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External workload from matches is considered one of the most important muscle injury risk factors for football teams. However, there is scarce published evidence to support this belief. This study examined whether a particular profile of external match workload existed prior to a muscle injury. A total of 144 professional football players belonging to 2 teams were monitored over three seasons. For each muscle injury, a profile of external workload variables was determined for 5 to 8 games and expressed as: time playing exposure, total distance (TD) covered and high-speed running (HSR) covered. In addition, acute:chronic workload ratio (ACWR) was calculated. Sixty players (41.6%) reported a total of 86 muscle injuries during the three seasons. Muscle injuries occurred principally in matches (79.1%), the hamstring being the most affected muscle (44.1%). Injured players displayed substantially lower accumulated exposure time (ES = 0.45), TD (ES = 0.45) and HSR (ES = 0.39) in comparison with uninjured players in the last 5 games prior to injury. Compared to the uninjured players, ACWR for exposure (ES = -0.29/0.02) and running load (ES = -0.24/0.00) did not differ between match 5 and 2 prior to the injury, although uninjured players displayed a substantially greater ACWR in all 3 variables (ES = 0.31/0.35) than injured players in match 1 prior to the injury. Lower playing exposure (minutes played) and associated reduced running distances (TD and HSR) were observed in injured football players. Being under-loaded in official games could be a mediator for muscle injury in this cohort of elite football players.

The aim of the investigation was to verify the validity and reliability of a low-end 50-Hz Global Navigation Satellite System receiver (GNSSr) for different soccer-specific run distances and average speed assessments. Six soccer players were assessed on two different days while performing eight different running paths with changes of direction for a final total of 44 runs. During the runs, each participant was equipped with the GNSSr, while the time for each single run was recorded using a photocell gate. Reference vs. receiver assessment correspondences for distance and average speed were evaluated by calculating the standard error of the estimate (SEE), coefficient of variation (CV), and mean bias. Residual vs. predicted value comparison was performed by means of Bland-Altman plots. Finally, calculating the intra-class correlations coefficient (ICC) assessed the test-retest reliability of the measurement. Receiver distance assessment showed an SEE of 0.52 m (0.73%), and mean bias of 0.06 m. Receiver average speed assessment showed an SEE of 0.02 m·s (0.74%) and mean bias of 0.001 m·s . The Bland-Altman plot showed a small difference between the two assessments with the 95% limits of agreement=±1.08 m/0.046 m·s . Receiver distance/speed assessment was found to be reliable, with ICC=0.999. In spite of its low cost, the new low-end GNSSr provides valid and reliable assessments of distance and average speed for young adults performing several standardized running actions of differing lengths within delimited setup spaces.

This study aimed to analyze and compare the match running performance during official matches across four seasons (2015/2016–2018/2019) in the top two professional leagues of Spanish football. Match running performance data were collected from all matches in the First Spanish Division (Santander; n = 1520) and Second Spanish Division (Smartbank; n = 1848), using the Mediacoach® System. Total distance and distances of 14–21 km·h−1, 21–24 km·h−1, and more than 24 km·h−1, and the number of sprints between 21 and 24 km·h−1 and more than 24 km·h−1 were analyzed. The results showed higher total distances in the First Spanish Division than in the Second Spanish Division (p < 0.001) in all the variables analyzed. Regarding the evolution of both leagues, physical demands decreased more in the First Spanish Division than in the Second Spanish Division. The results showed a decrease in total distance and an increase in the high-intensity distances and number of sprints performed, although a clearer trend is perceived in the First Spanish Division (p < 0.001; p < 0.01, respectively). Knowledge about the evolution of match running performance allows practitioners to manage the training load according to the competition demands to improve players’ performances and reduce the injury rate.

Background: The relationship of pulmonary functions and running performance has always been a topic of debate among the fraternity of physiologists. The relationship of submaximal exercise with lactate threshold, respiratory muscle fatigue, and echocardiography has also been widely studied. But these tests are equipment and lab intensive. Aims and Objective: To study relationship between run timings for short distance and variables of pulmonary function tests (PFTs). Materials and Methods: In the present study 142 healthy males participated who were non - sedentary and non-athletically trained. They performed a 400m distance run and time taken to finish the run was recorded in seconds. These same set of subjects also underwent PFT and data was recorded as % of predicted values. Results: The recorded variables were subjected to statistical analysis and their Mean, SD, Pearsons correlation were derived. Time taken to finish 400-m run were correlated with percentage predicted values for forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEFR), FEV1/FVC, and maximal voluntary ventilation (MVV), and the r-values were obtained: - 0.12 (- 0.27 to - 0.32); - 0.15 (- 0.30 to - 0.01); - 0.09 (- 0.25 to 0.06); - 0.07 (- 0.15 to 0.06); - 0.12 (- 0.17 to 0.02), respectively. Conclusion: A negative correlation was found between the PFT variables and 400-m run finish timings. Therefore, evaluation of pulmonary functions may be used to screen potential athletes. This may also be used an additional criterion to monitor progress in level of physical fitness of selected athletes during the course of their supervised training period. [Natl J Physiol Pharm Pharmacol 2015; 5(2.000): 149-152]

Athletes and coaches may seek to improve running performance through adjustments to running form. Running form refers to the biomechanical characteristics of a runner’s movement, and can distinguish individual runners as well as groups of runners, such as long-distance and short-distance runners. Yet, in long-distance running it is still unclear whether certain running forms lead to better performance. In this study, we used a neural network to test the extent to which individual running forms, measured from foot kinematics, exist within long-distance runners and whether running forms can predict performance. To accomplish this goal, 119 participants ran on a treadmill at three different speeds and overground at a self-selected sub- maximal speed while we collected data from insole-embedded Inertial Measurement Units (IMUs) mounted in both shoes. Participants reported their personal best 10 km run times. We used these data to train the neural network to identify individual runners from their running data. Then, we trained the same neural network architecture to predict the runners’ performance. With enough data, the neural network was successful in identifying individual runners, but was comparable to a random coin flip (57 % accuracy) in predicting whether an individual runner is slow or fast. We interpret the success of the model to identify runners, but the subsequent failure of the same model to predict running performance as evidence that individual running form measured from foot kinematics contains insufficient information about a runner’s performance.

This study investigated the effects of three uphill gradients; shallow (SHG ~ 2.5%), intermediate (IHG ~ 5.1%), and steeper (STHG ~ 7.6%) on maximal velocity (Vmax), 800 m time trial (TT), and strength endurance (SE) performance in middle-distance runners. Forty moderately trained athletes (aged 16–20) were randomly assigned to SHG, IHG, STHG, or control (CG) groups ( n  = 10 each). Over 8 weeks, participants completed gradient-specific training. Vmax (30 m sprint), TT (800 m), and SE (1-min burpees) were assessed pre- and post-intervention. Two-way RM-ANOVA revealed significant main effects on Vmax (F(3,36) = 2.87, p  = .049, = 0.20), TT (F(3,36) = 7.60, p < .001, = 0.39), and SE (F(3,36) = 5.19, p = .004, = 0.30). Post-hoc analysis showed STHG significantly outperformed CG in Vmax (mΔ = 0.93, p = .040), TT (mΔ = -0.29, p  = .001), and SE (mΔ = 3.90, p  = .007). IHG also improved TT vs. CG (mΔ = − 0.25, p  = .007). The finding revealed that, uphill training, particularly steeper gradients, significantly enhances speed, endurance, and running performances. Therefore, coaches and athletes should customize training programs using uphill while carefully matching the strengths and weaknesses of the athlete and the demands of the event.

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. Key points The study provides indirect evidence of the performance-enhancing effects of advanced footwear technology, particularly for longer distances and in women. Compared to before the introduction of advanced footwear technology, the greatest gains in performance were seen in long-distance events (up to 3.5% for women and 1.4% for men) and smaller gains in sprint and middle-distance events. However, limitations of the study should be considered, such as the observational nature of the analysis and potential confounding factors such as performance-enhancing drugs.

Running performance from sprint to long distance is largely determined by the interplay between basic speed and endurance. Existing power-law, physiological, and theoretical models describe and explain the characteristic decline in pace with increasing distance. However, normative and statistically validated measures that capture both the average and variability of pace decline across standard track distances remain incomplete. To address this gap, we analysed over 14,000 race times from competitive male runners and introduce the coefficient of special endurance (KsA), a novel metric that quantifies relative pace loss between adjacent race distances, from 100/200 to 5000/10,000 m. The KsA values obtained for seven distance pairs are nearly constant over decades in national runners, show low variability, and predict race times with less than one percent. The KsA-based reference ranges allow performance to be evaluated from the international to the regional level. This provides specific insight into runners’ strengths, weaknesses and progression for individualizing training, selecting the most promising race distance, and identifying and developing talent. Overall, we provide empirically derived KsA values that serve as statistical norms for pace loss from 100 m to 10,000 m to evaluate running performance of males. The current approach should also be applicable to women, juniors, and road runners.

Our aim was to validate a sacral-mounted inertial measurement unit (IMU) for reconstructing running kinematics and comparing movement patterns within and between runners. IMU data were processed using Kalman and complementary filters separately. RMSE and Bland–Altman analysis assessed the validity of each filtering method against a motion capture system. Running data from 24 recreational runners were analyzed using Fourier transform coefficients, PCA, and k-means clustering. High agreement was found for Kalman-filtered data in the frontal, sagittal, and transverse planes, with a Bland–Altman bias of ~2 mm on average, compared to a bias of ~10.5 mm for complementary-filtered data. Pelvic angles calculated from Kalman-filtered data had superior agreement, with systematic biases of ~0.3 versus 3.4 degrees for complementary-filtered data. Our findings suggest that inertial sensors are viable alternatives to motion capture for reconstructing pelvic running kinematics and movement patterns. In the second part of our study, negligible intra-individual differences were observed with changes in speed, while inter-individual differences were large. Two clusters of runners were identified, each showing distinct movement patterns and ranges of motion. These observations highlight the potential usefulness of inertial sensors for performance analysis and rehabilitation as they may permit the use of individual-specific and cluster-specific practice programs.

The aim of the present study was to analyze the influence of time winning and time losing on position-specific match physical demands with and without ball possession in the top Spanish professional soccer league. All matches played in the First Spanish soccer league over four consecutive seasons (from 2015/16 to 2018/19) were recorded using an optical tracking system (i.e., ChyronHego), and the data were analyzed via Mediacoach®. Total distance (TD), and TD > 21 km·h−1 covered with and without ball possession were analyzed using a Linear Mixed Model, taking into account the contextual variables time winning and losing. Results showed that TD and TD > 21 km·h−1 covered by central midfielders (0.01 and 0.005 m/min, respectively), wide midfielders (0.02 and 0.01 m/min, respectively), and forwards (0.03 and 0.02 m/min, respectively) significantly increased while winning (p < 0.05). By contrast, TD and TD > 21 km·h−1 covered by central defenders (0.01 and 0.008 m/min, respectively) and wide defenders (0.06 and 0.008 m/min, respectively) significantly increased while losing (p < 0.05). In addition, for each minute that teams were winning, total distance with ball possession (TDWP) decreased, while, for each minute that teams were losing, TDWP increased. Instead, TDWP > 21 km·h−1 obtained opposite results. Total distance without ball possession increased when teams were winning, and decreased when teams were losing. Therefore, the evolution of scoreline significantly influences tactical–technical and physical demands on soccer matches.