Distance Runners Research Articles

Prescribing playing intensity in small-sided games using rating of perceived effort among youth soccer players: a randomized crossover trial

ABSTRACT In this study, we examined whether the 0–10 rating of perceived effort (RPE) scale can serve as a method for prescribing playing intensity in small-sided games (SSGs). We conducted a randomized crossover trial involving 25 young male football players (age range 16–18 years). Participants completed a familiarization and three experimental sessions where game intensity was regulated using prescribed intensities equal to RPE of 6, 8, or 10. Each session involved six teams of three players playing in three SSGs, with 4 min of rest, in a playing area of 133 square meters per player. Outcomes included total distance, high-speed running distance (HSRD), intense acceleration and deceleration (IAD) counts, and average heart rate (HR). We fitted mixed models and estimated 95% confidence intervals (CIs) to analyze the results. The CIs for all locomotive outcomes indicated an increase at RPE-8 and RPE-10 compared to RPE-6. Notably, the effects on HSRD and IAD were substantial, with differences between RPE-10 and 8 to RPE-6 ranging from 28% to 97%. Conversely, differences in the total distance the players covered per game between RPE-10 and 8 to 6 were minor (~5%). We could not identify clear differences between RPE-10 and 8 in the locomotive outcomes (differences range 0%–9.6%, CIs containing zero) nor in HR across all RPE conditions (differences range 1–3.5 bpm, CIs containing zero). We conclude that RPE can serve as a practical tool to prescribe medium or high intensity during SSGs, although its ability to differentiate between higher intensity levels or influence heart rate is limited.

How did match running performance change after an extra time match during FIFA 2022 World Cup and 2023 Women`s World Cup?

ObjectiveThis study aimed to explore the changing characteristics of running performance before and after extra time matches (ET) at the World Cup under new substitution rules and in special seasonal periods.MethodsMatch running data of starting players who played ET compared to matches before and after the ET matches from the FIFA 2022 World Cup and the FIFA 2023 Women’s World Cup were used for the analysis by using repeated-measures ANOVA.ResultsMost of the relative running distance per minute for the ET match was lower than the pre and post ET match in both men and women World Cups. However, no significant differences (p > 0.05) were found between pre and post ET matches neither in men’s nor women’s World Cups, except total distance and low speed running distance per minute for men`s football (p < 0.05). Significant interaction effects of gender × match (ET/Post-ET) were found in total distance, walking and jogging distance, low speed running distance and high-speed running distance per min (p < 0.05). In contrast, no significant interaction effects were found in moderate speed running distance, sprint distance, number of high-speed running bouts, number of sprints per min and top speed (p > 0.05).ConclusionThe present findings revealed that players display limited fatigue and can maintain running performance in the match after extra time matches across both genders during World Cups with 4–5 days between matches. Coaches should continue to focus on approaches to reduce fatigue and speeding up athlete recovery after extra time matches in international tournaments.

Sprint runners have longer Achilles tendon moment arm than distance runners.

Sprint runners have longer Achilles tendon moment arm than distance runners.

Pre-Season Energy Deficiency Predicts Poorer Performance During a Competitive Season in Collegiate Female Long-Distance Runners.

Female distance runners are at a high risk for chronic energy deficiency (ED). ED during predominantly high-volume and/or high-intensity training phases may compromise performance. The relationship between pre-season energy status and running performance in female runners across a season is unclear. To test if energy status as defined by resting metabolic rate ratio (RMRratio) is associated with running performance, female collegiate distance runners (18-25yr; n=38) were assessed across 10-12wks. Energy status, body composition, and 5km time trial (measure of performance) were assessed pre- and post-competitive season. Runners were categorized at baseline based on pre-season measured-to-Cunningham1991-predicted RMRratio: metabolically suppressed (SUP: RMRratio <0.92, n=12) and energy replete (NSUP: RMRratio ≥0.92, n=26). Repeated measures ANOVA tested effects of pre-season RMRratio groups, time, and group*time on performance. Linear regression analysis tested whether factors (body composition or total triiodothyronine, TT3) predicted performance across the season. Twenty-one runners (19.6±0.2yr, 20.2±0.4kg/m2) completed pre- and post-season performance runs. Groups had similar body mass, body mass index, percent body fat, and lean body mass. ANOVA revealed a significant group effect of RMRratio on running performance, but no effect of time or group*time. SUP had slower 5km time trial performance compared to NSUP (22.4 vs. 20.4min, p=0.04). Controlling for post-season VO2max, pre-season TT3 predicted post-season 5km times (R2=0.614, p=0.001). Pre-season energy deficient female runners exhibited poorer running performance during a collegiate competitive season compared to pre-season energy replete runners. Early detection of metabolic compensation in runners may be necessary for optimal performance across a competitive season.

Role of CTRP14/C1QL1 in motor coordination and learning across the lifespan.

Role of CTRP14/C1QL1 in motor coordination and learning across the lifespan.

Acetabular orientation, pelvic shape, and the evolution of hominin bipedality.

Acetabular orientation, pelvic shape, and the evolution of hominin bipedality.

Dehydroandrographolide succinate attenuates dexamethasone-induced skeletal muscle atrophy by regulating Akt/GSK3β and MuRF-1 pathways.

Dehydroandrographolide succinate attenuates dexamethasone-induced skeletal muscle atrophy by regulating Akt/GSK3β and MuRF-1 pathways.

Cardiorespiratory, Metabolic, and Perceptual Responses to Blood Flow Restricted Running in Female Distance Runners.

Cardiorespiratory, Metabolic, and Perceptual Responses to Blood Flow Restricted Running in Female Distance Runners.

Comparison of Muscle Damage Markers and Myokines between Adult and Middle-Aged Marathon Runners

This study compared markers of muscle damage and myokines between adult and middle-aged runners before and after the marathon. Seventy-four male runners: 48 adults aged 30-44 years (AA group), and 26 middle-aged individuals aged 45-59 years (MA group) participated of the study. Blood samples were collected 24 hours before, immediately after, 24 hours and 72 hours after the marathon to measure skeletal and cardiac muscle damage markers (CK, LDH, troponin, and proBNP) and myokines (IL-6, IL-15, decorin, BDNF, GDF-15, FGF-21, apelin, musclin, myostatin, and follistatin). Before the marathon, it was observed that serum concentrations of BDNF were higher, and those of IL-15, GDF-15, apelin, and musclin were lower in the MA group. Immediately after the marathon, both groups showed higher activity of CK and LDH, as well as higher serum concentrations of ProBNP, troponin, IL-6, decorin, FGF-21, BDNF, and GDF-15. After the marathon and in the recovery period, GDF-15 concentrations remained lower and BDNF concentrations higher in the MA group compared to the AA group. In both groups, long-distance running induced muscle and cardiac damage and modulated myokines responsible for skeletal and cardiac muscle repair/adaptation. Middle-aged individuals show a reduction in the serum concentration of myokines that may contribute to muscle and cardiometabolic dysfunction in senescence. The role of higher levels of BDNF in middle-aged runners on cardiometabolic adaptation should be investigated to elucidate the molecular mechanisms of senescence.

Strength Training Improves Running Economy Durability and Fatigued High-Intensity Performance in Well-Trained Male Runners: A Randomized Control Trial.

Strength training improves running economy (RE) in a non-fatigued state and performance after prolonged exercise at moderate intensity. However, it is unknown if strength training improves RE durability at marathon race intensity, or high-intensity performance akin to the final stages of a competitive race. This study quantified the effect of a supplementary 10-week strength training program on RE throughout 90 min of running in the heavy-intensity domain, and subsequent fatigued performance in runners. Twenty-eight well-trained male runners (maximal oxygen uptake (V̇O2max) 58.6 ml·kg-1·min-1; 10 km 39:02 mm:ss) were performance-matched and randomly assigned to a habitual running-only control (E; n = 14) or supplementary strength training group (E + S; n = 14) that performed maximal strength and plyometric training twice weekly for 10 weeks. Before the training, participants performed a 90 min run at 10% Δ between lactate threshold 1 and 2 (13.1 ± 1.4 km/h, 79.7% V̇O2max). RE, quantified as oxygen cost (ml·kg-1·km-1), was recorded at 15 min intervals during the run, immediately thereafter, participants ran a time to exhaustion (TTE) at 95% pre-test V̇O2max (16.1 ± 1.6 km/h). The 90 min run and TTE were repeated after the training intervention. A large interaction effect of training x group x run time was found for RE (p = 0.003, ηp2 = 0.13), with E + S improving vs E at 90 min (-2.1% vs +0.6; p = 0.04). For TTE, a large group x training interaction effect was detected (p = 0.004, ηp2 = 0.28), changing by +35% in E + S and -8% in E. This study demonstrated that adding strength and plyometrics training to a programme of endurance running improved RE durability and substantially increased high-intensity TTE at the end of a 90 min run in the heavy intensity domain in well-trained male runners.

Thermal sensitivity of respiration and ROS emission of muscle mitochondria in deer mice.

The impacts of heat exposure on mitochondrial physiology are poorly understood in most mammals. We examined the thermal effects on muscle mitochondrial function in deer mice (Peromyscus maniculatus), a species in which running endurance is impaired when heat exposure increases body temperature beyond 40°C. Mitochondrial physiology was examined at 37, 40, and 42°C using both permeabilized fibres and isolated mitochondria from the gastrocnemius muscle. Hot temperatures increased leak respiration, reduced the coupling efficiency of oxidative phosphorylation, and increased reactive oxygen species (ROS) emission. These results suggest that heat exposure reduces mitochondrial efficiency, which could contribute to impairments in running performance, and may also induce oxidative stress. Thermal effects on mitochondrial function may thus represent a potential vulnerability during heat exposure in mammals.

Advanced Footwear Technology, but not Acute Ingestion of a Ketone Monoester, Improves Running Economy in Middle- and Long-Distance Runners.

This study examined the separate and combined effects of advanced footwear technology (AFT) and acute ingestion of a ketone monoester on running economy (RE), time-to-exhaustion (TTE), and other metabolic and cardiorespiratory parameters. In a four-condition, placebo-controlled, randomized crossover design, 18 middle- and long-distance runners (male/female, 10/8, V̇O2peak: 59.4 ± 7.2 mL·kg-1·min-1) completed five 8 min stages of submaximal running (male: 10-14 km·h-1; female: 9-13 km·h-1) on a motorized treadmill, immediately followed by a ramp test to volitional exhaustion. Participants consumed 500 mL of either a 10% carbohydrate solution (CHO) or 500 mg·kg-1 body mass of an (R)-3-hydroxybutyl (R)-3-hydroxybutyrate ketone monoester with flavored water (KME) 20 min before exercise, and an additional 300 mL of the 10% carbohydrate solution or 250 mg·kg-1 body mass of KME during exercise, while wearing either Nike Pegasus Turbo (PEG) or Nike ZoomX Vaporfly Next% 3 (VAP) running shoes. The four randomized conditions were PEG+CHO, PEG+KME, VAP + CHO, and VAP + KME. RE was significantly improved during the third and fourth submaximal running stages in VAP + CHO and VAP + KME compared to PEG+CHO and PEG+KME (all P < 0.05; ES = 0.53-0.84). RE was also improved during the fifth submaximal running stage in VAP + KME compared to PEG+CHO, and in VAP + CHO and VAP + KME compared to PEG+KME (all P < 0.05; ES = 0.56-0.66). No differences in RE were found between CHO and KME conditions. TTE was significantly longer in VAP + CHO (381 ± 125 s) than PEG+CHO (356 ± 140 s; ES = 0.18, P = 0.023) and PEG+KME (329 ± 131 s, ES = 0.40, P < 0.001) and in VAP + KME (375 ± 125 s) than PEG+KME (ES = 0.35, P < 0.001). AFT, but not the acute ingestion of a ketone monoester, improved the RE of trained male and female middle- and long-distance runners at submaximal running speeds.

Fluctuating Running Speed During 10-km Running Elevates Physiological Strain.

Although it is anecdotally believed that fluctuating running speed during competition has a negative impact on running performance, its influence on physiological strain remains unclear. Therefore, the purpose of the present study was to determine the effect of fluctuating running speed during 10-km running on physiological strain compared with constant running speed. Ten male endurance runners completed 2 trials on different days, consisting of either fluctuating (FLU) or constant (CON) running speed during 10-km running on a treadmill. In the CON trial, running speed was constant at 80% of maximal oxygen uptake (V˙O2max), while running speed fluctuated between 75% and 85% of V˙O2max in the FLU trial. Blood lactate levels were evaluated before and after running. Moreover, oxygen uptake (V˙O2) and expired minute ventilation (V˙E) were measured with running. The time to complete 10-km running was the same between the 2 trials (FLU 38.6 [5.1]min, CON 38.6 [5.1]min). The FLU trial showed greater exercise-induced blood lactate elevation compared with the CON trial (FLU 4.5 [1.5]mmol/L, CON 2.9 [1.4]mmol/L). The mean values of V˙O2 (FLU 48.6 [3.5]mL·kg-1·min-1, CON 47.1 [3.6]mL·kg-1·min-1) and V˙E (FLU 95 [14]L/min, CON 87 [11]L/min) during running were significantly higher in the FLU trial than in the CON trial. Fluctuating running speed elevated physiological strain compared with constant running speed during 10-km running, even if the time to complete 10-km running was the same.

The influence of high-intensity interval running bouts on distal anterior femoral cartilage in competitive distance and middle-distance runners

ABSTRACT Competitive runners compared with recreational runners have increased odds of osteoarthritis and running-related injury, potentially from different running types. We compared distal anterior femoral cartilage deformation in competitive runners following a continuous and high-intensity interval run (10 × 400 m, 300 m jog) and evaluated the association between running kinetics and cartilage deformation. Twenty-four competitive runners (11 females and 13 males), between 18 and 35 years old underwent femoral cartilage ultrasound imaging before and after both running conditions in a counterbalanced order 2–7 days apart. Footwear was instrumented with force-sensing insoles to extract peak ground reaction force, loading rate, and impulse. A 2 (time) by 2 (condition) ANOVA with repeated measures evaluated the change in cartilage thickness after running between conditions. The lateral cartilage region showed greater deformation after interval compared with continuous running (p = 0.003). A main effect of time was seen where cartilage was thinner after running compared with baseline regardless of condition (1.92 (1.82, 2.02) vs. 1.83 (1.73, 1.93) mm; mean difference = −0.094 (−0.147, −0.042) mm, p = 0.001). No significant associations were found between cartilage deformation and loading rate, peak ground reaction force, or impulse (all r < 0.32, all p > 0.05). Interval running contributed to greater lateral distal anterior femoral cartilage deformation.

Isoliquiritigenin, an Extract from Licorice, Attenuates Dexamethasone-Induced Muscle Atrophy via Akt/mTOR Pathway.

Muscle atrophy is a pathological condition characterized by the excessive degradation of muscle proteins, leading to impaired physical performance. Isoliquiritigenin (ISL) is a promising extract known for its medical effects; however, its impact on muscle atrophy remains unclear. We investigated the effects of ISL on muscle atrophy both in vitro and in vivo. The results showed that 5-µM ISL exhibited no significant cytotoxicity on C2C12 cells, as reflected by cell count kit-8 and 5-ethynyl-2'-deoxyuridine (EdU) tests. ISL increased the diameter of myotubes and downregulated forkhead box O proteins, muscle-specific RING finger protein 1 (MuRF-1), and Atrogin-1 induced by Dexamethasone (Dex). ISL could also enhance the phosphorylation of Akt, the mammalian target of rapamycin (mTOR), eIF4E-binding protein 1, and p70 S6 kinase in C2C12 myotubes. In animal experiments, ISL increased the muscle mass, improved the cross-sectional area of muscles, and inhibited the expression of MuRF-1 and Atrogin-1 in muscle tissues. For physical performance, ISL enhanced grip strength and running endurance. ISL ameliorated Dex-induced muscle atrophy both in vitro and in vivo, associated with increased diameter of myotubes and decreased Atrogin-1 and MuRF-1 expression via the Akt/mTOR signaling pathway. This suggested that ISL could be used as a natural drug for muscle atrophy.

Comparative Analysis of U17, U20, and Senior Football Team Performances in the FIFA World Cup: From Youth to Senior Level.

This study aimed to investigate differences in match physical and technical/tactical performance of teams across different competitive levels in international soccer: FIFA Men's World Cup Qatar 2022 (MWC), FIFA U20 World Cup Argentina 2023 (U20WC), and FIFA U17 World Cup Indonesia 2023 (U17WC). From a total of 168 games, 138 games were analyzed (N = 276 game observations) using an optical tracking system. On average, the U17WC teams exhibited reduced total running(3% less), high-intensity running (14%-16% less), and sprinting (18%-26% less) distance than the MWC and U20WC teams (P ≤ .0023; effect size [ES]: 0.8-1.5). The MWC teams displayed 4% to 5% higher accuracy in passing and executing line breaks (P ≤ .0188; ES: 0.6-0.7), along with increased offers to receive the ball (53%-118% more) and movements to receive the ball (44%-101% more), and received the ball (61%-137%) more often than the U20WC and U17WC teams (P < .001; ES: 1.1-2.1). Moreover, notable decreases in defensive pressure (-18% to -32%) and forced turnovers (-26% to -32%) were observed in the U17WC than other competitions (P ≤ .0001; ES: 0.8-2.2). Greater variability was observed among the U17WC teams in several metrics, including high-intensity/sprinting distances, attempts at goal, and receptions in the final third. These findings demonstrate that as the competitive level increases, so do the physical demands, advanced technical skills, and tactical fluidity/adaptability. However, caution should be exercised when interpreting match performance of younger age groups, as higher variability was evident in both physical and technical/tactical performance in matches.

Menstrual Phase and Postmatch Perceptual Recovery Responses for Naturally Menstruating Football Players.

To explore the influence of menstrual phase on postmatch perceptual responses and the time course of recovery for professional footballers. Thirteen naturally menstruating footballers tracked their menstrual cycle and reported perceptual responses for up to 4 cycles. Menstrual phases were determined by calendar-based tracking and urinary hormone tests and classified as menstruation, follicular, or luteal. On match days (MDs) and the following 2days (MD+1 and MD+2), players completed perceptual questionnaires on fatigue, soreness, stress, sleep, and perceived recovery status (PRS). Total high-speed running distance during matches was recorded using GPS devices to represent load. Data were analyzed using linear mixed models. Day × total high-speed running distance affected PRS (P < .001), total wellness (P < .001), fatigue (P = .047), soreness (P < .001), and stress (P = .044). Significant main effects were found for menstrual phase on PRS (P = .038), Day on stress (P = .034), and total high-speed running distance on soreness (P = .045). During the menstruation phase, moderate effect sizes (ES) existed for worse PRS on MD and MD+2 (P = .07-.28, ES > 0.51) and better sleep quality on MD+2 (P = .13, ES = 0.56). No significant differences between menstrual phases existed (P > .05), and all other ESs were trivial to small (ES < 0.50). All perceptual measures, except stress, differed significantly between days (P < .05), with differences based on match load and, to a lesser extent, menstrual phase. PRS may be worse during menstruation, although menstrual phase has limited association with postmatch perceptual responses. Variability in the recovery time course for perceptual measures exists between menstrual phases, but evidence for consistently impaired recovery time course in any phase was not evident.

Comparison of physiological and physical demands between small-sided games and official matches in youth football players

Abstract Purpose This study aimed to compare the physiological and physical demands between two spatial formats of small-sided games (SSGs) and competitive matches in youth football players. Method Fifteen U14 sub-elite players were monitored using WIMU PRO™ devices (Huddle, USA) during competition and training. The training involved two 7 vs. 7 SSGs formats: small (SSGs-S; 132 m2 per player) and large (SSGs-L; 232 m2 per player). Variables such as relative maximum heart rate (HRMAX), total distance (TD), high-intensity running distance (HIRD), high-metabolic load distance (HMLD), maximum speed (SpeedMAX), average speed (SpeedAVG), and acceleration distance were evaluated. Results Repeated measures ANOVA revealed that players covered more TD, HIRD, and HMLD per minute during SSGs-L than in both competition and SSGs-S (p &lt; .01; effect size [ES] = .81, .76, .73, respectively). Competitive matches showed higher SpeedMAX (p &lt; .01; ES = .93) and SpeedAVG (p &lt; .01; ES = .84) compared to SSGs. Both SSGs formats exhibited higher distances covered in accelerations (&gt; 2 m/s2) than competitive matches (p &lt; .01; ES = .86). Conclusion This study emphasizes the importance for fitness coaches to manipulate pitch size during SSGs to replicate, increase or decrease physiological and physical demands relative to competitive conditions.

Effect of Repetitive Loading From 5 Km of Running on Plantar Pressure in Healthy Young Participants.

Repetitive loading during running is associated with the occurrence of running injuries. Several previous studies have assessed plantar pressure before, during, and after running. However, the difference in plantar pressure before and after 5 km of running has not been investigated. A 5-km running distance can be easily achieved by novice and recreational runners. There is evidence that novice runners are more likely to suffer injuries from running compared with experienced runners. This study aimed to examine changes in plantar pressure before and after 5 km of running. The participants were 10 healthy adult men who were asked to run 5 km on a treadmill. The foot plantar pressure area was measured before and after running. Plantar pressure data were divided according to the following areas: toe, metatarsal, heel, medial, lateral, anterior, posterior. The peak values of each area during the stance phase were compared before and after 5 km of running using paired t-test or Wilcoxon signed-rank test. The peak value of plantar pressure on the hallux (p=0.01), first metatarsal (p<0.01), toe (hallux and 2nd-5th toe) (p=0.04), and medial (metatarsal, first metatarsal, medial heel) (p=0.04) areas was significantly lower after running than before running. The plantar pressure of the medial and anterior foot areas after 5 km of running decreased. This may be because the participants were adopting a strategy that avoided overloading the medial and anterior foot area throughout 5 km of running. To elucidate this involved mechanism, future research should focus on related muscle activity.

Gastrointestinal bleeding in long-distance runners: a systematic review.

Long-distance running has become increasingly popular in recent decades all over the world. Besides musculoskeletal injuries, gastrointestinal (GI) complaints are also very common in athletes. A systematic search limited to articles in the English language was performed to identify studies on GI bleeding in long-distance runners. The primary outcomes were the incidence and outcome of overt and occult GI bleeding in long-distance runners. A total of 51 articles were included in the final analysis. We found 22 articles reporting 36 cases of overt GI bleeding in long-distance runners. GI bleeding has been reported as a cause of death in one patient. Conservative treatment was used in most of the cases, and surgery was performed on four patients. We found 22 articles (759 runners included) related to occult GI bleeding and seven articles (6671 runners included) related to occult GI bleeding, based on questionnaire-based surveys. Gastrointestinal bleeding may occur in long-distance runners, highlighting the need for further investigation into this issue. It is essential to conduct well-designed prospective studies on this topic, preferably using noninvasive diagnostic methods, such as capsule panendoscopy, to improve our understanding and management of this condition.