Running Research Articles

Analysis of stiffness changes and factors induced by smart suit with trunk kinetic chain SLIP model

We are currently developing a suit that assists human running motion based on the Smart Suit (SS). The SS is a wearable assistive device that intervenes in trunk kinetic chain movements by linking trunk rotation to hip flexion and extension through elastic belts. By intervening in the trunk kinetic chain, our goal is to enhance stiffness, thereby improving running economy and speed. The purpose of this study is to acquire fundamental insights into the changes in leg and trunk rotational stiffness induced by the SS, as well as the underlying mechanisms. We defined the SS torque intervention rate pss, which focuses on the magnitude of force, and the peak time difference index, elag, between SS and humans, which focuses on the timing of force, and analyzed the relationship between the stiffness change rate due to SS wearing. The results of the analysis suggest that SS affects human running sensitively rather than mechanically. We also confirmed that the degree of adaptation to SS, assessed by the timing gap between SS exertion and human exertion, contributes significantly to changes in trunk rotation stiffness.

Relationship of Age and Running Biomechanics in Female Recreational Runners.

Middle-age and older runners demonstrate differences in running biomechanics compared with younger runners. Female runners demonstrate differences in running biomechanics compared with males, and females experience hormonal changes during menopause that may also affect age-related changes in running biomechanics. The purpose of this study was to determine the relationship between age and running biomechanics in healthy female recreational runners. Fifty-two participants (ages 27-65y) ran on an instrumented treadmill at 2 different self-selected speeds: easy pace and 5km race pace. Lower-extremity kinematic and kinetic variables were calculated from 14 consecutive strides. Linear regression was used to determine the relationship between age and lower-extremity running biomechanics, controlling for self-selected running speed. There was a negative relationship between age and easy pace (R = -.49, P < .001) and age and 5km race pace (R = -.43, P = .001). After controlling for self-selected running speed, there were no significant relationships between age and running biomechanics for either running speed. Several biomechanical variables were moderately to strongly correlated with running speed. Running speed should be considered when investigating age-related differences in running biomechanics.

Classifying Impact Loading Using Axial Peak Tibial Acceleration and Impact-Related Biomechanical Differences During Treadmill Running.

Measuring lower extremity impact acceleration is a common strategy to identify runners with increased injury risk. However, existing axial peak tibial acceleration (PTA) thresholds for determining high-impact runners typically rely on small samples or fixed running speeds. This study aimed to describe the distribution of axial PTA among runners at their preferred running speed, determine an appropriate adjustment for investigating impact magnitude at different speeds, and compare biomechanics between runners classified by impact magnitude. A total of 171 runners ran on an instrumented treadmill at their preferred running speed during 3D motion capture. Axial PTA was collected at the distal tibia. The relationship between axial PTA and running speed was investigated using linear regression. Runners were categorized into impact sub-groups, with high- and low-impact runners identified if their axial PTA was ±1 standard deviation of the model predicted value. Differences in demographics, training, and running biomechanics between impact sub-groups were compared. Mean axial PTA was 7.8 g across all running speeds. Axial PTA increased with running speed, with a 1.7 g increase for every 1.0 m/s increase. There were no differences in axial PTA between males and females (p = 0.214) and lower limbs (p = 0.312). High-impact runners had higher vertical loading rates (p < 0.001) and greater ankle dorsiflexion at initial contact (p < 0.001) compared to low-impact runners. No differences in age, body mass, height, or weekly running distances were observed across impact sub-groups. This study proposes a method to identify the impact classification of runners based on their axial PTA for screening, monitoring, or gait retraining.

The impact of asymmetry in lower limb muscle strength and power on straight-line running speed in female soccer players

The aim of this study was to investigate and determine the impact of asymmetries in muscle strength and power between the right and left lower limbs on straight-line running speed in female soccer players.30 right-footed female soccer players playing in the Ekstraliga participated in the study. The Modulus. Number formula was used to avoid negative results and to assess only the difference in relative strength and power between the lower limbs, not the dominance of one of them. A result equal to or below the threshold defined group G1 "with lower asymmetry," and a result above the threshold defined group G2 "with greater asymmetry." It should be emphasized that the level of asymmetry in no way allows determining the strength and power results achieved by the players. Therefore, some players were classified into group G1 or G2 depending on the test. Analysis indicated no significant differences between groups G1 and G2 in straight-line speed (criterion: MVSLJ). The same analysis indicated higher speeds in G1 (criterion: LSLJ), meaning players with lower asymmetry in lower limb muscle strength were faster in straight-line running compared to those with higher asymmetry. The one-way ANOVA for running speed between groups G1 and G2 (criterion: PPLP) indicated statistically significant differences in running speed between groups over 20m and 30m segments. Players in the lower asymmetry group (G1) achieved higher speeds on straight-line segments of 20m and 30m. The one-way ANOVA for running speed between groups G1 and G2 (criterion: SLS) indicated statistically significant differences in running speed between groups over the 10m distance. Players in the lower asymmetry group (G1) achieved higher speeds over the 10m distance. In conclusion, this study highlights the significant impact of lower limb muscle strength and power asymmetry on straight-line running speed in female soccer players. The findings underscore the necessity for balanced muscle development to enhance performance and reduce injury risk. By addressing these asymmetries through targeted training interventions, coaches and trainers can help athletes achieve their full potential on the field.

Analyzing exercise-to-rest ratios in U19 American football European championship: implications for team success and injury prevention

BackgroundThe teams' collective playing strategy rather than the individual player attitudes could explain event outcome and risk of injuries.ObjectiveThe study aimed to examine the playing style of European teams and compare it to the USA.Method12 matches from the U19 European championship of American Football were analysed. We characterized each team by their running-passing activities ratio during the offensive phase: running (RUN), passing (PASS), or balanced (BAL).ResultsThe BAL style of play accurately described 75% of European teams (n = 6). The remaining two national teams adopted either the RUN or PASS style of play. This finding is similar to what was observed in NCAA Division IA. All RUN style teams had a higher percentage of rushing plays (80.7% ± 9.7%) compared to PASS (33.0% ± 14.7%) and BAL teams (46.0 ± 0.8%) (p &amp;lt; 0.05). The mean playing time for RUN and PASS teams was longer than the average duration of plays for BAL teams (p &amp;lt; 0.05). The mean duration of plays ranged from 5.3 ± 1.9 to 5.7 ± 2.1 s, with a significant style of play effect (p &amp;lt; 0.05). Rest duration for BAL teams (46.7 ± 44.1 s) was shorter than that of RUN (55.9 ± 34.7 s) and PASS (54.5 ± 32.9 s) teams (p &amp;lt; 0.05). Finally, the European top final team was the team that was able to shift their game style during the tournament and presented a low coefficient of variation in offensive plays per drive.ConclusionBased on the running-passing activities ratio, the video match analysis can provide a foundation for the strength and conditioning program for long-term athlete development and injury prevention.

Pes Planus Level and Foot Pain Affect Selected Performance Parameters: A Study on Team Sport Athletes

Aims to investigate the relationship between pes planus (PP) with foot pain (FP) and performance in team sport athletes. Correlational research was adopted to reveal the relationship between PP with FP and performance. There were 84 athletes were involved in this research. Measurement of PP with footprint test (FT), FP with knee pain intensity-visual analogue scale (KPI-VAS) and performance with items 30m sprint (30ms), modified agility t-test (MATT), counter movement jump (CMJ), standing stock balance test (SSBT). We observed that FT-PP variable has a moderate negative correlation with FP-KPI-VAS (p = 0.003), which shows that PP significantly causes foot pain. In CMJ (p = 0.035) and SSBT (p = 0.004) there is a moderate negative correlation, which shows that the PP level reduced the level of power and balance. Meanwhile, there is a moderate positive correlation with 30mS (p &lt; .001), and MATT (p &lt; .001), which shows that the level of PP will reduce the level of running speed and agility. At the same time, FP-KPI-VAS had a small negative correlation with 30mS (p = 0.017), MATT (p = 0.017) and CMJ (p = 0.048). Finally, FP-KPI-VAS was found to have a large positive correlation with SSBT (p &lt; .001). Thus, we confirm that PP is significantly correlated with FP and performance related to 30ms, MATT, CMJ, SSBT in team sports athletes.

Analysis of the 10-day ultra-marathon using a predictive XG boost model

ObjectiveUltra-marathon running races are held as distance-limited or time-limited events, ranging from 6 h to 10 days. Only a few runners compete in 10-day events, and so far, we have little knowledge about the athletes’ origins, performance, and event characteristics. The aim of the present study was to investigate the origin and performance of these runners and the fastest race locations. A machine learning model based on the XG Boost algorithm was built to predict running speed from the athlete´s age, gender, country of origin, country where the race takes place, the type of race and the kind of running surface. The model explainability tools were then used to investigate how each independent variable would influence the predicted running speed.ResultsThe model rated the origin of the athlete as the most important predictor, followed by age group, running on dirt path, gender, running on asphalt, and event location. Running on dirt path led to a significant reduction of running speed, while running on asphalt showed faster running speeds compared to other surfaces. Most athletes came from USA, followed by Russia, Germany, Ukraine, the Czech Republic, and Slovakia. Most of the runners competed in USA. The fastest 10-day runners were from Finland and Israel. The fastest 10-day races were held in Greece.ConclusionsMost 10-day runners originated from USA, but the fastest runners originate from Finland and Israel. The fastest race courses were in Greece. Running on dirt paths leads to a significant reduction in running speed while running on asphalt leads to faster running speeds.

Revamping Pace Distribution: A Case Study on Elevating the Men's 400 m Track and Field Japanese National Record After 32 Years.

Chiba, Y, Sato, K, Yoshimoto, T, Ohnuma, H, Yamanaka, R, Takahashi, K, Kobayashi, K, Matsubayashi, T, and Takai, Y. Revamping pace distribution: A case study on elevating the men's 400 m track and field Japanese national record after 32 years. J Strength Cond Res XX(X): 000-000, 2024-Many studies have investigated the 400-m sprint, and the optimal pacing strategy is subject to debate. Little information is available regarding the effects of changes in the pacing strategy on running speed and spatiotemporal variables in the official 400-m race. This case study analyzed changes in running speed and spatiotemporal variables of a Japanese elite long sprinter who set a new Japanese national record in the 400-m race by modifying his pace distribution based on the analysis of his previous races and the performances of world-class long sprinters. To revamp his pace distribution, 25 preceding races (ranging from 45.47 to 46.95 seconds) were analyzed, spanning from June 2015 to June 2023. The independent variables were the 50-m split time, average running speed, percentage of the 50-m split time relative to the 400-m record, step length, and step frequency. K.S. broke his own record by modifying the pacing distribution based on the development of his previous race and the world-class long sprinters. The modified pacing strategy increased running speed in the 200- to 300-m section. Step lengths were longer throughout the 400 m, and step frequencies were higher in the last 200 m than before the alteration in the pace distribution. Modifying the pacing strategy from leading to driving may enhance the personal records of long sprinters. This improvement is attributed to the maintenance of longer step lengths over the entire 400-m range and an increase in the step frequency in the last 200 m.

Research on a Novel Flux-Switching Permanent Magnet Motor with Adjustable Torque Ripple Using an Auxiliary Rotor

In the field of material manufacturing, torsional vibration has some benefits for cutting or forming processing. In principle, torsional vibration can be caused by the torque ripples of a motor. Flux-switching permanent magnet (FSPM) motors are doubly salient and generate torque ripples, making them an option for manufacturing. However, the amplitude of the torque ripples is related to the motor structure, and frequency has a linear relationship with running speed. The torque ripples cannot be controlled separately from the motor running speed at conventional current excitations. Thus, a novel FSPM machine with an auxiliary rotor (AR-FSPM) is proposed to adjust the torque ripples. The main rotor (m-rotor) outputs the power, and the auxiliary rotor (a-rotor) adjusts the ripple frequency. When the speed difference between two rotors is six times the m-rotor speed, the torque ripple waveforms overlap. In this case, by controlling the phase difference between the two rotors, the amplitudes of the torque ripples can be adjusted. In this study, the principle of this novel machine is introduced, and the relationship between the torque ripple performance and the geometric parameters of the auxiliary rotor is studied. Then, the torque ripple amplitude adjustment method for this machine is discussed. Finally, the prototype of this novel machine is presented to verify its feasibility.

Evaluation of WIMU Sensor Performance in Estimating Running Stride and Vertical Stiffness in Football Training Sessions: A Comparison with Smart Insoles.

Temporal parameters are crucial for understanding running performance, especially in elite sports environments. Traditional measurement methods are often labor-intensive and not suitable for field conditions. This study seeks to provide greater clarity in parameter estimation using a single device by comparing it to the gold standard. Specifically, this study aims to investigate how the temporal parameters and vertical stiffness (Kvert) of running stride exerted by IMU sensors are related to the parameters of the smart insole for outdoor acquisition. Ten healthy male subjects performed four 60-meter high-speed runs. Data were collected using the WIMU PRO™ device and smart insoles. Contact time (CT) and flight time (FT) were identified, and Kvert was calculated using Morin's method. Statistical analyses assessed data normality, correlations, and reliability. WIMU measured longer CT, with differences ranging from 26.3% to 38.5%, and shorter FT, with differences ranging from 27.3% to 54.5%, compared to smart insoles, across different running speeds. Kvert values were lower with WIMU, with differences ranging from 23.96% to 45.01% depending on the running activity, indicating significant differences (p < 0.001). Using these results, a multiple linear regression model was developed for the correction of WIMU's Kvert values, improving the accuracy. The improved accuracy of Kvert measurements has significant implications for athletic performance. It provides sports scientists with a more reliable metric to estimate player fatigue, potentially leading to more effective training regimens and injury prevention strategies. This advancement is particularly valuable in team sports settings, where easy-to-use and accurate biomechanical assessments of multiple athletes are essential.

Investigation of the Effect of Casing-to-Wellbore Clearance on Equivalent Circulating Density During Casing Running

As drilling depth increases, the demand for a multi-layer wellbore structure grows. However, with the upper wellbore diameter fixed, reducing the casing-to-wellbore clearance becomes necessary to increase the number of casing strings. This poses a significant challenge to maintaining adequate casing-to-wellbore clearance. However, in actual drilling operations, the casing-to-wellbore clearance cannot be continuously reduced. Equivalent circulating density (ECD) during running casing becomes a critical factor to consider. When the casing-to-wellbore clearance is too small, excessive surge pressures can occur, increasing the risk of lost circulation. In this study, a surge pressure calculation model was developed for the casing running process to analyze the variation in ECD under 10,000 m well conditions in China. Focusing on key formations with narrow density windows, the effects of different casing-to-wellbore clearances on ECD were evaluated. The analysis determined that under the constraints of fracture pressure, the minimum allowable casing-to-wellbore clearance for this casing string is 27 mm. Subsequently, using response surface methodology, a fitting formula was derived to describe the relationship between the selected variables—drilling fluid density, casing running speed, and casing-to-wellbore clearance—and the ECD during casing operations. This provides a theoretical basis for the optimal matching of casing-to-wellbore clearance.

Temporal Changes and Between-Competition Differences in the Activity Profile of Elite Hurling Referees.

Background/Objectives: This study examined the activity profile of elite hurling referees during games in the National Hurling League (NHL) and All-Ireland Championship (AIC) and across all divisions of the NHL and phases of the AIC. Temporal changes between the first and second half and across the four quarters were also examined. Methods: Data were collected from 36 referees using 10-Hz global positioning system technology during 106 NHL and 85 AIC games and analyzed for duration, total distance, very low-speed movement (<0.69 m·s-1), walking (≥0.69-1.59 m·s-1), low-speed running (≥1.60-3.08 m·s-1), moderate-speed running (≥3.09-4.62 m·s-1), high-speed running (HSR) (≥4.63-6.34 m·s-1), and very high-speed running (VHSR) (≥6.35 m·s-1) distance and peak running speed. Results: Total distance was not significantly different between games in the NHL (120.7 ± 9.4 m·min-1) and AIC (122.8 ± 9.9 m·min-1, ES = 0.04). There was also no significant difference in HSR distance between the NHL (17.1 ± 6.5 m·min-1) and AIC (18.0 ± 7.2 m·min-1, ES = 0.10). The only significant difference between the NHL and AIC was in LSR distance, which was higher in the AIC (ES = 0.24). VHSR distance was significantly higher during games in Division 3A+3B (0.7 ± 0.8 m·min-1) compared to Division 1A+1B (0.2 ± 0.3 m·min-1) and Division 2A+2B (0.1 ± 0.3 m·min-1). HSR distance was significantly lower during games in the All-Ireland Series (15.7 ± 6.7 m·min-1) compared to games in the Leinster (21.1 ± 8.5 m·min-1) and Munster (17.9 ± 5.4 m·min-1) Championships. Conclusions: The findings of this study can be used to support the development of physical conditioning programs that are specific to the demands experienced during competitive match play.

Gender Differences in the Dynamics and Kinematics of Running and Their Dependence on Footwear.

Previous studies on gender differences in running biomechanics have predominantly been limited to joint angles and have not investigated a potential influence of footwear condition. This study shall contribute to closing this gap. Lower body biomechanics of 37 recreational runners (19 f, 18 m) were analysed for eight footwear and two running speed conditions. Presenting the effect size Cliff's Delta enabled the interpretation of gender differences across a variety of variables and conditions. Known gender differences such as a larger range of hip movement in female runners were confirmed. Further previously undiscovered gender differences in running biomechanics were identified. In women, the knee extensors are less involved in joint work. Instead, compared to men, the supinators contribute more to deceleration and the hip abductors to acceleration. In addition to differences in extent, women also show a temporal delay within certain variables. For the foot, ankle and shank, as well as for the distribution of joint work, gender differences were found to be dependent on footwear condition, while sagittal pelvis and non-sagittal hip and thigh kinematics are rather consistent. On average, smaller gender differences were found for an individual compared to a uniform running speed. Future studies on gender differences should consider the influence of footwear and running speed and should provide an accurate description of the footwear condition used. The findings of this study could be used for the development of gender-specific running shoes and sports and medical products and provide a foundation for the application of smart wearable devices in gender-specific training and rehabilitation.

One Shoe to Fit Them All? Effect of Various Carbon Plate Running Shoes on Running Economy in Male and Female Amateur Triathletes and Runners at Individual Training and Race Paces

Carbon plate running shoes (CPRSs) have gained widespread popularity among elite and amateur runners, representing one of the most substantial changes in running gear over the past decade. Compared to elite runners, however, amateurs run at lower speeds and show more diverse running styles. This is a meaningful difference as many previous studies on CPRSs focus either on highly trained male runners and higher speeds or only on a single CPRSs manufacturer. The present study aims at bridging this gap by investigating how CPRSs from four different manufacturers affect running economy in amateurs of both sexes at their individual running speeds. For this purpose, 21 trained amateur triathletes (12 men; 9 women) completed an incremental treadmill test until volitional exhaustion, yielding running speeds at ventilatory thresholds 1 (vVT1) and 2 (vVT2). In a second session, subjects ran five trials of 3 × 3 min (speeds of 90% vVT1, ½ (vVT1 + vVT2), and 100% vVT2), wearing one out of four different pairs of CPRSs or their own preferred non-CPRS shoes in each trial. Our results show that tested CPRS models resulted in a significant reduction in the mean energy cost of transport, compared to the non-CPRS control condition, with Cohen’s d amounting to −1.52 (p = 0.016), 2.31 (p &lt; 0.001), 2.57 (p &lt; 0.001), and 2.80 (p &lt; 0.001), respectively, although effect sizes varied substantially between subjects and running speeds. In conclusion, this study provides evidence that amateur athletes may benefit from various manufacturers’ CPRS models at their typical running speeds to a similar degree as highly trained runners. It is recommended that amateur athletes evaluate a range of CPRSs and select the shoe that elicits the least subjective sensation of fatigue over a testing distance of at least 400–1000 m.

BRTPillar: boosting real-time 3D object detection based point cloud and RGB image fusion in autonomous driving

PurposeIn autonomous driving, the inherent sparsity of point clouds often limits the performance of object detection, while existing multimodal architectures struggle to meet the real-time requirements for 3D object detection. Therefore, the main purpose of this paper is to significantly enhance the detection performance of objects, especially the recognition capability for small-sized objects and to address the issue of slow inference speed. This will improve the safety of autonomous driving systems and provide feasibility for devices with limited computing power to achieve autonomous driving.Design/methodology/approachBRTPillar first adopts an element-based method to fuse image and point cloud features. Secondly, a local-global feature interaction method based on an efficient additive attention mechanism was designed to extract multi-scale contextual information. Finally, an enhanced multi-scale feature fusion method was proposed by introducing adaptive spatial and channel interaction attention mechanisms, thereby improving the learning of fine-grained features.FindingsExtensive experiments were conducted on the KITTI dataset. The results showed that compared with the benchmark model, the accuracy of cars, pedestrians and cyclists on the 3D object box improved by 3.05, 9.01 and 22.65%, respectively; the accuracy in the bird’s-eye view has increased by 2.98, 10.77 and 21.14%, respectively. Meanwhile, the running speed of BRTPillar can reach 40.27 Hz, meeting the real-time detection needs of autonomous driving.Originality/valueThis paper proposes a boosting multimodal real-time 3D object detection method called BRTPillar, which achieves accurate location in many scenarios, especially for complex scenes with many small objects, while also achieving real-time inference speed.

Neural and Motor Differences in Acceleration and Running Speed of Children Aged 6 to 11 Years in the North-Eastern Part of Romania

&lt;p dir="ltr"&gt;&lt;span&gt;A&lt;/span&gt;&lt;span&gt;cceleration and running speed develop in childhood based on biological growth. The research aims to compare, according to gender and age, the running times of 5, 10, and 15 m of children aged 6 to 11 years in the north-eastern area of Romania. Our proposed distance analysis is scarce in the literature and we want to enrich and update the existing data, especially for the north-eastern region of Romania. Our research included 3460 primary school students whom we grouped according to chronological age and gender. Using the TracTronix TF100, the 12 groups formed were measured for 5, 10, and 15 m running times during physical education classes. The first hypothesis states that boys will have higher acceleration and speed values. Second, we assume that growth from 6 to 11 years will improve acceleration and speed for both genders. The unpaired t-test and one-way ANOVA confirmed both hypotheses (p&amp;lt;0.05). Both criteria we tested influence acceleration and running speed. Boys achieved better times than girls in all three events, except for 5 m at 10 and 11. Advancing in age improves acceleration and speed, there is a stagnation from 10 to 11 years for both genders, as well as the 7-8 years threshold for boys. Our study reinforces the effect that gender and age have on children's acceleration and speed, and can be a benchmark for practitioners.&lt;/span&gt;&lt;/p&gt;&lt;div&gt;&lt;span&gt;&lt;br /&gt;&lt;/span&gt;&lt;/div&gt;

Does running speed affect the performance improvements experienced by elite distance runners wearing advanced footwear technology spikes?

Elite distance runners have exhibited race time improvements since the 2020 introduction of advanced footwear technology (AFT) for track and field, also known as "super" spikes. The observed performance improvements may be due to changes in midsole compliance, which could affect leg stiffness while wearing AFT spikes. Since increased leg stiffness has been associated with running speeds greater than 6 m/s, race time improvements for elite distance runners wearing AFT spikes may be reduced at faster running speeds. To investigate the relationship between the use of AFT spikes, running speed, and race performance, we conducted a statistical analysis of the race times from the top 100 male and female elite runners for 800-m to 10,000-m events from 2001 to 2023. We calculated race performance improvement (RPI) as the percentage difference between the pre-AFT spike (2001-2019) regression equation predicted average race times from the top 100 athletes and actual average race times from the top 100 athletes for 2021, 2022, and 2023. Overall, RPI after the introduction of AFT spikes was 0.89 ± 0.58% (range: 0.22-2.03%; P < 0.001) or roughly 1.2 s faster per kilometer than predicted by the regression equations. In addition, average running speed is faster as race distance decreases and we found that RPI was negatively associated with running speed from 10,000-m to 800-m (P < 0.001). Although overall race performances have improved since the introduction of AFT spikes, the use of AFT spikes may disproportionately improve race performance based on running speed.NEW & NOTEWORTHY After accounting for historical race time trends, average race times from the top 100 elite male and female athletes competing in the 800-m to 10,000-m events have improved since the introduction of advanced footwear technology spikes. However, the percentage performance improvement is smaller at faster average running speeds. Thus, future research is warranted to determine the interaction of footwear compliance, running speed, and performance for elite runners.

A037: The Influence of Absolute-Speed Training Under Long-Jump in Take-Off Area on Run-Up Performance and Results

Purpose: Recently, the IAAF put forward the idea of changing the long jump to the starting area, and the implementation of this rule will inevitably change the training strategy of the long jump event. Compared with pedal take-off, the speed of running under the take-off zone rule has a greater impact on performance. Therefore, this study adopted the measurement methods of take-off zone and take-off board. The take-off zone was to take the take-off position in the area as the starting point for measuring the long jump distance. Compared with the traditional pedal take-off, the difference in the run-up performance and results of absolute speed training under these two take-off methods were analyzed. Method: In this study, 16 student-athletes were divided into the area group and the board group by the method of literature, experiment and video analysis. Before and after the intervention, three times a week for eight weeks, the 30-meter run, the 30-meter run between marching, the standing long jump and the long jump were tested. The average speed of the last 5 meters and the last 5-10 meters of the long jump run-up were collected and the differences before and after the experiment were compared. Results: (1) Both the 30-meter run and the 30-meter run between the two groups improved, and the standing long jump performance did not change significantly. (2) There were no significant differences in the speed of the last 5-10 meters of the run-up between the two groups, but the speed of the last 5 meters of the board group decreased significantly along with decreased stride length (p &lt; 0.01). (3) The speed of the last 5 meters and the last 5-10 meters in the zone group did not change and the stride length was average. Discussion: (1) For the starting area long jump, absolute speed training can improve performance. However, the effect is not satisfactory in the springboard long jump, because the stride length and rhythm change with speed. (2) In the starting board long jump in the speed training at the same time with the run-up rhythm of training to achieve the best results. (3) If the IAAF promotes the starting area long jump, athletes with strong speed will have greater advantage, while "technical" athletes who rely on pedal accuracy may face greater challenges.

A057: Effects of Aerobic Exercise on Glutamate Homeostasis in NAC During Withdrawal Period of Nicotine Addiction

Background/Purpose: The disturbed glutamate homeostasis in the nucleus accumbens (NAc) plays a key role in the induction of relapse during nicotine withdrawal. The uptake of excessive extracellular glutamate relies on astrocytic glutamate transporter-1 (GLT-1) and transporter for cysteine (x-CT). Nicotine abuse leads to decreases in expressions of GLT-1 and xCT in NAc. The purpose of this study was to explore the effects of exercise on the expressions of GLT-1 and x-CT during nicotine withdrawal. Method: (1) 2-month-old male C57BL/6J mice were used in this experiment. Mice were randomly divided into four groups: saline sedentary (SS) group, saline exercise (SE) group, nicotine sedentary (NS) group, and nicotine exercise (NE) group. After the establishment of nicotine addiction model with conditioned place preference (CPP) behavioral paradigm, SE and NE group mice were subjected to moderate intensity treadmill exercise. SS and NS group mice were not given exercise intervention. (2) Exercise program: the first 10min running speed is 12m/min, the last 50min is 15m/min, the slope is 0,60 min/day, 5 days/week, 2 weeks. (3) The nicotine dependence during withdrawal was tested using CPP. (4) The expression of GLT-1 and x-CT in NAc were detected by western blot. (5) The results were expressed as mean ± standard error. Two-way analysis of variance was performed. P &lt; 0.05 was statistically significant. Results: (1) After the establishment of nicotine addiction, CPP scores of NS and NE groups were higher than those in SS group (P &lt; 0.001). After two weeks of aerobic exercise, CPP score of NE group was lower than that in NS group (P &lt; 0.05). (2) GLT-1 expression in NS group was lower compared with SS group (P &lt; 0.05). GLT-1 expression in NE group was higher compared with NS group (P &lt; 0.05). (3) x-CT expression in NS group was lower compared with SS group (P &lt; 0.05). x-CT expression in NE group was higher compared with NS group (P &lt; 0.01). Conclusion/Discussion: The expressions of GLT-1 and x-CT in the NAc are lower, which might be one of the mechanisms of nicotine relapse during withdrawal. Aerobic exercise increases the expression of GLT-1 and x-CT in the NAc from nicotine withdrawal mice, which might be one of the mechanisms of exercise-induced reduction of nicotine relapse during withdrawal.

The effect of icky shuffle training on 30 meter running speed in intensive development high school futsal players in Surabaya

Abstract Speed ​​is one of the fitness elements that might help in playing futsal. The ability to perform a task quickly or travel a long distance in the shortest time is called speed. This study aims to determine the potential impact of Icky shuffle training on 30 meter operating speed among futsal participants at Taruna Pembangunan Intensive High School Surabaya, as well as the efficacy of certain types of Icky shuffle training on increasing 30 meter running speed. running speed. This research uses quantitative research methods with a one-group pretest-posttest design. The following data results show these findings: comparison of pretest and posttest scores obtained from the 30 meter running test. The two-sided sig p value is 0.023, which is less than (&lt;0.05), as can be observed. As a result, the 30 meter running speed of the Surabaya Taruna Pembangunan Intensive High School futsal players was affected by the unpleasant shuffle training. Keywords: Icky shuffle, sprint, futsal.