ABSTRACT THE RELATIONSHIP BETWEEN PHYSICAL FACTORS TO AGILITY PERFORMANCE IN COLLEGIATE TENNIS PLAYERS Ian McKinley and Dr. Kimitake Sato, Department of Exercise and Sport Sciences, College of Education, East Tennessee State University, Johnson City, Tennessee Tennis players change direction numerous times within a tennis match and game making agility an important skill for them to possess. The purpose of this study was to investigate at the significance of physical factors as they relate to agility performance in collegiate tennis players. The physical factors looked at were anthropomorphic measurements; isometric peak force, rate of force development, and force scale; countermovement jump performance, and squat jump performance. The participants were seventeen (Male: N = 8, Female: N=9) NCAA Division I collegiate level tennis players. Anthropomorphic measurements included height, body mass, and body fat percentages were also considered. Strength was measured by an isometric mid-thigh pull, and lastly power was measured by vertical jumps. Significance was set at 0.05 for statistical analysis. Correlation analysis showed that isometric rate of force development from isometric mid-thigh pull was significant (p = 0.033). In conclusion both anthropomorphic measurements and vertical jumps have little effect on agility performance but the rate of force development in the isometric mid-thigh pull test has statistically significant relationship to agility performance in tennis players, indicating agility movement is influenced by how fast you can develop force against ground.

Background: A lot of previous research have studied the correlation between bilateral jumps with performance in change of direction (COD) even though COD occurs unilateral. Only a few researches have studied the relationship between COD and unilateral jumps but the results are conflicting. Neither of these have studied the correlation between COD, measured with the Zigzag agility test, and both unilateral horizontal jumps (UHJ) and unilateral lateral jumps (ULJ) among young soccer players.  Aim: The aim was to study the magnitude of the correlation between UHJ and the Zigzag agility test and between ULJ and the Zigzag agility test among young male soccer players.  Method: Thirty young male soccer players between 17-19 years were tested in a Zigzag agility test and two different jumps (UHJ and ULJ). The time of the Zigzag agility test was measured in seconds and the length of the two jumps in meters. Everything were tested during one test session. Pearson correlation coefficient was used to calculate the relationships between UHJ, ULJ and the Zigzag agility test. Following guidelines were used to determine the magnitude of the correlation: r below -0.29 for a small correlation, r= -0.30 to -0.49 for a medium correlation and r -0.50 to -1.0 for a strong correlation.    Results: Small correlation were found between UHJ and the Zigzag agility test (r= -0.028) and as well as between ULJ the Zigzag agility test (r= -0.27). The mean value (SD±) was 6.41s (0.18) for the Zigzag agility test, 1.87m (0.15) for UHJ and 1.65m (0.13) for ULJ.  Conclusion: The findings of this study showed that both UHJ and ULJ had small correlations with the Zigzag agility test as a measurement of COD performance, with a slightly higher correlation for the ULJ. This means that unilateral jumps and COD performance probably are two different skills and should be trained in different ways. Not much research has been done in this area and the results concerning the correlation between COD and unilateral jumps are still mixed. More research is needed to declare the relationship with unilateral jumps and COD performance. Interesting for the further research would also be to involve other factors such as running technique and straight sprinting to determine the importance of each factor.

INTRODUCTION: Sensory systems within the head provide us with rich perceptual information and may require complex control of the head during locomotion when changing direction. Head position in space is maintained by head on trunk motion as well as lower extremity kinematic modifications, such as increased knee flexion and increased stance time in order to facilitate shock attenuation and reduce vertical CoM displacement. It has been established that the body organizes its degrees of freedom of the trunk, pelvis and lower extremities differently during anticipated and unanticipated sidestepping, which raises the question of how these modifications affect head control during change of direction tasks. METHODS: Fourteen collegiate soccer players performed 7 anticipated and 7 unanticipated sidestepping tasks. Kinematic data were recorded using an 11-camera motion capture system (Qualysis, Inc., Gothenburg, Sweden) sampling at 240 Hz. Head and trunk orientation was quantified at penultimate toe off. A modified vector coding analysis was used to quantify the coordination and coordination variability between the head and trunk during the anticipated and unanticipated side-stepping trials. Differences in head-trunk orientation and coordination pattern frequencies were assessed with a paired t-test with an . One-dimensional statistical parametric mapping (SPM1D) was used to compare coordination variability waveforms. RESULTS: The head (p < 0.01, ES = 0.82) and trunk (p < 0.05, ES = 0.59) were significantly more oriented toward the new travel direction during anticipated compared to unanticipated sidestepping. No significant differences in transverse or sagittal plane coordination were observed throughout the change of direction stride. However, during unanticipated sidestepping we observed significantly reduced in-phase head-trunk coordination during the preparatory phase in the sagittal (p = 0.04, ES = 0.63) and transverse (p = 0.02, ES = 0.73) planes but did not find differences in the stance or post-transition phases. Coordination variability did not differ between anticipated and unanticipated conditions. Irrespective of planning time, greater transverse plane coordination variability was observed during the flight phases compared to the stance phase (p < 0.01) of the change of direction stride. Sagittal plane coordination variability was significantly greater during the preparatory phase than the stance phase (p < 0.01), and stance phase coordination variability was significantly greater than post-transition phase variability (p < 0.01). SIGNIFICANCE: Our results suggest differences in coordination between the head and trunk between anticipated and unanticipated sidestepping emerge during the preparatory phase of the change of direction stride, from penultimate step toe off to transition step heel strike. Anticipated and unanticipated sidestepping are different tasks, but individuals are consistent in the way the head-trunk coupling is controlled. Relating variability to task goals may allow for a better understanding of the beneficial aspects of variability observed at the head.

Title: Development of agility during on-ice and off-ice trainings for ice hockey players in the youth category. Objectives: This diploma thesis is mainly focusing on verify whether off-ice training or on-ice training is more effective and cause better agility improvement on the ice. Another goal of the thesis is to experimentally verify if there is a motoric transfer to agility on ice due to agility training off the ice. Methods: In this experiment, I had seven participants divided into two separated groups. The task for the groups was to undergo two, one month training programs, on - ice and off - ice. Results were measured by method of quantitative analysis of motoric test results. Results: In both of the monitored groups, the results were improved in two out of six tests. For the research, the participants were divided into two groups. Both groups completed a month long training program on ice and off ice. In the direct 6.1m sprint test, direct 35m sprint and S - Corner, the results did not change. In the slalom-puck test, a difference was found in the Cohen d values between the group which began only on ice and in the group that was beginning office after both periods. The result of the reaction test was by Cohen's d same as in the slalom-puck test. Keywords: Ice hockey, agility, training,...

Change of direction speed (CODS) is an important determinant of performance in many sports. Greater stiffness of the lower limb should be beneficial to CODS, but this had not been well investigated. The purpose of this thesis was to establish the relationship between vertical stiffness, vertical stiffness asymmetries and CODS, with a view to augmenting CODS performance. The pilot study and studies 1-2 sought to determine the most reliable and ecologically valid method to assess stiffness in athletes required to perform changes of direction. The pilot study reported that the use of ultrasonography to determine Achilles tendon stiffness did not demonstrate appropriate reliability for inclusion in subsequent studies. Coefficients of variation (CVs) in excess of 27% were reported during an isometric plantar flexion task. Study 1 reported that CVs for vertical stiffness were lower when assessed during unilateral drop jumping (~7%) than during bilateral drop jumping (~12%) or bilateral hopping (~14%). Study 2 reported that the expression of vertical stiffness (P = 0.033) and vertical stiffness symmetry angle (P = 0.006) was significantly different across three performance tasks: unilateral drop jumping, bilateral drop jumping and bilateral hopping. Asymmetry percentages between compliant and stiff limbs were 5.6% (P < 0.001; d: 0.22), 23.3% (P = 0.001; d = 0.86) and 12.4% (P = 0.001; d = 0.39), respectively. Given the findings of studies 1 and 2, this thesis demonstrated the reliability and validity of a novel method by which to assess vertical stiffness - the unilateral drop jump. This task was used in subsequent studies to measure vertical stiffness. Study 3 sought to determine if vertical stiffness and vertical stiffness asymmetries influenced CODS performance determined during a 90o cutting task. Multiple regression analyses reported that mean vertical stiffness and asymmetry in jump height explained 63% (r2 = 0.63; P = 0.001) of CODS performance. Study 3 was the first investigation to demonstrate the importance of vertical stiffness to CODS performance. Study 4 sought to determine if acute exercise interventions designed to augment vertical stiffness would improve CODS. Unilateral and bilateral ‘stiffness’ interventions were evaluated against a control condition. CODS performances following the unilateral intervention were significantly faster than control (1.7%; P= 0.011; d = -1.08), but not significantly faster than the bilateral intervention (1.0% faster; P = 0.14; d = -0.59). Versus control, vertical stiffness was 14% greater (P = 0.049; d = 0.39) following the unilateral intervention. Study 4 demonstrated that a novel unilateral ‘stiffness’ intervention improved vertical stiffness and CODS performance. This highlights that the potential applicability of unilateral stiffness interventions in the pre-performance preparation of athletes.

Högintensiva aktioner är tydliga markörer för bra prestationer i fotboll. Exempel på högintensiva aktioner med bevisad koppling till prestation är riktningsförändringar och sprinter. Det är dock fortfarande oklart hur de olika spelpositionerna påverkar kravbilden för spelarna. För att bättre förstå positionens kravprofil observerades under 6 veckor 24 svenska manliga elitfotbollspelare, från samma förening, i träning under den svenska försäsongen med hjälp av GPS utrustning. Träningstypen som utfördes var smålagsspel 3v3, 6v6 och 9v9. Syftet med observationen var att undersöka spelpositionens (back, mittfält eller anfall) påverkan på antal riktningsförändringar och dess kraft och distansen i olika hastighetszoner. Resultatet visar att anfallare utför färre riktningsförändringar av låg kraft oavsett speltyp (p=0,04). Ingen signifikant skillnad för distans i hastighetszoner mellan positioner i någon speltyp. Sammanfattningsvis rekommenderas ytterligare studier i mer kontrollerad miljö och med fler deltagare för att förstå hur spelarpositionen påverkar de fysiska kraven i smålagsspel för manliga elitfotbollsspelare. / Football today is all about high intensity actions with high intensity running and change of direction as two of the markers related to performance in football. What is still relatively unclear is the players position on the field and the demands that follows with that position. 24 swedish male elite footballplayers took part in a 6 week observation during the swedish pre-season. Using GPS equipment data was collected during small sided games (SSG) 3v3, 6v6 and 9v9 in the teams regular trainingschedule. The aim of this observation was to better understand the role of player position (defender, midfielder and forward) assosiated with the frequency and force produced in changes of direction and the distance in speedzones. The result showed that strikers performed fewer changes of direction in the lowest forcezone compared to both defenders and midfielders in all of the SSGs. No significant difference was observed regarding distance in the speedzones in any SSG. In conclusion further researsch is needed to better understand the role of player positioning during SSG in elite football.

The purpose of this study was to determine the acute effects of heavy resistance exercise on agility performance in court-sport athletes. Five men (age: 20.6 ± 1.9 years; body mass: 79.36 ± 11.74 kg; body height: 1.93 ± 0.09 m) and five women (age 21.2 ± 2.7 years; body mass: 65.8 ± 10.18 kg; body height 1.77 ± 0.08 m) volunteered to participate in the present study. All subjects were NCAA Division II athletes who currently participated in tennis or basketball and all had previous resistance training experience of at least one year. In a counterbalanced design, agility performance during a 10 m shuttle test was assessed following either a dynamic warm-up (DW) or heavy resistance warm-up (HRW) protocol. The HRW protocol consisted of three sets of squats at 50, 60, and 90% of 1-RM. Agility performance was captured using an eight camera motion analysis system and the mechanical variables of stride length, stride frequency, stance time, flight time, average ground reaction force, as well as agility time were recorded. No significant differences were reported for the HRW and DW protocols for any of the mechanical variables (p>0.05), although there was a trend towards the HRW protocol producing faster agility times compared to the control protocol (p = 0.074). Based on the trend towards a significant effect, as well as individual results it is possible that HRW protocols could be used as an acute method to improve agility performance in some court-sport athletes.

The purpose of this study was to determine the acute effects of heavy resistance exercise on agility performance in court-sport athletes. Five men (age: 20.6 ± 1.9 years; body mass: 79.36 ± 11.74 kg; body height: 1.93 ± 0.09 m) and five women (age 21.2 ± 2.7 years; body mass: 65.8 ± 10.18 kg; body height 1.77 ± 0.08 m) volunteered to participate in the present study. All subjects were NCAA Division II athletes who currently participated in tennis or basketball and all had previous resistance training experience of at least one year. In a counterbalanced design, agility performance during a 10 m shuttle test was assessed following either a dynamic warm-up (DW) or heavy resistance warm-up (HRW) protocol. The HRW protocol consisted of three sets of squats at 50, 60, and 90% of 1-RM. Agility performance was captured using an eight camera motion analysis system and the mechanical variables of stride length, stride frequency, stance time, flight time, average ground reaction force, as well as agility time were recorded. No significant differences were reported for the HRW and DW protocols for any of the mechanical variables (p>0.05), although there was a trend towards the HRW protocol producing faster agility times compared to the control protocol (p = 0.074). Based on the trend towards a significant effect, as well as individual results it is possible that HRW protocols could be used as an acute method to improve agility performance in some court-sport athletes.

The purpose of this study aimed to evaluate the efficacy of resistance training with accentuated eccentric loading (AEL) and cluster sets (CS) versus traditional resistance training (TRAD) on general sports skills and power performance in recreationally trained individuals. Seventeen subjects (11 males, 6 females; mean age 23.2 ± 4.1 years; body mass 81.3 ± 22.2 kg; height 172.1 ± 10.0 cm; relative 1 RM back squat 1.5 ± 0.3) were randomly assigned to AEL (n = 9) or TRAD (n = 8) groups. After an initial familiarization and baseline testing, both groups underwent a four-week strength-endurance training regimen. The AEL group incorporated AEL in a CS format every other repetition for back squat and bench press. Pre- and post-intervention assessments included accelerative sprint (10- and 20-meter split time), change of direction (505), COD deficit (CODD), countermovement jump height, and peak power. Statistical significance was set at p ≤ 0.05. Both groups showed significant improvements in 505 and CODD (p < 0.01), with the AEL group demonstrating a greater effect size than TRAD for 505 (g: -0.90; and -0.45, respectively) and CODD (g: -0.87; and -0.26, respectively). No other measures showed significant changes (p > 0.05). These data suggest that a strength-endurance training block can enhance change of direction ability, with potential added benefits from AEL with CS, although further research is warranted to confirm these effects.

Soccer players change direction repeatedly throughout a game, making agility an important component of their performance. The purpose of this project was to identify how anatomical and physical characteristics influence agility performance among soccer players. The influences of anthropometry, strength, and power on agility performance in soccer players were investigated. The participants were NCAA Division I soccer players (N = 65). Anthropometric measures included height, body mass, percent body fat, lean body mass. Strength was evaluated using an isometric mid-thigh pull, and power was measured by vertical jumps. In correlation analysis, agility performance showed a statistically significant correlation (p<0.05) with peak power (PP) from 0kg and 20kg counter-movement jumps (r=-.379 & r=-.364 respectively) for the male players. Also for the males, percent body fat showed significant correlations (p<0.05) with Average 2 (r=-.438), 3 (r=-.411), and All (r=-.436). I conclude that the anthropometric measures evaluated have little influence on agility performance.