bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Yo-Yo Test: Reliability and Association with a 20-m Shuttle Run and VO2max
Authors: Thomas Andrew , Dawson Brian , Goodman Carmel 
Published: August 2016

Purpose:The purpose of the study was to determine the reliability of yo-yo intermittent recovery test (yo-yo) scores and their degree of association with a 20-m shuttle run (20MSR) and VO2max values.Methods:Subjects were elite (Australian Football League [AFL], n = 23), state-level (hockey, n = 15, and cricket, n = 27), and recreational team-sport players (n = 33). All performed a 20MSR and the yo-yo at either level 1 (recreational and state level) or level 2 (AFL). A recreational subgroup (n = 19) also performed a treadmill VO2max test.Results:Test–retest results found the yo-yo (levels 1 and 2) to be reliable (ICC = .86 to .95). The 20MSR and yo-yo level 1 scores correlated (P < .01) in the recreational (r = .81 to .83) and state-level groups (r = .84 to .86), and 20MSR and yo-yo level 2 scores, in the elite (r = .86) and recreational groups (r = .55 to .57). The VO2max and yo-yo level 1 scores in the recreational group correlated (P < .01, r = .87), but no association was found with yo-yo level 2 (r = .40 to .43, non significant).Conclusions:We conclude that level 1 (recreational and state level) and level 2 (elite) yo-yo scores were both strongly associated with 20MSR scores and VO2max (level 1: recreational subjects only). The yo-yo appears to measure aerobic fitness similarly to the 20MSR but may also be used as a field test of the ability to repeat high-intensity efforts.
Physical Fitness Components Associated With Performance in a Multiple-Sprint Test
Authors: Durandt Justin , Tee Jason C. , Prim Sebastian K. , Lambert Michael I. 
Published: August 2016

Purpose:The 5-m repeat-sprint test (5-m RST) measures resistance to fatigue after repeated bouts of short-duration, high-intensity activity. This study determined the components of fitness associated with performance in 5-m RSTs.Methods:Speed (10-m and 40-m sprints), strength (bench press), agility, strength endurance (pull-ups and push-ups), and aerobic power (20-m shuttle-run test) were measured in male provincial- or national-level rugby (n = 110), hockey (n = 59), and soccer (n = 55) players.Results:Subjects with either high (HI) or low (LO) resistance to fatigue in the 5-m RST differed in body mass (76.9 ± 11.6 kg vs 102.1 ± 18.9 kg, HI vs LO, respectively, P < .001), agility (14.55 ± 0.41 seconds vs 15.56 ± 0.30 seconds, P < .001), bench press (86 ± 20 kg vs 114 ± 33 kg, P = .03), pull-ups (13 ± 4 vs 8 ± 5, P = .02), push-ups (56 ± 12 vs 39 ± 13, P = .002), and 20-m shuttle-run test (20-m SRT; 133 ± 11 vs 87 ± 12 shuttles, P < .001). Body mass, strength, and aerobic power were the best predictors of 5-m RST performance: 5-m RST = –1.274(mass) + 0.756(1RM bench press) + 2.053(number of 20-m SRT shuttles) + 549.409 (R2 = .66).Conclusions:Performance in the 5-m RST is predicted best by a combination of factors including body mass, strength, and aerobic ability, rather than by any single component of fitness.
Water Immersion: Does It Enhance Recovery From Exercise?
Authors: Wilcock Ian M. , Cronin John B. , Hing Wayne A. 
Published: August 2016

Purpose:To assess the effect that post exercise immersion in water has on subsequent exercise performance.Methods:A literary search and review of water-immersion and performance studies was conducted.Results:Seven articles were examined. In 2, significant benefits to performance were observed. Those 2 articles revealed a small to large effect on jump performance and isometric strength.Practical Application and Conclusions:It is possible that water immersion might improve recovery from plyometric or muscle-damaging exercise. Such a statement needs to be verified, however, because of the scarcity of research on water immersion as a recovery strategy.
Side Effects of Creatine Supplementation in Athletes
Authors: Francaux Marc , Poortmans Jacques R. 
Published: August 2016

Context:Allegations about side effects of creatine supplementation by athletes have been published in the popular media and scientific publications.Purpose:To examine the experimental evidence relating to the physiological effects of creatine supplementation.Results:One of the purported effects of oral creatine supplementation is increased muscle mass. A review of the literature reveals a 1.0% to 2.3% increase in body mass, which is attributed to fat-free mass and, more specifically, to skeletal-muscle mass. Although it is unlikely that water retention can completely explain these changes, increase in muscle-protein synthesis has never been observed after creatine supplementation. Indirect evidence based on mRNA analyses suggests that transcription of certain genes is enhanced. Although the effect of creatine on muscle-protein synthesis seems irrefutable according to advertising, this allegation remains under debate in the scientific literature. The kidneys appear to maintain their functionality in healthy subjects who supplement with creatine, even over several months.Conclusion:The authors, however, think that creatine supplementation should not be used by an individual with preexisting renal disease and that risk should be evaluated before and during any supplementation period. Even if there is a slight increase in mutagenic agents (methylamine and formaldehyde) in urine after a heavy load of creatine (20 g/day), their excretion remains within a normal range. No data are currently available regarding the potential production of heterocyclic amines with creatine supplementation. In summary, the major risk for health is probably associated with the purity of commercially available creatine.
Power Output During a Professional Men’s Road-Cycling Tour
Authors: Ebert Tammie R. , Martin David T. , Stephens Brian , Withers Robert T. 
Published: August 2016

Purpose:To quantify the power-output demands of men’s road-cycling stage racing using a direct measure of power output.Methods:Power-output data were collected from 207 races over 6 competition years on 31 Australian national male road cyclists. Subjects performed a maximal graded exercise test in the laboratory to determine maximum aerobic-power output, and bicycles were fitted with SRM power meters. Races were described as fl at, hilly, or criterium, and linear mixed modeling was used to compare the races.Results:Criterium was the shortest race and displayed the highest mean power output (criterium 262 ± 30 v hilly 203 ± 32 v fl at 188 ± 30 W), percentage total race time above 7.5 W/kg (crite-rium 15.5% ± 4.1% v hilly 3.8% ± 1.7% v fl at 3.5% ± 1.4%) and SD in power output (criterium 250 v hilly 165 v fl at 169 W). Approximately 67%, 80%, and 85% of total race time was spent below 5 W/kg for criterium, hilly and fl at races, respectively. About 70, 40, and 20 sprints above maximum aerobic-power output occurred during criterium, hilly, and fl at races, respectively, with most sprints being 6 to 10 s.Conclusions:These data extend previous research documenting the demands of men’s road cycling. Despite the relatively low mean power output, races were characterized by multiple high-intensity surges above maximum aerobic-power output. These data can be used to develop sport-specific interval-training programs that replicate the demands of competition.
Monitoring Different Types of Resistance Training Using Session Rating of Perceived Exertion
Authors: Singh Favil , Foster Carl , Tod David , McGuigan Michael R. 
Published: August 2016

Purpose:To evaluate the effectiveness of session rating of perceived exertion (RPE) to measure effort during different types of resistance training.Method:Fifteen male subjects (age 26.7 ± 4.3 years) performed 3 protocols. All protocols consisted of same 5 exercises but with different intensities, rest periods, and numbers of repetitions. One-repetition maximum (1-RM) was defined as the maximal amount of weight that an individual could lift 1 time without support. The strength protocol included 3 sets of 5 repetitions at 90% of 1-RM with 3 minutes rest between. The hypertrophy session included 3 sets of 10 repetitions at 70% with 1 minute of rest, and the power session included 3 sets of 5 repetitions at 50% with 3 minutes of rest. Session RPE is a modification of the standard RPE scale. Session and standard RPE were measured after the completion of each set and 30 minutes postexercise, respectively.Results:Results showed a difference between both the 2 RPE values of the strength and hypertrophy protocols (P ≤ .05) but no difference between mean and session RPE values for the power protocol. During the familiarization session, session RPE was measured at 5-minute intervals for 30 minutes postexercise. There was a significant difference (P ≤ .05) between the mean RPE values at the fifth and tenth minutes postexercise when compared with 30 minutes postexercise. All other session RPE values showed no significant difference.Conclusion:The session RPE method appears to be effective in monitoring different types of resistance training, and session RPE after 30 minutes was a better indicator of the overall resistance sessions than average RPE.
Bilateral Comparison of Barbell Kinetics and Kinematics During a Weightlifting Competition
Authors: Rossi Stephen J. , Buford Thomas W. , Smith Douglas B. , Kennel Robin , Haff Erin E. , Haff G. Gregory 
Published: August 2016

Purpose:The primary purpose of this study was to simultaneously analyze both ends of the barbell with 19 weightlifters (age 18.0 ± 3.2 years, body mass 84.0 ± 14.2 kg, height 167.3 ± 8.7 cm) participating in a weightlifting competition to determine whether there were asymmetries in barbell kinematics and kinetics between the right and left sides of the barbell. The second purpose was to compare barbell-trajectory classification of the snatch and clean lifts between the right and left sides of the barbell.Methods:Barbell kinematic and kinetic data were collected and analyzed with 2 VS-120 weightlifting-analysis systems (Lipman Electronic Engineering Ltd, Ramat Hahayal, Israel). Barbell trajectories (A, B, and C) for the right and left sides were analyzed for each lift.Results:No significant difference was found in trajectory classification between sides of the barbell for either lift. The frequencies analysis revealed that type C barbell trajectories were the most prevalent in each lift. When the right and left sides of the barbell were compared during the snatch and clean, no significant differences were determined for any kinematic or kinetic variables.Conclusions:The V-scope system appears to facilitate analysis of barbell kinematics, kinetics, and trajectories during weightlifting competition regardless of which side of the barbell is analyzed.
Highland Dance: Heart-Rate and Blood Lactate Differences Between Competition and Class
Authors: Baillie Yvonne , Wyon Matt , Head Andrew 
Published: August 2016

Purpose:This study looked at the physiological effects of performance in Highland-dance competition to consider whether the traditional methods used during class and rehearsal provide an appropriate training stimulus toward this performance.Methods:Nine championship standard, female Highland dancers (age 14.2 ± 1.47 years) had their heart rate and blood lactate concentrations measured before and after 3 dances during a championship competition. Heart rate was also measured during the same 3 dances in rehearsal and during class.Results:Repeated-measures analysis of variance showed significant differences in pre dance lactate concentrations between the first dance (Highland Fling, 1.4 ± 0.3 mM/L), the second dance (Sword dance, 2.3 ± 0.8 mM/L), and the third dance (Sean Truibhas, 3.5 ± 1.8 mM/L;F2,16= 11.72,P< .01. This, coupled with a significant rise in lactate concentration during the dances (F1,8= 76.75,P< .001), resulted in a final post dance lactate concentration of 7.3 ± 2.96 mM/L. Heart-rate data during competition, rehearsal, and class (195.0 ± 6.5, 172.6 ± 5.4, and 151.9 ± 7.4 beats/min, respectively) showed significant differences between all 3 (F2,16= 107.1,P< .001); these are comparable to research on other dance forms.Conclusions:Given the disparity between the anaerobic predominance of competition and the aerobic predominance during class, it is suggested that the class does not provide an appropriate training stimulus as preparation for competitive performance in Highland dance.
Effect of Instability and Resistance on Unintentional Squat-Lifting Kinetics
Authors: Drinkwater Eric J. , Pritchett Erica J. , Behm David G. 
Published: August 2016

Context:Resistance training while using an instability-training device is known to increase activation of stabilizing muscle groups while decreasing the force generated by the prime movers during isometric contractions.Purpose:To investigate differences in squat kinetics during dynamic resistance training in an increasingly unstable training environment.Methods:Fourteen active men participated in this study. In each testing session, each participant performed 3 repetitions of squats with a 10-repetition maximum (10-RM) resistance, 40% of their 10-RM resistance, and 20.45 kg. The 3 testing session consisted of standing on a stable foor, foam pads, or BOSU balls. All repetitions were recorded with an optical encoder to record barbell kinetics.Results:The transition from stable (floor) to very unstable (BOSU) resulted in high likelihoods (>75%) of clinically meaningful differences ranging from small to large (effect size [ES] 0.31–1.73) in factors relating to concentric kinetics, eccentric power, and squat depth, regardless of the resistance used for training. There were also likely differences at the heaviest resistance in peak concentric power (stable to foam: ES 2.06; foam to BOSU: ES 0.38), eccentric power (stable to foam: ES 1.88; foam to BOSU: ES 0.74), and squat depth (stable to foam: ES 0.50; foam to BOSU: ES 0.67).Conclusions:Resistance training in an unstable environment at an intensity sufficient to elicit strength gains of the prime movers results in deleterious effects in concentric squat kinetics and squat technique. Such observations are particularly evident on very unstable platforms.
Relationship Between Throwing Velocity, Muscle Power, and Bar Velocity During Bench Press in Elite Handball Players
Authors: Marques Mário C. , van den Tillaar Roland , Vescovi Jason D. , González-Badillo Juan José 
Published: August 2016

Purpose:The purpose of this study was to examine the relationship between ball-throwing velocity during a 3-step running throw and dynamic strength, power, and bar velocity during a concentric-only bench-press exercise in team-handball players.Methods:Fourteen elite senior male team-handball players volunteered to participate. Each volunteer had power and bar velocity measured during a concentric-only bench-press test with 26, 36, and 46 kg, as well as having 1-repetition-maximum (1-RMBP) strength determined. Ball-throwing velocity was evaluated with a standard 3-step running throw using a radar gun.Results:Ball-throwing velocity was related to the absolute load lifted during the 1-RMBP (r = .637, P = .014), peak power using 36 kg (r = .586, P = .028) and 46 kg (r = .582, P = .029), and peak bar velocity using 26 kg (r = .563, P = .036) and 36 kg (r = .625, P = .017).Conclusions:The results indicate that throwing velocity of elite team-handball players is related to maximal dynamic strength, peak power, and peak bar velocity. Thus, a training regimen designed to improve ball-throwing velocity in elite male team-handball players should include exercises that are aimed at increasing both strength and power in the upper body.
A Time–Motion Analysis of Elite Solo Synchronized Swimming
Authors: Alentejano Teresa , Marshall Dru , Bell Gordon 
Published: August 2016

Purpose:To determine the total amount and relative time periods of face immersion (FI) in a synchronized swimming solo routine and the relationship between FI, distance covered, and the technical-merit score of the 11 top Canadian soloists at a synchronized swimming national championship (mean age 20 ± 1.8 y, height 173.3 ± 4.1 cm, and body mass 58.3 ± 4 kg).Methods:Videotape and timing of solo performances combined with manual tracking of pool patterns.Results:Analysis of performance revealed that an average of 18 FI periods, mean of 6.8 s, were performed for an average total time of 133.7 ± 27.1 s (range 102.2 to 199.8 s). The average longest FI time period was 25.45 ± 6.2 s (range 18.18 to 38.72 s), and most (10/11) of these were in the first third of the solo. The mean total horizontal distance covered was 57.61 ± 6.84 m (range 48.61 to 68.2 m), and the total horizontal distance covered relative to time was 0.276 ± 0.034 m/s (range 0.235 to 0.340 m/s). No significant relationships were found between any of the FI periods and the distance covered or between the technical-merit score and FI periods. Each solo contained 6 to 8 underwater sequences, none of which were longer than 40 seconds, the cutoff deemed dangerous by FINA (Fédération Internationale de Natation).Conclusion:This study shows that the times underwater for solos in Canada are within safety limits recommended by FINA and that judging in Canada is not related to underwater periods of swimming.
Seasonal Changes of Body Mass, Body Composition, and Muscular Performance in Collegiate Wrestlers
Authors: Buford Thomas W. , Smith Douglas B. , O’Brien Matthew S. , Warren Aric J. , Rossi Stephen J. 
Published: August 2016

Purpose:The purpose of the present investigation was to examine the physiological response of collegiate wrestlers to their competitive season.Methods:Eleven Division I collegiate wrestlers (mean ± SD; 19.45 ± 1.13 y) volunteered and completed 4 testing sessions throughout the course of the collegiate wrestling season. Testing sessions were conducted pre-, mid-, and postseason, as well as before the national tournament. Testing consisted of weigh-in, skinfold body composition testing, and a 50-rep concentric, isokinetic leg extension muscle endurance test (180°/s). Muscular performance variables measured included peak torque, peak torque at fatigue, percent decline, and peak torque/body mass ratio.Results:A significant increase (P < .05) of 2.9% was observed for body mass between midseason and postseason (2.38 kg). From pre- to postseason, a mean increase of 3.8% (3.1 kg) was observed for body mass. An increase (P < .05) in BF% of 2.9% was observed between prenationals and postseason. No significant differences (P > .05) were observed between consecutive time points for quadriceps peak torque; however, there was a significant increase (P < .05) between preseason and prenationals (23.39 N·m). Peak torque at fatigue was greater (P < .05) at midseason than preseason, representing an increase of 9.82 N·m. Between midseason and prenationals testing, we observed an 11% increase (P < .05) in %DCLN. Finally, we noted an increase (P < .05) from 0.6 to 0.69 in peak torque/body mass ratio between preseason and prenationals.Conclusions:Our results indicate that while force values seem to suffer at midseason, the wrestlers compensated and were strongest just before their national competition.
The Use of Sprint Tests for Assessment of Speed Qualities of Elite Australian Rules Footballers
Authors: Young Warren , Russell Andrew , Burge Peter , Clarke Alex , Cormack Stuart , Stewart Glenn 
Published: August 2016

Purpose:The purpose of this study was to determine the relationships between split times within sprint tests over 30 m and 40 m in elite Australian Rules footballers.Methods:Data were analyzed from two Australian Football League (AFL) clubs. The first club (n = 35) conducted a 40-m sprint test and recorded split times at 10 m and 20 m. The second club (n = 30) conducted a 30-m sprint test and recorded splits at 10 m and 20 m. Analyses included calculation of Pearson correlations and common variances between all the split times as well as “flying” times (20–40 m for the first club and 20 to 30 m for the second club).Results:There was a high correlation (r = 0.94) between 10-m time and 20-m time within each club, indicating these measures assessed very similar speed qualities. The correlations between 10-m time and times to 30 m and 40 m decreased, but still produced common variances of 79% and 66% respectively. However when the “flying” times (20–40 m and 20–30 m) were correlated to 10-m time, the common variances decreased substantially to 25% and 42% respectively, indicating uniqueness.Conclusions:It was concluded that 10-m time is a good refection of acceleration capabilities and either 20 to 40 m in a 40-m sprint test or 20 to 30 m in a 30-m sprint test can be used to estimate maximum speed capabilities. It was suggested that sprint tests over 30 m or 40 m can be conducted indoors to provide useful information about independent speed qualities in athletes.
Effect of Blood Lactate Sample Site and Test Protocol on Training Zone Prescription in Rowing
Authors: Garland Stephen W. , Atkinson Greg 
Published: August 2016

Purpose:To assess the effect of sample site (earlobe vs toe) and incremental exercise protocol (continuous vs discontinuous) on training zone prescription in rowing.Methods:Twenty-six rowers performed two incremental exercise tests on an ergometer: (1) a five-step discontinuous test with 4-min stages and 30-W increment, with blood samples taken from the earlobe and toe at the start of the 1-min break between steps; (2) a continuous test, with 2-min stages and 30-W increment, with blood samples taken from the right first toe at the end of each stage. Blood was analyzed for lactate concentration.Results:At a lactate concentration of 2 mmol·L−1, the mean (95% CI) power output was 8.1 (± 15.4) W greater for the continuous protocol, the random error between the methods (1.96 × SD of differences) was ± 58.8 W, and there was no evidence of any relationship between power output and error between methods. At a lactate concentration of 4 mmol·L−1, the mean (95% CI) power output was 24.2 (± 17.0) W greater for the continuous protocol, and the random error was ± 64.8 W. At 4 mmol·L−1, systematic bias between methods increased with high power outputs.Conclusions:The continuous protocol with toe sampling led to higher power outputs for a given lactate concentration compared with the discontinuous protocol with earlobe sampling. This was partly due to the choice of sample site and largely due to the choice of protocol. This bias, and also random variability, makes direct comparison of these tests inappropriate.