Klaus Wirth

Klaus Wirth
Goethe-Universität Frankfurt am Main · Institute of Sports Sciences

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101
Publications
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Publications

Publications (101)
Article
Problem: Since segment lengths of the lower extremities influence joint kinematics in multi-joint movements, anthropometric standardization seems necessary to study the force-length-velocity relationships of muscles in vivo. Mathematical approaches to calculate the needed linear velocities for the desired angular kinematics from individual anthropo...
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Previous research points out high relevance of maximal strength measurement in the diagnostics of different populations. However, there is inconsistency in procedures of maximum strength measurements. Thus, it must be questioned whether the results from different studies are actually comparable. Due to the aforementioned problems in standardization...
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In basketball high intensity jumping and sprinting performance is of high importance. There seems to be a relationship between maximal strength (MSt) and jumping performance in general, but influence of MSt in the plantar flexors and jumping performance seems not to be investigated very well. Thus, the aim of this study was to investigate the influ...
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PurposeMuscle strength and power are important requirements in many sports. The correlation of jumping performance as manifestation of muscle power and squatting one-repetition maximum (1RM) has been shown in several investigations. Correlations with maximum force in a linear isokinetic leg press are still pending. Since different testing devices p...
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This study aims to analyze the influence of relative strength performance, determined by parallel back squats (REL SQ), on 30 m sprinting (LS) and on jumping performance (squat [SJ], countermovement [CMJ]) in a large sample (n = 492) of elite youth soccer players. The soccer players were divided into subgroups based on their strength performance: s...
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This narrative review deals with the topic of strength training in swimming, which has been a controversial issue for decades. It is not only about the importance for the performance at start, turn and swim speed, but also about the question of how to design a strength training program. Different approaches are discussed in the literature, with two...
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A high level of sprinting performance is relevant in various sports. Because of the transition of movement patterns in different sprint sections there is a shift in the relevance of speed-strength of the knee and hip extensors, and stretch-shortening cycle performance seems conceivable. Fifty-six physical education students (23.70 ± 3.00 years, 176...
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The aim of this investigation was to analyze significant differences in performance depending on the level of play (elite vs. amateur) in youth soccer players (under 17 years. old (U17) and U19). A cross-sectional study was conducted, and 45 elite and amateur male youth soccer players (16.56 +/- 0.9 years old) were evaluated in their performances i...
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Keiner, M, Wirth, K, Fuhrmann, S, Kunz, M, Hartmann, H, and Haff, GG. The influence of upper-and lower-body maximum strength on swim block start, turn, and overall swim performance in sprint swimming. J Strength Cond Res XX(X): 000-000, 2019-Maximum strength and speed strength are 2 major factors that determine a swimmer's performance, including sw...
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Artistic gymnastics consist of a high amount of jumping actions with rotations around one or more axes. To achieve an optimal flight height to perform the desired number of rotations, the movement pattern and the floor characteristics have to be concerted optimally. To account for the required leg stiffness to utilize the floor’s elasticity, the le...
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Background: Speed and strength performance have an essential role in soccer. It is well known there is a moderate to strong correlation between maximum strength, speed and jump performance. However most studies have analyzed only maximum strength values of the knee and hip extensors for the correlation analysis. Studies on the maximum strength of t...
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Die Durchführung eines Krafttrainings im Schwimmsport stellt ein seit Jahr-zehnten kontrovers diskutiertes Thema dar. Dabei geht es sowohl um die Be-deutung für die Leistung bei Start, Wenden und die Schwimmgeschwindigkeit, als auch um die Frage, wie ein Krafttraining zu gestalten ist. Unabhängig von der Leistungsentwicklung der Sportler, sollten a...
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Möck, S, Hartmann, R, Wirth, K, Rosenkranz, G, and Mickel, C. Relationship between maximal dynamic force in the deep back squat and sprinting performance in consecutive segments up to 30 m. J Strength Cond Res XX(X): 000-000, 2018-The sprint (in track and field athletics) is characterized by a fluent transition from predominantly knee extending mus...
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Change of direction (COD) performance has an essential role in soccer. In the literature, there is a wide range of explained variance in correlation analyses between linearsprint performance, concentric power and maximum strength and COD performance. Therefore this study has (1) analyzed the influence of linear-sprint performance, concentric power...
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The current study aimed to compare the effects of plyometric and sprint vs. functional vs. strength training on linear sprint (LS 20 m), change of direction (COD; i.e., turning right and left), jump (squat jump [SJ]), and maximum strength (1 repetition maximum [1RM] for a quat) performance in elite adolescent soccer players. A longitudinal design w...
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Water polo is a multifaceted sport that is characterized by explosive actions, including sprint swimming, jumping, throwing, and struggling against opponents. Based upon these factors, maximal and speed strength may be important characteristics to develop in water polo players. However, more research is needed to further understand the relationship...
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Problem: Sprinting represents a relevant task in many sports. The correlation of sprinting performance and squatting strength (1RM) has been shown in several investigations. Correlations with maximum strength in a linear isokinetic leg press are still pending. Since different devices produce different relationships and rotational isokinetic measure...
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Full-text available
Change of direction (COD) is a performance limiting factor in team sports. However, there are no exact definitions of which physical abilities limit the COD performance. Nevertheless, different methods are used or are recommended as equally effective in professional practices to measure COD performance. Therefore, the aim of this study is to evalua...
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Purpose: To evaluate the predictive validity of critical power (CP) and the work above CP (W') on cycling performance (mean power during a 20-min time trial; TT20). Methods: On 3 separate days, 10 male cyclists completed a TT20 and 3 CP and W' prediction trials of 1, 4, and 10 min and 2, 7, and 12 min in field conditions. CP and W' were modeled...
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Sprinting is characterized by a transition from propulsion via knee extending musculature during initial acceleration towards ischiocrural musculature thereafter. This may lead to a decrease of correlation of the maximal strength in the back squat and sprinting performance with increasing distance. The aim of this investigation was to show the corr...
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This study was designed to evaluate the effects of long-term (2 years) strength training on reactive strength. To control the effect of the strength training intervention, reference data in trained and untrained adolescents were determined. Therefore, part 1 of this investigation evaluated a cross-sectional analysis of untrained adolescents (studen...
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Sprinting represents a result-relevant task in many sports. The correlation of sprinting performance and one-repetition maximum (1RM) in a squat has been assumed as assured. Results of the correlation with 1RM of the plantar flexors are still pending. Assuming an increasing relevance of the reactive working capacity with increasing distance, a decr...
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To assess the validity and reliability of the Garmin Vector against the SRM power meter, 6 cyclists completed 3 continuous trials at power outputs from 100-300 W at 50-90 rev·min(-1) and a 5-min time trial in laboratory and field conditions. In field conditions only, a 30-s sprint was performed. Data were compared with paired samples t-tests, with...
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Over the last two decades, exercise of the core muscles has gained major interest in professional sports. Research has focused on injury prevention and increasing athletic performance. We analyzed the guidelines for so-called functional strength training for back pain prevention and found that programs were similar to those for back pain rehabilita...
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The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodiz...
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Despite the common use of jogging strollers, only a few studies cover their influence on running patterns. Kinematic studies have shown differences in the upper body movement, while potential changes in plantar pressure remain unclear. Therefore, 30 healthy sport students were asked to run at a self-selected speed with and without a jogging strolle...
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For the development of speed strength in professional sports, “specific” strength training in the half or the quarter squat have been recommended. Due to the better lever ratios, higher loads have to be used to induce the necessary training stimuli compared to the deep squat. Therefore, intradiscal pressure and compressive forces on vertebral bodie...
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Strength training-induced increases in speed-strength seem indisputable. For trainers and athletes the most efficient exercise selection in the phase of preparation is of interest. Therefore, this study determined how the selection of training exercise influences the development of speed-strength and maximal strength during an 8-week training inter...
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This study investigated the trainability of decision-making and reactive agility via video-based visual training in young athletes. Thirty-four members of a national football academy (age: 14.4 � 0.1 years) were randomly assigned to a training (VIS; n = 18) or a control group (CON; n = 16). In addition to the football training, the VIS completed a...
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The purpose of this study was to establish whether physical attributes can differentiate between professional, amateur and elite youth soccer players; such a distinction could aid in the selection process for youth soccer. Therefore, this investigation evaluated a suspected difference in the performance tests of the slow and fast stretch and the sh...
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The training of the trunk muscles has become a standard practice for improving strength and speed-strength and reducing one’s susceptibility to injury. Athletic movements, such as sprints, lead to high forces acting on the torso and hips. The trunk muscles must control the extremities and transfer these forces so that efficient locomotion is ensure...
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Dividing training objectives into consecutive phases to gain morphological adaptations (hypertrophy phase) and neural adaptations (strength and power phases) is called strength-power periodization (SPP). These phases differ in program variables (volume, intensity, and exercise choice or type) and use stepwise intensity progression and concomitant d...
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The aim of this investigation was to analyze the effects of an eccentric strength training protocol using supramaximal loads (> 1RM; 1RM = one-repetition maximum) on different maximal and explosive strength parameters of the lower extremity. The eccentric maximal strength (EX max), maximal isometric strength (MVC = "maximal voluntary contraction"),...
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Abstract Objectives. - Strength and speed are 2 major factors that determine a swimmer’s sprint performance, especially swim sprint performance and swim starts. This study identified and examined variables that determine the influence of maximal strength performance on different swim performance styles and distances in trained adolescent swimmers....
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For track, field and team sports, many authors advise sport-specific strength training with half and quarter squats instead of parallel squats. Due to the sport-specific argument, higher correlations with sprint performance could be expected for half and quarter squats. Hence, correlations between sprint performance (30 m linear sprint) and both On...
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Objectives An early-established strength training regimen brings many benefit young athletes, especially those engaged in competitive sports. Strength training also leads to improve athletic performance, strength training is used for rehabilitation and injury prevention. The aim of this study was to evaluate how 2 years of additional strength trai...
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The aim of the study was the evaluation of the correlation between maximal strength and muscle mass depending on the kind of analysis which was used. Two different methods of strength evaluation and several morphological parameters were used. 77 male participants (age: 27,2 ± 6,6 years; body height: 179,9 ± 4,0 cm; body weight: 82,5 ± 10,4 kg) join...
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Erweiterter Überblicksartikel mit detaillierter Diskussion über die korrekte Übungsausführung der tiefen Kniebeuge 1. Mechanische Belastung und Beanspruchung des tibio- und patellofemoralen Gelenks in Abhängigkeit von Kniebeugetiefe und Lasthöhe 2. Kniegelenk- und Wirbelsäulenbelastung in der Kniebeuge in Abhängigkeit von der Übungsausführung 3....
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In Wissenschaft und Praxis des Krafttrainings wird mitunter angenommen, dass die tiefe Kniebeuge eine erhöhte Verletzungsgefahr der Lendenwirbelsäule und des Kniegelenks aufweist. Ein Verzicht auf tiefe Gelenkpositionen soll das Ausmass der Kniegelenkskräfte minimieren. Entsprechend wird bei Überlastungsbeschwerden und degenerativen Veränderungen d...
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The aim of the study was the evaluation of the correlation between maximal strength and muscle mass depending on the kind of analysis which was used. Two different methods of strength evaluation and several morphological parameters were used. 77 male participants (age: 27,2 ± 6,6 years; body height: 179,9 ± 4,0 cm; body weight: 82,5 ± 10,4 kg) join...
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In the science and practice of strength training it is sometimes suggested that the deep squat entails an increased injury risk of the lumbar spine and the knee joint. Avoiding deep flexion is believed to minimize the magnitude of knee joint forces. Because within the first 50° of knee flexion calculated retropatellar compressive stress is lower, e...
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It has been suggested that deep squats could cause an increased injury risk of the lumbar spine and the knee joints. Avoiding deep flexion has been recommended to minimize the magnitude of knee-joint forces. Unfortunately this suggestion has not taken the influence of the wrapping effect, functional adaptations and soft tissue contact between the b...
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Abstract In soccer, strength, power and speed are very important because of the large number of power actions performed during the game. Therefore, the aim of this study was to examine the influence of periodised strength training for power performance more than 2 years. In this study, 134 elite youth soccer players were recruited from two youth tr...
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It has been suggested that deep squats could cause an increased injury risk of the lumbar spine and the knee joints. Avoiding deep flexion has been recommended to minimize the magnitude of knee-joint forces. Unfortunately this suggestion has not taken the influence of the wrapping effect, functional adaptations and soft tissue contact between the b...
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Training and activity level are important predictors of motor development. At present, many children and adolescents do not participate in any sport activity in their leisure time.In this investigation, we analyzed the level of performance of the stretch and shortening cycle in childhood and youth. Data of 801 participants were recorded for two sep...
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The requirement profiles of sports such as soccer, football, tennis and rugby demonstrate the importance of strength and speed-strength abilities, in addition to other conditional characteristics. During a game, these athletes complete a large number of strength and speed-strength actions. In addition to the linear sprint, athletes perform sprints...
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The process of warming up prepares athletes for subsequent stress and increases their level of performance. Functional exercises are often included in warm-up programs for power sports, although a positive effect of functional exercises has not been confirmed. The aim of this study was to measure a possible effect on sprint performance of functiona...
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A basic question for many athletic coaches pertains to the maximum attainable strength level for youth athletes. The aim of this investigation was to establish reference values for the strength performance in the front and back squat in youth athletes. The strength performance in front and back squat of 141 elite youth soccer players was tested by...
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Es existieren keine Vergleichsstudien über die Auswirkungen eines periodisierten Maximalkrafttrainings in unterschiedlichen Kniebeugevarianten auf das Einer-Wiederholungsmaximum und das isometrische Explosiv- und Maximalkraftvermögen im 120 Grad Kniegelenkwinkel. Ziel war es, im Rahmen von zehnwöchigen Längsschnittstudien mit 23 weiblichen und 36 m...
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It is unclear if increases in one repetition maximum (1-RM) in quarter squats result in higher gains compared to full depth squats in isometric force production and vertical jump performance. The aim of the research projects was to compare the effects of different squat variants on the development of 1-RM and their transfer effects to Countermoveme...
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Kraft und Schnellkraftleistungen stellen, neben anderen konditionellen Anforderungen, bzw. technischen, taktischen und psychischen Anforderungen in vielen Mannschaftssportarten einen leistungsdeterminierenden Faktor dar. Die Maximalkraft wird dabei als die höchste Kraft verstanden, die das neuromuskuläre System bei einer maximalen willkürlichen Kon...
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Aufgrund des Anforderungsprofils im Fußball sind Kraft- und Schnellkraftfähigkeit von hoher Bedeutung. Um einen Leistungsvorteil zu generieren, ist die Ausprägung der Komponente Kraft als sinnvoll zu erachten. In dieser Untersuchung wurde der Einfluss eines einjährigen Krafttrainings auf die Sprintleistung über eine Distanz von 30 Metern bei jugend...
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Zusammenfassung Die Maximalkraft gilt in den meisten Spielsportarten als Grundlage für ein hohes Leistungsniveau. Unter Maximalkraft wird die höchste Kraft verstanden, die das neuromuskuläre System in einer maximal willkürlichen Kontraktion erzeugen kann. In der vorliegenden Untersuchung wurde die Leistungsfähigkeit der Maximalkraft von jugendliche...
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Summary Functional training and specific strength training are widely used terms. In the last two decades a lot of strength training interventions were named functional of specific in the field of fitness training and competitive sports. This occurred without any substantive reason beside the argument that the interventions are kinematically and ki...
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Es existieren keine Vergleichsstudien über die Entwicklung der Sprungleistung in Squat (SJ) und Countermovement Jump (CMJ) durch unterschiedliche Kniebeugevarianten, die eine Bevorzugung einer bestimmten Beugetiefe rechtfertigen könnten. Aus diesem Grund wurden in zwei Forschungsprojekten an 23 weiblichen und 36 männlichen Sportstudierenden (24,11±...
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Strength and power are next to the other conditional requirements, as well as the technical, tactical, psychological requirements, a limiting factor in team sports. Therefore, it makes sense to also train strength. The maximal strength is understood as the maximal force the neuromuscular system can produce during a maximal voluntary contraction. A...
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In many team sports maximum strength is the basis for a high performance level. Maximum strength is understood as the maximal force the neuromuscular system can produce during a maximal voluntary contraction. In this investigation, the strength performance of elite youth soccer players (n = 135) with and without experience in strength training was...
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In this investigation, the stretch-shortening cycle (SSC) performance of untrained male children and juveniles was measured and compared to that of soccer-playing children of equivalent age. Te subjects were between 9 and 18 years old. Five age cohorts were formed. Every cohort consisted of two adjacent ages. Te groups including the soccer-playing...