Pacing strategies in marathons: A systematic review.

Background: The pacing strategy embodies the tactical behavior of athletes in distributing their energy across different segments of a race; therefore, a quantitative analysis of pacing strategies in marathon races could deepen the understanding of both pacing behavior and physical capacity in marathon athletics. Objective: The objective of this systematic review was to synthesize and characterize pacing strategies in marathon road races by exploring the categories of pacing strategies and the factors that influence these strategies during marathon events. Methods: Preferred Reporting Items for Systematic Reviews guidelines were followed for systematic searches, appraisals, and syntheses of literature on this topic. Electronic databases such as Science Direct, SPORTDiscuss, PubMed, and Web of Science were searched up to July 2024. Records were eligible if they included pace performance measurements during competition, without experimental intervention that may influence their pace, in healthy, adult athletes at any level. Results: A total of 39 studies were included in the review. Twenty-nine were observational studies, and 10 were experimental (randomized controlled trials). The assessment of article quality revealed an overall median NOS score of 8 (range 5-9). The included studies examined the pacing profiles of master athletes and finishers in half-marathon (n = 7, plus numbers compared to full marathon), full-marathon (n = 21), and ultramarathon (n = 11) road races. Considering that some studies refer to multiple pacing strategies, in general, 5 studies (∼13 %) reported even pacing, 3 (∼8 %) reported parabolic pacing, 7 (∼18 %) reported negative pacing, and 30 (∼77 %) reported positive pacing during marathon competitions. Gender, age, performance, pack, and physiological and psychological factors influence pacing strategies. Conclusion: This study synthesized pacing performance in marathons and highlighted the significance of examining pacing strategies in these events, offering valuable insights for coaches and athletes. Several key findings were highlighted: (1) pacing profiles and pacing ranges were identified as the primary indicators of pacing strategies; (2) the pacing strategy was found to be dynamic, with the most substantial effects attributed to gender and distance; and (3) three distinct types of pacing strategies for marathons were classified: positive, negative, and even pacing. These findings advance the understanding of marathon pacing strategies by shedding light on the factors that influence athletes' pacing decisions and behaviors. Additionally, these findings offer practical benefits, aiding athletes in making well-informed tactical choices and developing effective pace plans to enhance marathon performance. However, due to the complex nature of marathon racing, further research is required to explore additional factors that might impact pacing strategies. A better grasp of optimal pacing strategies will foster progress in this area and serve as a basis for future research and advancements.

Self-perceived middle-distance race pace is faster in advanced footwear technology spikes.

BACKGROUND: Quantifying the potential benefits of advanced footwear technology (AFT) track shoes (i.e., "spikes") in middle-distance events is challenging, because repeated maximal effort trials (as in sprinting) or aerobic running economy trials (as in long-distance running) are not feasible. METHODS: We introduce a novel approach to assess the benefits of AFT spikes, consisting of a series of 200-m runs at self-perceived middle-distance race pace with 10 min recovery, and conduct 4 experiments to evaluate its validity, sensitivity, reproducibility, and utility. RESULTS: In Experiment 1, participants ran 1.2% slower in spikes with 200 g added mass vs. control spikes, which is exactly equal to the known effects of shoe mass on running performance. In Experiment 2, participants ran significantly faster in AFT prototype spikes vs. traditional spikes. In Experiment 3, we compared 2 other AFT prototype spikes against traditional spikes on 3 separate days. Group-level results were consistent across days, but our data indicates that at least 2 separate sessions are needed to evaluate individual responses. In Experiment 4, participants ran significantly faster in 2 AFT spike models vs. traditional spikes (2.1% and 1.6%). Speed was similar between a third AFT spike model and the traditional spikes. These speed results were mirrored by changes in step length as participants took significantly longer steps in the 2 faster AFT spike models (2.3% and 1.9%), while step length was similar between the other spikes. CONCLUSION: Our novel, interval-based approach is a valid and reliable method for quantifying differences between spikes at middle-distance running intensity.

Impacts of Wearable Resistance Placement on Running Efficiency Assessed by Wearable Sensors: A Pilot Study.

Wearable resistance training is widely applied to enhance running performance, but how different placements of wearable resistance across various body parts influence running efficiency remains unclear. This study aimed to explore the impacts of wearable resistance placement on running efficiency by comparing five running conditions: no load, and an additional 10% load of individual body mass on the trunk, forearms, lower legs, and a combination of these areas. Running efficiency was assessed through biomechanical (spatiotemporal, kinematic, and kinetic) variables using acceleration-based wearable sensors placed on the shoes of 15 recreational male runners (20.3 ± 1.23 years) during treadmill running in a randomized order. The main findings indicate distinct effects of different load distributions on specific spatiotemporal variables (contact time, flight time, and flight ratio, p ≤ 0.001) and kinematic variables (footstrike type, p < 0.001). Specifically, adding loads to the lower legs produces effects similar to running with no load: shorter contact time, longer flight time, and a higher flight ratio compared to other load conditions. Moreover, lower leg loads result in a forefoot strike, unlike the midfoot strike seen in other conditions. These findings suggest that lower leg loads enhance running efficiency more than loads on other parts of the body.

Clustering analysis across different speeds reveals two distinct running techniques with no differences in running economy.

Establishing the links between running technique and economy remains elusive due to high inter-individual variability. Clustering runners by technique may enable tailored training recommendations, yet it is unclear if different techniques are equally economical and whether clusters are speed-dependent. This study aimed to identify clusters of runners based on technique and to compare cluster kinematics and running economy. Additionally, we examined the agreement of clustering partitions of the same runners at different speeds. Trunk and lower-body kinematics were captured from 84 trained runners at different speeds on a treadmill. We used Principal Component Analysis for dimensionality reduction and agglomerative hierarchical clustering to identify groups of runners with a similar technique, and we evaluated cluster agreement across speeds. Clustering runners at different speeds independently produced different partitions, suggesting single speed clustering can fail to capture the full speed profile of a runner. The two clusters identified using data from the whole range of speeds showed differences in pelvis tilt and duty factor. In agreement with self-optimisation theories, there were no differences in running economy, and no differences in participants' characteristics between clusters. Considering inter-individual technique variability may enhance the efficacy of training designs as opposed to 'one size fits all' approaches.

Match running performance is influenced by possession and team formation in an English Premier League team.

The aim of this study was to examine the possession (very low, low, high, and very high), team formation (3-5-2 and 4-3-3) and position (centre-backs, full-backs, centre midfielders, attacking midfielders, and centre forwards) on match load across two consecutive seasons in elite soccer. Twenty-seven English Premier League outfield players were recruited. Data was monitored through an 18 Hz Global Positioning System and a 25 Hz semi-automated camera tracking system, respectively, and all variables were analysed per minute. Main effects for formation on total distance (TD) (p = 0.006; η 2 = 0.010), high-speed running (HSR) (p = 0.009; η 2 = 0.009), number of high metabolic load (HML) efforts (p = 0.004; η 2 = 0.011) were observed. In addition, there were significant interaction effects with formation × possession on TD (p < 0.001; η 2 = 0.043), HSR (p = 0.006; η 2 = 0.018), sprinting (p < 0.001; η 2 = 0.030), HML efforts (p < 0.001; η 2 = 0.035), accelerations (p < 0.001; η 2 = 0.025). From the position-specific analysis, only the running performance of centre-backs was affected by formation or positional factors. These results indicate that formation and possession can have a significant impact on TD, HSR, and HML distance. Furthermore, players performed more high-intensity efforts in 3-5-2 than 4-3-3 formation. These findings suggest that coaches can evaluate running performance in the context of formation and possession and tailor tactical strategies to optimise physical performance.

Factors Affecting the Running Performance of Soccer Teams in the Turkish Super League.

Performance analysis in sports is a rapidly evolving field, where academics and applied performance analysts work together to improve coaches' decision making through the use of performance indicators (PIs). This study aimed to provide a comprehensive analysis of factors affecting running performance (RP) in soccer teams, focusing on low (LI), medium (MI), and high-speed distances (HI) and the number of high-speed runs (NHI). Data were collected from 185 matches in the Turkish first division's 2021-2022 season using InStat Fitness's optical tracking technology. Four linear mixed-model analyses were conducted on the RP metrics with fixed factors, including location, team quality, opponent quality, ball possession, high-press, counterattacks, number of central defenders, and number of central forwards. The findings indicate that high-press and opponent team quality affect MI (d = 0.311, d = 0.214) and HI (d = 0.303, d = 0.207); team quality influences MI (d = 0.632); location and counterattacks impact HI (d = 0.228, d = 0.450); high-press and the number of central defenders affects NHI (d = 0.404, d = 0.319); and ball possession affects LI (d = 0.287). The number of central forwards did not influence any RP metrics. This study provides valuable insights into the factors influencing RP in soccer, highlighting the complex interactions between formations and physical, technical-tactical, and contextual variables. Understanding these dynamics can help coaches and analysts optimize team performance and strategic decision making.

Acute physiological, biomechanical, and perceptual responses of runners wearing downward-curved carbon fiber insoles.

In a randomized controlled cross-over study ten male runners (26.7 ± 4.9 years; recent 5-km time: 18:37 ± 1:07 min:s) performed an incremental treadmill test (ITT) and a 3-km time trial (3-km TT) on a treadmill while wearing either carbon fiber insoles with downwards curvature or insoles made of butyl rubber (control condition) in light road racing shoes (Saucony Fastwitch 9). Oxygen uptake, respiratory exchange ratio, heart rate, blood lactate concentration, stride frequency, stride length and time to exhaustion were assessed during ITT. After ITT, all runners rated their perceived exertion, perceived shoe comfort and perceived shoe performance. Running time, heart rate, blood lactate levels, stride frequency and stride length were recorded during, and shoe comfort and shoe performance after, the 3-km TT. All parameters obtained during or after the ITT did not differ between the two conditions [range: p = 0.188 to 0.948 (alpha value: 0.05); Cohen's d = 0.021 to 0.479] despite the rating of shoe comfort showing better scores for the control insoles (p = 0.001; d = -1.646). All parameters during and after the 3-km TT showed no differences (p = 0.200 to 1.000; d = 0.000 to 0.501) between both conditions except for shoe comfort showing better scores for control insoles (p = 0.017; d = -0.919). Running with carbon fiber insoles with downwards curvature did not change running performance or any submaximal or maximal physiological or biomechanical parameter and perceived exertion compared to control condition. Shoe comfort is impaired while running with carbon fiber insoles. Wearing carbon fiber insoles with downwards curvature during treadmill running is not beneficial when compared to running with control insoles.

Correlations of Aerobic Capacity with External and Internal Load of Young Football Players during Small-Sided Games.

Aerobic capacity plays a crucial role in football performance, making it a focal point in training processes. Small-sided games (SSGs) are widely used in football training, but the relationship between aerobic capacity and running performance during SSGs remains unclear. The aim of this study was to investigate possible correlations between maximum oxygen uptake (VO2max) and running performance in youth football players in SSGs (4:4, 3:3, 2:2, 1:1) with three different pitch sizes per player (150, 100, 75 m2/player). Sixteen male U15 football players participated in the study. Players underwent the Yo-Yo intermittent recovery test level 1, and their VO2max was estimated based on their performance. Subsequently, players participated in SSGs wearing GPS devices to measure internal and external load. Pearson or Spearman correlation was applied for statistical analysis depending on the normal distribution of the data. The results reveal that, for 4:4 and 3:3 relationships, larger pitches led to a greater impact of aerobic capacity (total distance (TD): 4:4, 150 m2/pl, r = 0.715, p = 0.002; 100 m2/pl, r = 0.656, p = 0.006; 75 m2/pl, r = 0.586, p = 0.017). In the 2:2 relationship, the opposite was observed, with more correlations appearing on smaller pitches (TD: 2:2, 100 m2/pl, r = 0.581, p = 0.018; 75 m2/pl, r = 0.747, p < 0.001). In the 1:1 relationship, correlations with VO2max, total distance, and speed were observed only on the larger pitch. In conclusion, the aerobic capacity of young football players can influence running performance indicators in SSGs. Therefore, aerobic capacity could serve as a criterion for team composition, making SSGs more competitive. Additionally, the variation in correlations in the 2:2 relationship and their limited presence in the 1:1 relationship may be attributed to technical-tactical factors, such as increased ball contacts and one-on-one situations typically occurring in smaller setups.

Myoglobin deficiency impairs maximal oxygen uptake and exercise performance: a lesson from Mb-/- mice.

Myoglobin (Mb) plays an important role at rest and during exercise as a reservoir of oxygen and has been suggested to regulate NO• bioavailability under hypoxic/acidic conditions. However, its ultimate role during exercise is still a subject of debate. We aimed to study the effect of Mb deficiency on maximal oxygen uptake ( V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_2}\max }}$ ) and exercise performance in myoglobin knockout mice (Mb-/- ) when compared to control mice (Mb+/+ ). Furthermore, we also studied NO• bioavailability, assessed as nitrite (NO2 - ) and nitrate (NO3 - ) in the heart, locomotory muscle and in plasma, at rest and during exercise at exhaustion both in Mb-/- and in Mb+/+ mice. The mice performed maximal running incremental exercise on a treadmill with whole-body gas exchange measurements. The Mb-/- mice had lower body mass, heart and hind limb muscle mass (P < 0.001). Mb-/- mice had significantly reduced maximal running performance (P < 0.001). V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_2}\max }}$ expressed in ml min-1 in Mb-/ - mice was 37% lower than in Mb+/+ mice (P < 0.001) and 13% lower when expressed in ml min-1  kg body mass-1 (P = 0.001). Additionally, Mb-/- mice had significantly lower plasma, heart and locomotory muscle NO2 - levels at rest. During exercise NO2 - increased significantly in the heart and locomotory muscles of Mb-/- and Mb+/+ mice, whereas no significant changes in NO2 - were found in plasma. Our study showed that, contrary to recent suggestions, Mb deficiency significantly impairs V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_2}\max }}$ and maximal running performance in mice. KEY POINTS: Myoglobin knockout mice (Mb-/- ) possess lower maximal oxygen uptake ( V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_2}\max }}$ ) and poorer maximal running performance than control mice (Mb+/+ ). Respiratory exchange ratio values at high running velocities in Mb-/- mice are higher than in control mice suggesting a shift in substrate utilization towards glucose metabolism in Mb-/- mice at the same running velocities. Lack of myoglobin lowers basal systemic and muscle NO• bioavailability, but does not affect exercise-induced NO2 - changes in plasma, heart and locomotory muscles. The present study demonstrates that myoglobin is of vital importance for V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_2}\max }}$ and maximal running performance as well as explains why previous studies have failed to prove such a role of myoglobin when using the Mb-/- mouse model.

The Effects of a Supramaximal Intermittent Training Program on Aerobic and Anaerobic Running Measures in Junior Male Soccer Players.

This study investigated the effectiveness of supplementing regular preseason soccer training with a supramaximal intermittent shuttle-run training (ISRT) model prescribed from Carminatti's Test peak speed (PST-CAR) in aerobic performance-related indices and sprinting speed in male junior soccer players. Twenty-three national-level soccer players (mean ± SD; age 18.07 ± 0.9 y, body height 1.76 ± 0.65 m, body mass 71.9 ± 8.7 kg) were assigned to either an experimental group (EG; n = 13) performing ISRT + soccer training or a control group (CG; n = 10) that followed regular preseason soccer training alone. The following tests were applied before and after the eight-week training intervention: (i) incremental treadmill tests (VO2max and lactate minimum speed - LMS); (ii) linear 30-m sprint test and Carminatti's Test (PST-CAR). Results indicated larger gains for the EG in LMS (Δ = 9.53% vs. 2.82%) and PST-CAR (Δ = 5.50% vs. 2.10%) than in the CG. Furthermore, changes in VO2max produced higher effect size (d) values for the EG (Δ = 6.67%; d = 0.59) than the CG (Δ = 1.88%; d = 0.18). Both groups improved (p = 0.002) their flying 20-m sprint speed (EG: Δ = 1.01%; CG: Δ = 1.56%). However, small decreases were observed for 10-m sprint speed in the CG (Δ = -2.19%; d = -0.44), while only trivial changes were noticed for the EG (Δ = -0.50%; d = -0.16). Our data support that additional supramaximal ISRT is an effective training stimulus to enhance aerobic performance-related indices and promote small improvements in maximal running speed without impairing the soccer players' acceleration capacity. This study also shows that PST-CAR can be useful for individualizing running intensity in supramaximal ISRT modes.

Does Advanced Footwear Technology Improve Track and Road Racing Performance? An Explorative Analysis Based on the 100 Best Yearly Performances in the World Between 2010 and 2022.

Advanced footwear technology (AFT) is currently being debated in sports. There is a direct evidence that distance running in AFT improves running economy. In addition, there is indirect evidence from competition performance for improved running performance from using AFTs in middle- and long-distance running and sprinting events. However, the extent to which world-class performance is affected across the full range of track and road racing events between genders has not been systematically analyzed. This study examined publicly available performance datasets of annual best track and road performances for evidence of potential systematic performance effects following the introduction of AFT. The analysis was based on the 100 best performances per year for men and women in outdoor events from 2010 to 2022, provided by the world governing body of athletics (World Athletics). We found evidence of progressing improvements in track and road running performances after the introduction of AFT for road races in 2016 and AFT for track racing in 2019. This evidence is more pronounced for distances longer than 1500 m in women and longer than 5000 m in men. Women seem to benefit more from AFT in distance running events than men. For the sprint events (100 m to 400 m hurdles), the peak performance gains in 2021 and 2022 compared to the pre-AFT period ranged from 0.6 to 1.1% and from 0.4 to 0.7% for women and men, respectively. For middle-distance events (400 m to 3000 m steeplechase), peak performance gains ranged from 0.6 to 1.9% and from 0.6 to 0.7% for women and men, respectively. For distances from 5000 m to the marathon, performance gains ranged from 2.2% to 3.5% and 0.7% to 1.4% for women and men, respectively. While the observational study design limits causal inference, this study provides a database on potential systematic performance effects after introducing advanced shoes/spikes in track and road running events in world-class athletes. Further research is needed to examine the underlying mechanisms and, in particular, potential gender differences in the performance effects of AFT.

Belief That Caffeine Ingestion Improves Performance in a 6-Minute Time Trial Test without Affecting Pacing Strategy.

This study aimed to analyze the placebo effect associated with caffeine ingestion on running performance. METHODS: Thirteen recreationally trained males in long-distance running (age: 38.5 ± 11.9 years, 11.0 ± 8.8 years of running experience) performed a 6 min time trial test in each experimental condition (caffeine-informed/placebo ingested (placebo) and non-ingested (control)) separated by 7 days. The total distance covered was measured, and partial times of each 400 m were used to analyze the pacing strategy. Heart rate and kinematic variables were recorded for each split. In addition, the rate of perceived exertion and prevalence of caffeine side effects was measured using questionnaires. RESULTS: Placebo ingestion improved running performance in the 6 min time trial test (1668 ± 139 m placebo vs. 1642 ± 158 m control, t = 2.49; p = 0.03; moderate ES = 0.69), while pacing, heart rate, RPE, and kinematic variables were similar between conditions (p > 0.05 in all cases). Minor side effects were reported. CONCLUSIONS: Beliefs of caffeine ingestion can improve running performance at speeds around maximal aerobic speed in recreationally trained runners without affecting pacing strategy so this "nutritional" strategy could be useful in competition scenarios. As a practical application, recreationally trained runners could improve ≈5 s in 1500 m or mile competitions.

Influence of different midsole foam in advanced footwear technology use on running economy and biomechanics in trained runners.

BACKGROUND: Ethylene and vinyl acetate (EVA) and polyether block amide (PEBA) are recently the most widely used materials for advanced footwear technology (AFT) that has been shown to improve running economy (RE). This study investigated the effects of these midsole materials on RE and biomechanics, in both fresh and worn state (after 450 km). METHODS: Twenty-two male trained runners participated in this study. Subjects ran four 4-min trials at 13 km‧h-1 with both fresh EVA and PEBA AFT and with the same models with 450 km of wear using a randomized crossover experimental design. We measured energy cost of running (W/kg), spatiotemporal, and neuromuscular parameters. RESULTS: There were significant differences in RE between conditions (p = 0.01; n2 = 0.17). There was a significant increase in energy cost in the worn PEBA condition compared with new (15.21 ± 1.01 and 14.87 ± 0.99 W/kg; p < 0.05; ES = 0.54), without differences between worn EVA (15.13 ± 1.14 W/kg; p > 0.05), and new EVA (15.15 ± 1.13 w/kg; ES = 0.02). The increase in energy cost between new and worn was significantly higher for the PEBA shoes (0.32 ± 0.38 W/kg) but without significant increase for the EVA shoes (0.06 ± 0.58 W/kg) (p < 0.01; ES = 0.51) with changes in step frequency and step length. The new PEBA shoes had lower energy cost than the new EVA shoes (p < 0.05; ES = 0.27) with significant differences between conditions in contact time. CONCLUSION: There is a clear RE advantage of incorporating PEBA versus EVA in an AFT when the models are new. However, after 450 km of use, the PEBA and EVA shoes had similar RE.

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.

Perspectives on Player Performance during FIFA World Cup Qatar 2022: A Brief Report.

Changing the date of the FIFA World Cup Qatar 2022 may represent a factor to consider for the expected performance of participating players. This was due to fixture congestion at the start of the season and expected weather conditions during the competition. Thus, the main purpose of this brief report was to critically analyze the potential impact of changing the competition date and weather conditions on players' performance. In addition, a brief description about the performance during the World Cup is also provided. For the research, the Web of Science, PubMed and SPORTDiscus databases were accessed using the primary keywords FIFA World Cup and World Soccer Cup associated with the secondary keywords match running performance, fixture congestion, fatigue and weather conditions. After applying inclusion and exclusion criteria, 52 articles were considered for analysis. The results seem to indicate that although changes were expected due to the modifications made (i.e., the competition date and scheduling congestion), the performance of the players seems not to have been affected in terms of the analyzed indicators. Furthermore, it seems possible to identify some patterns in the behavior of the teams that reached the most advanced stages of the competition.

Is ball-possession style more physically demanding than counter-attacking? The influence of playing style on match performance in professional soccer.

In soccer, the offensive style of play describes characteristic behavioral features of the players at team level during the offensive phase of matches. This study aimed to investigate the effect of offensive playing style (i.e., while in ball possession) on physical and technical match performance during offensive play as well as success-related factors. The sample consisted of official tracking and event data of 153 matches of the 2020/21 German Bundesliga season. For every team in every match an offensive playing style coefficient was calculated to locate teams on a continuum between ball possession and counter-attacking style. This calculation contains 11 technical and physical performance parameters and has already been validated. In addition, dependent physical (e.g., sprinting distance), technical (e.g., passes), and success-related (e.g., goals) variables were examined. A separate linear mixed model was calculated for each dependent variable. While teams with lower playing style coefficient values (= counter-attacking style) covered more high-intensity (p ≤ 0.01; R2 = 0.13) and sprinting distances per second in possession (p ≤ 0.01; R2 = 0.14), teams with higher playing style coefficient values (= ball possession style) were physically more demanded over a whole match (e.g., more accelerations (p ≤ 0.01; R2 = 0.69), decelerations (p ≤ 0.01; R2 = 0.69), high-intensity (p ≤ 0.01; R2 = 0.36), sprint distance (p = 0.03; R2 = 0.08)). Furthermore, teams with higher playing style coefficient values played more horizontal passes (p ≤ 0.01; R2 = 0.73) and revealed better passing success rates (p ≤ 0.01; R2 = 0.17). In contrast, teams with lower playing style coefficient values played more long passes (p < 0.01; R2 = 0.58). The influence of the playing style coefficient on success-related variables was smaller (p ≤ 0.36; R2 = 0.10-0.13). Concluding, offensive playing style affects physical and technical match performance, but has limited influence on success. Hence, coaches can use the findings to optimize training contents to prepare players for the physical demands of a match.

The effects of L-Citrulline and Glutathione on Endurance performance in young adult trained males.

BACKGROUND: Citrulline may amplify the effects of L-arginine and nitric oxide concentration, which may augment vasodilation and blood flow, thereby enhancing aerobic exercise performance. The purpose of this randomized, double-blind, placebo-controlled crossover study was to investigate effects of L-citrulline + Glutathione on aerobic exercise performance and blood flow in well-trained men. METHODS: Twenty-five males (Mean ± SD; Age: 22.2 ± 2.4 yrs; Height: 177.0 ± 4.8 cm; Weight: 75.3 ± 6.9 kg) were randomly assigned to the L-citrulline + Glutathione (Setria Performance Blend: SPB; L-citrulline [2 g] + glutathione [200 mg], 6 capsules) or placebo (PL; 3.1 g cellulose, 6 capsules) group. Participants performed a maximal oxygen consumption treadmill test to determine peak velocity (PV) and returned after eight days of ingesting either PL or SPB. Three timed treadmill runs to exhaustion (TTE) were performed at 90%, 100%, and 110% PV. Brachial artery blood flow and vessel diameter were assessed using ultrasound at 1-hr prior to exercise (1hrPrEX), after each exercise bout, immediately post-exercise (immediate PEX), and 30 minutes post exercise (30minPEX) at visits 2 and 4. Blood analytes were assessed via venous blood draws at visit 1, visit 3, and 1hrPEX, immediate PEX, and 30minPEX at visits 2 and 4. After a 14-day washout, participants repeated the same procedures, ingesting the opposite treatment. Separate repeated measures ANOVAs were performed for TTE, vessel diameter, blood flow, and blood analytes. RESULTS: Blood flow was significantly augmented 30minPEX (p = 0.04) with SPB in comparison with PL. L-citrulline and L-arginine plasma concentrations were significantly elevated immediately PEX (p = 0.001) and 30-minPEX (p = 0.001) following SPB in comparison to PL. CONCLUSION: Acute ingestion of SPB after eight days may enhance blood flow, L-citrulline, and L-arginine plasma concentrations after high-intensity exercise, which may enhance performance. CLINICAL TRIAL REGISTRATION: [https://clinicaltrials.gov/ct2/show/nct04090138], identifier [NCT04090138].

Is There Evidence for the Development of Sex-Specific Guidelines for Ultramarathon Coaches and Athletes? A Systematic Review.

BACKGROUND: There is evidence of sex differences in the physiology of endurance exercise, yet most of the advice and guidelines on training, racing, nutrition, and recovery for ultramarathons are based on research that has largely excluded female athletes. The objective was therefore to review the current knowledge of sex differences in ultramarathon runners and determine if sufficient evidence exists for providing separate guidelines for males and females. METHODS: This systematic review was carried out in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Three databases were searched for studies investigating differences in elite and recreational male and female ultramarathon runners. Studies were included if they compared males and females and looked at outcomes relating to the performance or health of ultramarathon runners. The quality of the included studies was determined using the Grading of Recommendations Assessment Development and Evaluation (GRADE) approach. RESULTS: The search strategy identified 45 studies that met the inclusion criteria. Most studies were observational in design, with only three papers based on randomised controlled trials. The overall quality of the evidence was low. Sex differences in the predictors of ultramarathon performance; physiological responses to training, racing, and recovery; chronic and acute health issues; and pacing strategies were found. There were areas with contradictory findings, and very few studies examined specific interventions. CONCLUSION: The results from this review suggest that the development of sex-specific guidelines for ultramarathon coaches and athletes could have a significant effect on the performance and health of female runners. At present, there is insufficient high-quality evidence on which to formulate these guidelines, and further research is required.

Aerobic high-intensity intervals are superior to improve V̇O2max compared with sprint intervals in well-trained men.

Maximal oxygen uptake (V̇O2max ) may be the single most important factor for long-distance running performance. Interval training, enabling high intensity, is forwarded as the format that yields the largest increase in V̇O2max . However, it is uncertain if an optimal outcome on V̇O2max , anaerobic capacity, and running performance is provided by training with a high aerobic intensity or high overall intensity. Thus, we randomized 48 aerobically well-trained men (23 ± 3 years) to three commonly applied interval protocols, one with high aerobic intensity (HIIT) and two with high absolute intensity (sprint interval training; SIT), 3× week for 8 weeks: (1) HIIT: 4 × 4 min at ~95% maximal aerobic speed (MAS) with 3 min active breaks. (2) SIT: 8 × 20 s at ~150% MAS with 10 s passive breaks. (3) SIT: 10 × 30 s at ~175% MAS with 3.5 min active breaks. V̇O2max increased more (p < 0.001) following HIIT, 4 × 4 min (6.5 ± 2.4%, p < 0.001) than SIT, 8 × 20 s (3.3 ± 2.4%, p < 0.001) and SIT, 10 × 30 s (n.s.). This was accompanied by a larger (p < 0.05) increase in stroke volume (O2 -pulse) following HIIT, 4 × 4 min (8.1 ± 4.1%, p < 0.001) compared with SIT, 8 × 20 s (3.8 ± 4.2%, p < 0.01) and SIT, 10 × 30 (n.s.). Anaerobic capacity (maximal accumulated oxygen deficit) increased following SIT, 8 × 20 s (p < 0.05), but not after HIIT, 4 × 4 min, nor SIT, 10 × 30 s. Long-distance (3000-m) endurance performance increased (p < 0.05-p < 0.001) in all groups (HIIT, 4 × 4 min: 5.9 ± 3.2%; SIT, 8 × 20 s: 4.1 ± 3.7%; SIT, 10 × 30 s: 2.2 ± 2.2%), with HIIT increasing more than SIT, 10 × 30 s (p < 0.05). Sprint (300-m) performance exhibited within-group increases in SIT, 8 × 20 s (4.4 ± 2.0%) and SIT, 10 × 30 s (3.3 ± 2.8%). In conclusion, HIIT improves V̇O2max more than SIT. Given the importance of V̇O2max for most endurance performance scenarios, HIIT should typically be the chosen interval format.