bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Compression Garments on Intermittent Exercise Performance and Recovery on Consecutive Days
Authors: Duffield Rob , Edge Johann , Merrells Robert , Hawke Emma , Barnes Matt , Simcock David , Gill Nicholas 
Published: August 2016

Purpose:The aim of this study was to determine whether compression garments improve intermittent-sprint performance and aid performance or self-reported recovery from high-intensity efforts on consecutive days.Methods:Following familiarization, 14 male rugby players performed two randomized testing conditions (with or without garments) involving consecutive days of a simulated team sport exercise protocol, separated by 24 h of recovery within each condition and 2 weeks between conditions. Each day involved an 80-min high-intensity exercise circuit, with exercise performance determined by repeated 20-m sprints and peak power on a cart dynamometer (single-man scrum machine). Measures of nude mass, heart rate, skin and tympanic temperature, and blood lactate (La−) were recorded throughout each day; also, creatine kinase (CK) and muscle soreness were recorded each day and 48 h following exercise.Results:No differences (P = .20 to 0.40) were present between conditions on either day of the exercise protocol for repeated 20-m sprint efforts or peak power on a cart dynamometer. Heart rate, tympanic temperature, and body mass did not significantly differ between conditions; however, skin temperature was higher under the compression garments. Although no differences (P = .50) in La− or CK were present, participants felt reduced levels of perceived muscle soreness in the ensuing 48 h postexercise when wearing the garments (2.5 ± 1.7 vs 3.5 ± 2.1 for garment and control; P = .01).Conclusions:The use of compression garments did not improve or hamper simulated team-sport activity on consecutive days. Despite benefits of reduced self-reported muscle soreness when wearing garments during and following exercise each day, no improvements in performance or recovery were apparent.
Effect of Vibration on Forward Split Flexibility and Pain Perception in Young Male Gymnasts
Authors: Sands William A. , McNeal Jeni R. , Stone Michael H. , Haff G. Gregory , Kinser Ann M. 
Published: August 2016

Serious stretching in many sports involves discomfort and is often an early ceiling on improvements.Purpose:To continue investigation of the use of vibration to enhance acute range of motion while assessing the influence of vibration and stretching on pressure-to-pain threshold perception.Methods:Ten young male gymnasts were assessed for split range of motion. One side split was randomly assigned as the experimental condition, and the other side split was assigned as the control. Both side splits were performed on a vibration device; the experimental condition had the device turned on and the control condition was performed with the device turned off. In addition, the athletes were assessed for pressure-to-pain transition using an algometer on the biceps femoris (stretched muscle) and vastus lateralis (nonstretched muscle) bilaterally.Results:Pre-post difference scores between the vibrated split (most improved) and the nonvibrated split were statistically different (P = .001, 95% confidence interval of the difference 2.3 to 5.8 cm). Following the stretching protocol, the force values for the pressure-to-pain threshold comparing the vibrated and nonvibrated biceps femoris muscle were not statistically different. The nonstretched vastus lateralis muscle also showed no statistical difference in pressure-to-pain threshold between the vibration and nonvibration conditions.Conclusion:This study showed that vibration improved split range of motion over stretching alone, but did not show a difference in pressure-to-pain perception in either the stretched or nonstretched muscles.
Hypervolemia and Blood Alkalinity: Effect on Physiological Strain in a Warm Environment
Authors: Nelson Michael D. , Stuart-Hill Lynneth A. , Sleivert Gordon G. 
Published: August 2016

Purpose:To evaluate the influence of acute hypervolemia, achieved through the ingestion of a sodium citrate-rich beverage, on cardiovascular strain and thermoregulatory function, during moderate-intensity aerobic exercise in a warm environment. Sodium citrate’s ability to increase buffering capacity was also assessed.Methods:Twelve endurance-trained athletes completed two blind randomized treatment trials, separated by a minimum of seven days, on a cycle ergometer under heat stress (30.9°C, 64% RH). The subjects ingested 12 mL·kg−1of (1) Gatorade, the control (CNT), or (2) sodium-citrate plus Gatorade (NaCIT: 170 mmol Na+L−1) before cycling at 15% below ventilatory threshold (VT) for 62 minutes. Core and skin temperature, expired gas samples, heart rate, and perceived exertion were measured throughout exercise. Blood samples were taken before drinking each beverage, before commencing exercise, and throughout the exercise bout.Results:Plasma volume (PV) was significantly expanded in the NaCIT trial (3.6 ± 5.5%) and remained significantly higher throughout exercise in the NaCIT trial compared with the CNT trial (P≤ .05). No significant differences were found in heart rate, in core and skin temperature, or in the metabolic data between the treatment groups. NaCIT significantly increased [HCO3−], base excess, and pH throughout the trial.Conclusion:Acute oral ingestion of high-sodium citrate beverages before moderate exercise induces mild levels of hypervolemia and improves blood-buffering capacity in humans; however, mild hypervolemia during 62 minutes of moderate exercise does not reduce physiological strain or improve thermoregulation.
Hamstring Activation During Lower Body Resistance Training Exercises
Authors: Ebben William P. 
Published: August 2016

Purpose:The purpose of this study was to evaluate differences in hamstring activation during lower body resistance training exercises. This study also sought to assess differences in hamstring-to-quadriceps muscle activation ratios and gender differences therein.Methods:A randomized repeated measures design was used to compare six resistance training exercises that are commonly believed to train the hamstrings, including the squat, seated leg curl, stiff leg dead lift, single leg stiff leg dead lift, good morning, and Russian curl. Subjects included 34 college athletes. Outcome measures included the biceps femoris (H) and rectus femoris (Q) electromyography (EMG) and the H-to-Q EMG ratio, for each exercise.Results:Main effects were found for the H (P < 0.001) and Q (P < 0.001). Post hoc analysis identified the specific differences between exercises. In addition, main effects were found for the H-to-Q ratio when analyzed for all subjects (P < 0.001). Further analysis revealed that women achieved between 53.9 to 89.5% of the H-to-Q activation ratios of men, for the exercises assessed. In a separate analysis of strength matched women and men, women achieved between 35.9 to 76.0% of the H-to-Q ratios of men, for these exercises.Conclusions:Hamstring resistance training exercises offer differing degrees of H and Q activation and ratios. Women compared with men, are less able to activate the hamstrings and/or more able to activate the quadriceps. Women may require disproportionately greater training for the hamstrings compared with the quadriceps.
Combined Uphill and Downhill Sprint Running Training Is More Efficacious Than Horizontal
Authors: Paradisis Giorgos P. , Bissas Athanassios , Cooke Carlton B. 
Published: August 2016

Purpose:This study examined the effects of sprint running training on sloping surfaces (3°) on selected kinematic and physiological variables.Methods:Fifty-four sport and physical education students were randomly allocated to one of two training groups (combined uphill–downhill [U+D] and horizontal (H)) and a control group (C). Pre- and post training tests were performed to examine the effects of 8 wk of training on the maximum running speed (MRS), step rate, step length, step time, contact time, eccentric and concentric phase of contact time (EP, CP), fight time, selected posture characteristics of the step cycle, and 6-s maximal cycle sprint test.Results:MRS, step rate, contact time, and step time were improved significantly in a 35-m sprint test for the U+D group (P < .01) after training by 4.3%, 4.3%, -5.1%, and -3.9% respectively, whereas the H group showed smaller improvements, (1.7% (P < .05), 1.2% (P < .01), 1.7% (P < .01), and 1.2% (P < .01) respectively). There were no significant changes in the C group. The posture characteristics and the peak anaerobic power (AWT) performance did not change with training in any of the groups.Conclusion:The U+D training method was significantly more effective in improving MRS and the kinematic characteristics of sprint running than a traditional horizontal training method.
Placebo Effects of Caffeine on Short-Term Resistance Exercise to Failure
Authors: Duncan Michael J. , Lyons Mark , Hankey Joanne 
Published: August 2016

Purpose:This study examined the placebo effect of caffeine on number of repetitions (reps), rating of perceived exertion (RPE), blood pressure (BP), and peak heart rate (PHR) during resistance-training exercise with repetitions (reps) performed to volitional failure.Methods:Following determination of 1-rep maximum in single-leg leg extension, 15 males performed reps to failure at 60% 1-RM in 3 conditions: control, perceived caffeine condition, and perceived placebo condition presented in a randomized order. Participants were informed they would ingest 250 mL of solution that contained either 3 mg·kg−1caffeine or 3 mg·kg−1placebo 1 h before each exercise trial. A deceptive protocol was employed and subjects consumed a placebo solution in both conditions. During each condition, total reps, RPE for the active muscle and overall body, and PHR were recorded.Results:Subjects completed 2 more reps when they perceived they had ingested caffeine. RPE was significantly (P= .04) lower in the perceived caffeine and control conditions and RPE for the active muscle was significantly higher across all conditions compared with RPE for the overall body. No substantial differences were evident in PHR across conditions.Conclusions:Results of this study are similar to studies of actual caffeine ingestion. However, the perception of consuming a substance that purportedly enhances performance is sufficient enough to enable individuals to complete a greater number of reps to failure during short-term resistance exercise.
Relationship Between Muscle Strength, Power and Stiffness and Running Economy in Trained Male Runners
Authors: Dumke Charles L. , Pfaffenroth Christopher M. , McBride Jeffrey M. , McCauley Grant O. 
Published: August 2016

Purpose:In this study, a comparison was made between muscle strength, power and muscle and tendon (km and kt respectively) stiffness of the triceps surae muscle group and running economy (RE) in trained male runners.Methods:Twelve well-trained male runners (age = 21 + 2.7 y, height = 178.1 ± 7.1 cm, body mass = 66.7 + 3.2 kg, VO2 max = 68.3 + 4.3 mLkg–1min–1, 5000-m time = 15:04 min:s) underwent passive stiffness testing using a free oscillation method. Muscle strength was determined via a maximal isometric squat test and power determined via a maximal countermovement jump (CMJ). On a separate day, subjects performed an incremental treadmill test and their RE, lactate threshold, and VO2 max were determined. Fingertip blood lactate was determined at the end of each 3-min stage. Lactate threshold was defined as a nonlinear increase in lactate accumulation.Results:A statistically significant correlation was found between k m and VO at stage 6 (r = -0.69, P = .01). In addition, statistically significant correlations were observed between CMJ peak force production and VO2 at stage 2 (r = .66, P = .02), stage 3 (r = .70, P = .01), and stage 4 (r = .58, P = .04). No other statistically significant correlations were observed.Conclusion:These data suggest that greater muscle stiffness and less power are associated with greater RE. Future study in this area should focus on determining the mechanisms behind this relationship and how to best apply them to a running population through training techniques.
Kinematic Comparison of Team Handball Throwing With Two Different Arm Positions
Authors: Wagner Herbert , Buchecker Michael , von Duvillard Serge P. , Müller Erich 
Published: August 2016

Purpose:The aims of the present study were: (1) to compare the differences in the ball release speed and throwing accuracy between the ABOVE and SIDE throw; (2) to analyze kinematic differences of these two throwing techniques; and (3) to give practical applications to team handball coaches and players.Methods:Ball release speed, throwing accuracy, and kinematics were measured via the Vicon MX 13 (Vicon Peak, Oxford, UK) from 12 male elite right-handed team handball players.Results:Results of our study suggest that the two throwing techniques differ significantly (P < .0073) in the angles and/or angular velocities of the trunk (flexion, left tilt and rotation) and shoulder (flexion and abduction) of the throwing arm that result in a significantly different ball release speed (1.4 ± 0.8 m/s; P < .001) and that throwing accuracy was not significantly different.Conclusion:Our results indicated that the different position of the hand at ball release of the ABOVE and SIDE throws is primarily caused by different trunk flexion and tilt angles that lead to differences in ball release speed but not in throwing accuracy, and that the participants try to move their throwing arm similarly in both throwing techniques.
Concurrent Fatigue and Potentiation in Endurance Athletes
Authors: Boullosa Daniel A. , Tuimil José L. , Alegre Luis M. , Iglesias Eliseo , Lusquiños Fernando 
Published: August 2016

Purpose:Countermovement jump (CMJ) and maximum running speed over a distance of 20 m were evaluated for examination of the concurrent fatigue and post-activation potentiation (PAP) in endurance athletes after an incremental feld running test.Methods:Twenty-two endurance athletes performed two attempts of CMJ on a force plate and maximum running speed test before and following the Université de Montréal Track Test (UMTT).Results:The results showed an improvement in CMJ height (3.6%) after UMTT that correlated with the increment in peak power (3.4%), with a concurrent peak force loss (–10.8%) that correlated with peak power enhancement. The athletes maintained their 20 m sprint performance after exhaustion. Cluster analysis reinforced the association between CMJ and peak power increments in responders with a reported correlation between peak power and sprint performance increments (r= .623;P= .041); nonresponders showed an impairment of peak force, vertical stiffness, and a higher vertical displacement of the center of mass during the countermovement that correlated with lactate concentration (r= –0.717;P= .02).Conclusions:It can be suggested that PAP could counteract the peak force loss after exhaustion, allowing the enhancement of CMJ performance and the maintenance of sprint ability in endurance athletes after the UMTT. From these results, the evaluation of CMJ after incremental running tests for the assessment of muscular adaptations in endurance athletes can be recommended.
The Effects of Fatigue on Soccer Skills Performed During a Soccer Match Simulation
Authors: Russell Mark , Benton David , Kingsley Michael 
Published: August 2016

Purpose:This study examined the effects of exercise-induced fatigue on soccer skills performed throughout simulated match play.Methods:Fifteen academy soccer players completed a soccer match simulation (SMS) including passing, dribbling, and shooting skills. Precision, success rate, and ball speed were determined via video analysis for all skills. Blood samples were obtained before exercise (preexercise), every 15 min during the simulation (15, 30, 45, 60, 75, and 90 min), and 10 min into half-time.Results:Preliminary testing confirmed test-retest repeatability of performance, physiological, and metabolic responses to 45 min of the SMS. Exercise influenced shooting precision (timing effect: P = .035) and passing speed (timing effect: P = .011), such that shots taken after exercise were 25.5 ± 4.0% less accurate than those taken before exercise and passes in the last 15 min were 7.8 ± 4.3% slower than in the first 15 min. Shot and pass speeds were slower during the second half compared with the first half (shooting: 17.3 ± 0.3 m·s-1 vs 16.6 ± 0.3 m·s-1, P = 0.012; passing: 13.0 ± 0.5 m·s-1 vs 12.2 ± 0.5 m·s-1, P = 0.039). Dribbling performance was unaffected by exercise. Blood lactate concentrations were elevated above preexercise values throughout exercise (time of sample effect: P < .001).Conclusions:These findings demonstrate that soccer-specific exercise influenced the quality of performance in gross motor skills, such as passing and shooting. Therefore, interventions to maintain skilled performance during the second half of soccer match play are warranted.
A Comparison of Asynchronous and Synchronous Arm Cranking During the Wingate Test
Authors: Lovell Dale I. , Mason Dale , Delphinus Elias , McLellan Chris 
Published: August 2016

Purpose:The aim of this study was to compare asynchronous (AS Y) arm cranking (cranks at 180° relative to each other) with synchronous (SYN) arm cranking (parallel crank setting) during the 30 s Wingate anaerobic test.Methods:Thirty-two physically active men (aged 22.1 ± 2.4 y) completed two Wingate tests (one ASY and one SYN) separated by 4 d in a randomized counterbalanced order. The Wingate tests were completed on a modified electromagnetically braked cycle ergometer. Performance measures assessed during the two tests include peak power, mean power, minimum power, time to peak power, rate to fatigue and maximum cadence (RPMmax). Blood lactate concentration was also measured before and 5 min after the tests.Results:Peak and mean power (both absolute and relative to body weight) during SYN arm cranking were significantly (p < 0.001) less than during ASY arm cranking. Rate to fatigue and RPMmax were also significantly (p = 0.012) lower during SYN arm cranking compared with ASY arm cranking. No significant difference was found between test conditions for minimum power, time to peak power or blood lactate concentration.Conclusions:These findings demonstrate that ASY arm cranking results in higher peak and mean anaerobic power compared with SYN arm cranking during the Wingate test. Therefore, an ASY arm crank configuration should be used to assess anaerobic power in most individuals although specific population groups may require further testing to determine which crank configuration is most suitable for the Wingate test.
The COL5A1 Gene, Ultra-Marathon Running Performance, and Range of Motion
Authors: Brown James C. , Miller Caron-Jayne , Posthumus Michael , Schwellnus Martin P. , Collins Malcolm 
Published: August 2016

Purpose:Endurance running performance is a multifactorial phenotype that is strongly associated with running economy. Sit and reach range of motion (SR ROM) is negatively associated with running economy, suggesting that reduced SR ROM is advantageous for endurance running performance. TheCOL5A1gene has been associated with both endurance running performance and SR ROM in separate cohorts. The aim of this study was to investigate whetherCOL5A1is associated with ultra-marathon running performance and whether this relationship could be partly explained by prerace SR ROM.Methods:Seventy-two runners (52 male, 20 female) were recruited from the 56 km Two Oceans ultra-marathon and were assessed for prerace SR ROM. The cohort was genotyped for theCOL5A1 BsfUI restriction fragment length polymorphism, and race times were collected after the event.Results:Participants with a TT genotype (341 ± 41 min, N = 21) completed the 56 km Two Oceans ultra-marathon significantly (P= 0.014) faster than participants with TC and CC genotypes (365 ± 39 min, N = 50). TheCOL5A1genotype and age accounted for 19% of performance variance. When the cohort was divided into performance and flexibility quadrants, the T allele was significantly (P= 0.044) over-represented within the fast and inflexible quadrant.Conclusion:TheCOL5A1genotype was found to be significantly associated with performance in a 56 km ultra-endurance run. This study confirms previous findings and it furthers our understanding of the relationships among ROM,COL5A1,and endurance running performance. We continue to speculate that theCOL5A1gene alters muscle-tendon stiffness.
A Quasi-Experimental Study of Chinese Top-Level Speed Skaters’ Training Load: Threshold Versus Polarized Model
Authors: Yu Hongjun , Chen Xiaoping , Zhu Weimo , Cao Chunmei 
Published: August 2016

Purpose:To examine the effectiveness of threshold and polarized models in the training organization of Chinese top-level sprint speed skaters using a 2-y quasi-experimental design.Methods:Two years (2004–05 and 2005–06 seasons) of the Chinese national speed-skating team’s daily training load (N = 9; 5 men, 23.6 ± 1.7 y, weight 76.6 ± 4.1 kg, competitive experience 5.0 ± 0.8 y, 500-m time 35.45 ± 0.72 s, 1000-m time 71.18 ± 2.28 s; 4 women, 25.3 ± 6.8 y, 73.0 ± 8.5 kg, 6.3 ± 3.5 y, 37.81 ± 0.46 s, 75.70 ± 0.81 s) were collected and analyzed. Each season’s training load included overall duration (calculated in min and km), frequency (calculated by overall sessions), and training intensity (measured by ear blood lactate or estimated by heart rate), Their performances at national, World Cup, and Olympic competitions during the 2 seasons (2004–06), as well as lactate data measured 15 and 30 min after these competitions, were also collected and analyzed. Based on the lactate data (<2, 2–4, >4 mmol/L), training zones were classified as low, moderate, and high intensity.Results:The total durations and frequencies of the training load were similar across the seasons, but a threshold-training model distribution was used in 2004–05, and a polarized-training-load organization in 2005–06. Under the polarized-training model, or load organization, all speed skaters’ performance improved and their lactate after competition decreased considerably.Conclusion:Training-intensity distribution based on a polarized-training model led to the success in top Chinese sprint speed skaters in the 2005–06 season.
Effect of Contrast Water Therapy Duration on Recovery of Running Performance
Authors: Versey Nathan G. , Halson Shona L. , Dawson Brian T. 
Published: August 2016

Purpose:To investigate whether contrast water therapy (CWT) assists acute recovery from high-intensity running and whether a dose-response relationship exists.Methods:Ten trained male runners completed 4 trials, each commencing with a 3000-m time trial, followed by 8 × 400-m intervals with 1 min of recovery. Ten minutes postexercise, participants performed 1 of 4 recovery protocols: CWT, by alternating 1 min hot (38°C) and 1 min cold (15°C) for 6 (CWT6), 12 (CWT12), or 18 min (CWT18), or a seated rest control trial. The 3000-m time trial was repeated 2 h later.Results:3000-m performance slowed from 632 ± 4 to 647 ± 4 s in control, 631 ± 4 to 642 ± 4 s in CWT6, 633 ± 4 to 648 ± 4 s in CWT12, and 631 ± 4 to 647 ± 4 s in CWT18. Following CWT6, performance (smallest worthwhile change of 0.3%) was substantially faster than control (87% probability, 0.8 ± 0.8% mean ± 90% confidence limit), however, there was no effect for CWT12 (34%, 0.0 ± 1.0%) or CWT18 (34%, –0.1 ± 0.8%). There were no substantial differences between conditions in exercise heart rates, or postexercise calf and thigh girths. Algometer thigh pain threshold during CWT12 was higher at all time points compared with control. Subjective measures of thermal sensation and muscle soreness were lower in all CWT conditions at some post-water-immersion time points compared with control; however, there were no consistent differences in whole body fatigue following CWT.Conclusions:Contrast water therapy for 6 min assisted acute recovery from high-intensity running; however, CWT duration did not have a dose-response effect on recovery of running performance.