Average Running Speed Research Articles

Prevalence and impact of knee osteoarthritis in runners

Purpose: The aim of this study was to investigate the prevalence and impact of knee osteoarthritis among recreational runners. Methods: This study is part of a randomized-controlled trial that investigated the effectiveness of an evidence-based online injury prevention program on running injuries, in preparation for a running event (from 5 km up to marathon) in recreational runners (N=2378). After registration, a baseline questionnaire informed on demographics, lifestyle characteristics, running characteristics and injury history. All participants received three follow-up questionnaires during the study period; two weeks before the running event they registered for, one day after the running event and one month after the running event. The follow-up questionnaires informed on running related injuries (RRIs) during follow-up. Participants that reported a new running related knee injury (RRKI) during the study period (N=277)were sent a knee-specific questionnaire after a mean of 16-months (range 11.7-18.6) follow-up. This questionnaire informed on the type of knee complaints, morning stiffness, activity related knee pain and self-reported diagnosis. In addition, the National Institute for Health and Care Excellence (NICE) guideline was followed to diagnose clinical knee osteoarthritis (OA).Participants were asked if they were recovered from their RRKI (yes/no) and time to recovery(weeks) was questioned. Information on medical consumption was obtained and all were asked whether the RRKI restricted their running in terms of running speed, duration and/or frequency. The subscales symptoms and sports of the Knee injury and Osteoarthritis Outcome Score (KOOS/100) and the Anterior Knee Pain Score (AKPS/100) were used to administer OA and patellofemoral specific outcomes at follow-up. T-tests and chi-square tests were used to describe differences between runners with and without knee OA. With cox regression analysis, the association between time-to-recovery and potential prognostic factors was determined. Results: Of the 277 runners that reported a new RRKI (11.6%) during follow-up, a total of 138 (49.8%) responded to the knee-specific follow-up questionnaire and were consequently included in the current study. Responders were on average significantly older (42.3 vs. 39.3 years, p=0.04). No other differences between responders and non-responders were observed. At baseline, study participants (N=138) were on average 42.3 (SD 12.2) years old, had an average BMI of 23.3 (SD 3.0) kg/m2 and the majority was male (59.4%). Participants trained on average 2.2 (SD 0.9) times a week, spend 2.6 (SD 1.5) hours a week on training with an average running speed of 6.0 (SD 0.9) min/km. At baseline, 36.2% of the participants reported an RRKI in the previous 12 months. At 16 month follow-up, 71.0% of the runners were recovered from their knee injury, with a mean recovery time of 10.5 (SD 9.9) weeks. Non-recovered participants had complaints for 54.4 (SD 4.8) weeks up to follow-up. Following self-diagnosis, most participants suffered from knee OA/degenerative meniscus lesions (23.2%)and iliotibial band syndrome (23.2%). Morning stiffness was reported by 26.0% of the participants. Following the NICE guidelines, 13.8% of the runners with incident knee injuries were diagnosed with knee OA at follow-up. Within the group of participants that had clinical knee OA following the NICE guideline, 5.1% was recovered and 35% was not-recovered from their knee injury (p<0.001). The presence of morning stiffness was associated with recovery rate (83.3% versus 36.1%, p<0.001). Runners with clinical knee OA had a significantly lower KOOS symptom score (65.3(20.0) vs 84.8(20.0), p<0.001) and AKPS (80.9(10.7) vs. 93.3(9.6), p<0.001) compared to runners with other types of RRKIs. Runners with a self-reported diagnosis of knee OA more frequently visited a health care professional (78.1% vs. 43.4%, p<0.001) compared to runners with other types of RRKIs, with especially a high percentage of visits to the physiotherapist (80%). The results of the COX regression for time to recovery shows that male sex (HR 1.90; 95%CI 1.17-3.09) was associated with a shorter time to recover from RRKIs, while participants diagnosed with knee OA following the NICE guideline (HR 0.18; 95%CI 0.06-0.53) had a longer time to recovery. Conclusions: Time-to-recovery from RRKIs is relatively long, which emphasizes the need for optimal treatment, education and injury prevention programs in recreational runners, especially in female runners. Furthermore, more knowledge on the impact of running with knee OA is important, given the high number of runners with knee OA symptoms and the longer time-to-recovery of RRKI in runners with knee OA.

A New Approach to the Analysis of Pitch-Positions in Professional Soccer.

The purpose of the study was to examine how various playing positions affected the number of (and percentage breakdowns for) physical and technical activities of soccer players in the Germany’s Bundesliga. A further objective was to identify and present features distinguishing between the activities of players within the Defender, Midfielder and Forward formations. The study sample comprised 4426 individual match observations of 473 soccer players competing in the Bundesliga during the 2016/2017 domestic season. Data from the Impire AG motion analysis system, and the so-called ”heat maps” it supplies, revealed areas in which players spent most time during a match, with 22 different playing positions on the pitch identified in consequence. Players in the formation comprising Defenders did not differ significantly in relation to the number of accelerations, the number of shots or the percentage of duels won. Furthermore, there were no significant differences among Midfielders in regard to total distance covered, mean running speed, the number of accelerations, the number of duels and the percentage of duels won. Likewise, Forwards did not differ in distances covered at ≥24 km/h, average running speed, the number of sprints, the number of shots, the proportion of on-target passes, the number of duels, or the percentage share of duels won. Irrespective of the formation or position on the pitch, today’s game of soccer also pays great importance to the number of accelerations, as well as the number of duels engaged in, and their effectiveness.

The Duration-specific Peak Average Running Speeds of European Super League Academy Rugby League Match Play.

Whitehead, S, Till, K, Weaving, D, Dalton-Barron, N, Ireton, M, and Jones, B. Duration-specific peak average running speeds of European Super League Academy rugby league match play. J Strength Cond Res 35(7): 1964-1971, 2021-This study aimed to quantify the duration-specific peak average running speeds of Academy-level rugby league match play, and compare between playing positions. Global positioning system data were collected from 149 players competing across 9 teams during 21 professional Academy (under-19) matches. Players were split into 6 positions: hookers (n = 40), fullbacks (n = 24), halves (n = 47), outside backs (n = 104), middles (n = 118), and backrow forwards (n = 104). Data were extracted and the 10-Hz raw velocity files exported to determine the peak average running speeds, via moving averages of speed (m·min-1), for 10- and 30-second, and 1- to 5- and 10-minute durations. The data were log transformed and analyzed using linear mixed-effect models followed by magnitude-based inferences, to determine differences between positions. Differences in the peak average running speeds are present between positions, indicating the need for position-specific prescription of velocity-based training. Fullbacks perform possibly to most likely greater average running speeds than all other positions, at each duration, except at 10 seconds vs. outside backs. Other differences are duration dependent. For 10 seconds, the average running speed is most likely greater for outside backs vs. the hookers, middles, and backrow forwards, but likely to most likely lower for 10 minutes. Hookers have possibly trivial or lower average speed for 10 seconds vs. middles and backrow forwards, but very likely greater average running speed for 10 minutes. The identified peak average running speeds of Academy-level match play seem similar to previously reported values of senior professional level.

Comparative study of real-world driving cycles, energy consumption, and CO2 emissions of electric and gasoline motorcycles driving in a congested urban corridor

This study compared the real-world driving patterns of electric and gasoline motorcycles. The developed onboard system was installed on test motorcycles to collect real-world driving patterns in a mixed traffic and congested urban corridor. The driving cycles of both electric and gasoline motorcycles were developed, and their driving parameters, energy consumption, CO2 emissions, and energy cost were compared. The results reveal that under the same driving behaviors and traffic conditions, certain driving parameters of the electric motorcycle, including average speed, average running speed, and proportion of time spent idling, were close to those of the gasoline motorcycle. However, the maximum speed and proportion of time spent in acceleration and deceleration were lower for the electric motorcycle than those of the gasoline motorcycle. In contrast, average acceleration, average deceleration, and proportion of time spent cruising were higher for the electric motorcycle than the gasoline motorcycle. The energy consumption, CO2 equivalent emissions, and energy cost of the electric motorcycle was approximately eight, two, and six times lower than those of the gasoline motorcycle, respectively, when driving in a congested urban corridor.

I Smell a Mouse: Indirect Genetic Effects on Voluntary Wheel-Running Distance, Duration and Speed.

Indirect genetic effects (IGEs; the heritable influence of one organism on a conspecific) can affect the evolutionary dynamics of complex traits, including behavior. Voluntary wheel running is an important model system in quantitative genetic studies of behavior, but the possibility of IGEs on wheel running and its components (time spent running and average running speed) has not been examined. Here, we analyze a dataset from a replicated selection experiment on wheel running (11,420 control and 26,575 selected mice measured over 78 generations) in which the standard measurement protocol allowed for the possibility of IGEs occurring through odors because mice were provided with clean cages attached to a clean wheel or a wheel previously occupied by another mouse for 6days. Overall, mice ran less on previously occupied wheels than on clean wheels, and they ran significantly less when following a male than a female. Significant interactions indicated that the reduction in running was more pronounced for females than males and for mice from selected lines than control mice. Pedigree-based "animal model" analyses revealed significant IGEs for running distance (the trait under selection), with effect sizes considerably higher for the initial/exploratory phase (i.e., first two of six test days). Our results demonstrate that IGEs can occur in mice interacting through scent only, possibly because they attempt to avoid conspecifics.

PO-200 Research on the running ability of young male soccer player

Objective Running is the main form of sports in a football match, and running distance is an important factor affecting the outcome. Monitoring the running ability of the athletes in the competition can fully understand the load and physical fitness of the athletes, and provide data reference for the coaches to formulate scientific and systematic training programs.&#x0D; Methods The first 7 warm-up matches of the Guangdong U18 men's football team in 2017 were selected as the research object, and the MT-sports football training monitoring system was used to collect the running data of 10 first players. According to the position on the field, they are divided into the outside fullback, the center back, the center defence midfield, the center attack midfield, the outside attackers and striker. For the purpose of comparison, this study used the running grade standard formulated by Danish scholar Bosber.&#x0D; Results (1)overall movement of athletes&#x0D; The average running distance of the 7 warm-up matches is 7945m, and the jogging distance is 4368m, accounting for 55% of the total running distance; the middle speed running distance is 2574m, accounting for 32.4% of the total running distance; the running distance above the high speed running is 1006m, accounting for 12.6% of the total running distance. The average running speed of the 7 games is 1.30m/s, and the average maximum speed is 7.80m/s.&#x0D; (2)The running distance of athletes at different speeds on different positions&#x0D; The average total running distance of the center attack midfield is 8759m, and the high-speed running distance is 1226m, which is the highest, and the high-speed running distance accounts for 13.9% of the total running distance. The high speed running distance between the outside fullback and the outside attackers is basically equal, the field is 1215m and 1158m respectively, but the high speed running distance has the highest total distance, reaching 14.7% and 15.3% respectively. The average running distance of the striker is 8134m, and the distance from the high speed running is 1027m, which is only higher than that of the center defence midfield and the center back. The running distance and the high speed distance of the center backs are below the average.&#x0D; Conclusions (1)There is a certain gap between athletes and elite athletes in running ability, but in high-intensity running ability is more prominent.&#x0D; (2)Athletes have more walking distance, which suggests that players should be encouraged to move actively in the future training process.&#x0D; (3) The center attack midfield has prominent running ability and strong speed running ability in the competition.&#x0D; (4) The running situation of the center defence midfield is similar to that of the center attack midfield, but the high-speed running distance of the center defence midfield is only slightly higher than that of the center back, which also reflects the running form of the center defence midfield players.&#x0D; (5) The striker's running ability is general in the competition. The high-intensity running distance is lower than that between the center attack midfield and the outside attackers, even the the Outside fullback, which may lead to tactical failure.

Small-sided games activities with external wildcard soccer players

Aim: The Small-Sided Games (SSG) is technical exercises presented as modified games by coaches and conditioning trainers according to the objective of the training session. The aim of the study is to evaluate and compare the external load of the professional player using GPS devices and to describe the speed run and power events in 6vs6 and 7vs7 SSG with external wildcard players. Methods: 14 professional soccer players Results: The study shows that values ​​of average speed, average power and the power events number were statistically significant in 6vs6 versus 7vs7 (p&lt;0.05); the low intensity (p&lt;0.05) and moderate intensity travel volumes are higher in 6vs6, while the high intensity runs and the sprint number are clearly higher in 7vs7 (p&lt;0.001). Conclusion: The results showed that the two SSG formats determine very different external workload in professional soccer players. The 7vs7 format shows a greater sprint number while the 6vs6 imposes average running speeds up to medium intensity but does not require, if not to a very small extent, high speed and sprint performance.

Online Model Updating and Dynamic Learning Rate-Based Robust Object Tracking.

Robust visual tracking is a significant and challenging issue in computer vision-related research fields and has attracted an immense amount of attention from researchers. Due to various practical applications, many studies have been done that have introduced numerous algorithms. It is considered to be a challenging problem due to the unpredictability of various real-time situations, such as illumination variations, occlusion, fast motion, deformation, and scale variation, even though we only know the initial target position. To address these matters, we used a kernelized-correlation-filter-based translation filter with the integration of multiple features such as histogram of oriented gradients (HOG) and color attributes. These powerful features are useful to differentiate the target from the surrounding background and are effective for motion blur and illumination variations. To minimize the scale variation problem, we designed a correlation-filter-based scale filter. The proposed adaptive model’s updating and dynamic learning rate strategies based on a peak-to-sidelobe ratio effectively reduce model-drifting problems by avoiding noisy appearance changes. The experiment results show that our method provides the best performance compared to other methods, with a distance precision score of 79.9%, overlap success score of 59.0%, and an average running speed of 74 frames per second on the object tracking benchmark (OTB-2015).

A minimum-cost model for bus timetabling problem

In urban traffic, a bus’ running speed is greatly influenced by the time-dependent road conditions. Based on historical GPS data, this paper formulates a bus’ running speed between each pair of adjacent stops as a step function. A minimum-cost timetabling model is proposed, in which the total operation cost consists of the cost for a fixed setup and that for variable fuel consumption. Furthermore, a genetic algorithm with self-crossover operation is used to optimize the proposed integer nonlinear programming model. Finally, a real-world case study of Yuntong 128 bus line in Beijing is presented. Comparisons among popular timetabling models are given, involving time-dependent running speed, minimum running speed, maximum running speed and average running speed. The results demonstrate that the consideration of time-dependent running speed is helpful to improve the prediction accuracy of the fuel consumption cost by around 12.7%.

BCH–LSH: a new scheme of locality‐sensitive hashing

Similarity searching of high-dimensional data is fundamental in the multimedia research field. In recent years, the binary code indexing has achieved significant applications in the context of similarity searching. However, most of the existing binary coding methods adopt a random generation method in near neighbour cluster problems, which involve unnecessary computations and degrade similarity in object points. To avoid the uncertainty of random generation codes, in this study, the authors propose a new locality sensitive hashing (LSH) algorithm based on q -ary Bose-Chaudhuri-Hocquenghem (BCH) code. BCH-LSH algorithm utilises the characteristics of the designed distance of BCH codes and uses the BCH codes generator matrix as a transform basis of the hash function to map the source data into the hash space. The experiments show that the BCH-LSH algorithm is superior to the E2LSH algorithm in average precision, average recall ratio and running speed.

Pacing of an Untrained 17-Year-Old Teenager in a Marathon Attempt.

Although there has been increased scientific interest for physiological responses to endurance running and pacing, limited information exists for adolescents participating in endurance events. We are reporting the case of an untrained 17-year-old female teenager (body mass 50.6 kg, height 167 cm and body mass index 18.1 kg/m2) who intended to run a marathon within 6 hours without preparation. The young woman missed her goal by just 2 km. When the average running speed per hour was analysed, there was a major effect of race hour on running speed (p = 0.013, η2 = 0.320), where the running speed in the fifth hour (6.3 ± 0.2 km/h) was lower than in the second hour (6.9 ± 0.1 km/h). Despite a progressive decrease in running speed, she was still able to put on a final spurt, indicated by a 4th degree non-linear regression (R2=0.55). Creatine-kinase reached the initial value again after 5 days and the fall of hemoglobin and hematocrit indicated expansion of plasma volume. Running a marathon as a teenager did not impair physical health, especially when a self-selected pace was adopted. Laboratory parameters during running showed similar changes as have been reported for teenagers and adults after running a marathon. Increased values returned to base line within a few days. In summary, a female teenager at the age of 17 years without specific running preparation is able to achieve nearly a marathon distance during 6 hours of continuous running without harmful effects on health.

Maternal exposure to Western diet affects adult body composition and voluntary wheel running in a genotype-specific manner in mice

Some human diseases, including obesity, Type II diabetes, and numerous cancers, are thought to be influenced by environments experienced in early life, including in utero. Maternal diet during the perinatal period may be especially important for adult offspring energy balance, potentially affecting both body composition and physical activity. This effect may be mediated by the genetic background of individuals, including, for example, potential “protective” mechanisms for individuals with inherently high levels of physical activity or high basal metabolic rates. To examine some of the genetic and environmental factors that influence adult activity levels, we used an ongoing selection experiment with 4 replicate lines of mice bred for high voluntary wheel running (HR) and 4 replicate, non-selected control lines (C). Dams (half HR and half C) were fed a “Western” diet (WD, high in fat and sucrose) or a standard diet (SD) from 2weeks prior to mating until their pups could feed on solid food (14days of age). We analyzed dam and litter characteristics from birth to weaning, and offspring mass and physical activity into adulthood. One male offspring from each litter received additional metabolic and behavioral tests. Maternal WD caused pups to eat solid food significantly earlier for C litters, but not for HR litters (interaction of maternal environment and genotype). With dam mass as a covariate, mean pup mass was increased by maternal WD but litter size was unaffected. HR dams had larger litters and tended to have smaller pups than C dams. Home-cage activity of juvenile focal males was increased by maternal WD. Juvenile lean mass, fat mass, and fat percent were also increased by maternal WD, but food consumption (with body mass as a covariate) was unaffected (measured only for focal males). Behavior in an elevated plus maze, often used to indicate anxiety, was unaffected by maternal WD. Maximal aerobic capacity (VO2max) was also unaffected by maternal WD, but HR had higher VO2max than C mice. Adult lean, fat, and total body masses were significantly increased by maternal WD, with greater increase for fat than for lean mass. Overall, no aspect of adult wheel running (total distance, duration, average running speed, maximum speed) or home-cage activity was statistically affected by maternal WD. However, analysis of the 8 individual lines revealed that maternal WD significantly increased wheel running in one of the 4 HR lines. On average, all groups lost fat mass after 6days of voluntary wheel running, but the absolute amount lost was greater for mice with maternal WD resulting in no effect of maternal WD on absolute or % body fat after wheel access. All groups gained lean and total body mass during wheel access, regardless of maternal WD or linetype. Measured after wheel access, circulating leptin, adiponectin, and corticosterone concentrations were unaffected by maternal WD and did not differ between HR and C mice. With body mass as a covariate, heart ventricle mass was increased by maternal WD in both HR and C mice, but fat pads, liver, spleen, and brain masses were unaffected. As found previously, HR mice had larger brains than C mice. Body mass of grand-offspring was unaffected by grand-maternal WD, but grand-offspring wheel running was significantly increased for one HR line and decreased for another HR line by grand-maternal WD. In summary, maternal Western diet had long-lasting and general effects on offspring adult morphology, but effects on adult behavior were limited and contingent on sex and genetic background.

THE IMPACT OF RUNNING LEVEL ON THE ASSOCIATION BETWEEN RUNNING DISTANCE AND INJURY RISK

BackgroundRunning distance has previously been identified as a risk factor for running-related injury. It is likely that the runner's fitness level may also influence injury risk.ObjectiveTo investigate if running level...

Tracheobronchoscopic Assessment of Exercise-Induced Pulmonary Hemorrhage and Airway Inflammation in Barrel Racing Horses.

BackgroundPoor performance is often suspected to be associated with EIPH in barrel racing horses; however, there are no published reports of EIPH for this discipline. The prevalence of EIPH in barrel racing horses is also unknown.ObjectivesThis study was performed to determine the prevalence of EIPH and signs of airway inflammation in barrel racing horses under normal racing conditions in Alberta.AnimalsAbout 170 barrel racing horses.MethodsObservational cross‐sectional study. Tracheobronchoscopic examinations were performed at least 30 minutes postrace. Video recordings were scored off‐site independently by two observers for EIPH and tracheal mucus accumulation (TMA). Horses with an EIPH score ≥2 were not assessed for TMA. Interobserver agreement was calculated by weighted κ statistics. Run times, environmental variables, and clinical information were also recorded for analysis.Results77/170 (45.3%) of horses examined showed evidence of EIPH (grade ≥ 1). Interobserver agreement was 0.94. 140/141 (99.3%) of horses assessed for TMA showed evidence of tracheal mucus accumulation (grade ≥ 1) with 104/141 (73.8%) having a TMA score ≥ 2. Interobserver agreement was 0.73. A weak positive association was found between EIPH scores and average run speed, the presence of cough at rest reported by the riders, increased recovery time, exercise intolerance, and outdoor pattern.Conclusions and clinical importanceThe high prevalence of EIPH observed in the sampled population indicates that barrel racing induces substantial stress on the lungs. The presence of EIPH did not impact negatively on performance. Factors such as environmental dust and frequent traveling might have contributed to the high prevalence of TMA observed.

Running Speed Is More Genetically Influenced Than Duration Or Distance Run With Aging Male Mice

Many factors are believed to influence the decline in physical activity with aging. Recent evidence from our laboratory suggests genetic background participates in the declining physical activity level. PURPOSE: To determine the impact of genetic background on daily physical activity throughout the lifespan of male mice in four inbred strains. METHODS: Twenty-six, seven-week old male mice from four inbred strains (C57Bl/6J, CBA/J, DBA/2J, and SWR/J) were individually housed with a running wheel. Standard chow and water were provided ad libitum. Daily physical activity, as assessed by voluntary running wheel activity, was measured with a sensor and digital odometer every day from eight to eighty weeks of age and calculated for monthly averages. RESULTS: Daily duration (p<0.0001), running speed (p=0.0004), and distance (p=0.042) were different between strains across lifespan (3 to 18 months). Duration (p=0.001) and distance (p=0.0008) decreased from 3 to 18 months of age, but average running speed (p=0.15) did not change. SWR/J mice averaged greater daily durations and distances than the remaining strains of mice (p<0.0001). Average running speed was faster for the C57Bl/6J mice compared to the other strains (p<0.0001). Broad-sense heritability estimations increased from 3 to 6 months for duration, 3 to 5 months for average speed, and 3 to 8 months for distance (p<0.001). Broad-sense heritability estimates decreased for duration and distance throughout the second half of the lifespan (p<0.0001). The highest monthly averages for broad-sense heritability were 47.7±1.1% for duration, 61.8±6.8% for average speed, and 35.1%±4.5% for distance. CONCLUSIONS: For males, genetic influence on physical activity variables increased throughout the first third of the lifespan and declined throughout the remainder of the lifespan for only duration and distance. A consistent genetic influence was found with running speed throughout most of the lifespan for male mice. Additionally, running speed exhibited the highest broad-sense heritability estimates, indicative of more highly influenced by genetic background, compared to duration and distance in aging mice. Supported by National Institutes of Health Grant AG-022417 (M.J. Turner) and UNC Charlotte Faculty Grant Program (Turner, Hubbard-Turner, Wikstrom).

The Effect of Photoluminescence of Bioceramic Irradiation on Middle Cerebral Arterial Occlusion in Rats.

The purpose of this study is to determine the possible effect of photoluminescence of bioceramic (PLB) on ischemic cerebral infarction (stroke), by using an animal model of transient middle cerebral artery occlusion (MCAO). Sprague-Dawley rats were used to induce MCAO to block the origin of the left MCAO; three months later, the positive chronic stroke rats were selected by running tunnel maze; the MCAO rats with significant chronic stroke and neurological defects were used for treadmill experiments with varying speed settings to test their capability for restoration after muscular fatigue under conditions of with and without PLB irradiation. As a result, PLB irradiation could improve exercise completion rate and average running speed during slow and fast treadmill settings. After PLB irradiation, the selected MCAO rats successfully completed all the second-round treadmill exercises at the maximum speed setting, and they had better restoration from muscular fatigue. An in vitro cell study on astrocytes of rats by bioceramic irradiation further demonstrated increased intracellular nitric oxide. To explain these results, we suggest that cortical brain stimulation of microcirculation and enhancement of peripheral muscular activity are the main causes of the improved exercise performance in MCAO rats by PLB.

Predictive value of ventilatory inflection points determined under field conditions

ABSTRACTThe aim of this study was to evaluate the predictive potential provided by two ventilatory inflection points (VIP1 and VIP2) examined in field without using gas analysis systems and uncomfortable facemasks. A calibrated respiratory inductance plethysmograph (RIP) and a computerised routine were utilised, respectively, to derive ventilation and to detect VIP1 and VIP2 during a standardised field ramp test on a 400 m running track on 81 participants. In addition, average running speed of a competitive 1000 m run (S1k) was observed as criterion. The predictive value of running speed at VIP1 (SVIP1) and the speed range between VIP1 and VIP2 in relation to VIP2 (VIPSPAN) was analysed via regression analysis. VIPSPAN rather than running speed at VIP2 (SVIP2) was operationalised as a predictor to consider the covariance between SVIP1 and SVIP2. SVIP1 and VIPSPAN, respectively, provided 58.9% and 22.9% of explained variance in regard to S1k. Considering covariance, the timing of two ventilatory inflection points provides predictive value in regard to a competitive 1000 m run. This is the first study to apply computerised detection of ventilatory inflection points in a field setting independent on measurements of the respiratory gas exchange and without using any facemasks.

Risco de fadiga prematura, percepção subjetiva de esforço e estratégia de prova durante uma corrida de 10 km

O objetivo do estudo foi verificar as modificações na estratégia de prova frente às alterações do risco de fadiga prematura e da percepção subjetiva de esforço (PSE) em corredores durante uma corrida de 10 km. Participaram do estudo 55 corredores com tempo nos 10 km de 41:39 ± 3:52 min:s. A estratégia de prova e a PSE foram avaliadas a cada quilômetro. O risco de fadiga prematura foi determinado pelo produto entre a PSE e a distância restante de prova e a estratégia de prova foi determinada pela curva da velocidade e distância. A ANOVA de um caminho para medidas repetidas foi utilizada para determinar as diferenças na velocidade, PSE e risco de fadiga a cada quilômetro e entre a velocidade a cada quilômetro e a velocidade média da prova. O coeficiente de correlação de Pearson foi calculado entre a PSE e o risco de fadiga prematura com a velocidade. A velocidade do primeiro quilômetro foi 8,1% maior do que a média (p ≤ 0,001). A velocidade diminuiu gradualmente ao longo da prova, ocorrendo um novo aumento no décimo quilômetro. A PSE aumentou linearmente ao longo da prova e o risco de fadiga diminuiu significantemente após o terceiro quilômetro. Houve forte correlação negativa entre a PSE e a velocidade desenvolvida durante a prova (r = -0,80; p = 0,006). Foi observada uma correlação moderada negativa entre o risco de fadiga prematura e a velocidade (r = -0,57; p = 0,04). Com isso, os achados do presente estudo sugerem que a PSE parece ter importante papel sobre os ajustes da velocidade ao longo da prova, sendo que o aumento da velocidade observado no último quilômetro pode estar associado ao baixo risco de fadiga prematura.

Pacing strategy in male elite and age group 100 km ultra-marathoners.

Pacing strategy has been investigated in elite 100 km and elite 161 km (100 mile) ultra-marathoners, but not in age group ultra-marathoners. This study investigated changes in running speed over segments in male elite and age group 100 km ultra-marathoners with the assumption that running speed would decrease over segments with increasing age of the athlete. Running speed during segments in male elite and age group finishers for 5-year age groups (ie, 18–24 to 65–69 years) in the 100 km Lauf Biel in Switzerland was investigated during the 2000–2009 period. Average running speed over segment time station (TS) TS1–TS2 (56.1 km) was compared with running speed Start–TS1 (38 km) and Start–TS3 (76.7 km) and running speed TS2–TS3 was compared with running speed Start–Finish. For the top ten athletes in each edition, running speed decreased from 2000 to 2009 for TS1–TS2 and TS2–TS3 (P<0.0001) but not in TS3–Finish (P>0.05). During TS1–TS2, athletes were running at 98.0%±2.1% of the running speed of Start–TS1. In TS2–TS3, they were running at 94.6%±3.4% of the running speed of TS1–TS2. In TS3–Finish, they were running at 95.5%±3.8% of running speed in TS2–TS3. For age group athletes, running speed decreased in TS1–TS2 and TS2–TS3. In TS3–Finish, running speed remained unchanged with the exception of the age group 40–44 years for which running speed increased. Running speed showed the largest decrease in the age group 18–24 years. To summarize, the top ten athletes in each edition maintained their running speed in the last segment (TS3–Finish) although running speed decreased over the first two segments (TS1–TS2 and TS2–TS3). The best pacers were athletes in the age group 40–44 years, who were able to achieve negative pacing in the last segment (TS3–Finish) of the race. The negative pacing in the last segment (TS3–Finish) was likely due to environmental conditions, such as early dawn and the flat circuit in segment TS3–Finish of the race.

Do non-elite older runners slow down more than younger runners in a 100 km ultra-marathon?

BackgroundThis study investigated changes in normalised running speed as a proxy for effort distribution over segments in male elite and age group 100 km ultra-marathoners with the assumption that older runners would slow down more than younger runners.MethodsThe annual ten fastest finishers (i.e. elite and age group runners) competing between 2000 and 2009 in the ‘100 km Lauf Biel’ were identified. Normalised average running speed (i.e. relative to segment 1 of the race corrected for gradient) was analysed as a proxy for pacing in elite and age group finishers. For each year, the ratio of the running speed from the final to the first segment for each age cohort was determined. These ratios were combined across years with the assumption that there were no ‘extreme’ wind events etc. which may have impacted the final relative to the first segment across years. The ratios between the age cohorts were compared using one-way ANOVA and Tukey’s post-hoc test. The ratios between elite and age group runners were investigated using one-way ANOVA with Dunnett’s multiple comparison post-hoc tests. The trend across age groups was investigated using simple regression analysis with age as the dependent variable.ResultsNormalised average running speed was different between age group 18–24 years and age groups 25–29, 30–34, 35–39, 40–44, 45–49, 50–54, 55–59 and 65–69 years. Regression analysis showed no trend across age groups (r2 = 0.003, p > 0.05).ConclusionTo summarize, (i) athletes in age group 18–24 years were slower than athletes in most other age groups and (ii) there was no trend of slowing down for older athletes.