High-intensity Running Research Articles

Physical Performance in Highest-Level Soccer: Comparison between FIFA World Cup and UEFA Champions League Matches

Match running performance (RP) of Union of European Football Associations Champions League (UCL) and Fédération Internationale De Football Association World Cup (WC) players are often investigated separately; however, no study to simultaneously observed RP in both competitions. Therefore, the main objective of this study was to provide a comparative analysis of RP of professional soccer match-play across two highest-level soccer competitions: UCL and WC. The RPs (UCL; n=244, WC; n=581) of professional soccer players were analyzed using optical systems, and classified according to their playing positions as: central defenders (CD), fullbacks (FB), central midfielders (CM), wide midfielders (WM) and forward (FW). The RP variables included total distance and high intensity running (>5.5 m/s). One-way analysis of variance was used to examine position-specific differences between RP in WC and UCL, while Cohen’s d was used to identify effect sizes. Results indicated that CDs, FBs, CMs, and WMs from UCL covered significantly greater total distance than their counterparts from WC (all moderate effect sizes). In addition, CDs from UCL achieved greater amount of high intensity running than CDs from WC (small effect size). This study demonstrated differences in various aspects of physical performance between two highest-level soccer competitions with variations dependent upon playing position. The findings enabled a more thorough understanding of the physical requirements for playing in UCL and WC, and may have direct consequences for specific training programs.

Effect of Different Nonstarter Compensatory Strategies on Training Load in Female Soccer Players: A Pilot Study.

In soccer, the day of the week with the highest external load is match day (MD), with starters (>60 minutes per match) showing higher levels of physical fitness and seasonal high-intensity loading. It is necessary, therefore, to determine training strategies to reduce the differences between starters and nonstarters. The aim of this study was to analyze and compare the external load of different training compensatory strategies with match external load in female nonstarters. A strategy combining small-sided games (SSG) and running-based drills (RBD) would reproduce match demands, with RBD leading to greater high-intensity running and SSG leading to a greater number of accelerations and decelerations. Descriptive and comparative study. Level 4. The training and match external load of 14 female players belonging to the same reserve squad of a Spanish First Division Club (Liga Reto Iberdrola) was registered. In the first session after the match (MD+1), nonstarters (<60 minutes in the match) performed 1 of 3 different compensatory strategies: RBD, SSG, or a mixed intervention combining the previous strategies (RBD+SSG). Starters carried out a recovery session. A marked difference in load was observed between the compensatory training strategies and MD. In comparison with MD, RBD showed greater high-intensity and sprint distances and lower acceleration, SSG showed less high-intensity running and sprint distances, lower peak velocity, and greater acceleration, and RBD+SSG registered lower accelerations. In addition, nonstarters covered greater high-intensity running and sprint distances in RBD and achieved higher accelerations in SSG. RBD and SSG compensatory strategies could be recommended to nonstarter female soccer players in MD+1 to compensate for match external load deficits. This study provides comprehensive information on the compensatory exercises of female soccer players, which can be useful for strength and conditioning coaches when developing recovery strategies during a microcycle.

Ultramarathon induces metabolite changes associated with the pathophysiology of cardiovascular diseases- in silico and in vivo analysis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Science Centre (NCN) and Internal source of Medical University of Warsaw. Introduction Regular physical exercise is analogous to improved cardiovascular health and increased longevity. However, if in excess it can act as a double edged sword. Acute bouts of extreme physical activity trigger complex molecular responses reflected by changes in inflammatory markers and metabolic pathways that are believed to yield detrimental effects on the cardiovascular system (CVS)[1]. Purpose We aimed to assess the effects of high-intensity and long-lasting exercise prototype (100km run) on the metabolomic changes in a unique population of high-level long-term ultra-marathon runners. Methods Plasma samples were collected from ultramarathon runners (n=22) with 2-time points: before and after the run (Completion (100 km) or exhaustion (52 - 91 km, median 74 km)). For untargeted metabolomic analysis we used ultra-high resolution Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry with an electrospray ion source in direct injection. Mass spectra were analyzed by T-Rex2D algorithm in the MetaboScape5.0. Identified compounds were ontologically analyzed using MetaboAnalystR. MetscapeCytoscape plugin was used for metabolite-gene interaction analysis and gene lists were obtained from Biomart and DisGeNet. Results Mann-Whitney test (FDR&amp;lt;0.05) identified 1601 up and 1030 downregulated metabolites with a at least 2 fold of difference after high-intensity run. Enrichment analysis showed that the top pathways affected by analyzed metabolites were the TCA cycle (FDR=0.0442), metabolism of; Sphingolipids (p=0.00774), Glyoxylate and dicarboxylate (p=0.0249) and Butanoate (p=0.0352). Top disease phenotypes associated with differentially regulated metabolites were critical illness (major trauma, severe septic shock, or cardiogenic shock) (p=0.00154) and multiple CVS-related diseases (Fig1). Top after the run up-regulated metabolites identified in the study included heart failure associated acetylcarnitines[2] CAR(14:2) (log2FC=11.57; AUC=0.97), Dodecanoylcarnitine (2.00;0.960), 9-Decenoylcarnitine (1.78;0.95), CAR(DC8:0) (14.99;0.94), but also 2-Carboxy-5,7-dimethyl-4-octanolide (8.04;0.98), Methylmalonic acid (9.33;0.96) and cardiotoxic Cyclophosphamide (16.29;0.940)[3]. Top down-regulated metabolites after the run included potentially cardio-protective Gamma Glutamylglutamic acid (log2FC=-1.81; AUC=0.85), Fructose 1,6-bisphosphate (-2.42;0.88)[4], Oleamide (-1.82;0.86) and gamma-Glutamylglycine (-7.98;0.85). Interaction network analysis focused on genes associated with CVS identified atherosclerosis/ obesity-related Phospholipase A2 Group IB (PLA2G1B) as potentially the most affected gene by analyzed metabolites (Fig2). Conclusion Results show a twofold post run increase in metabolites that are both potential markers for acute exercise and that are strongly associated with CV diseases. This calls for consideration of the detrimental effects of excessive exercise and implementation of monitoring in amateur athletes.

Movement analysis of match play in U16-U21 youth Hungarian soccer players - the influence of age, position, and contextual variables

ABSTRACT The purpose of this study was to demonstrate the locomotor match-performance of youth Hungarian football players according to age groups, playing positions and effects of contextual match factors. The sample consisted of 574 individuals in four youth age groups (U16, U17, U19, U21) in four playing positions: central defenders (n = 139), fullbacks (n = 148), central midfielders (n = 185), and forwards (n = 102). Tactically, all teams used a 4-4-2 diamond formation. Data was collected from 114 matches from elite Hungarian football academy matches during the 2018–2019 season, using a GPS technology (10 Hz). The main results were: (a) U16, U19, U21 age groups matches played against strong opponents presented greater values (but not significantly) of high-intensity running distances compared to matches against weak opponents; (b) U21 players covered greater high-intensity running distances when winning than drawing the matches; (c) the U16, U19, U21 age groups performed better (but not significantly) at home than away in terms of high-intensity running. The forwards (735 ± 176 m) and fullbacks (654 ± 185 m) performed best in total high-intensity running (>19.8 km/h). With regard to maximum speed, forwards reached significantly higher results (30.44 ± 1.64 km/h) than players in other positions. Since international football players demonstrate better measures in high-intensity running and sprinting than Hungarian players.

High-Intensity Interval Cycling and Running Yield a Similar Myokine and Osteokine Response in Young Adult Females

Background: The differential responses of the myokine irisin, in combination with changes in markers and regulators of bone remodeling to high-intensity interval exercise of high and low impact, were examined in 18 young adult females (22.5 ± 2.7 years). Methods: Participants performed two high-intensity interval exercise trials in random order: running on a treadmill and cycling on a cycle ergometer. Trials consisted of eight 1 min running or cycling intervals at ≥ 90% of maximal heart rate, separated by 1 min passive recovery intervals. Blood samples were collected at rest (pre-exercise) and 5 min, 1 h, and 24 h following each exercise trial. Irisin, osteocalcin, sclerostin, osteoprotegerin (OPG), receptor activator nuclear factor kappa-β ligand (RANKL), and parathyroid hormone (PTH) were analyzed in serum, with post-exercise concentrations being corrected for exercise-induced changes in plasma volume. Results: Irisin was elevated 24 h post-exercise compared to its resting values in both trials (20%, p &lt; 0.05) and was higher after cycling compared to running (exercise mode effect, p &lt; 0.05) with no interaction. Osteocalcin, sclerostin, PTH, and RANKL increased from pre- to 5 min post-exercise (18%, 37%, 83%, and 33%, respectively, p &lt; 0.05), returning to baseline levels in 1 h, with no trial or interaction effects. OPG showed a time effect (p &lt; 0.05), reflecting an overall increase at 5 min and 1 h post-exercise, which was not significant after the Bonferroni adjustment. Conclusions: In young adult females, high-intensity interval exercise induced an immediate response in markers and regulators of bone remodeling and a later response in irisin concentrations, which was independent of the gravitational impact.

The seven phases of match status differentiate the running performance of soccer players in UEFA Champions League

The purpose of this research was to investigate the running performance of professional soccer players in relation to seven phases which resulted in the changing or maintaining the match status in the UEFA Champion League games during season 2020/2021. Moreover, we aimed to define which match status phases occur at the earliest stage of regular game time. This study involved professional soccer players from 24 teams participating in the group stage of UEFA Champions League in season 2020/21. The match status was divided into seven phases that result in changing or maintaining the match outcome: DW (Drawing to Winning); LD (Losing to Drawing); WW (Winning to Winning); DD (Drawing to Drawing); LL (Losing to Losing); DL (Drawing to Losing); WD (Winning to Drawing). Such running performance variables as: total distance covered (TDC) and distance covered in high-intensity running (HIR) were analyzed. Players participating in the UEFA Champions League matches cover the longest TDC in DW, DL and DD phases. TDC in these stages was between 111 and 123 m min−1. The highest HIR was recorded during phases: DW, DL and LL (range between 9.91 and 10.82 m min−1). In contrast, the lowest total distance and distance in HIR is covered during WD phase (only 105.57 ± 1.89 m min−1 and 7.34 m min−1 respectively). On average, phases resulting in the change of the match status occur during the first half, while all phases maintaining the result in the second half. Coaching staffs should consider registering and analysing the physical match performance in relation to described seven match status phases. Such information allows to prepare team-specific training drills, that players should perform more often in order to change or maintain the status of the game.

Effects of aerobic exercise on metabolic indicators and physical performance in adult NAFLD patients: A systematic review and network meta-analysis.

nonalcoholic fatty liver disease (NAFLD) is characterized by excessive accumulation of fat in the liver without alcoholism. We conducted a systematic review and meta-analysis to elucidate the efficacy of aerobic exercise on metabolic indicators and physical performance of adult patients with NAFLD. To conduct the systematic review and network meta-analysis, 2 researchers searched PubMed, EBSCO, and Web of science databases to identify randomized clinical trials of aerobic exercise interventions for adults with NAFLD published between inception and July 2022. We assessed the methodological quality of the included literature using the Cochrane Risk Assessment Scale and the PEDro Scale. Relevant data were extracted, variables were converted to the same units, and meta-analysis was performed using RevMan 5.4 software. We compared mean differences (MD) between experimental and control groups. For each outcome analyzed, we expressed data as MD with 95% CI to compare metabolic markers and exercise capacity between the experimental and control NAFLD patients. Eleven randomized clinical trials with a total of 491 individuals with NAFLD were included in accordance with the criteria of this study. Types of aerobic exercise include moderate or high-intensity interval running, cycling, Nordic walking, equipment training, etc; Training duration 4 to 16 weeks, 30 to 60 minutes 3 or more times a week. Compared with the control group, aerobic exercise group had reduced weight of patients, (MD) 1.20 kg (95% CI: -1.38 to -1.01 kg, P < .00001). Seven studies confirmed that aerobic exercise significantly reduced triglycerides, (MD) 3.00 mg/dL (95% CI: -5.80 to -0.21 mg/dL, P = .04); increased high density lipoproteins (MD) 5.96 mg/dL (95% CI: 2.95 to 8.96 mg/dL, P = .0001) and reduced low-density lipoproteins (MD) 6.45 mg/dL (95% CI: -8.53 to -4.37 mg/dL, P < .00001); the study also showed that aerobic exercise reduced the liver enzymes aspartate aminotransferase and alanine aminotransferase to varying degrees. Aerobic exercise can improve physical performance and increase peak oxygen consumption of (MD) 6.29 mL/Kg*minutes, (95% CI: 3.05-9.53mL/Kg*minutes, P = .0001). Aerobic exercise significantly reduced weight and improved metabolic index and physical performance. Impacted by the limitations of various regimens, doses, duration, center settings, populations enrolled, the study had certain limitations. The randomized controlled trials with larger sample sizes, multiple centers, and high quality should be conducted to validate the above conclusion. Further studies will be required to focus on the total duration of the intervention, duration and frequency of sessions, and intensity that are optimal for the promotion of physical performance and metabolic capacity in this population.

New Zealand Youth Rugby Sevens: A Comparative Match Demands Study

Rugby sevens has established itself on the world stage since its inclusion in the 2016 Olympics. Participation among New Zealand (NZ) youth has surged. Sevens games have specific high demands, but little is known about these competitive demands in regards to youth. Two NZ male youth squads (U15, n = 13; U19, n = 14) were monitored during a national sevens tournament. Microsensor technology captured heart rate (HR) and kinematic performance. The rating of perceived exertion (RPE) was collected for U15 matches only. U19 and U15 players ran 108 ± 11 and 116 ± 13 m·min-1 at an average speed (VAVG) of 6.5 ± 0.6 and 6.9 ± 0.8 km·h-1. Peak speeds (VPEAK) reached 33.7 km·h-1, and high-intensity running distance (HIRD) averaged 252 ± 102 m. U15 (44.3 ± 9.2 game-1) and U19 (39.4 ± 6.1 game-1) showed different sprint rates. U15 covered more moderate-velocity distance (20-80% VMAX) and less low-velocity distance (<20% VMAX). RPE was 13 ± 1 (U15). An average HR of 90.0 ± 3.9% HRMAX was recorded. Upwards of 57% of game time was played at >95% HRMAX. Youth sevens competition is specifically demanding. U15 can experience greater loads than older peers in rugby. Coaches can use this information to optimize players' physical development.

In-season autoregulation of one weekly strength training session maintains physical and external load match performance in professional male football players

ABSTRACT The aim of this study was to compare the effects of autoregulating strength training volume based on an objective (external load match performance) versus a subjective (self-selected) method in professional male football players. Sixteen players completed a 10-week strength training programme where the number of sets was regulated based on football match high-intensity running distance (HIR >19.8 km/h, AUTO, n = 7), or self-selected (SELF, n = 9). In addition to traditional physical performance assessments (30-m sprint, countermovement jump, leg-strength, and body composition), external load match performance was assessed with five matches in the beginning and in the end of the study period. Both groups performed ~ 1 weekly bout of ~ 6 sets in leg extensor exercises during the 10-week period, and maintained physical performance during the competitive season, with no group differences detected after the training period. Non-overlap of all pairs (NAP) analysis showed weak-to-moderate effects in external load match performance from before to after the study period, suggesting that players maintained or improved their performance. In conclusion, no group differences were observed, suggesting that both external load autoregulated and self-selected, low-volume in-season strength training maintained physical, and external load match performance in professional male football players.

Recovery of kicking kinematics and performance following repeated high-intensity running bouts in the heat: Can a rapid local cooling intervention help young soccer players?

ABSTRACT The effects of a cooling strategy following repeated high-intensity running (RHIR) on soccer kicking performance in a hot environment (>30ºC) were investigated in youth soccer players. Fifteen academy under-17 players participated. In Experiment 1, players completed an all-out RHIR protocol (10×30 m, with 30s intervals). In Experiment 2 (cross-over design), participants performed this running protocol under two conditions: (1) following RHIR 5 minutes of cooling where ice packs were applied to the quadriceps/hamstrings, (2) a control condition involving passive resting. Perceptual measures [ratings of perceived exertion (RPE), pain and recovery], thigh temperature and kick-derived video three-dimensional kinematics (lower limb) and performance (ball speed and two-dimensional placement indices) were collected at baseline, post-exercise and intervention. In Experiment 1, RHIR led to small-to-large impairments (p < 0.03;d = −0.42–-1.83) across perceptual, kinematic and performance measures. In experiment 2, RPE (p < 0.01; Kendall’s W = 0.30) and mean radial error (p = 0.057; η2 = 0.234) increased only post-control. Significant small declines in ball speed were also observed post-control (p < 0.05; d = 0.35). Post-intervention foot centre-of-mass velocity was moderately faster in the cooling compared to control condition (p = 0.04; d = 0.60). In youth soccer players, a short cooling period was beneficial in counteracting declines in kicking performance, in particular ball placement, following intense running activity in the heat.

Increased oxygen uptake in well-trained runners during uphill high intensity running intervals: A randomized crossover testing.

The time spent above 90% of maximal oxygen uptake ( O2max) during high-intensity interval training (HIIT) sessions is intended to be maximized to improve O2max. Since uphill running serves as a promising means to increase metabolic cost, we compared even and moderately inclined running in terms of time ≥90% O2max and its corresponding physiological surrogates. Seventeen well-trained runners (8 females & 9 males; 25.8 ± 6.8yrs; 1.75 ± 0.08m; 63.2 ± 8.4kg; O2max: 63.3 ± 4.2ml/min/kg) randomly completed both a horizontal (1% incline) and uphill (8% incline) HIIT protocol (4-times 5min, with 90s rest). Mean oxygen uptake ( O2mean), peak oxygen uptake ( O2peak), lactate, heart rate (HR), and perceived exertion (RPE) were measured. Uphill HIIT revealed higher (p ≤ 0.012; partial eta-squared (pes) ≥ 0.351) O2mean (uphill: 3.3 ± 0.6 vs. horizontal: 3.2 ± 0.5L/min; standardized mean difference (SMD) = 0.15), O2peak (uphill: 4.0 ± 0.7 vs. horizontal: 3.8 ± 0.7L/min; SMD = 0.19), and accumulated time ≥90% O2max (uphill: 9.1 ± 4.6 vs. horizontal: 6.4 ± 4.0 min; SMD = 0.62) compared to even HIIT. Lactate, HR, and RPE responses did not show mode*time rANOVA interaction effects (p ≥ 0.097; pes ≤0.14). Compared to horizontal HIIT, moderate uphill HIIT revealed higher fractions of O2max at comparable perceived efforts, heartrate and lactate response. Therefore, moderate uphill HiiT notably increased time spent above 90% O2max.

Positional differences in match running performance of women soccer players

This study aimed to identify positional differences in the running performance (RP) of professional women soccer players. Seventy match performances were observed during the official matches (n = 13) over the course of half of a season at the highest levelof national soccer competition in Slovenia. Players’ RP were obtained using global positioning system technology and were classified into five playing positions: central defender (CD; n = 11), fullback (FB; n = 15), central midfielder (CM; n = 9), winger (WM; n = 25) and forward (FW; n = 10). RP variables included total distance, high-intensity running, high-metabolic load distance, high-intensity accelerations and decelerations, and maximal running speed. Univariate and multivariate differences in RP among playing positions were analyzed by one-way analysis of variance and discriminate canonical analysis, respectively. Significant univariate differences were found for all RP variables (f = 3.77 –8.68, μ = 0.19 –0.33). Specifically, WMs, FBs, and CMs covered more total distance than CDs or FWs. High-intensity running, high metabolic load distance, high-intensity accelerations, and decelerations were greater for FBs or WMs compared to the players in all other playing positions. Analysis of multivariate differences showed significant differentiation between FBs and CMs, CDs, and FWs in high-intensity running distance, high-metabolic load distance, and high-intensity decelerations (CanR= 0.4 –0.77, all p &lt; 0.01), respectively, with higher occurrence in FBs. These findings demonstrated the differing physical demands placed on national-level women's soccer players in different playing positions, offering valuable insights for their preparation

Inter-system and inter-unit reliability of Polar Team Pro and WIMU PRO devices during external load measurements indoors

The aim was to examine inter-system and inter-unit reliability of both WIMU PRO (UWB) and Polar Team Pro devices in measuring indoor sport-specific movements. Seventeen active and healthy adults (age: 21.4 ± 5.2 years; height 170.3 ± 8.2 cm; body mass: 71.2 ± 4.5 kg) completed one repetition of an indoor team sport circuit (i.e. accelerations, decelerations, change of direction, jumps and arc runs). Participants carried two 10-Hz Polar Team Pro GPS and wore two 20-Hz GPS (UWB) WIMU PRO chest- and back-mounted devices, respectively. Distance (absolute, relative and in different speed thresholds), mean and peak speed, accelerations and decelerations at different intensities and jumps were recorded. A repeated-measures two-way analysis of variance and ICC and CV were utilised. There was a significant ( p ≤ 0.001) main effect of the system for all variables except the total distance, mean speed and distance covered during low- and high-intensity running. There were significant differences ( p &lt; 0.05) between the two Polar Team Pro units for all external load variables except for distance covered during submaximal speed, moderate-intensity accelerations (ACC), and moderate-intensity and total decelerations (DCC). No significant differences ( p &gt; 0.05) between the two WIMU PRO units were detected. Poor inter-system reliability was ascertained, with inter-unit reliability being moderate-excellent for most variables of both systems.

Running demands in club, regional, national, and international provincial New Zealand rugby union competitions.

The demands of national and international professional rugby union matches are well established, however, there has not been a comparative study investigating running demands in New Zealand teams playing in club (amateur), Heartland Championship (semi-professional Div 2), the Mitre 10 Cup (semi-professional Div 1) or Super Rugby (professional) competitions. This information could enable specific training and rehabilitation that programmes to be developed to meet the needs of players in the different competitions. Players wore 10 Hz GPS units during games for one rugby season to determine absolute (m) and relative (m.min-1) measures for total distance, running volume (∼≥7 km·h-1) and high intensity running (∼≥16 km·h-1). There were typically minimal differences (1-2 m.min-1) in running distance measures between amateur level front row forwards and inside backs compared to players in these positions at higher levels of competition. Therefore, amateur players in these positions may find the transition to higher competitions less challenging with respect to running load. In contrast, amateur outside backs and back row forwards may find the increased pace of higher levels of competition more challenging due to typically covering significantly less running and high intensity running distances in amateur games. Differences for half backs were more variable between the levels of competition. Based on our results, it cannot be assumed that amateur rugby has lower running demands than higher competitions or that there is a continuum of increased running demands with increasing competition levels, as some playing positions in the semi-professional (Div 2) (second lowest level of competition) team recorded the largest values for total distance, running and high intensity running. Therefore, the specificity of running demands in a position and competition need to be considered individually for each player when transitioning between competitions. The practice and perception of returning a professional player to amateur club rugby due to the belief that running loads being lower may also be flawed, as we found considerable positional variation in running demands within-and-between competitions.

Match running performance characterizing the most elite soccer match-play.

In order to identify match running performance (MRP) characterizing the most elite soccer match-play, this study aimed to examine position-specific differences in the MRP of players competing in "big five" (BFLTs) and "non-big five" league teams (N-BFLTs). The data were obtained from 24 teams (BFLTs; n = 14, N-BFLTs; n = 10) during the UEFA Champions League (UCL) matches (n = 20) in the 2020/21 season using a semiautomatic video system. The differences in MRP between BFLTs and N-BFLTs, while controlling for contextual factors, were examined using linear mixed model. No differences in overall MRP between fullbacks, central midfielders, wide midfielders and forwards from BFLTs and their peers from N-BFLTs were found, while only central defenders from BFLTs covered more high-intensity running than central defenders from BFLTs (moderate effects size). For players on all playing positions from BFLTs, total- and low-intensity distance covered were lower in offensive phase of game and greater in defensive phase of game compared to their peers from N-BFLTs (all large effect sizes). This study demonstrated that the most elite match-play in soccer is characterized by increased efforts in defensive phase of game, and decreased efforts in offensive phase of game. Soccer training programmes should be adapted accordingly.

Factors affecting match running performance in elite soccer: Analysis of UEFA Champions League matches.

This study aimed to examine the independent effect of different match-related factors on match running performance (MRP) in elite soccer. Players' MRPs (n = 244) were collected during UEFA Champions League (UCL) group stage matches in the 2020-21 season. All MRP data were collected by the semi-automatic optical system InStat Fitness (InStat Limited, Limerick, Republic of Ireland). Match-related factors included match outcome, team quality, match location, opponent quality and difference in team quality, while MRP included cumulative and relative measures of total distance (TD and R-TD), low-intensity running (LIR and R-LIR) (≤ 4 m/s), moderate-intensity running (MIR and R-MIR) (4-5.5 m/s) and high-intensity running (HIR and R-HIR) (≥ 5.5 m/s). Linear mixed models were used to examine the collective effect of match-related factors on MRPs when controlling for between-player, between-playing position and between-team variation. The main findings were that match outcome was associated with reduced HIR (d = -0.38, p = 0.04), match location was associated with increased TD, R-TD, LIR and R-LIR (d = 0.54-0.87, all p < 0.01), while team quality, opponent quality and difference in team quality were not associated with MRP. These results show that (i) winning UCL matches was not strongly influenced by players' physical performance, (ii) away UCL matches were characterized by a slower match pace and greater match volume, and (iii) players' physical performance was similar irrespective of playing either in or against high- or low-quality teams. The findings from this study may help soccer coaches to ensure optimal physical preparation of players in elite soccer.

Does player age influence match physical performance? A longitudinal four-season analysis in Spanish Soccer LaLiga.

This study aims to analyse the evolution of match running performance in relation to the age distribution of professional soccer players using a large-scale analysis. An explorational-longitudinal and retrospective study was designed and a total of 36,883 individual match observations were collected on outfield players competing across four consecutive Spanish LaLiga seasons (from 2015/16 to 2018/19), using an optical tracking system (ChyronHego). Soccer players were divided into 3 age groups: young (18-24 years old), middle-aged (25-30 years old), and seniors (31-41 years old). Relative total distance (TD/min), distance covered at 21-24 km · h-1 (HIRD/min), and > 24 km · h-1 per minute (VHIRD/min) were analysed; also, the number of efforts at 21-24 km · h-1 (Sp21) and > 24 km · h-1 (Sp24) were taken into consideration. Seasons were divided into four phases (P): P1 (matches 1-10), P2 (11-19), P3 (20-29), and P4 (30-38). The results showed that young players covered significantly greater TD, HIRD and VHIRD than the rest of the players (p < .05) in all season phases. In addition, TD significantly decreased along season phases in all player age group (p < .01). Crucially, young players performed significantly greater numbers of Sp21 and Sp24 than the rest of the players (p < .05) in all season phases. In addition, Sp21 and SP24 significantly decreased in middle-aged (p < .01) and senior players (p < .05) across the seasons. This study demonstrated that players' match running performance decreases with increasing years, especially in high-intensity running distances.

Improvement of low-intensity long-time running performance in rats by intake of glucosyl hesperidin.

Recently, the use of ergogenic aids in sports by both athletes and fans has increased. Moreover, the overall demand for new ergogenic aids has increased. Hesperidin is a polyphenol that is useful for improving exercise performance by activating energy generation through β-oxidation and oxidative phosphorylation in skeletal muscles. However, it is difficult to use this compound as an ergogenic aid because of its poor water solubility and low bioavailability. Glucosyl hesperidin is formed when one molecule of glucose is transferred to hesperidin via glycosyl-transferase. It is 10,000× more soluble and has 3.7× higher bioavailability than hesperidin. In this study, we assessed whether continuous (14 days) intake of glucosyl hesperidin improves the aerobic exercise capacity of rats during long-term acute exercise. Although glucosyl hesperidin intake did not improve the performance of high-intensity running (30 m/min), we did observe improvement in low-intensity running (15 m/min) (p < 0.05). We demonstrate that in sedentary rats, glucosyl hesperidin intake increased β-oxidation and oxidative phosphorylation in the skeletal muscle (p < 0.05 and p < 0.01, respectively). Glucosyl hesperidin intake may have created a metabolic state useful for long-term exercise. In conclusion, the continuous intake of glucosyl hesperidin improved the aerobic exercise capacity of rats during long-term acute exercise.

Intensity demands and peak performance of elite soccer referees during match play.

This study examined the peak physical and physiological (heart rate) performance intensities andassociated decrements in elite soccer referees during match play. Longitudinal study. Physical performancevariables and heart rate were analyzed during 457 matches across two seasons. Differences between halves, and the rate ofdecline in peak performance intensities across moving average durations of 1-10 minutes were assessed using linear mixed models and power-law analysis, respectively. Large significant differences were observed between halves for mean total distance, mean velocity, mean heart rate, and percentage of maximal heart rate (p ≤ 0.05; r = 0.51-0.64). Peak intensities (p ≤ 0.05; r = 0.15-0.17) and the rate of decline (p < 0.001; r = 0.17-0.37) were significantly higher in the 2nd half compared to the 1st half, for relative total distance, relative high-intensity running and mean velocity. The rate of decline was significantly greater in the 2nd half than the 1st half for relative distance covered by high-intensity acceleration (>2 m/s-2/min), deceleration (<-2 m/s-2/min), and relative mean heart rate (p < 0.001; r = 0.28-0.61). Elite soccer referees might have experienced transient fatigue during match play, as relative high-intensity running immediately following the most intense 5-minute period significantly declined by 61.2% ( p< 0.001; r = 0.94), and was 16.2% lower than the mean 5-minute period (p < 0.001; r = 0.34). Increased physical and physiological demands during match play, with associated declines in the second half and transient signs of fatigue throughout the match, supports the inclusion of high-intensity interval and endurance training programs to prepare soccer referees for the intensity demands and peak performance outcomes of match play.

Contextualised high-intensity running profiles of elite football players with reference to general and specialised tactical roles

The present study aimed to contextualise physical metrics with tactical actions according to general and specialised tactical roles. A total of 244 English Premier League players were analysed by coding player's physical-tactical actions via the fusion of tracking data and video. Data were analysed across 5 general (Central Defensive Players = CDP, Wide Defensive Players = WDP, Central Midfield Players = CMP, Wide Offensive Players = WOP, Central Offensive Players = COP) and 11 specialised positions (Centre Backs = CB, Full-Backs = FB, Wing-Backs = WB, Box-to-Box Midfielders = B2BM, Central Defensive Midfielders = CDM, Central Attacking Midfielders = CAM, Wide Midfielders = WM, Wide Forwards = WF, Centre Forwards = CF). COP covered more distance at high-intensity (> 19.8 km · h-1) when performing actions such as 'Break into Box', Run in Behind/Penetrate', and 'Close Down/Press' than other positions (ES: 0.6-5.2, P < 0.01). WOP covered more high-intensity 'Run with Ball' distance (ES: 0.7-1.7, P < 0.01) whereas WDP performed more 'Over/Underlap' distance than other positions (ES: 0.9-1.4, P < 0.01). CDP and WDP covered more high-intensity 'Covering' distances than other positions (ES: 0.4-2.4, P < 0.01). Nonetheless, data demonstrated that implementing specialised positional analysis relative to a generalised approach is more sensitive in measuring physical-tactical performances of players with the latter over or underestimating the match demands of the players compared to the former. A contextualised analysis may assist coaches and practitioners when designing position or even player-specific training drills since the data provides unique physical-tactical trends across specialised roles.