High-intensity Distance Research Articles

The Influence of Menstruation and Hormonal Birth Control on the Performance of Female Collegiate Lacrosse Players

This study compared the mechanical and physiological load placed on Division I female collegiate lacrosse athletes (1) with and without hormone contraceptive (HC) use and (2) with and without menstruation during training and games. Athletes’ (20.6 ± 1.5 years, HC users = 9, naturally cycling (NC) athletes = 9) workloads—total distance traveled (TD, m), max speed (km∙hr−1), accelerations (repetitions), decelerations (repetitions), and high-intensity distance (HID, m)—were measured through VX Sport wearable microtechnology in training sessions (n = 87/athlete) and games (n = 17/athlete). Analyses showed no statistical group differences based on HC use or not, and no differences during menstruation versus non-menstruation for training or games. However, while not statistically different, athletes taking HCs performed worse during menstruation, with a 5.1% decline in decelerations, 3.4% decline in TD and HID, 1.2% decline in max speed, and 1% decline in accelerations. NC athletes did not show this same decline with menses. Given that withdrawal bleeding exacerbates performance reduction of HC users, it may be beneficial for these athletes to consider skipping their withdrawal bleed if it is likely to coincide with a game. Further research needs to be carried out to see if these trends are consistent across other female athletes in other sports.

The Impact of a Congested Match Schedule (Due to the COVID-19 Lockdown) on Creatine Kinase (CK) in Elite Football Players Using GPS Tracking Technology

The aim was to analyse the consequences of a congested schedule (due to the COVID-19 lockdown) on creatine kinase (CK) in elite football players using GPS tracking technology. A total of 17 elite football players were monitored in training and competition with a global positioning system. Variables including total distance, high-intensity distance, and distance acceleration and deceleration were analysed. Different measurements of serum creatine kinase (CK) concentration were performed on match day (MD) and at 24 h (MD+1), 48 h (MD+2), and 72 h (MD+3) after each match to study the muscle damage of each individual player caused during the match. The results showed a significant increase in physical demands in training (in relative terms regarding the match) at MD+3 compared to MD+1 and MD+2. Furthermore, at +72 h, CK decreases to a value almost the same as that before MD. On the other hand, the players with lower demands for high-intensity actions in the match showed a higher reduction in the concentration of CK at MD+3 compared to MD+1 and MD+2 (p < 0.05). It became evident that players with high-intensity demand and a high number of accelerations and decelerations need more time to assimilate the match load and can remain in a state of muscle fatigue for up to 3 days. In addition, a congested schedule can lead to a state of chronic fatigue in elite football players, limiting physical performance and possibly increasing the potential risk of injury for football players.

Professional football training and recovery: A longitudinal study on the effects of weekly conditioning session and workload variables.

The main purpose of this longitudinal study was to investigate football players' recovery status, through hormonal response, in relation to accumulated workload at two comparable time points of the first (T1) and second half (T2) of the competitive season. Moreover, this study investigated athletes' hormonal response to a typical weekly conditioning session (5 days before match: MD-5), at T1 and T2, to detect changes in players' recovery capability over time. Salivary cortisol (sC) and testosterone (sT) of 24 professional players (27.8 ± 4.1 years of age) were collected before, after, and 24 hours following MD-5 in two comparable microcycles of T1 and T2. GPS training data (total and high-intensity distance) of the 7 and 28 days before sampling were used to obtain athletes' acute and chronic workloads. Results showed a pre-training significant decrease of sT and an increase of sC (p<0.05) in T2, compared to T1. Moreover, athletes showed high sC and low sT levels before, after and 24 hours following MD-5 in T2. Workload analysis revealed significant correlations of chronic load with sC (r = 0.45, p = 0.056) and T/C ratio (r = -0.59; p = 0.007). These results suggested that, in professional football, chronic workload has a greater impact on players' recovery time than acute workload over the sport season. Moreover, athletes' hormonal response to the weekly conditioning session at T2 revealed an altered anabolic/catabolic balance, highlighting the key role of continuous internal and external workload monitoring during the season.

Talent identification in soccer: The influence of technical, physical and maturity-related characteristics on a national selection process.

The present study examines the influence of technical, physical, and relative age characteristics on players selection success within the Scottish Performance School trials. Ninety adolescent players (81 males, 9 females; mean ± standard deviation: age = 11.3 ± 0.4 years, height = 149.6 ± 6.9 cm, mass 38.1 ± 4.7 kg) performed a battery of physical fitness (20m Sprint, CMJ, 5-0-5 agility test), anthropometric, and 8 small-sided games (SSG; 9v9) as part of a talent identification (TID) programme. Players technical (ball touches, time on the ball, high-speed releases) and locomotor activities (high-speed running distance, sprint distance, accelerations, and decelerations) were monitored using foot-mounted inertial measurements units during SSG's. The data was analysed using independent sample T-tests. Mann-Whitney U analyses were conducted to examine the differences between groups whose data was determined as being (non)parametric, with Cohen effect sizes applied. Successful players performed significantly better during physical tests (Effect size ± confidence limits: Left 5-0-5 = -0.89±0.13, Right 5-0-5 = -0.51±0.11), had significantly higher locomotor activities during SSG (high-intensity distance = 0.4±26.6, horizontal accelerations = 0.59±1.19) and significantly higher technical outputs during SSG (touches = 0.71±6.1, releases = 0.49±2.5, high-speed releases = 0.59±2.7, time on the ball = 0.52±3.4) compared to unsuccessful players. Successful players had significantly higher locomotor activities and technical outputs during SSG than their unsuccessful counterparts. Monitoring technical and locomotor activities during SSG may compliment or replace physical testing batteries for assessing TID processes in soccer.

'Setting the Benchmark' Part 2: Contextualising the Physical Demands of Teams in the FIFA World Cup Qatar 2022.

This study aimed to contextualise and benchmark the physical demands of teams in the FIFA World Cup Qatar 2022. With FIFA's official approval, all sixty-four games were analysed during the competition (n = 32 teams) using a multi-camera computerised tracking system. On average, teams during Qatar 2022 covered around 108.1 ± 3.6 km in total, with 9.0 ± 0.9 and 2.3 ± 0.3 km covered at the higher intensities (≥20.0 and ≥25.0 km · h-1), respectively. Compared to the FIFA World Cup Russia 2018, national teams in Qatar 2022 covered only 3% more total distance but 16-19% more distance at the higher intensities (P < 0.01; Effect Size [ES]: 0.9-2.0). When the data was adjusted based on the number of minutes played, tournament differences at the higher intensities were less pronounced (9-12%; P < 0.01; ES: 0.7-1.3). The United States, Canada, Saudi Arabia, Germany and IR Iran covered 19-34% more high-intensity distance than Argentina, Ecuador, Qatar, Poland and Costa Rica during the 2022 tournament (P < 0.01; ES: 3.2-3.5). Match-to-match variation of each team in Qatar 2022 revealed Ecuador and Uruguay were particularly consistent for the distances covered at higher intensities (Coefficient of Variation [CV]: 2-3%), whilst Japan demonstrated considerable variation (CV: 23-29%). Teams generally covered more total distance on a per-minute basis in the first versus the second half (P < 0.01; ES: 1.2), but no differences existed at higher intensities (P > 0.05; ES: 0.0-0.1). Correlations between the number of high-intensity runs and various phase of play events across all teams were strongest for defensive transitions and recoveries, in addition to progressions up the pitch and into the final third (r = 0.63-0.75; P < 0.01). The present findings provide valuable context into the contemporary team demands of international football. This information could be useful for practitioners to benchmark team performances and to potentially understand the myriad of factors impacting physical performances.

The relationships between distances covered above generic and relative speed thresholds by male soccer players in English Premier League matches across two competitive seasons. The effects of positional demands and possession.

The aims of this study were to: a) examine the relationships between high-intensity distances covered above generic and relative speed thresholds in English Premier League (EPL) matches across two consecutive seasons and b) analyze the effects of playing position and team possession. Sixteen elite male soccer players (seven defenders, six midfielders and three forwards) participated in this study (age 27.8 ± 3.5 years, height 183.7 ± 5.4 cm, body mass 83.9 ± 7.1 kg). An Optical Tracking System was used to collect the following variables: total distance covered; high-speed running distance (HSRD) (> 5.5 m/s); high-intensity running distance (HIRD) (5.5-7 m/s); sprint distance (> 7 m/s); total distance covered above Maximal Aerobic Speed (MAS); distance covered > 85% peak speed (PS); and distance > 30% Anaerobic Speed Reserve (ASR). All measures were analyzed as whole match totals and as distances covered in the periods of the team in possession (TIP), opponent team in possession (OTIP), and ball out of play (BOP). Analysis by position based on defenders, midfielders and forwards was also performed. Distance > 30% ASR was almost perfectly correlated with HSRD (r = 0.98), while distances > MAS were highly correlated with both HIRD (r = 0.91) and HSRD (r = 0.91), and distance > 85% PS were highly correlated with SD (r = 0.70). Although the generic and relative speed thresholds show almost perfect correlation, the differences between HSRD, HIRD and distance > MAS indicate that players may be exposed to more HIRD when using relative thresholds.

Exploring the impact of professional soccer substitute players on physical and technical performance

BackgroundSubstitutions are generally used to promote the match performance of the whole team. This study aimed to analyze the performance of substitute players and explore the performance difference among substitute players, completed players, and replaced players across each position.MethodsChinese Super Soccer League (CSL) matches in the season 2018 including 5871 individual observation from 395 professional soccer players were analyzed by establishing linear mixed models to quantify the performance difference among substitute players (SP) (n = 1,071), entire match players (EMP) (n = 3,454), and replaced players (RP) (n = 1,346), and then separately for each position (central defenders, fullbacks, central midfielders, wide midfielders, and attackers).ResultsThe results show SP display higher high intensity distance and sprint distance significantly (p < 0.05) relative to playing time than RP and EMP. SP in offensive positions (attackers, wide midfielders) showed significantly higher (p < 0.05) passing and organizing performance such as passes, ball control, short passes, and long passes than RP or EMP. The scoring performances of central midfielders of SP including goals, shots, and shots on target are significantly higher (p < 0.05) than RP or EMP. Central defenders of SP showed higher shot blocks and pass blocks (p < 0.05) while lower passing and organizing performance (p < 0.05).ConclusionDepending on different playing positions, substitute players could indeed improve physical and technical performance related to scoring, passing, and defending as offensive substitute players can boost organizing performance and substitute defenders enhance defending performance. These could help coaches better understand substitute players’ influence on match performance and optimize the substitution tactic.

Comparisons Of Weekly Training Volumes Across A Season In Collegiate Female Lacrosse Athletes

The purpose of this study was to describe the in-season variations of acute:chronic workload ratio (ACWR) of distance, high intensity distance (HID), sprints, accelerations, and decelerations between player positions of a Division I collegiate women’s lacrosse team. Data were collected via wearable microtechnology across a total of 17 games and 64 training sessions on a total of 15 participants (attackers n=5, midfielders n=5, defenders n=5). ACWRs were calculated weekly by dividing the workload from the past seven days by the workload from the past 28 days for each metric. Two repeated measures analyses of variance (RM-ANOVA) were used to compare positional differences and weekly changes in all five metrics for 1) ACWR and 2) weekly training totals. There were several differences in weekly totals and ACWRs across all five metrics evaluated (p&lt;.05), but no positional differences were noted. Apart from the early training weeks, ACWR primarily stayed within the optimal window of 0.8-1.5 to maximize performance and reduce injury risk. These data indicate that there is variation in weekly totals for the main five metrics studied that cause “spikes” and “valleys” in workload. However, the athletes had built enough of a base in their chronic workload that it did not affect their ACWR to move outside of the optimal window. Using this information, coaches and team physicians can more effectively program training not only to optimize performance, but also to limit injuries, fatigue, and lack of fitness.

The Effects of 8 Aerobic Endurance Training Weeks of 4vs.4+GK Small-Sided Games versus Traditional Training on Physical Fitness and Skills among U18 Football Players

The aim of the research was to identify the effect of 4vs.4 small-sided games (SSGs) with goalkeepers (4vs.4+GK), applied twice a week, for 8 weeks, on U18 football players’ physical ability, compared to that of the athletes who performed specific aerobic endurance training. The research included 40 football players U18, divided into two groups: 20 in the experiment group (EG) aged 17.49 ± 0.61 years and 20 in the control group (CG) aged 17.66 ± 0.54 years. From the initial test (IT) to final tests (FT) performed on the parameters, maximum oxygen consumption (VO2max) and 10 m and 20 m sprint and agility with and without a ball showed a significant increase for both groups. The first and last SSG training was monitored, using total distance (TD), high-intensity distance (HSR—high-speed running) and maximum intensity distance (VHSR—very-high-speed running). Comparative analyses of EG and CG parameters at the FT shows that the differences between the means of two groups are statistically significant in favor of the experimental group in terms of all parameters, except 10 m sprint (p &lt; 0.05). Referring to SSGs, the experimental group had a 7.78% increase rate in TD (p &lt; 0.0005), a 30.90% (p &lt; 0.0005) increase rate with HSR and no significant differences (p &gt; 0.05) with VHSR. The experimental training program of 4vs.4+GK SSGs, applied to U18 football players, produced significant progress in the physical, and functional parameters.

Running Performance Profile among Playing Positions and Quarters in Elite Female Field Hockey Players

PURPOSE: This study aimed to compare the running-related variables during competitions across playing positions and quarters in elite female field hockey players.METHODS: A total of 136 data from 41 players were collected using GPS units during national-level competitions. The running-related variables included the total distance covered (TD, unit: m), relative distance (RD, unit: m/min), proportion of low-(LID, 0-6 km/h), moderate-( MID, 6.1-15 km/h), and high-intensity (HID, ≥15.1 km/h) distance of the total distance covered (unit: %), and sprint efforts (SE, ≥19.1 km/h, ≥1s; unit: bouts).RESULTS: The defenders’ TD (5,619.77±1,046.14 m) was shorter than that of midfielders (5,475±1,043.33 m) and forwards (4,684.22± 1,066.11 m), and the RD of midfielders (103.64±9.10 m/min) was longer than that of forwards (99.03±10.37 m/min) and defenders (92.42±10.85 m/min). The midfielders had the highest MID(47.08±5.51%), while the highest HID (16.23±3.62%) was observed in the forwards. Defenders performed 35.12±5.25 bouts, with the highest number of sprints among the playing positions. Regardless of the playing positions, 1 quarter had the highest TD, RD, and HID, and the SE was the highest in 4 quarter.CONCLUSIONS: The players’ specific requirements can be managed by practitioners and coaches using the running performance profile; further, it can be used to design training programs containing suitable running volumes to improve players’ performance.

External Training Load Monitoring and the Impact on Training Load Management in Collegiate Male Soccer Players.

Gdovin, JR, Galloway, R, Tomasiello, LS, Seabolt, M, and Booker, R. External training load monitoring and the impact on training load management in collegiate male soccer players. J Strength Cond Res 37(7): 1434-1439, 2023-Soccer is a physically demanding sport within the National Collegiate Athletic Association and continuously increases in popularity. To ensure athletes are adequately prepared for weekly physical stressors, coaches can use global positioning system technology to monitor external workloads and exercise intensity. These data can subsequently help coaches and practitioners better implement individualized training programs to ensure athletes are properly balancing the overreaching and overtraining paradigm. Therefore, the purpose of this observational study was to retrospectively analyze 3 consecutive seasons of external workload (total and high intensity distance) and injury data, which were derived from all training sessions and matches in 46 Division-I collegiate male soccer players. A coach's interpretation sought to provide practical insight into the functionality behind load management and how it prepares athletes for the physical stressors placed on them throughout a season. Two separate 3 × 3 repeated measures ANOVAs were conducted to determine differences between total distance and distance at high-intensity with an alpha level set at 0.05. Total distance between preseason and in-season ( p = 0.003), acute high-intensity distance ( p < 0.001), and chronic high-intensity distance ( p < 0.001) yielded significant differences. These results conclude the demands of each athlete change weekly and between seasons. It is recommended that sport coaches and practitioners develop individualized training programs by workload monitoring while considering variables such as a team's style of play, experience, position, role within a program, training intensity, and the length of time between conditioning sessions, practices, and matches.

Generation of Photonic Nanojet Using Gold Film Dielectric Microdisk Structure.

Due to their narrow beam waist size, high intensity, and long propagation distance, photonic nanojets (PNJs) can be used in various fields such as nanoparticle sensing, optical subwavelength detection, and optical data storage. In this paper, we report a strategy to realize an SPP-PNJ by exciting a surface plasmon polariton (SPP) on a gold-film dielectric microdisk. In detail, an SPP is excited by the grating-coupling method, then it irradiates the dielectric microdisk to form an SPP-PNJ. The characteristics of the SPP-PNJ, including maximum intensity, full width at half maximum (FWHM), and propagation distance, are studied by using finite difference time domain (FDTD) numerical solutions. The results demonstrate that the proposed structure can produce a high-quality SPP-PNJ, the maximum quality factor of which is 62.20, and the propagation distance of the SPP-PNJ is 3.08 λ. Furthermore, the properties of the SPP-PNJ can be modified flexibly by changing the thickness and refractive index of the dielectric microdisk.

Running more than before? The evolution of running load demands in the English Premier League

Purpose The purpose of this study was to assess running load trends (total distance (TD), high-intensity distance (HID; &gt; 5.5ms−1) and sprinting distance (SprD; &gt; 7ms−1)) in the English Premier League (EPL) between the 2014/2015 and 2018/2019 seasons using a semi-automated optical tracking system. Methods A total of 1634 games across 5 seasons (2014/2015–2018/2019) were analysed for team and positional TD, HID and SprD. All matches were tracked using TRACAB® Gen-4 HD motion cameras. Data were analysed to identify significant team and positional differences for each metric. Results Small to moderate increases were seen in team running load for TD ( p = 0.02; effect size (ES): 0.21), HID ( p &lt; 0.001; ES: 0.88) and SprD ( p &lt; 0.001; ES: 0.67) between 2014/2015 and 2018/2019. Positional analysis showed significant increases in TD for all except for defensive midfielders (DM), attacking midfielders (AM) and wide midfielders (WM) ( p &lt; 0.001–0.009; ES: 0.14–0.36); HID for all positions excluding goalkeepers (GK) ( p &lt; 0.001–0.007; ES: 0.2–0.54) and SprD for all positions except for GK, central midfielders (CM) and AM, ( p &lt; 0.001–0.020; ES: 0.19–0.39). Trivial to small differences were seen in season-to-season comparisons for TD ( p &lt; 0.001–0.023; ES: −0.16–0.52), HID ( p &lt; 0.001–0.033; ES: 0.10–0.38) and SprD ( p &lt; 0.001–0.025; ES: 0.13–0.27) for both team and positional differences. Conclusion Small to moderate increases in team TD, HID and SprD occurred in the EPL between 2014/2015 and 2018/2019, with trivial to small changes in season-to-season variations. Actual changes in running load over time appear to be dependent on playing position. Running load trends should be updated regularly and practitioners should be aware of the variability within their team, and programme accordingly.

Comparison of Match Load and Wellness between Friendly and World Cup Matches in Elite Female Soccer Players

(1) Objetive: Compare the internal load (ILO), external load (ELO) and wellness (WS) between official preparation friendly matches (FM) and France 2019 women world cup (WWC) matches in female soccer players. (2) Methods: Ten field players of the Chilean national football team (age 27 ± 3.4 years, height 162.8 ± 4.32 cm, weight 60.5 ± 4.6 kg, fat percentage 24.7 ± 1.62% and muscle percentage 49.2 ± 1.63%) participated in the study. Participants were compared across three FM before the world cup and three matches of the group stages in the WWC in June 2019. Both, ELO and ILO were recorded using GPS (Catapult Sports®, 10 Hz) and rating of perceived exertion (RPE), respectively. In addition, wellness was analyzed via personal questionnaire at 24 and 48 h after match. The intra subject difference was analyzed with a Student’s t-test for related samples. (3) Results: Moderate differences were observed between WWC and FM for total and relative total distance covered [TD and TDr, respectively] (p = 0.025, ES = −0.74 and p = 0.017, ES = −0.6). In addition, a non-significant (p = 0.088; ES = −0.43) larger high-intensity distance (HSR) was also found for WWC. Likewise, greater RPE was observed in WWC (p = 0.001; ES = −1.50) when compared to FM. Finally, significantly better wellness scores were shown for FM at stress ST24h, fatigue FT48h, and muscle pain MS48h (p = 0.038; ES = 0.72, p = 0.066; ES = 0.71; and p = 0.63; ES = 0.77) when compared to WWC matches. (4) Conclusion: It was concluded that ELO and ILO were greater at WWC soccer matches, whereas WS scores were better for FM. Moreover, ILO measures (i.e., TD, HSR and TDr) were greater in WWC, which could be at least in part, be the reason behind the differences in the values reported in the wellness questionnaires at 24 and 48 h after the match.

Effective playing time affects physical match performance in soccer: An analysis according to playing position.

This study aimed to analyse the influence of effective playing time on physical match performance according to playing position in professional soccer. Official match data from 267 matches (3,731 single observations) during the 2018/2019 season of the German Bundesliga were used and the effective playing time (duration of play after subtracting the time taken up by stoppages, substitutions, injuries, and goals) was captured for each match. The physical match performance parameters total distance, high-intensity distance, sprinting distance, maximum velocity, and accelerations were analysed. Players were categorized as central defender, wide defender, central defensive midfielder, central offensive midfielder, wide midfielder, and forward. Effective playing time influenced physical match performance, with total distance and accelerations (r = 0.48-0.61) being the most and high-intensity distance, sprinting distance, and maximum velocity (r = -0.17-0.03) the least affected parameters. Players covered on average 10% more total distance and performed 13% more accelerations, while sprinting 7-10% less in matches with long (> 65 min) compared to short (< 50 min) effective playing times. The influence of effective playing time was rather similar between playing positions. Still, physical performance of wide midfielders and forwards partly deviated from the pattern observed in the other positions. Coaches and practitioners should be aware that effective playing time influences physical match performance in the German Bundesliga, while special attention should be given to wide midfielders and forwards. Effective playing time and its general and position-specific effects should be taken into account when interpreting physical match performance, thereby facilitating load management practices and training design.

Quantification of training load across two competitive seasons in elite senior and youth male soccer players from an English Premiership club.

This study aimed to compare the daily training load (TL) in first-team and U-18 soccer players from an English Premiership club. 36 first-team (age 23.2 ± 5.9 years, weight 75.2 ± 8.1 kg, height 1.83 ± 0.06 m), and 22 U-18 players (age 17.5 ± 1.1 years, weight 71.1 ± 8.2 kg, height 1.78 ± 0.08 m) participated. GPS metrics were measured during all pitch training sessions throughout the 2020-21 and 2021-22 seasons. Linear mixed-effect model analyses revealed that, irrespective of training day, U-18 players covered greater total and explosive distance than first-team players, and performed a higher number of accelerations and decelerations, whereas first-team players covered greater sprint distance. Irrespective of the team, all examined variables were greater at match-day (MD)-3, while the number of accelerations and decelerations were higher at MD-4. Significant team-by-training day interactions revealed that U-18 players covered greater total and high-intensity distances than first-team players at MD-4, MD-2, and MD-1, whereas first-team players covered greater total and high-intensity distances at MD-3. Sprint distance was greater for first-team players at MD-3 and MD-4, while explosive distance was greater for U-18 players at MD-2. Also, U-18 players performed a higher number of accelerations than first-team players at MD-3 and MD-2, and a higher number of decelerations at MD-4. The present results provide novel information on TL patterns in English Premiership soccer and contribute to understanding how training methods to physically develop players are implemented in different countries and leagues.

Comparison of the Physical Response During Official Matches and Small-Sided Games in International Cerebral Palsy Footballers: Implications for Evidence-Based Classification.

This study aimed to analyze whether there are differences and associations in the physical responses in international-level cerebral palsy footballers between official matches and 2v2 small-sided games (2v2-SSG). One hundred seventy international cerebral palsy footballers participated in this study during three international championships. The physical responses of mean and maximum velocities, total distance, distance covered at different intensities, short-term actions, and player load were collected during 2v2-SSG and the real competition. The mean velocity, total distance, jogging, medium- and high-intensity distances, the number of moderate/high accelerations, decelerations, and player load were relatively higher in the 2v2-SSG than in the official matches. Even though the 2v2-SSG could become an appropriate drill to include during the classification process, due to the differences between a 2v2-SSG and the official competition, it is necessary to deepen the scientific knowledge for developing observation methods during real competition to strengthen the relationships between eligible impairments and activity limitation.

Validity and reproducibility of match-derived ratios of selected external and internal load parameters in soccer players: A simple way to monitor physical fitness?

The study aim was to assess whether match-derived external-to-internal load ratios are a valid and reliable tool to measure physical fitness. Sixteen elite youth soccer players (17 ± 1 years) performed two maximal fitness tests. Subsequently, players participated in three intra-squad soccer matches in three consecutive weeks. Three GPS-based parameters of external load (total distance, PlayerLoad, high-intensity distance) were divided by three heart rate-based parameters of internal load (iTRIMP, Banister TRIMP, average percentage heart rate reserve) for the ratio calculations. Validity was established by comparing the ratios with results of the fitness tests, while between-athlete and within-athlete reliability were quantified. Most integrated load ratios were moderately-to-largely correlated with the various fitness parameters. Overall, a ratio consisting of PlayerLoad and average percentage heart rate reserve demonstrated the most consistent correlations with maximum treadmill speed (r = 0.69, P = 0.003) and the speeds associated with 4 mmol/L of blood lactate (r = 0.56, P = 0.024) and 80% of heart rate reserve (r = 0.54, P = 0.031). Most of the ratios displayed acceptable levels of reproducibility (intraclass correlation coefficient > 0.8 and coefficient of variation < 10%), with the minimal detectable change of all ratios ranging between 7.1 and 37.8%. Given their associations with physical fitness and non-invasive nature, certain external-to-internal load ratios may be used to monitor physical fitness in soccer players. However, the ratios may not be sensitive enough to detect small yet practically relevant alterations in player fitness.

The Physical Demands of Match-Play in Academy and Senior Soccer Players from the Scottish Premiership.

The present study aimed to assess the physical match performance among senior and youth soccer players from an elite Scottish Premiership club during the 2021/2022 season. Twenty-two first team (25.9 ± 4.5 years, 78.3 ± 8.2 kg, 1.82 ± 0.07 cm) and 16 youth players (16.8 ± 0.9 years, 70.1 ± 6.8 kg, 177 ± 5.8 cm) were examined. A selection of physical match performance variables were measured using a global positioning system. Linear mixed-effect regressions revealed for all examined variables no significant differences between first team and U-18 players and no significant differences between playing level by position interaction. Across both teams, Centre Backs compared to Wing Backs, showed a 295 m (p < 0.01) lower high-intensity distance, and performed on average 36 fewer very-high intensity decelerations (p = 0.03). Comparing to Wide Midfielders, Centre Backs showed lower total (1297 m, p = 0.01), high-intensity (350 m, p = 0.01), and sprint (167 m, p < 0.01) distances. Sprint distance was also lower in Centre Backs vs. Strikers (118 m, p = 0.03), and in Central Midfielders vs. both Strikers (104 m, p = 0.03) and Wide Midfielders (154 m, p = 0.01). The present findings highlight the physical match performance of elite Scottish players and provide useful information within the context of understanding how methods of physical development of youth soccer are implemented in different countries.

Pre-covid Vs. Covid Differences In Workloadandwellness In Division I Women’s Lacrosse

PURPOSE: COVID-19 altered training programs and the mental well-being of athletes. This study aimed to assess differences in weekly training volume and wellness of collegiate women’s lacrosse athletes pre-COVID (PC, 2019-2020) and during COVID (DC, 2020-2021). METHODS: Microtechnology and wellness questionnaires were used to monitor athletes (n = 17) daily throughout the PC and DC training and competitive seasons. On-field data included total distance, high-intensity distance (HID), sprints, accelerations, and decelerations. Weekly sums of training and wellness means were aligned within each year for comparison. For fall training, there were 14 viable weeks for analyses from PC, but DC only had six weeks available for analyses due to COVID. There were nine usable weeks for analyses for the PC competitive season, and of these weeks, eight had complete data sets DC due to team quarantine procedures. RESULTS: There were higher values PC in distance, sprints, accelerations, and decelerations for the first two weeks of training (p = .001-.003) and a difference in distance for the last two weeks (p < .001). The first two weeks of training showed lower wellness scores DC compared to PC (p = .001-.008) and for week 6, after the team was quarantined DC (p = .009). The competitive season had higher values in distance for the first three weeks PC than DC (p = .001-.002) and higher decelerations PC than DC in weeks two and three (p = .003-.005). HID was lower PC for the final four weeks of competitive season (p = .001-.002) and sprints were lower PC in the final two weeks (p < .001). There were no differences in wellness scores between competitive seasons. CONCLUSIONS: Due to the late start of training DC, load metrics were comparatively low in the first two weeks of training. Coaches did not significantly alter demands DC outside of these two weeks despite two separate breaks in training due to quarantine procedures. A slow start to the DC competitive season was also revealed. A reduction in high-intensity work was shown in the latter portion of the PC competitive season despite the team playing seven games versus three DC. Lower wellness scores early DC indicate that athletes’ physical and mental well-being were affected by the pandemic, but this was not seen in the competitive season.