bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying Training Intensity Distribution in a Group of Norwegian Professional Soccer Players
Authors: Algrøy Erling A. , Hetlelid Ken J. , Seiler Stephen , Pedersen Jørg I. Stray 
Published: August 2016

Purpose:This study was designed to quantify the daily distribution of training intensity in a group of professional soccer players in Norway based on three different methods of training intensity quantification.Methods:Fifteen male athletes (age, 24 ± 5 y) performed treadmill test to exhaustion to determine heart rate and VO2 corresponding to ventilatory thresholds (VT1, VT2), maximal oxygen consumption (VO2max) and maximal heart rate. VT1 and VT2 were used to delineate three intensity zones based on heart rate. During a 4 wk period in the preseason (N = 15), and two separate weeks late in the season (N = 11), all endurance and on-ball training sessions (preseason: N = 378, season: N= 78) were quantified using continuous heart rate registration and session rating of perceived exertion (sRPE). Three different methods were used to quantify the intensity distribution: time in zone, session goal and sRPE.Results:Intensity distributions across all sessions were similar when based on session goal or by sRPE. However, intensity distribution based on heart rate cut-offs from standardized testing was significantly different (time in zone).Conclusions:Our findings suggest that quantifying training intensity by using heart rate based total time in zone is not valid for describing the effective training intensity in soccer. The results also suggest that the daily training intensity distribution in this representative group of high level Norwegian soccer players is organized after a pattern where about the same numbers of training sessions are performed in low lactate, lactate threshold, and high intensity training zones.
Table Tennis: Cardiorespiratory and Metabolic Analysis of Match and Exercise in Elite Junior National Players
Authors: Sperlich Billy , Koehler Karsten , Holmberg Hans-Christer , Zinner Christoph , Mester Joachim 
Published: August 2016

Purpose:The aim of the study was to determine the cardiorespiratory and metabolic characteristics during intense and moderate table tennis (TT) training, as well as during actual match play conditions.Methods:Blood lactate concentration (Lac), heart rate (HR, beats per minute [bpm]), oxygen uptake (VO2), and energy expenditure (EE) in 7 male participants of the German junior national team (age: 14 ± 1 y, weight: 60.5 ± 5.6 kg height; 165 ± 8 cm) were examined during six training sessions (TS) and during an international match. The VO2 was measured continuously with portable gas analyzers. Lac was assessed every 1 to 3 min during short breaks.Results:Mean (peak) values for Lac, HR, VO2, and EE during the TS were 1.2 ± 0.7 (4.5) mmol·L–1, 135 ± 18 (184) bpm, 23.5 ± 7.3 (43.0) mL·kg–1· min–1, and 6.8 ± 2.0 (11.2) METs, respectively. During match play, mean (peak) values were 1.1 ± 0.2 (1.6) mmol·L–1, 126 ± 22 (189) bpm, 25.6 ± 10.1 (45.9) mL·kg–1·min–1, and 4.8 ± 1.4 (9.6) METs, respectively.Conclusions:For the frst time, cardiorespiratory and metabolic data in elite junior table tennis have been documented demonstrating low cardiorespiratory and metabolic demands during TT training and match play in internationally competing juniors.
Energy System Contributions to the Special Judo Fitness Test
Authors: Franchini Emerson , Sterkowicz Stanislaw , Szmatlan-Gabrys Urszula , Gabrys Tomasz , Garnys Michal 
Published: August 2016

Purpose:This study investigated the energy system contributions of judo athletes to the Special Judo Fitness Test (SJFT).Methods:Fourteen male judo athletes performed the SJFT, which comprised three periods of judo activity (A = 15 s, B and C = 30 s) interspersed with 10 s rest intervals. During this test, one athlete threw two others positioned 6 m from each other using the ippon-seoi-nage technique. The fractions of the aerobic, anaerobic alactic and anaerobic lactic systems were calculated based on oxygen uptake, the fast component of excess postexercise oxygen uptake, and changes in net blood lactate, respectively. The contribution of the three energy systems was compared using a repeated measures analysis of variance and Bonferroni’s multiple comparisons test. Compound symmetry, or sphericity, was determined by Mauchly’s test. A level of significance of 5% (P < .05) was adopted in all analyses.Results:The alactic energy system presented a higher (F = 20.9; P < .001; power observed = 1.0) contribution (86.8 ± 23.6 kJ; 42.3 ± 5.9%) during the test when compared with both aerobic (57.1 ± 11.3 kJ; 28.2 ± 2.9%) and lactic (58.9 ± 12.1 kJ; 29.5 ± 6.2%) energy systems (P < .001 for both comparisons).Conclusions:The higher alactic contribution seems to be a consequence of the high-intensity efforts performed during the test, and its intermittent nature. Thus, when using the SJFT, coaches are evaluating mainly their athletes’ anaerobic alactic system, which can be considered to be the most predominant system contributing to the actions (techniques) performed in the match.
The Relationship Between Serum and Salivary Cortisol Levels in Response to Different Intensities of Exercise
Authors: VanBruggen Mitch D. , Hackney Anthony C. , McMurray Robert G. , Ondrak Kristin S. 
Published: August 2016

Purpose:The effect of exercise intensity on the tracking of serum and salivary cortisol responses was examined in 12 endurance-trained males (maximal oxygen uptake [VO2max] = 58.2 ± 6.4 mL/kg/min).Methods:Subjects rested for 30 min (control) and exercised on a cycle ergometer for 30 min at 40% (low), 60% (moderate), and 80% (high intensity) of VO2max on separate days. Serum and saliva samples were collected pretrial, immediately posttrial, and 30 min into the recovery period from each trial.Results:Cortisol responses increased significantly for both serum (40.4%; P = .001) and saliva (170.6%; P = .007) only in response to high-intensity exercise. Peak saliva cortisol occurred at 30 min of recovery, whereas peak serum was at the immediate posttrial sampling time point. The association between serum and saliva cortisol across all trials was examined using concordance correlation (Rc) analysis, which accounts for repeated measures. The overall correlation between serum and saliva cortisol levels in all matched samples was significant (Rc = 0.728; P = .001). The scatter plot revealed that salivary cortisol responses tracked closely to those of serum at lower concentrations, but not as well at higher concentrations.Conclusions:Findings suggest salivary measurements of cortisol closely mirror those in the serum and that peak salivary concentrations do not occur until at least 30 min into the recovery from intense exercise.
Fitness Determinants of Repeated-Sprint Ability in Highly Trained Youth Football Players
Authors: Spencer Matt , Pyne David , Santisteban Juanma , Mujika Iñigo 
Published: August 2016

Variations in rates of growth and development in young football players can influence relationships among various fitness qualities.Purpose:To investigate the relationships between repeated-sprint ability and other fundamental fitness qualities of acceleration, agility, explosive leg power, and aerobic conditioning through the age groups of U1 1 to U18 in highly trained junior football players.Methods:Male players (n = 119) across the age groups completed a fitness assessment battery over two testing sessions. The first session consisted of countermovement jumps without and with arm swing, 15-m sprint run, 15-m agility run, and the 20-m Shuttle Run (U11 to U15) or the Yo-Yo Intermittent Recovery Test, Level 1 (U16 to U18). The players were tested for repeated-sprint ability in the second testing session using a protocol of 6 × 30-m sprints on 30 s with an active recovery.Results:The correlations of repeated-sprint ability with the assorted fitness tests varied considerably between the age groups, especially for agility (r = .02 to .92) and explosive leg power (r = .04 to .84). Correlations of repeated sprint ability with acceleration (r = .48 to .93) and aerobic conditioning (r = .28 to .68) were less variable with age.Conclusion:Repeated-sprint ability associates differently with other fundamental fitness tests throughout the teenage years in highly trained football players, although stabilization of these relationships occurs by the age of 18 y. Coaches in junior football should prescribe physical training accounting for variations in short-term disruptions or impairment of physical performance during this developmental period.
Anaerobic Work Capacity’s Contribution to 5-km-Race Performance in Female Runners
Authors: Baumann Cory W. , Rupp Jeffrey C. , Ingalls Christopher P. , Doyle J. Andrew 
Published: August 2016

Purpose:The purpose of this study was to examine the relationship between anaerobic characteristics and 5-km-race performance in trained female cross-country runners (N = 13).Methods:The runners performed 50-m sprints and a 5-km time trial on an outdoor 400-m track and maximal anaerobic (MART) and aerobic running tests on a motorized treadmill. Anaerobic characteristics were determined by the mean velocity of the 50-m sprint (v50m) and the peak velocity in the MART (vMART). The aerobic characteristics were obtained during the aerobic treadmill test and included maximal oxygen uptake (VO2max), running economy, and ventilatory threshold (VT).Results:Both the vMART (r = .69, P < .01) and VO2max (r = .80, P < .01) correlated with the mean velocity of the 5-km (v5km). A multiple-linear-regression analysis revealed that the combination of VO2max, vMART, and VT explained 81% (R2 = .81, P < .001) of the variation seen in the v5km. The vMART accounted for 31% of the total shared variance, while the combination of VO2max and VT explained the remaining 50%.Conclusions:These results suggest that among trained female runners who are relatively matched, anaerobic energy production can effectively discriminate the v5km and explain a significant amount of the variation seen in 5-km-race performance.
Wingate Anaerobic Test Reference Values for Male Power Athletes
Authors: Coppin Erin , Heath Edward M. , Bressel Eadric , Wagner Dale R. 
Published: August 2016

Purpose:The aim of this study was to develop reference values for the Wingate Anaerobic Test (WAnT) for peak power (PP), mean power (MP), and fatigue index (FI) in NCAA Division IA male athletes.Methods:Seventy-seven athletes (age 20.8 ± 1.8 y, mass 84.4 ± 9.4 kg, height 183.9 ± 6.2 cm) participating in American football (n = 52) and track and field (n = 25) performed a 30-s WAnT resisted at 0.085 kp/kg body mass (BM).Results:Absolute mean (± SD) values for PP and MP were 1084.2 ± 137.0 and 777.1 ± 80.9 W, respectively, whereas values normalized to BM were 12.9 ± 1.5 and 9.3 ± 0.9 W/kg BM, respectively. Mean FI values were 49.1% ± 8.4%. PP outputs >13.6, 12.4–13.6, and <12.4 W/kg BM were classified as high, medium, and low, respectively. MP outputs >9.8, 9.0–9.8, and <9.0 W/kg BM were classified as high, medium, and low, respectively.Conclusions:The reference values developed in this study can be used in various athletic training and research programs to more accurately assess athletes’ anaerobic fitness and to monitor changes resulting from anaerobic training.
Hemolytic Effects of a Football-Specific Training Session in Elite Female Players
Authors: Tan Daniel , Dawson Brian , Peeling Peter 
Published: August 2016

Purpose:This study aimed to quantify the hemolytic responses of elite female football (soccer) players during a typical weekly training session.Methods:Ten elite female football players (7 field players [FPs] and 3 goalkeepers [GKs]) were recruited from the Australian National Women’s Premier League and asked to provide a venous blood sample 30 min before and at the immediate conclusion of a typical weekly training session. During this training session, the players’ movement patterns were monitored via a 5-Hz global positioning system. The blood samples collected during the training session were analyzed for iron status via serum ferritin (SF) analysis, and the hemolytic response to training, via serum free hemoglobin (Hb) and haptoglobin (Hp) measurement.Results:50% of the participants screened were found to have a compromised iron stores (SF <35 μg/L). Furthermore, the posttraining serum free Hb levels were significantly elevated (P = .011), and the serum Hp levels were significantly decreased (P = .005), with no significant differences recorded between the FPs and GKs. However, the overall distance covered and the movement speed were significantly greater in the FPs.Conclusions:The increases in free Hb and decreases in Hp levels provide evidence that a typical team-sport training session may result in significant hemolysis. This hemolysis may primarily be a result of running-based movements in FPs and/or the plyometric movements in GKs, such as diving and tackling.
Mechanical Efficiency of Treadmill Running Exercise: Effect of Anaerobic-Energy Contribution at Various Speeds
Authors: Keir Daniel A. , Zory Raphaël , Boudreau-Larivière Céline , Serresse Olivier 
Published: August 2016

Objectives:Mechanical efficiency (ME) describes the ratio between mechanical (PMECH) and metabolic (PMET) power. The purpose of the study was to include an estimation of anaerobic energy expenditure (AnE) into the quantification ofPMETusing the accumulated oxygen deficit (AOD) and to examine its effect on the value of ME in treadmill running at submaximal, maximal, and supramaximal running speeds.Methods:Participants (N = 11) underwent a graded maximal exercise test to determine velocity at peak oxygen uptake (vVO2peak). On 4 separate occasions, subjects ran for 6 min at speeds corresponding to 50%, 70%, 90%, and 110% ofvVO2peak. During each testing session,PMETwas measured from pulmonary oxygen uptake (VO2p) using opencircuit spirometry and was quantified in 2 ways: from VO2pand an estimate of AnE(from the AOD method) and from VO2ponly.PMECHwas determined from kinematic analyses.Results:ME at 50%, 70%, 90%, and 110% ofvVO2peakwas 59.9% ± 11.9%, 55.4% ± 12.2%, 51.5% ± 6.8%, and 52.9% ± 7.5%, respectively, when AnEwas included in the calculation ofPMET. The exclusion of AnEyielded significantly greater values of ME at all speeds: 62.9% ± 11.4%, 62.4% ± 12.6%, 55.1% ± 6.2%, and 64.2% ± 8.4%;P= .001 (for 50%, 70%, 90%, and 110% ofvVO2peak, respectively).Conclusions:The data suggest that an estimate of AnEshould be considered in the computation ofPMETwhen determining ME of treadmill running, as its exclusion leads to overestimations of ME values.
Cooling and Performance Recovery of Trained Athletes: A Meta-Analytical Review
Authors: Poppendieck Wigand , Faude Oliver , Wegmann Melissa , Meyer Tim 
Published: August 2016

Purpose:Cooling after exercise has been investigated as a method to improve recovery during intensive training or competition periods. As many studies have included untrained subjects, the transfer of those results to trained athletes is questionable.Methods:Therefore, the authors conducted a literature search and located 21 peer-reviewed randomized controlled trials addressing the effects of cooling on performance recovery in trained athletes.Results:For all studies, the effect of cooling on performance was determined and effect sizes (Hedges’ g) were calculated. Regarding performance measurement, the largest average effect size was found for sprint performance (2.6%, g = 0.69), while for endurance parameters (2.6%, g = 0.19), jump (3.0%, g = 0.15), and strength (1.8%, g = 0.10), effect sizes were smaller. The effects were most pronounced when performance was evaluated 96 h after exercise (4.3%, g = 1.03). Regarding the exercise used to induce fatigue, effects after endurance training (2.4%, g = 0.35) were larger than after strength-based exercise (2.4%, g = 0.11). Cold-water immersion (2.9%, g = 0.34) and cryogenic chambers (3.8%, g = 0.25) seem to be more beneficial with respect to performance than cooling packs (−1.4%, g= −0.07). For cold-water application, whole-body immersion (5.1%, g = 0.62) was significantly more effective than immersing only the legs or arms (1.1%, g = 0.10).Conclusions:In summary, the average effects of cooling on recovery of trained athletes were rather small (2.4%, g = 0.28). However, under appropriate conditions (whole-body cooling, recovery from sprint exercise), postexercise cooling seems to have positive effects that are large enough to be relevant for competitive athletes.
Foot-Strike Pattern and Performance in a Marathon
Authors: Kasmer Mark E. , Liu Xue-cheng , Roberts Kyle G. , Valadao Jason M. 
Published: August 2016

Purpose:To determine prevalence of heel strike in a midsize city marathon, if there is an association between foot-strike classification and race performance, and if there is an association between foot-strike classification and gender.Methods:Foot-strike classification (forefoot, midfoot, heel, or split strike), gender, and rank (position in race) were recorded at the 8.1-km mark for 2112 runners at the 2011 Milwaukee Lakefront Marathon.Results:1991 runners were classified by foot-strike pattern, revealing a heel-strike prevalence of 93.67% (n = 1865). A significant difference between foot-strike classification and performance was found using a Kruskal-Wallis test (P< .0001), with more elite performers being less likely to heel strike. No significant difference between foot-strike classification and gender was found using a Fisher exact test. In addition, subgroup analysis of the 126 non-heel strikers found no significant difference between shoe wear and performance using a Kruskal-Wallis test.Conclusions:The high prevalence of heel striking observed in this study reflects the foot-strike pattern of most mid-distance to long-distance runners and, more important, may predict their injury profile based on the biomechanics of a heel-strike running pattern. This knowledge can help clinicians appropriately diagnose, manage, and train modifications of injured runners.
The Effects of Wearing Lower Body Compression Garments During a Cycling Performance Test
Authors: Driller Matthew W. , Halson Shona L. 
Published: August 2016

Purpose:Compression garments have been commonly used in a medical setting as a method to promote blood flow. Increases in blood flow during exercise may aid in the delivery of oxygen to the exercising muscles and, subsequently, enhance performance. The aim of the current study was to investigate the effect of wearing lower body compression garments during a cycling test.Methods:Twelve highly trained cyclists (mean ± SD age 30 ± 6 y, mass 75.6 ± 5.8 kg, VO2peak 66.6 ± 3.4 mL · kg−1 · min−1) performed two 30-min cycling bouts on a cycle ergometer in a randomized, crossover design. During exercise, either full-length lower body compression garments (COMP) or above-knee cycling shorts (CON) were worn. Cycling bouts involved 15 min at a fixed workload (70% of VO2max power) followed by a 15-min time trial. Heart rate (HR) and blood lactate (BL) were measured during the fixed-intensity component of the cycling bout to determine the physiological effect of the garments. Calf girth (CG), thigh girth (TG) and perceived soreness (PS) were measured preexercise and postexercise.Results:COMP produced a trivial effect on mean power output (ES = .14) compared with CON (mean ± 95% CI 1.3 ±1.0). COMP was also associated with a lower HR during the fixed-workload section of the test (−2.6% ± 2.3%, ES = −.38). There were no differences between groups for BL, CG, TG, and PS.Conclusion:Wearing compression garments during cycling may result in trivial performance improvements of ~1% and may enhance oxygen delivery to the exercising muscles.
Is Gross Efficiency Lower at Acute Simulated Altitude Than at Sea Level?
Authors: Noordhof Dionne A. , Schoots Thijs , Hoekert Derk H. , de Koning Jos J. 
Published: August 2016

Purpose:The purpose of this study was to test the assumption that gross efficiency (GE) at sea level (SL) is representative of GE at altitude (AL). It was hypothesized that an increased cost of ventilation and heart rate, combined with a higher respiratory-exchange ratio, at AL might result in a decrease in GE.Methods:Trained men (N = 16) completed 2 maximal incremental tests and 2 GE tests, 1 at SL and 1 at an acute simulated AL of 1500 m (hypobaric chamber). GE was determined during submaximal exercise at 45%, 55%, and 65% of the altitude-specific power output attained at VO2max.Results:GE determined at the highest submaximal exercise intensity with a mean RER ≤1.0, matched for both conditions, was significantly lower at AL (AL 20.7% ± 1.1% and SL 21.4% ± 0.8%, t15 = 2.9, P < .05).Conclusion:These results demonstrate that moderate AL resulted in a significantly lower GE during cycling exercise than SL. However, it might be that the lower GE at AL is caused by the lower absolute exercise intensity.
The Reliability of a Rugby League Movement-Simulation Protocol Designed to Replicate the Performance of Interchanged Players
Authors: Waldron Mark , Highton Jamie , Twist Craig 
Published: August 2016

Purpose:This study assessed the reliability of a rugby league movement-simulation protocol, relative to interchanged players (RLMSP-i).Methods:Fifteen male participants completed 2 trials of the RLMSP-i, separated by 1 wk. The RLMSP-i comprised low- to moderate-intensity running, interspersed by high-intensity sprinting and tackling activity, based on global positioning system (GPS) data recorded during Super League performances.Results:The lowest coefficient of variation (CV ± 95% CI) was observed for total m/min during both interchange bout 1 (1.1% ± 0.2%) and bout 2 (1.0% ± 0.2%). The percentage of heart rate peak and ratings of perceived exertion demonstrated CVs of 1.2–2.0% and 2.9–3.5%, respectively. The poorest agreement between trials was found for blood lactate concentration (16.2% ± 2.8%). In no case was the CV smaller than the smallest worthwhile change, yet in every case the moderate changes were larger than the CV.Conclusions:The RLMSP-i’s reliability is sufficient to enable the detection of moderate changes in various performance and physiological measurements that accurately simulate some, but not all, aspects of rugby league matches.