bluuebunny/crossref_metadata_2025_split huggingface dataset:
The acute effect of commercial "energy drink" on hematological, biochemical and strength parameters induced by eccentric contractions
Authors: Hismiogullari Adnan Adil , Punduk Zekine , Hismiogullari Sahver Ege , Yavuz Ozlem 
Published: October 2018

BACKGROUND: Commercial energy drink usage is reported to be higher in athletes and adolescents. However, the impact of pre-exercise consumption of energy beverages on hematologic and biochemical responses and skeletal muscle contractile properties has not been fully elucidated. METHOD: Ten male subjects performed 50 maximal eccentric actions on an isokinetic dynamometer at 90°/sec followed by two identical trials that were preceded by consuming either a placebo (P) or energy drink (ED) beverage. The test was repeated after 7–10 days while consuming the alternate beverage. Complete blood counts and chemistry profile was conducted before and immediately after exercise. RESULTS: Eccentric contractions resulted in an increased number of neutrophils (Neut) and decreased lymphocytes (Lymph), decreased eosinophils(EOS) and did not change basophil (BASO) levels in control. However, the BASO levels increased immediately after the exercise with P and ED beverage consumption. In contrast, P and ED beverage consumption had no effect on Neut, Lymph, MONO or EOS counts after exercise compared to pre-exercise values. Acute exercise increased creatinine kinase (CK) and decreased phosphorus (Pi) but did not have any effect on other blood chemistry parameters. The biochemical profile and eccentric muscle contractile properties were not significantly affected by any of the beverages. CONCLUSIONS: Consumption of pre-exercise energy drink does not have a favorable effect on immune blood cells induced in the acute eccentric exercise model.
The reproducibility of three different indicators of fatigue from plantar-flexion isokinetic testing at two knee flexion angles is not sufficient to be termed 'acceptable'
Authors: Hébert-Losier Kim , Willis Sarah J. , Holmberg Hans-Christer 
Published: October 2018

OBJECTIVE: To characterize the reproducibility of three indicators of fatigue (FIs) specific to concentric plantar-flexion isokinetic testing at knee flexion (KF) angles of 0° (straight) and 45° (bent). METHODS: On two separate days one week apart, thirty-four males performed 50 consecutive maximal concentric isokinetic plantar-flexion contractions at 60°/s with 0° and 45° of KF. Differences in the pre- and post-maximal voluntary isometric contraction torques(FI $_{static}$ ), powers during the initial five and last five isokinetic contractions (FI $_{dynamic}$ ) and powers during the 50 isokinetic contractions (FI $_{slope}$ ) were used as FIs. Changes in means, intra-class correlation coefficients (ICCs) and coefficients of variations (CVs) were computed to quantify the reproducibility of the FIs. Comparisons were made between the two KF angles and three FIs using two-way repeated measures ANOVA. RESULTS: For both KF angles and three FIs, ICCs ranged from 0.52 to 0.71 and CVs from 10.0 to 29.3%. The CVs from the two isokinetic-based FIs were lower than those from the isometric FI and a trend towards larger ICCs at 0° was observed. CONCLUSIONS: The reproducibility of the three FIs was not sufficient to be termed 'acceptable'. The FI $_{slope}$ and FI $_{dynamic}$ were more reproducible than FI $_{static}$ and are recommended – with the knee straight rather than bent – until more reliable indicators become available.
Between-day reliability of pedal forces for cyclists during an incremental cycling test to exhaustion
Authors: Bini Rodrigo R. , Hume Patria A. 
Published: October 2018

BACKGROUND: Reliability of pedal forces during cycling specific tests needs to be established if pedal forces are to be used in longitudinal studies evaluating performance improvements. METHOD: We assessed the reliability of pedal force measures during two incremental cycling tests to exhaustion separated by two to seven days. The number of competitive cyclists completing each workload increment varied (n=10 for 100 W to 250 W; n=8 for 300 W; n=6 for 350 W). Pedal forces were measured via strain gauge instrumented pedals and pedal-to-crank angles via angular potentiometers attached to the pedal spindles. Mean and standard deviations, typical error of measurement percentage (TE%) and effect sizes (ES) between days across workloads for oxygen uptake (VO $_{2}$ ), peak normal force (PNF), peak anterior-posterior force (PAPF), average total force on the pedal (ATF) and index of effectiveness percentage (IE) for right and left pedals were calculated. RESULTS: Averages across all workloads showed high reliability and trivial differences between two to seven days of testing for all variables(TE%, ICC, ES; VO $_{2}$ =4%, 0.94, 0.1; PNFright=6%, 0.98, 0.1; PNFleft=12%, 0.98, 0.1; PAPFright=13%, 0.95, 0.2; PAPFleft=14%, 0.96, 0.1; ATFright=5%, 0.98, 0.1; ATFleft=11%, 0.97, 0.1; IEright=10%, 0.94, 0.2; IEleft=14%, 0.91, 0.1). CONCLUSION: Pedal force measures during incremental cycling tests to exhaustion can be used to assess changes in performance given the high reliability reported in our study.
Single-joint isometric rate of torque development is not related to counter- movement jump performance in soccer players
Authors: Wilhelm Eurico N. , Radaelli Regis , da Silva Bruna G.C. , Botton Cíntia E. , Barbosa Rafael , Bottaro Martim , Brown Lee E. , Pinto Ronei S. 
Published: October 2018

BACKGROUND AND OBJECTIVE: The quadriceps rate of torque development(RTD) is frequently used to evaluate explosive performance, but its functional meaning has been questioned. Thus, the aim of this study was to investigate if isometric quadriceps RTD correlates with multi-joint dynamic performance and if it has greater correlation with dynamic performance than with a single-joint isokinetic test in soccer players. METHODS: Thirty-nine male soccer players (age 21 ± 5 years, body mass 75 ± 7.5 kg, height 179 ± 5 cm) performed five maximal concentric knee extension isokinetic contractions at a velocity of 180°/s, followed by three maximal voluntary isometric contractions (MVIC) with knee angle of 60°, and five countermovement jumps (CMJ). The RTD was derived from MIVC over various time intervals (of 0.05, 0.1, 0.2, 0.3 seconds, and peak RTD) and CMJ height was calculated by flight time method. Pearson Product Moment Correlations were used to determine the relationships between variables. RESULTS: Absolute and relative isokinetic PT correlated positively with CMJ height (p< 0.001, r=0.513 and p=0.0007, r=0.521, respectively). However, none of the isometric RTD measures showed significant relationship with CMJ height (p> 0.05, r from −0.272 to 0.296). CONCLUSION: These results indicate that single-joint isometric RTD does not correlate with dynamic multi-joint performance. Thus, more specific tests in relation to contraction type, velocity and/or movement pattern should be used.
Effect of optimal cycling repeated-sprint combined with classical training on peak leg power in female soccer players
Authors: Nebil Gmada , Zouhair Farhani , Hatem Bouhlel , Hamza Marzouki , Zouhair Tabka , Roy Shephard , Ezdine Bouhlel 
Published: October 2018

BACKGROUND: Muscle power is one of the most important factors influencing sport performance. Despite the variety of training methods used in the literature, more individualised, varied and enjoyable methods are needed to enhance muscle peak power in soccer. OBJECTIVE: To assess the effect of short-sprint cycle ergometer training on peak power output and field performance of female soccer players. METHODS: 7 female soccer players (age: 20.2 ± 1.5 (years); body mass: 55.1 ± 6.1 (kg); height: 1.61 ± 0.06 (m)) served as an experimental group, and seven female soccer players (age: 19.4 ± 1.5(years); body mass: 65.2 ± 6.1 kg; height: 1.69 ± 0.08 m) as a control group. Peak power output (� peak) during a cycle ergometer force-velocity test and field performance (5-jump test and speeds over 10, 20 and 30 m) were assessed both before and after training (3 months duration, with 3 sessions per week). Each training session comprised 2 series of 15 sprints, separated by a 15 min recovery interval. Individual sprints were of 5 sec duration, at the optimal pedalling velocity for the subject (100–110 rpm) and against the optimal frictional loading equal of the subject(7.5%–8.5% of body mass); a recovery period of 55 sec was allowed between sprints. RESULTS: The training regimen induced gains of peak power (p< 0.05), whether expressed in �, �/kg, or relative to leg muscle volume (�/l). There were also gains in 5-jump (p< 0.01), and 20 and 30 m sprint velocities (p< 0.01). Findings in the control participants remained unchanged. CONCLUSION: When combined with traditional soccer training, repeated short sprints on a cycle ergometer offer an effective strategy for enhancing leg power in female Tunisian soccer players.
The relationships between leg peak power and shot-put performance in national-level athletes
Authors: Landolsi Mounir , Bouhlel Ezzedine , Zarrouk Fayçal , Lacouture Patrick , Tabka Zouhair 
Published: October 2018

AIM: Was to study the relationships between leg peak power, leg muscle volume and Shot-put performance in trained shot-putter. METHODS: Twenty-three shot-putter participated in this study. Anthropometric measurements were carried out to estimate leg muscle volume. Leg peak power and others biomechanical parameters (maximal force, maximal velocity, optimal force, optimal velocity) were measured using leg force-velocity test on ergocycle Monark, and the Optojump device. The shot-put performances were measured during a simulated competition. RESULTS: We found significant correlations between peak power output(W) measured during leg force-velocity Test on ergocycle (PPO-Ergo) and muscle volume for men (r=0.79, p< 0.01) and women (r=0.72, p< 0.05). PPO-Ergo(W, W/kg) was significantly correlated with the vertical jump performance(r=0.56, p< 0.05; r=0.62, p< 0.01 respectively). Shot-put performance was significantly correlated with PPO-Ergo (W, W/kg) and maximal force (N) (r=0.72, p < 0.001; r=0.48, p< 0.05; r=0.85, p< 0.001 respectively). PPO as estimated from the vertical jump using the Optojump system (PPO-Opto) was not correlated to shot-put performances. CONCLUSION: The correlation between PPO-Ergo and shot-put performance showed that the force-velocity Test on ergocycle constitute a useful tool assessing PPO and others biomechanical parameters in shot-putter athletes. However, the Optojump system seems to be not accurate for such subjects. Fat mass constitute probably the limiting factor in shut-putter during this test.
The effects of selected forms of physical activity on trunk muscle function in women following breast cancer treatment
Authors: Hanuszkiewicz J. , Malicka I. , Woźniewski M. 
Published: October 2018

BACKGROUND: Appropriate physical training regimens are capable of restoring correct trunk muscle activity characteristics in women who have undergone breast cancer treatment. OBJECTIVE: Assessment of the effects of various forms of physical activity on trunk muscle function. STUDY GROUP: Sixty women who had received breast cancer treatment. The study group was further divided into three subgroups of 20 women who followed different exercise regimens: Nordic walking (NW), water resistance exercise(WE) or general fitness exercise (GE). METHODS: Assessment of strength and velocity parameters of trunk flexor and extensor was performed at 60 and 120°/s before and after completion of the exercise regimen. RESULTS: A significant improvement in strength and velocity parameters was noted in the NW and WE groups regardless of the muscle group and angular velocity. In the GE group, a significant improvement was noted for the flexors PT only at 120°/s. CONCLUSIONS: NW and WE exercise regimens enhance trunk muscle function in women following breast cancer treatment, whereas GE may be useful only for sustaining the existing level of trunk muscle performance. The diversity of changes in trunk muscle function that may be achieved depending on the type and nature of the physical training regimen demonstrates the need of appropriate exercise selection to attain the desired corrective effect.
Chronic ankle instability impairs quadriceps femoris contractility and it is associated with reduced stretch-shortening cycle function
Authors: Váczi Márk , Ambrus Míra 
Published: October 2018

BACKGROUND: It is well established that chronic ankle instability (CAI) is associated with reduced strength in the muscles around the ankle joint complex. OBJECTIVE: To examine the quadriceps femoris (QF) function in individuals with CAI. METHODS: The mechanical properties of the QF were assessed in10 physically active individuals with unilateral CAI, and were compared with 10 healthy controls. Peak torque, rate of torque development, and stretch-shortening cycle function were determined in both legs. Injured subjects were selected based on an instability index score, and were matched with controls by gender, weight, and leg dominance. RESULTS: In the CAI group, when the injured leg's performance was expressed as percent of the healthy, the fast velocity concentric torque and rate of torque development were smaller compared to the controls'. In the same group, reduced positive work and mechanical efficiency, and increased stretch-shortening cycle contraction time were associated with the magnitude of the ankle instability. CONCLUSIONS: CAI patients may suffer from high velocity contractility impairment in the QF of the injured side, possibly due to reduced recruitment of fast motor units. The severity of ankle instability may influence stretch-shortening cycle function, indicating reduced ability to store and reuse elastic energy.
The effects of gender and very short-term resistance training on peak torque, average power and neuromuscular responses of the forearm flexors
Authors: Traylor Daniel A. , Housh Terry J. , Lewis Robert W. , Bergstrom Haley C. , Cochrane Kristen C. , Jenkins Nathaniel D.M. , Schmidt Richard J. , Johnson Glen O. , Cramer Joel T. 
Published: October 2018

OBJECTIVE: This study examined the effects of %sex gender on peak torque (PT), average power (AP), and the time (AMP) and frequency (MPF) domain parameters of the electromyographic (EMG) and mechanomyographic (MMG) signals following very short-term resistance training (VST) of the forearm flexors. Based on the results of previous studies it was hypothesized that three training sessions would increase PT, EMG MPF, and MMG MPF of the forearm flexors at 60 and 180°/s in men only, without changes to AP, EMG AMP, or MMG AMP for either men or women. METHODS: Nine men and nine women completed two pretests, three training sessions, and a posttest that included concentric isokinetic muscle actions of the forearm flexors at 60 and 180°/s. The AMP and MPF of the EMG and MMG signals were recorded from the biceps brachii. RESULTS: The results indicate increases in PT, AP, and MMG AMP at 60 and 180°/s for the men only, but no changes in EMG AMP, EMG MPF, or MMG MPF for either the men or women. CONCLUSION: There were gender differences in the PT and AP responses to VST of the forearm flexors that were not associated with increased agonist muscle activation. These findings have implications for the development of gender-specific VST programs for the forearm flexors in clinical settings.
Is isokinetic eccentric exercise dangerous for the heart?
Authors: Le Goff C. , Kaux J.-F. , Laurent T. , Vannuscorps J. , Pincemail J. , Chapelle J.-P. , Cavalier E. , Croisier J.-L. 
Published: October 2018

BACKGROUND: Very strenuous exercises can be performed on an isokinetic dynamometer in order to evaluate the resistance to fatigue of different muscular groups. Good cardiac function is necessary in order to perform these very intensive exercises; otherwise an acute myocardial dysfunction could theoretically appear in predisposed patients. OBJECTIVE: Our study aimed to observe the cardiovascular impact of a maximal intense isokinetic eccentric exercise performed by a population of sedentary young men. METHODS: Resting and post-exercise (just after, 3 hours and 24 hours after the exercise) blood samples were taken from 12 young male sedentary healthy subjects. These subjects performed an intense maximal eccentric isokinetic exercise of the quadriceps muscle. We evaluated markers of cardiovascular risk (troponin I, highly sensitive troponin T, NT-proBNP, myoglobin), of inflammation (hsCRP) and of oxidative stress (myeloperoxydase, lipidic peroxides, reduced and oxidised glutathione). RESULTS: The following observations were made: no significant increase in cardiac (NT-proBNP, troponins) or inflammation (hsCRP) biomarkers; a significant increase in myoglobin, myeloperoxidase, lipidic peroxides, oxidised glutathione just after the exercise. CONCLUSIONS: No modification in cardiac biomarkers were observed after the maximal eccentric isokinetic exercise. We were thus able to prove that the exercise could be performed without any risk to cardiac function in young sedentary subjects. However, a significant level of oxidative stress was induced by this exercise.
Reliability of 1RM test in detrained men with previous resistance training experience
Authors: Ribeiro Alex Silva , do Nascimento Matheus Amarante , Mayhew Jerry L. , Ritti-Dias Raphael Mendes , Avelar Ademar , Okano Alexandre Hideki , Cyrino Edilson Serpeloni 
Published: October 2018

BACKGROUND: The one-repetition maximum (1RM) test is the most widely used method to analyze muscular strength. However, the 1RM reliability may be dependent on previous resistance training experience. OBJECTIVE: The purpose of the study was to analyze the reliability of 1RM test in detrained men with previous resistance training experience. METHODS: Sixty-seven men (21.1 years, 71.4 kg, 174.1 cm, 23.5 m/kg $^{2}$ ) were recruited and allocated to one of the three groups, according to their previous experience in resistance training: Novice (n=29, from 1 to 6 months), Intermediate (n=19, from 7 to 12 months), and Advanced(n=19, from 13 to 24 months). All subjects performed the 1RM test in the bench press, squat, and arm curl in four sessions. At each session the subjects performed three attempts to reach a peak strength level for each exercise. RESULTS: Significant increases (P< 0.05) in maximal strength between the first and fourth sessions were consistent for each group in bench press (8.3% to 9.8%), squat (14.9% to 18.5%), and arm curl (7.6% to 10.0%) with no group-by-time interaction. CONCLUSION: Despite two years of previous RT experience men need at least two 1RM sessions to achieve accurate maximal strength baseline scores, Thus, a minimum two-trial 1RM assessment may be the standard for determining a maximal strength baseline in order not to underestimate achievement.
Time-effects of horse simulator exercise on psychophysiological responses in men with chronic low back pain
Authors: Oh Hye-Won , Lee Min-Geol , Jang Jun-Young , Jin Jun-Jang , Cha Jun-Youl , Jin Young-Yoon , Jee Yong-Seok 
Published: October 2018

BACKGROUND: Although horse simulator riding is very beneficial for patients with several diseases, there are few studies relating to treating patients with chronic low back pain (CLBP) specifically in terms of physiological and psychological outcome measures. It also has not been medically verified yet on the aspects of psychological responses and physiological changes. As well as there are not known how it can decrease the pain, how it can increase the physical conditioning, and how much good time rides a horse simulator. OBJECTIVE: To investigate the time-effects of an 8 week horse simulator exercise on body composition, visual analogue scale(VAS), and isokinetic torques of the trunk and hip joints in patients with CLBP. METHODS: Forty one young men presenting with CLBP were divided into 4 groups: LBP control group (LCG), LBP horse simulator 10 min riding group(LHS10G), LBP horse simulator 20 min riding group (LHS20G), and LBP horse simulator 30 min riding group (LHS30G), respectively. Three horse simulator exercise groups completed a rehabilitation exercise protocol for 5 days per week during 8 weeks. VAS was used to measure the severity of CLBP and functional disability for checking psychological responses. Body composition measured by bioelectrical analyzer and isokinetic torques were used to consider the physiological pre-post changes. RESULTS: Compared with the baseline, the body composition indices did not change significantly. However, muscle mass and fat mass showed increasing and decreasing tendencies in the LHS30G. The VAS indices showed significant decrease in back pain including other 12 items. A significant decrease was observed for all items except for drug relief. Especially, most of items in the LHS20G were lower than those of the other groups in the post hoc comparison. The horse simulator exercise enhanced the isokinetic strength of trunk and hip muscles. Due to the increased strength, trunk flexor/extensor ratio, hip flexor/extensor ratio, and hip abductor/adductor were close to reference values. The deficit in the ratio scores: hip flexor and extensor and hip abductor and adductor evened out after an experiment. Especially, these improvements were associated particularly with LHS20G. CONCLUSIONS: The horse simulator exercise positively affected psychophysiological responses in patients with CLBP. However, with respect to pain, the 20 min horseback riding group was associated with the best results.
Isokinetic muscle strength profile of ladies professional tour golfers
Authors: Chung Seok Won , Song Byung Wook , Kim Joon Yub , Lim Jae-Young , Kim Sae Hoon , Oh Joo Han 
Published: October 2018

BACKGROUND: The highly trained professional tour golfers would likely have different strength profiles in their muscle groups from non-athletes, which may be associated with the level of golf performance. OBJECTIVES: To describe an isokinetic muscle strength profile of several upper and lower extremity muscles of ladies professional tour golfers in comparison to non-athlete controls, and to explore possible correlations between strength and driving distance and average score. METHODS: Sixty seven ladies professional tour golfers and 25 non-athletic women were enrolled. Absolute and weight-adjusted concentric isokinetic peak torque (PT) at 60°/s of the shoulder abductors, adductors and rotators, and elbow and knee flexors and extensors were measured bilaterally. RESULTS: All absolute and most weight-adjusted PTs were significantly higher in professional tour golfers than non-athletes. The weight-adjusted PT differed significantly only with respect to the shoulder adductors and knee muscles. Significantly higher strength ratios: bilateral shoulder adductor/abductor, right shoulder internal/external rotator, right elbow extensor/flexor, and bilateral knee flexor/extensor characterized the golfers. Further, the correlations between the strength of any of the tested muscles and either the driving distance or the average score were low to negligible. CONCLUSIONS: These results furnish a reference framework for isokinetic strength of the abovementioned muscles of professional tour golfers, and thus be used in setting realistic rehabilitation goals for lady golfers who suffer from some injury involving, directly or indirectly, these muscles.