Sprint Time Research Articles

Associations between biological maturity level, match locomotion, and physical capacities in youth male soccer players.

Biological maturity level has shown to affect sport performance in youths. However, most previous studies have used noninvasive methods to estimate maturity level. Thus, the main aim of the present study was to investigate the association between skeletal age (SA) as a measure of biological maturation level, match locomotion, and physical capacity in male youth soccer players. Thirty-eight Norwegian players were followed during two consecutive seasons (U14 and U15). Match locomotion was assessed with GPS-tracking in matches. SA, assessed by x-ray, physical capacities (speed, strength and endurance) and anthropometrics were measured in the middle of each season. Analysis of associations between SA, match locomotion, and physical capacities were adjusted for the potential confounding effect of body height and weight. In matches, positive associations were found between SA and maximal speed and running distance in the highest speed zones. Further, SA was associated with 40 m sprint time and countermovement jump (CMJ) height, and with intermittent-endurance capacity after adjusting for body height (U14). Associations between SA and leg strength and power, and between SA and absolute VO2max were not significant after adjusting for body weight. There was no association between SA and total distance covered in matches. Biological maturity level influence match locomotion and performance on physical capacity tests. It is important that players, parents and coaches are aware of the advantages more mature players have during puberty, and that less mature players also are given attention, appropriate training and match competition to ensure proper development.

Relationships between Functional Movement Quality and Sprint and Jump Performance in Female Youth Soccer Athletes of Team China.

This study aimed to determine the optimal functional movement screen (FMS) cut score for assessing the risk of sport injury, and to investigate the correlations between functional movement quality and sprint and jump performance. Twenty-four (N = 24) athletes performed all tests in one day at 10–30 min intervals, and the FMS test was performed first, without a warm-up session. After a standard warm-up, athletes then completed the Y-balance Test (YBT), sprint, counter-movement jump (CMJ), and standing long jump (SLJ), in turn. For each test, the best of three attempts was recorded for further analysis. A receiver operating characteristic (ROC) curve and area-under-the-curve (AUC) were used to determine the optimal FMS cut score for assessing the risk of sport injuries, and Spearman’s rank correlation analysis was used to quantify associations between functional movement scores and athletic performance. The average FMS score was 16.2 and the optimal FMS cut score for assessing the risk of sport injuries was 14.5. There were moderate relationships between total FMS score and 10–20 m sprint time (r = −0.46, p < 0.05), between In-line Lunge and 0–20 m sprint time (r = −0.47, p < 0.05), between Shoulder Mobility and 0–10 m sprint time (r = −0.48, p < 0.05), and between Trunk-stability Push-up and 10–20 m sprint time (r = −0.47, p < 0.05). Moreover, Hurdle Step score was largely correlated with 0–10 m time (r = −0.51, p < 0.05). For Y-balance, moderate correlations were observed between CMJ height and anterior asymmetry score (r = −0.47, p < 0.05) and posteromedial asymmetry score (r = −0.44, p < 0.05). However, there were no significant associations between YBT performance (asymmetric in three directions and composite score) and sprint performance (p > 0.05). Taken together, the results indicate that a FMS score of 14 is not a gold standard for assessing the risk of injury in all populations; we recommend that the FMS cut score of 14.5 should be the optimal score for assessing risk of injury in young female elite soccer players. Moreover, the FMS and YBT were introduced to assess the quality of functional movements, and they cannot be used to assess sprint and jump performance. Practitioners can use components of the FMS that have similar characteristics to specific sports to assess athletic performance.

Acute Effects of Different Overspeed Loads with Motorized Towing System in Young Athletes: A Pilot Study.

Simple SummaryThe towing system is a widely used method to increase running speed since it allows the athletes to run at a speed higher than the speed that they would achieve with their own methods. Currently, we dispose of motorized towing systems that provide overspeed conditions. In this study, we have analyzed the acute effects of using one of these devices with different loads in eight young athletes and thus determine the possible optimal load for their use during training. These effects have been analyzed on different variables of the sprint running technique, and it has been observed that the increase in speed is mainly due to the increase in stride length, flight time and horizontal distance of the vertical projection of the center of gravity to the first contact of the foot with the ground, as well as to reductions in contact time. However, it cannot be determined whether these results are produced by the muscular action of the athlete or by the action of the device. Following up the investigation of the effects of the motorized towing system and the individualization of loads may allow for the development of these training methods, giving them greater scientific evidence.Overspeed is a training method used to improve running speed, although its effects are not supported by consensual scientific evidence. The overspeed stimulus can be boosted by several methods, including motorized towing devices. Our objectives were to analyze the acute effects of three overspeed loads in young athletes and to select optimal loads for training periods. Eight young athletes (16.73 ± 1.69 years) performed one unassisted sprint and three assisted sprints, and kinematic and biomechanical data were compared. Significant increases (p < 0.05) in step velocity and step length were found with 2, 4, and 5.25 kg in maximum running speed, flight time and horizontal distance from the first contact to the vertical projection of the center of mass with 4 and 5.25 kg. Significant time decreases were found in 5 m flying sprint and contact time with 4 and 5.25 kg, and no significant changes were observed in step rate. The individually recommended loads would be between 3.47 ± 0.68% and 6.94 ± 1.35% body weight. Even having limitations, we can understand this work and its results as a pilot study to replicate the methodology and the use of new devices to more broadly investigate the effects of overspeed.

Individual and situational factors affecting the movement characteristics and internal responses to Touch match-play during an international tournament

ABSTRACT Purpose To examine the influence of individual and situational factors on the movement characteristics and internal responses of players to an international Touch tournament. Methods Using 47 International Touch players (25 men and 22 women), the associations between the movement characteristics and internal responses with individual (sprint, glycolytic test, Yo-Yo intermittent recovery test level 1 [Yo-Yo IR1], jump performance and well-being) and situational (sex, squad, position, competition day, points scored/conceded, result, and opposition rank) factors were examined using linear mixed modelling. Results Yo-Yo IR1 distance was associated with all movement characteristics and internal responses (r = −0.29 to 0.37), whilst sprint and glycolytic times only influenced mean heart rate (HRmean) (r = 0.15) and high-speed distance (r = 0.10), respectively. Sex influenced high-speed distance (r = −0.41), whilst squad was associated with playing time and HRmean (r = −0.10–0.33). Other associations included: playing position with all movement characteristics (r = −0.67–0.81); points conceded with relative distance (r = −0.14); winning with high metabolic power and session RPE (r = −0.07–0.09), and opposition rank with HRmean and RPE (r = 0.11–0.35). Conclusions Individual and situational factors can influence the movement characteristics and internal responses to Touch and should be considered when developing the characteristics of players and interpreting responses to match-play.

BUILDING A PROFILE OF SPECIFIC FITNESS INDICES FOR MALE TEENAGE CHINESE SPRINTERS

ABSTRACT Objectives: This study aimed to construct a profile of specific fitness indices for male teenage sprinters on the Chinese National Team to provide sprinting fitness assessments for teenage training. Material and Methods: 229 male teenage sprinters at the same level were recruited to participate in this test for the indices. The t- and Kruskal-Wallis tests were conducted for the first selection of fitness indices. In the second selection, principal components analysis was applied to select common factors with greater characteristic values. The fitness indices chosen were height, leg length, measurement B (ankle circumference/heel length×100%) and measurement A (thigh circumference/leg length×100%), hemoglobin, 60m sprint time, 100m sprint time, countermovement jump (CMJ), maximum countermovement jump velocity, CMJ flight time, CMJ maximum force, and CMJ force. Results: Thirteen indices were chosen for the specific fitness of male teenage Chinese male sprinters with 3 general categories and 9 subcategories. The weight of each fitness index was confirmed and used to construct a standard fitness assessment scale. Conclusion: Anthropometric indices indicate the athlete’s innate limits in the structure of the sprinting motion. Physiological indices indicate the athlete’s potential to expend energy and recover in a short time. Motor indices indicate the athlete’s maximum sprinting ability, lower limb reaction strength, power, and maximum strength. Level of evidence II, Diagnostic studies - Investigation of a diagnostic test.

Fundamental Movement Skills and Physical Fitness Are Key Correlates of Tactical Soccer Skill in Grassroots Soccer Players Aged 8–14 Years

One hundred and twenty-one children (58 boys and 63 girls) aged 8–14 years (mean ± SD = 12 ± 1 years) who were regularly engaged in grassroots soccer participated in this study. Participants undertook assessments of fundamental movement skill (FMS) using the Test of Gross Motor Development-3, perceived ability using the Perceived Physical Ability Scale for Children, physical fitness via 15-m sprint time, standing long jump distance, and technical skill using the university of Ghent dribbling test. The Procedural Tactical Knowledge Test was employed as a measure of tactical skill from which metrics for positioning and movement and recognizing spaces were derived. Maturation was determined from anthropometric measures. Analysis of covariance examined gender differences in tactical skills accounting for FMS, fitness, perceived ability, technical skill, maturation, and age. Results indicated no significant differences in tactical skills between boys and girls (p &gt; .05). For recognizing spaces, 56% of the variance was explained with FMS (p = .001), physical fitness (p = .02), and technical skill (p = .02) contributing to the model. For positioning and movement, a significant model explained 55% of the variance in this element of tactical behavior with FMS (p = .002) and technical skill (p = .02) significantly contributing to the model.

The impact of plyometric training program on sprinting speed and jumping ability in american football players of a german amateur club

Background: The profile of requirements for an American Football game is characterized by good sprinting and jumping performance. The literature highlights the benefits of plyometric training on sprinting speed and jumping ability. Due to an increasing professionalization of American football in Germany, a transfer to the training practice is obsolete. Aim: The aim of the study was to determine the impact of additional participation in a plyometric training program on sprinting speed and jumping ability of players of the American Football Team in Germany. Material and Methods: The study was conducted in May 2014, with 20 players of an amateur American Football Club in Germany including the treatment group of 10 participants (age: 22.44 3.4 years) and the control group of 10 participants (age: 17.10 1.20 years). The treatment group followed a plyometric training routine once per week for 2 months while the control group was attending only the team training. The variables assessed at baseline and after 2 months included the speed measurements of a 30 m sprint and acceleration in the first 5 m, and the results of CMJ, SJ, and DJ performed from the heights of 16cm, 24cm, and 32cm. Results: Analysis of variance did not confirm statistically significant improvements in sprint time in the 30m sprint and jumping performance in SJ and DJ in the treatment group. The sprint time in the first five meters of the 30-meter sprint showed a highly significant increase of 1.66%. In the CMJ, a marginally significant increase in jump height of 6.37% was found. Conclusions: significant improvements as a result of the plyometric strength training can be only found in the jump height in the CMJ. In order to reach more comprehensive conclusions, physical fitness of the subjects, a longer intervention duration, and a higher training volume should be taken into account in future studies.

The Role of Velocity-Based Training (VBT) in Enhancing Athletic Performance in Trained Individuals: A Meta-Analysis of Controlled Trials.

Velocity-based training (VBT) is a rising auto-regulation method that dynamically regulates training loads to promote resistance training. However, the role of VBT in improving various athletic performances is still unclear. Hence, the presented study aimed to examine the role of VBT in improving lower limbs’ maximum strength, strength endurance, jump, and sprint performance among trained individuals. A systematic literature search was performed to identify studies on VBT for lower limb strength training via databases, including PubMed, Web of Science, Embase, EBSCO, Cochrane, CNKI (in Chinese), and Wanfang Database (in Chinese). Controlled trials that deployed VBT only without extra training content were considered. Eventually, nine studies with a total of 253 trained males (at least one year of training experience) were included in the meta-analysis. The pooled results suggest that VBT may effectively enhance lower limbs’ maximum strength (SMD = 0.76; p < 0.001; I2 = 0%), strength endurance (SMD = 1.19; p < 0.001; I2 = 2%), countermovement jump (SMD = 0.53; p < 0.001; I2 = 0%), and sprint ability (SMD of sprint time = −0.40; p < 0.001; I2 = 0%). These findings indicate the positive role of VBT in serving athletic training. Future research is warranted to focus on the effect of velocity loss of VBT on athletic performance.

Effect of 6 weeks of short intermittent running training versus small-sided games on heart rate variability, aerobic and anaerobic performance in Indian elite soccer players

Background: Soccer is characterized by long periods of low to moderate intensity activity interspersed with periods of high-intensity actions, such as single and repeated sprints. Therefore, a well-prepared soccer player must be able to endure long periods of low- to moderate intensity activity and sustain periods of explosive match effort intensification. Objective: To evaluate the effects of 6-weeks short interval running training and Small Sided Games on Heart Rate Variability measurements, aerobic capacity and performance in well trained Indian elite soccer players. Methods: A pretest – posttest experimental design was used in our study. 90 elite male soccer players was assigned into three groups by computer generated block randomization. Group I- Short Interval running Training (N-30), Group II- Small sided game Training (N-30) and Group III- Generic Training (control group, N-30). Autonomic control by HRV, vertical jump height, agility, 10m-30m sprint performance and VO2max by multistage fitness test was analysed. Result: Pre- intervention and post- intervention results was analysed and compared. The difference in agility, vertical jump height, 10m sprint time and VO2max was more in the SIRT group as compared the SSG and Generic (control) group. This difference was statistically significant (p&lt;0.001).

{shorts}: An R Package for Modeling Short Sprints

Short sprint performance is one of the most distinguishable and admired physical traits in sports. Short sprints have been modeled using the mono-exponential equation that involves two parameters: (1) maximum sprinting speed (MSS) and (2) relative acceleration (TAU). The most common methods to assess short sprint performance are with a radar gun or timing gates. In this paper, we: 1) provide the shorts package that can model sprint timing data from these two sources; 2) discuss potential issues with assessing sprint time (synchronization and flying start, respectively); and 3) provide model definitions within the shorts package to help alleviate errors within the subsequent parameter outcomes.

A Data Analytics Approach to Assess the Functional and Physical Performance of Female Soccer Players: A Cohort Design.

Background and Objectives: The aim of this study was twofold: (i) to observe the individual results of fitness status [countermovement jump (CMJ)], hop test, linear sprinting time, stride frequency, stride distance, force–power–velocity, peak power maximal and maximal speed, and repeated sprint ability (RSA) and functional performance (overhead squat, single-leg squat test, dumbbell hip-hinge, Thomas test, hip extension, and internal and external hip rotators) and (ii) to analyze the relationship between anthropometrical measures and values of fitness status with % of difference in the Thomas test, hip extension, and internal and external hip rotators. Materials and Methods: The study followed a cohort design. Sixteen female soccer players competing in the second division of the Spanish league were monitored during the first days of the pre-season. These players were evaluated three times during the preseason of the cohort period. The dataset showed a negative moderate correlation between time and percentage of difference in hip angle and another positive moderate correlation between maximal sprint and percentage of difference in hip angle (r = −0.54, p = 0.02 and r = 0.53, p = 0.04), respectively. The correlations of stride time and distance with hip extension are interesting, as professional soccer players should have higher levels of hip flexor flexibility during the stride phase, recoil of the instep kick action.

Acute and prolonged effects of the simulated physical demands of a futsal match on lower limb muscle power and strength, sprint performance and muscle soreness

BACKGROUND: Prolonged fatigue effects may be a concern after futsal matches mainly because of the actions performed by futsal players (e.g., sprinting, jumping) that usually involve the stretch-shortening cycle (SSC). However, there no studies analyzed the prolonged effects of futsal-specific fatigue and how futsal players can recover from performance tasks. OBJECTIVE: To analyze the acute and prolonged effects of a protocol that simulates specific physical demands of futsal on countermovement-jump, sprint performance, muscle strength and muscle soreness. METHODS: Fifteen amateur futsal male athletes (18.3 ± 3.8 years) performed a futsal intermittent running protocol (FIRP) and were assessed for (moment production, sprint and jumping performance and muscle soreness) at pre, during half-time, immediately after, post 24 and 48 hours after the FIRP. Analysis of variance (repeated measures) was used to compare variable means over time. RESULTS: The main results indicated a decrement in the CMJ height (p= 0.03) and an increase of 10 m and 20 m sprint times (p= 0.01–p&lt; 0.01, respectively) during half-time and the post FIRP. There was a decrement in eccentric peak moment of the knee extensors (p= 0.02) and flexors (p&lt; 0.01) until 48h post protocol and a decrement in concentric peak moment of the flexors (p&lt; 0.01) post protocol. Athletes reported muscle soreness in the hamstrings (p= 0.03) post and 24 h after the FIRP. CONCLUSION: FIRP induced acute effects in the jump and sprint performances only. On the other hand, the knee moment production capability (mainly eccentric) suffered acute and also prolonged effects of the FIRP accompanied by delayed muscle soreness in the hamstring muscles.

A 7-min halftime jog mitigated the reduction in sprint performance for the initial 15-min of the second half in a simulated football match.

This study compared the effects of a 7-min shuttle jog during halftime to a control condition (seated rest) on subsequent athletic performance and lower-leg temperature in the second half. Eighteen male football players (22 years, 179 cm, 70 kg, 10 years of athletic career) randomly performed a 20-m shuttle jog (at an intensity of 70% of heart rate maximum) and a seated rest (sitting on a bench) during halftime in two separate sessions. A 5-min football simulation protocol consisting of football-specific activities (jumping, sprinting, kicking, passing, and dribbling at various intensities and distances) was repeated nine times to mimic the first and second half of a football match. Athletic performance (maximal vertical jump height, 20-m sprint time, and the Arrowhead agility test time) recorded during a 15-min period were averaged to represent each time point (first half: T1 to T3; second half: T4 to T6). Lower-leg skin and muscle (using the insulation disk technique) temperature was recorded before and after the first and second half. There was no condition effect over time in maximal vertical jump: F5,187 = 0.53, p = 0.75, Arrowhead agility test time: F5,187 = 1.25, p = 0.29, and lower-leg temperature (skin: F3,119 = 1.40, p = 0.25; muscle: F3,119 = 1.08, p = 0.36). The 20-m sprint time between conditions during the initial 15-min of the second half was different (condition × time: F5,187 = 2.42, p = 0.04) that subjects who performed the shuttle jog ran 0.09 sec faster (3.08 sec, p = 0.002, ES = 0.68), as compared with those who did the seated rest (3.17 sec). The results of our study confirmed that a decremental effect of the static rest on sprinting performance during the initial period of the second halftime can be attenuated by a halftime warm-up.

Immediate Effects of Spinal Manipulative Therapy on the Performance of Elite Brazilian Soccer Players: A Pilot Randomized Controlled Trial With an Internally Validated Sham Treatment

ObjectiveThe purpose of this study was to assess the feasibility of the procedures’ routine, the recruiting rate, the presence of any significant detrimental impact on the players’ training routine, and the sham efficacy in achieving blinding. MethodsA parallel randomized controlled clinical trial was performed with 20 elite soccer players who were randomly assigned to 1 of 2 groups: spinal manipulative therapy (SMT) and sham SMT. All players were from the same team, were injury free, and were naive to SMT. Measured outcome tests (30-m sprint run with a 10-m split and change of direction [COD] test) were performed at the same time by all participants immediately before and after interventions. Photocell devices were used for data acquisition. ResultsTwenty participants were analyzed (10 in each group). There were no changes to the sprint (10 m and 30 m) and COD test results immediately after either of the interventions. All participants in both groups (SMT and sham SMT) answered “yes” to a question after the intervention asking if they were treated by SMT. No adverse effects or training routine impairment were reported. ConclusionThis pilot study protocol showed it was an appropriate design for a confirmatory clinical trial. The study had minimal effect on the team training routine, and the recruitment rate was excellent. The proposed sham SMT strategy was successful in blinding the players. In this sample, SMT did not have any immediate effect on the performance of these elite soccer players, as measured by 10- and 30-m sprint times and COD sprint times.

A repeated shuttle sprint test with female and male international field hockey players is reliable and associated with single sprint but not intermittent endurance performance.

Field hockey is a high-intensity intermittent team sport that has recently undergone a series of rule changes that have resulted in a greater demand for repeated high-intensity movements. Coaches and practitioners now require a reliable assessment of repeated accelerations, decelerations and changes of direction to assess these important match qualities. This investigation assessed the test-retest reliability of a novel 6x40m repeated shuttle sprint test (20m + 20m with a 180° turn) and its association with 40m straight line sprint and YoYo Intermittent Recovery Test performance in 28 International field hockey players (n = 14 females and n = 14 males). The sum of 6 sprint times (SUM) demonstrated ‘excellent’ (ICC = 0.94 and CV = 0.59%) and ‘good’ (ICC = 0.84 and CV = 0.75%) reliability in females and males, respectively. Best sprint time during the repeated shuttle sprint test also demonstrated suitable reliability to evaluate field hockey physical performance (ICC = 0.92 & 0.76, CV = 0.76% & 1.00% in females and males, respectively). SUM was significantly associated with 40 m straight line sprint performance in females (r = 0.90; p<0.001) and males (r = 0.92; p<0.001), but only a weak association was found with YoYo Intermittent Recovery Test performance for either group (r = 0.20; p = 0.495 & r = -0.19; p = 0.525 in females and males, respectively). In summary, field hockey testing batteries that include a repeated shuttle sprint test should consider including a test of intermittent endurance. Further, changes in SUM greater than 1.0% can be confidently interpreted by coaches and practitioners as a real change for both female and male elite field hockey players.

Prediction of Propulsion Kinematics and Performance in Wheelchair Rugby.

Prediction of propulsion kinematics and performance in wheelchair sports has the potential to improve capabilities of individual wheelchair prescription while minimizing testing requirements. While propulsion predictions have been developed for daily propulsion, these have not been extended for maximal effort in wheelchair sports. A two step-approach to predicting the effects of changing set-up in wheelchair rugby was developed, consisting of: (One) predicting propulsion kinematics during a 5 m sprint by adapting an existing linkage model; and (Two) applying partial least-squares regression to wheelchair set-up, propulsion kinematics, and performance. Eight elite wheelchair rugby players completed 5 m sprints in nine wheelchair set-ups while varying seat height, seat depth, seat angle, and tire pressure. Propulsion kinematics (contact and release angles) and performance (sprint time) were measured during each sprint and used for training and assessment for both models. Results were assessed through comparison of predicted and experimental propulsion kinematics (degree differences) for Step One and performance times (seconds differences) for Step Two. Kinematic measures, in particular contact angles, were identified with mean prediction errors less than 5 degrees for 43 of 48 predictions. Performance predictions were found to reflect on-court trends for some players, while others showed weaker prediction accuracy. More detailed modeling approaches that can account for individual athlete activity limitations would likely result in improved accuracy in propulsion and performance predictions across a range of wheelchair sports. Although this would come at an increased cost, developments would provide opportunities for more suitable set-ups earlier in an athlete's career, increasing performance and reducing injury risk.

The Impact of Sleep Inertia on Physical, Cognitive, and Subjective Performance Following a 1- or 2-Hour Afternoon Nap in Semiprofessional Athletes.

This study examined the impact of sleep inertia on physical, cognitive, and subjective performance immediately after a 1- or 2-hour afternoon nap opportunity. Twelve well-trained male athletes completed 3 conditions in a randomized, counterbalanced order-9 hours in bed overnight without a nap opportunity the next day (9 + 0), 8 hours in bed overnight with a 1-hour nap opportunity the next day (8 + 1), and 7 hours in bed overnight with a 2-hour nap opportunity the next day (7 + 2). Nap opportunities ended at 4:00 PM. Sleep was assessed using polysomnography. Following each condition, participants completed four 30-minute test batteries beginning at 4:15, 4:45, 5:15, and 5:45 PM. Test batteries included a warm-up, self-ratings of readiness to perform, motivation to perform and expected performance, two 10-m sprints, 2 agility tests, a 90-second response-time task, and 5minutes of seated rest. Total sleep time was not different between conditions (P = .920). There was an effect of condition on readiness (P < .001), motivation (P = .001), and expected performance (P = .004)-all 3 were lower in the 8 + 1 and 7 + 2 conditions compared with the 9 + 0 condition. There was no effect of condition on response time (P = .958), sprint time (P = .204), or agility (P = .240), but a large effect size was observed for agility. After waking from a nap opportunity, agility may be reduced, and athletes may feel sleepy and not ready or motivated to perform. Athletes should schedule sufficient time (∼1h) after waking from a nap opportunity to avoid the effects of sleep inertia on performance.

Playing at altitude. Performance of a Mexican professional football team at different level of altitude

Football is the most popular sport in the world, and matches are commonly played at different levels of altitude. As the altitude increases, the availability of oxygen decreases. The dynamics of the ball will be altered due to the decrease in air resistance. These conditions can affect the physical and/or sports performance of football players. The objective of this study is to determine if there is a relationship between altitude and performance of a professional football team. A total of 130 matches of a Mexican professional football team were analyzed. Physical performance was measured by Match Analysis®, a video and statistical analysis; sports performance was measured according to the score. Altitude was measured with Geo Elevation. No relationship was found between altitude and total distance covered (p=0.165), Distance in first half (p=0.441) sprints number(p=0.115) and time between sprints (p=0.237) There was a significant increase between total distance covered during the second half (p=0.009) and mean speed on "Low altitude' (p=0.000) We found no relation between the altitude level and the obtained result (p=0.28) number of goals in favour (p=0.209) and against (p=0.629). We found no relationship between the altitude level and physical and sports performance of a professional football team

Evolution of determinant factors of maximal sprinting and repeated sprint ability in women soccer players

The present study aimed to determine the influence of force–power–velocity, vertical and horizontal jumps, and repeated sprint ability on the sprinting performance of adult women soccer players. Eighteen women soccer players from one team participating in the first female national Spanish soccer league were analyzed. Fitness assessments were performed twice in a period of three months. The following assessments were made to reach the aim of the study: (1) anthropometric measures, (2) CMJ (0%, 20% and 40%), (3) hop test (dominant and nondominant leg), (4) linear sprinting at 30 m and (5) RSA test. The main evidence of this study revealed the meaningful contribution of lower-limb power (vertical and horizontal jump), maximal sprint and peak power on sprinting time performance, while stride frequency was meaningfully explained by vertical jump and maximal sprinting. In fact, positive moderate and large correlations were found between Time and CMJ, CMJ 20%, CMJ 40%, Hop Test Dominant and Non-dominant, and Pmax and MS of Force–Power–Velocity (r = − 0.73, p = 0.001; r = − 0.68, p = 0.002; r = − 0.51, p = 0.03; r = − 0.64, p = 0.004; r = − 0.57, p = 0.013; r = − 0.78, p = 0.001, and r = − 0.83, p = 0.001, respectively). In sum, peak power, maximal speed, and lower-limb power (in vertical and horizontal jumps) were significant determinants of sprinting performance (time), while vertical jump was the determinant of stride frequency. In addition, our findings suggest that potentiation and explosive vertical power could be the emphasis for sustaining the stride frequency of women soccer players, while sprinting performance should be supported by strong acceleration and maximal velocity sustained by both vertical and horizontal force and concentric and eccentric strength and power.

The Relationship between the Hamstring-to-Quadriceps Ratio and Jumping and Sprinting Abilities of Young Male Soccer Players.

The correct torque ratio between the knee joint extensor and flexor muscle groups can effectively prevent injuries to the anterior cruciate ligament and hamstring strain. However, it is unclear whether a high torque ratio of the knee joint flexor muscles to the extensor muscles is beneficial for sport performance. Therefore, the aim of the study was to investigate the relationship between the hamstring-to-quadriceps (H/Q) ratio and sprint times (10- and 30-m) and jump heights (CMJ—countermovement jump and SJ—squat jump) in soccer players. The study examined 26 young elite soccer players (age: 18.1 ± 0.7 years; body height: 1.77 ± 0.05 m; body mass: 72.7 ± 5.7 kg). Knee joint flexor and extensor peak torques were assessed using the Cybex dynamometer (at 60°/s, 120°/s and 180°/s). Additionally, each participant performed the CMJ, SJ, and 30 m sprint. A significant relationship was obtained between the H/Q ratio (60°/s) and 30 m sprint time (r = 0.47). The positive direction of this relationship may indicate an important role of knee joint extensors in sprinting performance. Moreover, the H/Q ratio was not significantly associated with the CMJ, SJ or 10 m sprint performance. The H/Q ratio should be considered together with the peak torque values in terms of the assessment of sprinting and jumping performance.