High-intensity Running Ability Research Articles

Physical and Physiological Demands of Amateur Portuguese Field and Assistant Football Referees.

Referees are crucial elements in football, and they must meet the physical and physiological demands each match poses to them. The aim is to analyse the physical and physiological demands of amateur referees in games at the regional level (4th division), examining the differences between the first and second halves and between assistant (age: 25.10 ± 4.97) and main referees (age: 25.65 ± 5.12). A total of 29 matches were analysed with GPS devices, and internal and external load metrics were analysed. Overall, main referees, due to their central role in game management, showed higher levels of physical and physiological load than assistant referees, with more high-intensity activities, greater distance covered and higher heart rate. The results also revealed that there were no differences between the halves for total distance covered for either the main or assistant referees. However, the main referees covered a greater distance in high-intensity running during the first half (p = 0.05; d = 0.389). These findings emphasise the importance of tailored training protocols to enhance performance and reduce fatigue-related errors, highlighting the significance of endurance, high-intensity running ability, and strategies to manage transient fatigue in referee preparation.

Physical Fitness Tests as Predictors of High-Intensity Running Performance in Rugby.

Understanding the physical fitness elements that influence high-intensity running ability during rugby matches is crucial for optimizing player performance and developing effective training strategies. In this study, we aimed to investigate the relationships between various physical fitness components and high-intensity running ability in rugby. For this purpose, 60 Japanese university rugby players were randomized into four groups and two matches were played. The participants were monitored in two matches, and their running abilities were assessed using GPS sensors. The running time was divided into three running velocity categories: distance run at ≤5.4 km/h (low-intensity running); distance run at 5.5~17.9 km/h (medium-intensity running), and distance run at ≥18.0 km/h ≤(high-intensity running) and backs and forwards were evaluated separately. To determine which physical fitness test is more predictive of performance, we decided to correlate several physical test performances with the running time intensities during the matches. Independently of the position, the high-intensity running time correlated with the repeated sprint ability (RSA) and the 40 m sprint speed. The results suggest that RSA measured in the field is the most important high-intensity running ability predictor during a match for both positions.

Changes in anthropometric and fitness profile of Italian regional academy rugby union players.

In rugby union, physical characteristics may partially contribute to long-term career progression, especially during adolescence. Therefore, the primary purpose of the study was to evaluate Italian regional rugby union academy players’ (i.e., under-18) anthropometric and physical characteristics during a competitive season. Body mass, height, upper- and lower-body maximal strength, sprint, and high-intensity running ability were assessed in 29 elite players (backs, n = 13, forwards, n = 16). A mixed-design analysis of variance (ANOVA) for repeated measures showed that backs were shorter (ES = 0.59), lighter (ES = 0.94), stronger relative to body mass (bench press; ES = 0.60; deadlift; ES = 0.63; clean ES = 0.63; rowing ES = 0.67), and fitter (shuttle run max; ES = 0.38; shuttle run tot; ES = 0.79) than forwards. However, the forwards achieved greater sprint momentum (initial sprint momentum; ES = 0.97; maximal sprint momentum; ES = 0.98). During the season, players changed in stature, upper-body maximal strength, jumping, and high intensity running (p < 0.05), but not in body weight or lower-body maximal strength (p > 0.05). Maximal strength improved in the first part of the season, whereas jumping and sprinting performances increased in the last part of the season. Therefore, these findings highlight the importance of regularly monitoring the physical development in a long-term perspective, even suggesting that physiological adaptations are heterochronic between positional roles.

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.

The Influence of Rotations on Match Running Performance in Female Australian Football Midfielders.

With female Australian football (AF) gaining popularity, understanding match demands is becoming increasingly important. The aim of this study was to compare running performances of rotated and whole-quarter state-level female AF players during match quarters. Twenty-two state-level female AF midfielders wore Global Positioning System units during 14 games to evaluate activity profiles. The Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) was used as a measure of high-intensity running ability. Data were categorized into whole quarter, rotation bout 1, and rotation bout 2 before being further divided into quartiles. Players were separated into high- or low-Yo-Yo IR1 groups using a median split based on their Yo-Yo IR1 performance. Short (4-6 min), moderate (6-12 min), and long (12-18 min) on-field bout activity profiles were compared with whole-quarter players. High Yo-Yo IR1 performance allowed players to cover greater relative distances (ES = 0.57-0.88) and high-speed distances (ES = 0.57-0.86) during rotations. No differences were reported between Yo-Yo IR1 groups when players were required to play whole quarters (ES ≤ 0.26, likelihood ≤64%). Players who were on field for short to moderate durations exhibited greater activity profiles than whole-quarter players. Superior high-speed running ability results in a greater activity profile than for players who possess lower high-speed running ability. The findings also highlight the importance of short to moderate (4-12 min) rotation periods and may be used to increase high-intensity running performance within quarters in female AF players.

Anthropometric, Sprint, and High-Intensity Running Profiles of English Academy Rugby Union Players by Position.

The purpose of this study was to evaluate the anthropometric, sprint, and high-intensity running profiles of English academy rugby union players by playing positions, and to investigate the relationships between anthropometric, sprint, and high-intensity running characteristics. Data were collected from 67 academy players after the off-season period and consisted of anthropometric (height, body mass, sum of 8 skinfolds [∑SF]), 40-m linear sprint (5-, 10-, 20-, and 40-m splits), the Yo-Yo intermittent recovery test level 1 (Yo-Yo IRTL-1), and the 30-15 intermittent fitness test (30-15 IFT). Forwards displayed greater stature, body mass, and ∑SF; sprint times and sprint momentum, with lower high-intensity running ability and sprint velocities than backs. Comparisons between age categories demonstrated body mass and sprint momentum to have the largest differences at consecutive age categories for forwards and backs; whereas 20-40-m sprint velocity was discriminate for forwards between under 16s, 18s, and 21s. Relationships between anthropometric, sprint velocity, momentum, and high-intensity running ability demonstrated body mass to negatively impact on sprint velocity (10 m; r = -0.34 to -0.46) and positively affect sprint momentum (e.g., 5 m; r = 0.85-0.93), with large to very large negative relationships with the Yo-Yo IRTL-1 (r = -0.65 to -0.74) and 30-15 IFT (r = -0.59 to -0.79). These findings suggest that there are distinct anthropometric, sprint, and high-intensity running ability differences between and within positions in junior rugby union players. The development of sprint and high-intensity running ability may be impacted by continued increases in body mass as there seems to be a trade-off between momentum, velocity, and the ability to complete high-intensity running.

Match demands of professional rugby football codes: A review from 2008 to 2015

Rugby football codes have continually increased in popularity and are played professionally around the world at domestic, national and international level. Coaching professionals can use the findings of this review to guide training practices for the professional rugby football player, particularly those players who may be competing concurrently or transferring between codes. The development of repeated high-intensity exercise ability should be a key emphasis of training programmes especially for players who are aiming to compete at higher competition standards. Importantly, there are considerable differences in repeated high-intensity exercise demands of match-play for different positional groups. For greatest transference to match performance, training programs should replicate the frequency and duration of repeated high-intensity exercise bouts in addition to the relative contribution of high-intensity running, tackling and physical collisions. Training programmes should not neglect developing players’ prolonged high-intensity running ability as high-speed running efforts may occur separately from repeated high-intensity exercise bouts and likely place considerable demands on rugby football players, particularly in rugby sevens competition. Rugby football players have been shown to experience transient fatigue patterns during match-play where teams may be susceptible to conceding points or sustaining injury. Improved physical conditioning strategies may reduce development of match-fatigue; however, research is yet to investigate the influence of fitness levels and team strategies. A better understanding of these factors and how they interact with match-fatigue will assist with the improvement of training practices for professional rugby football players.

μ-Crystallin controls muscle function through thyroid hormone action.

μ-Crystallin (Crym), a thyroid hormone-binding protein, is abnormally up-regulated in the muscles of patients with facioscapulohumeral muscular dystrophy, a dominantly inherited progressive myopathy. However, the physiologic function of Crym in skeletal muscle remains to be elucidated. In this study, Crym was preferentially expressed in skeletal muscle throughout the body. Crym-knockout mice exhibited a significant hypertrophy of fast-twitch glycolytic type IIb fibers, causing an increase in grip strength and high intensity running ability in Crym-null mice. Genetic inactivation of Crym or blockade of Crym by siRNA-mediated knockdown up-regulated the gene expression of fast-glycolytic contractile fibers in satellite cell-derived myotubes in vitro These alterations in Crym-inactivated muscle were rescued by inhibition of thyroid hormone, even though Crym is a positive regulator of thyroid hormone action in nonmuscle cells. The results demonstrated that Crym is a crucial regulator of muscle plasticity, controlling metabolic and contractile properties of myofibers, and thus the selective inactivation of Crym may be a potential therapeutic target for muscle-wasting diseases, such as muscular dystrophies and age-related sarcopenia.-Seko, D., Ogawa, S., Li, T.-S., Taimura, A., Ono, Y. μ-Crystallin controls muscle function through thyroid hormone action.

Influence of physical qualities on post-match fatigue in rugby league players

This study examined the influence of physical qualities on markers of fatigue and muscle damage following rugby league match-play. Between subjects design. Twenty-one male youth rugby league players (age 19.2 ± 0.7 years; height 180.7 ± 5.6 cm; body mass 89.9 ± 10.0 kg) participated in the study. Yo-Yo intermittent recovery test (level 1), 3 repetition maximum back squat and bench press were assessed prior to 2 competitive fixtures. Neuromuscular fatigue (countermovement jump [CMJ] and plyometric push-up [PP]), and blood creatine kinase (CK) were assessed before and after match-play. During match-play, movements were recorded using microtechnology. Players were divided into high- and low-groups based on physical qualities. High Yo-Yo and squat performance resulted in greater loads during match-play (p<0.05). There were larger reductions in CMJ power in the low Yo-Yo group at both 24 (ES=-1.83), and 48 h post-match (ES=-1.33). Despite greater internal and external match loads, changes in CMJ power were similar between squat groups. There were larger increases in blood CK in the low Yo-Yo group at 24 (73% vs. 176%; ES=1.50) and 48 h post-match (28% vs. 80%; ES=1.22). Despite greater contact loads, the high squat group exhibited smaller changes in blood CK post-match (ES=0.25-0.39). Post-match fatigue is lower in players with well-developed high-intensity running ability, and lower body strength, despite these players having greater internal and external match loads.

Relationship Between Tests of Physical Qualities and Physical Match Performance in Elite Rugby League Players

Previous investigators have reported significant relationships between tests of physical qualities and physical match performance in high-intensity, intermittent team sport (e.g., soccer) players. Although rugby league requires competitors to perform high-intensity running, unlike most other high-intensity intermittent team sports, the physical demands are significantly increased through the large amounts of tackling, wrestling, and grappling that players are required to perform during match play. This study investigated the relationship between tests of physical qualities and match performance in professional rugby league players and determined whether running capacities were associated with the collision and repeated high-intensity effort demands of match play. Thirty-eight elite rugby league players (mean ± SD, age, 23.1 ± 2.7 years) performed tests of repeated sprint ability (12 × 20-m sprints on a 20-second cycle), prolonged high-intensity intermittent running ability (8 × 12-second shuttle sprints on a 48-second cycle), and estimated maximal aerobic power (VO2max) (multistage fitness test). Global positioning system data were collected during 16 professional rugby league matches. Players with better, prolonged, high-intensity intermittent running ability covered greater total distance and greater distance in high-speed running during match play. However, inconsistent relationships were found between tests of running abilities and other match performance variables, with prolonged high-intensity running ability (negative), VO2max (positive), and repeated-sprint ability (no relationship) differentially associated with the total number of collisions and repeated high-intensity effort bouts performed in competition. These findings demonstrate the importance of prolonged high-intensity running ability to the match running performance of elite rugby league players but also highlight the need for game-specific conditioning to prepare players for the high-intensity collision and repeated-effort demands of the game.