion:The smallest worthwhile changes in performance time (0.3× within-athlete variability) in canoeing and kayaking are approx. 0.3% to 0.6%. Effects of 1% to 2% in power output would be required to achieve such changes in this generally highly predictable sport.
A Comparison of the Physiological Demands of Wheelchair Basketball and Wheelchair Tennis
Authors: Croft Louise , Dybrus Suzanne , Lenton John , Goosey-Tolfrey Victoria 
Published: August 2016

Purpose:To examine the physiological profiles of wheelchair basketball and tennis and specifically to: (a) identify if there are differences in the physiological profiles of wheelchair basketball and tennis players of a similar playing standard, (b) to determine whether the competitive physiological demands of these sports differed (c) and to explore the relationship between the blood lactate [Bla−] response to exercise and to identify the sport specific heart rate (HR) training zones.Methods:Six elite athletes (4 male, 2 female) from each sport performed a submaximal and VO2 peak test in their sport specific wheelchair. Heart rate, VO2, and [Bla−] were measured. Heart rate was monitored during international competitions and VO2 was calculated from this using linear regression equations. Individual HR training zones were identified from the [Bla–] profile and time spent within these zones was calculated for each match.Results:Despite no differences in the laboratory assessment of HRpeak, the VO2peak was higher for the basketball players when compared with the tennis players (2.98 ± 0.91 vs 2.06 ± 0.71; P = .08). Average match HR (163 ± 11 vs 146 ± 16 beats-min–1; P = .06) and average VO2 (2.26 ± 0.06 vs 1.36 ± 0.42 L-min-1; P = .02) were higher during actual playing time of basketball when compared with whole tennis play. Consequently, differences in the time spent in the different training zones within and between the two sports existed (P < .05).Conclusions:Wheelchair basketball requires predominately high-intensity training, whereas tennis training requires training across the exercise intensity spectrum.
Sweat Rate and Electrolyte Concentration in Swimmers, Runners, and Nonathletes
Authors: Henkin Simone D. , Sehl Paulo L. , Meyer Flavia 
Published: August 2016

Because swimmers train in an aquatic environment, they probably do not need to sweat as much as runners who train on land and, therefore, should not develop the same magnitude of sweating adaptations.Purpose:To compare sweat rate and electrolyte concentration in swimmers, runners and nonathletes.Methods:Ten swimmers (22.9 ± 3.1 years old), 10 runners (25 ± 2.9 y) and 10 nonathletes (26.5 ± 2.2 y) cycled in the heat (32°C and 40% relative humidity) for 30 min at similar intensity relative to their maximal cycle test. Sweat volume was calculated from the difference of their body mass before and after cycling, since they were not allowed to drink. Sweat was collected from the scapula using absorbent patch placed on the skin that was cleaned with distilled water. After cycling, the patch was transferred to syringe and the sample was obtained when squeezing it to a tube. Concentration of sodium ([Na+]), chloride ([Cl–]) and potassium ([K+]) were analyzed using an ion selector analyzer.Results:The sweat volume, in liters, of swimmers (0.9 ± 0.3) was lower (P < .05) than that of runners (1.5 ± 0.2) and similar to that of nonathletes (0.6 ± 0.2). [Na+] and [Cl-], in mmolL-1, of swimmers (65.4 ± 5.5 and 61.2 ± 81), and nonathletes (67.3 ± 8.5 and 58.3 ± 9.6) were higher (P < .05) than those of runners (45.2 ± 7.5 and 38.9 ± 8.3). [K+] was similar among groups.Conclusions:The lower sweat volume and higher sweat [Na+] and [Cl-] of swimmers, as compared with runners, indicate that training in the water does not cause the same magnitude of sweating adaptations.
The Validity and Reliability of 1-Hz and 5-Hz Global Positioning Systems for Linear, Multidirectional, and Soccer-Specific Activities
Authors: Portas Matthew D. , Harley Jamie A. , Barnes Christopher A. , Rush Christopher J. 
Published: August 2016

Purpose:The study aimed to analyze the validity and reliability of commercially available nondifferential Global Positioning System (NdGPS) devices for measures of total distance during linear, multidirectional and soccer-specific motion at 1-Hz and 5-Hz sampling frequencies.Methods:Linear (32 trials), multidirectional (192 trials) and soccer-specific courses (40 trials) were created to test the validity (mean ± 90% confidence intervals), reliability (mean ± 90% confidence intervals) and bias (mean ± 90% confidence intervals) of the NdGPS devices against measured distance. Standard error of the estimate established validity, reliability was determined using typical error and percentage bias was established.Results:The 1-Hz and 5-Hz data ranged from 1.3% ± 0.76 to 3.1% ± 1.37 for validity and 2.03% ± 1.31 to 5.31% ± 1.2 for reliability for measures of linear and soccer-specific motion. For multidirectional activity, data ranged from 1.8% ± 0.8 to 6.88% ± 2.99 for validity and from 3.08% ± 1.34 to 7.71% ± 1.65 for reliability. The 1-Hz underestimated some complex courses by up to 11%.Conclusions:1-Hz and 5-Hz NdGPS could be used to quantify distance in soccer and similar field-based team sports. Both 1-Hz and 5-Hz have a threshold beyond which reliability is compromised. 1-Hz also underestimates distance and is less valid in more complex courses.
Which Jump Variables Should Be Used to Assess Explosive Leg Muscle Function?
Authors: Young Warren , Cormack Stuart , Crichton Michael 
Published: August 2016

Purpose:The main purpose of this study was to determine the relationships between countermovement jump (CMJ) variables and acceleration and maximum speed performance.Methods:Twenty-three elite Australian football players were tested on a CMJ, which yielded several kinematic and kinetic variables describing leg muscle function. A 40 m sprint was also conducted to assess acceleration (10 m time) and an estimate of maximum speed (fying 20 m time). Players from one Australian Football League (AFL) club were tested and Pearson correlations for CMJ variables and sprint performance were calculated.Results:Jump height, peak velocity, peak force, and peak power had less than 50% common variance, and therefore represented independent expressions of CMJ performance. Generally, the correlations between CMJ variables and sprinting performance were stronger for maximum speed (small to large effect sizes) than for acceleration (trivial to moderate sizes). The variable that produced the strongest correlation with acceleration was jump height (r = -0.430, P = .041) and with maximum speed was peak power/weight (r = -0.649, P = .001).Conclusions:The results indicate that if an integrated system comprising a position transducer and a force platform is available for CMJ assessment, jump height and peak power/weight are useful variables to describe leg muscle explosive function for athletes who perform sprints.
Reliability and Effect of Sodium Bicarbonate: Buffering and 2000-m Rowing Performance
Authors: Carr Amelia J. , Slater Gary J. , Gore Christopher J. , Dawson Brian , Burke Louise M. 
Published: August 2016

Purpose:The aim of this study was to determine the effect and reliability of acute and chronic sodium bicarbonate ingestion for 2000-m rowing ergometer performance (watts) and blood bicarbonate concentration [HCO3−].Methods:In a crossover study, 7 well-trained rowers performed paired 2000-m rowing ergometer trials under 3 double-blinded conditions: (1) 0.3 grams per kilogram of body mass (g/kg BM) acute bicarbonate; (2) 0.5 g/kg BM daily chronic bicarbonate for 3 d; and (3) calcium carbonate placebo, in semi-counterbalanced order. For 2000-m performance and [HCO3−], we examined differences in effects between conditions via pairwise comparisons, with differences interpreted in relation to the likelihood of exceeding smallest worthwhile change thresholds for each variable. We also calculated the within-subject variation (percent typical error).Results:There were only trivial differences in 2000-m performance between placebo (277 ± 60 W), acute bicarbonate (280 ± 65 W) and chronic bicarbonate (282 ± 65 W); however, [HCO3−] was substantially greater after acute bicarbonate, than with chronic loading and placebo. Typical error for 2000-m mean power was 2.1% (90% confidence interval 1.4 to 4.0%) for acute bicarbonate, 3.6% (2.5 to 7.0%) for chronic bicarbonate, and 1.6% (1.1 to 3.0%) for placebo. Postsupplementation [HCO3−] typical error was 7.3% (5.0 to 14.5%) for acute bicarbonate, 2.9% (2.0 to 5.7%) for chronic bicarbonate and 6.0% (1.4 to 11.9%) for placebo.Conclusion:Performance in 2000-m rowing ergometer trials may not substantially improve after acute or chronic bicarbonate loading. However, performances will be reliable with both acute and chronic bicarbonate loading protocols.
Salivary Immunoglobulin A and Upper Respiratory Symptoms During 5 Months of Training in Elite Tetraplegic Athletes
Authors: Leicht Christof A. , Bishop Nicolette C. , Paulson Thomas A.W. , Griggs Katy E. , Goosey-Tolfrey Victoria L. 
Published: August 2016

Purpose:Altered autonomic innervation in tetraplegic individuals has been shown to depress certain immune parameters at rest and alter exercise-related salivary immunoglobulin A (sIgA) responses. The purpose of this study was to examine resting sIgA responses as a function of training load and episodes of upper respiratory symptoms (URS) in elite tetraplegic athletes.Methods:Resting saliva samples were obtained from 14 tetraplegic athletes at 12 predefined time points over 5 months and analyzed for sIgA. Occurrence of self-reported URS and training load was recorded throughout the study’s duration. Regression analyses were performed to investigate the relationship between sIgA responses and training load. Furthermore, the relationships between sIgA responses and URS occurrence were examined.Results:sIgA secretion rate was negatively correlated with training load (P = .04), which only accounted for 8% of the variance. No significant relationships were found between sIgA responses and subsequent URS occurrence. Finally, sIgA responses did not differ between athletes with and without recorded URS during the study period.Conclusions:In line with findings in ablebodied athletes, negative relationships between sIgA secretion rate and training load were found in tetraplegic athletes. This may explain some of the higher infection risk in wheelchair athletes with a high training load, which has been previously observed in paraplegic athletes. However, the nonsignificant relationship between sIgA responses and URS occurrence brings into question the use of sIgA as a prognostic tool for the early detection of URS episodes in the studied population.
Wheelchair Tennis Match-Play Demands: Effect of Player Rank and Result
Authors: Sindall Paul , Lenton John P. , Tolfrey Keith , Cooper Rory A. , Oyster Michelle , Goosey-Tolfrey Victoria L. 
Published: August 2016

Purpose:To examine the heart-rate (HR) response and court-movement variables during wheelchair tennis match play for high- (HIGH) and low- (LOW) performance-ranked players. Analysis of physiological and movement-based responses during match play offers an insight into the demands of tennis, allowing practical recommendations to be made.Methods:Fourteen male open-class players were monitored during tournament match play. A data logger was used to record distance and speed. HR was recorded during match play.Results:Significant rank-by-result interactions revealed that HIGH winners covered more forward distance than HIGH losers (P< .05) and had higher average (P< .05) and minimum (P< .01) HRs than LOW winners. LOW losers had higher average (P< .01) and minimum (P< .001) HRs than LOW winners. Independent of result, a significant main effect for rank was identified for maximum (P< .001) and average (P< .001) speed and total (P< .001), reverse (P< .001), and forward-to-reverse (P< .001) distance, with higher values for HIGH. Independent of rank, losing players experienced higher minimum HRs (P< .05). Main effects for maximum HR and actual playing time were not significant. Average playing time was 52.0 (9.1) min.Conclusions:These data suggest that independent of rank, tennis players were active for sufficient time to confer health-enhancing effects. While the relative playing intensity is similar, HIGH players push faster and farther than LOW players. HIGH players are therefore more capable of responding to ball movement and the challenges of competitive match play. Adjustments to the sport may be required to encourage skill developmental in LOW players, who move at significantly lower speeds and cover less distance.
Factors That Affect Selection of Elite Women’s Sculling Crews
Authors: Lawton Trent W. , Cronin John B. , McGuigan Michael R. 
Published: August 2016

Purpose:There is no common theory on criteria to appropriately select crew rowers in pursuit of small performance gains. The purpose of this study was to establish whether anthropometry, rowing ergometry, or lower body strength were suitable criteria to identify differences between selected and nonselected sculling crews.Method:Twelve elite women performed a 2000-m ergometer time trial and a 5-repetition leg-press dynamometer test, were anthropometrically profiled, and participated in on-water national crew seat-racing trials. Log-transformed data were analyzed to compare percent (± SD) and standardized differences in group means (ES; ±90% confidence interval [CI]) between selected and nonselected oarswomen, with adjustments for body mass where appropriate.Results:Selected crew boats were 4.60% ± 0.02% faster and won by an average margin of 13.5 ± 0.7 s over 1500 m. There were no differences between crews on average in height, arm span, seated height, body mass, or 8-site skinfold sum (body fat). Difference in 2000-m ergometer times were also trivial (ES = 0.2, 90%CI = −0.6 to 1.1, P = .63); however, selected crews had moderately greater leg-press strength (ES = 1.1, 90%CI = 0.3−1.9, P = .03).Conclusion:Selected oarswomen with comparable anthropometry and 2000-m ergometer ability had greater lower body strength. Coaches of elite oarswomen might consider leg strength as part of crew-selection criteria, given acceptable on-water boatmanship and attainment of 2000-m ergometer benchmarks.
The ACTN3 XX Genotype’s Underrepresentation in Japanese Elite Wrestlers
Authors: Kikuchi Naoki , Ueda Dai , Min Seok-ki , Nakazato Koichi , Igawa Shoji 
Published: August 2016

Purpose:To examine the relationship betweenACTN3polymorphisms and level of athletic performance in Japanese wrestlers.Methods:The control group consisted of 243 healthy Japanese individuals. The authors divided 135 wrestlers into 3 groups based on their results in national or international competitions. They classified as elite 24 wrestlers who had placed in the top 8 in a world championship or participated in Olympic games, 28 wrestlers who had participated in world championships or become champions in Japan’s national championships were classified as subelite, and 83 wrestlers were classified as national (N-W, ie, national-level wrestler). In addition, the authors combined the elite and subelite to form the classification international-level wrestlers (I-W).Results:The frequency of the null X allele and the XX genotype were significantly lower in the I-W group than in the control group. However, there was no significant difference inACTN3genotype or allele frequency between the N-W and control groups. The frequency of theACTN3XX genotype in the elite groups was lower than that of all groups, and a linear tendency was observed betweenACTN3XX genotype and athletic status.Conclusions:In conclusion, the data indicated thatACTN3polymorphisms were related to athletic performance in Japanese wrestlers.
Designing a Warm-Up Protocol for Elite Bob-Skeleton Athletes
Authors: Cook Christian , Holdcroft Danny , Drawer Scott , Kilduff Liam P. 
Published: August 2016

Purpose:To investigate how different warm-ups influenced subsequent sled-pull sprint performance in Olympic-level bob-skeleton athletes as part of their preparation for the 2010 Winter Olympics.Methods:Three female and 3 male athletes performed 5 different randomized warm-ups of differing intensities, durations, and timing relative to subsequent testing, each 2 days apart, all repeated twice. After warm-ups, testing on a sledpull sprint over 20 m, 3 repeats 3 min apart, took place.Results:Performance testing showed improvement (P < .001, ES > 1.2) with both increasing intensity of warm-up and closeness of completion to testing, with 20-m sled sprinting being 0.1–0.25 s faster in higher-intensity protocols performed near testing In addition, supplementing the warm-ups by wearing of a light survival coat resulted in further performance improvement (P = .000, ES 1.8).Conclusions:Changing timing and intensity of warm-up and using an ancillary passive heat-retention device improved sprint performance in Olympic-level bob-skeleton athletes. Subsequent adoption of these on the competitive circuit was associated with a seasonal improvement in push times and was ultimately implemented in the 2010 Winter Olympics.
Effectiveness of Water Immersion on Postmatch Recovery in Elite Professional Footballers
Authors: Elias George P. , Wyckelsma Victoria L. , Varley Matthew C. , McKenna Michael J. , Aughey Robert J. 
Published: August 2016

Purpose:The efficacy of a single exposure to 14 min of contrast water therapy (CWT) or cold-water immersion (COLD) on recovery postmatch in elite professional footballers was investigated.Method:Twenty-four elite footballers participated in a match followed by 1 of 3 recovery interventions. Recovery was monitored for 48 h postmatch. Repeat-sprint ability (6 × 20-m), static and countermovement jump performance, perceived soreness, and fatigue were measured prematch and immediately, 24 h, and 48 h after the match. Soreness and fatigue were also measured 1 h postmatch. Postmatch, players were randomly assigned to complete passive recovery (PAS; n = 8), COLD (n = 8), or CWT (n = 8).Results:Immediately postmatch, all groups exhibited similar psychometric and performance decrements, which persisted for 48 h only in the PAS group. Repeatsprinting performance remained slower at 24 and 48 h for PAS (3.9% and 2.0%) and CWT (1.6% and 0.9%) but was restored by COLD (0.2% and 0.0%). Soreness after 48 h was most effectively attenuated by COLD (ES 0.59 ± 0.10) but remained elevated for CWT (ES 2.39 ± 0.29) and PAS (ES 4.01 ± 0.97). Similarly, COLD more successfully reduced fatigue after 48 h (ES 1.02 ± 0.72) than did CWT (ES 1.22 ± 0.38) and PAS (ES 1.91 ± 0.67). Declines in static and countermovement jump were ameliorated best by COLD.Conclusions:An elite professional football match results in prolonged physical and psychometric deficits for 48 h. COLD was more successful at restoring physical performance and psychometric measures than CWT, with PAS being the poorest.
Effects of Electrostimulation Therapy on Recovery From Acute Team-Sport Activity
Authors: Finberg Matthew , Braham Rebecca , Goodman Carmel , Gregory Peter , Peeling Peter 
Published: August 2016

Purpose:To assess the efficacy of a 1-off electrostimulation treatment as a recovery modality from acute teamsport exercise, directly comparing the benefits to contrast water therapy.Methods:Ten moderately trained male athletes completed a simulated team-game circuit (STGC). At the conclusion of exercise, participants then completed a 30-min recovery modality of either electrostimulation therapy (EST), contrast water therapy (CWT), or a passive resting control condition (CON). Twenty-four hours later, participants were required to complete a modified STGC as a measure of next-day performance. Venous blood samples were collected preexercise and 3 and 24 h postexercise. Blood samples were analyzed for circulating levels of interleukin-6 (IL-6) and C-reactive protein (CRP).Results:The EST trial resulted in significantly faster sprint times during the 24-h postrecovery than with CON (P < .05), with no significant differences recorded between EST and CWT or between CWT and CON (P > .05). There were no differences in IL-6 or CRP across all trials. Finally, the perception of recovery was significantly greater in the EST trial than in the CWT and CON (P < .05).Conclusions:These results suggest that a 1-off treatment with EST may be beneficial to perceptual recovery, which may enhance next-day performance.
Rapidity of Response to Hypoxic Conditions During Exercise
Authors: Harris Kayla B. Henslin , Foster Carl , de Koning Jos J. , Dodge Christopher , Wright Glenn A. , Porcari John P. 
Published: August 2016

Previous studies have found decreases in arterial oxygen saturation to be temporally linked to reductions in power output (PO) during time-trial (TT) exercise. The purpose of this study was to determine whether preexercise desaturation (estimated from pulse oximetry [SpO2]), via normobaric hypoxia, would change the pattern of PO during a TT.Purpose:The authors tested the hypothesis that the starting PO of a TT would be reduced in the EARLY trial secondary to a reduced SpO2 but would not be reduced in LATE until ~30 s after the start of the TT.Methods:Eight trained cyclists/triathletes (4 male, 4 female) performed 3 randomly ordered 3-km TTs while breathing either room air (CONTROL) or hypoxic air administered 3 min before the start of the TT (EARLY) or at the beginning of the TT (LATE).Results:There was no effect of hypoxia on PO during the first 0.3 km of either the EARLY or the LATE trial compared with CONTROL, although there was a significant decrease in pre-TT SpO2 in EARLY vs CONTROL and LATE. The time for PO to decrease was ~40 s after the start of the TT in both EARLY and LATE.Conclusions:The results support the strong effect of the preexercise template on the pattern of PO during simulated competition and suggest that reductions in SpO2 are not direct signals to decrease PO.