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1.
Abstract

The aim of the present study was to examine the relationship between intensities of exercise during match-play of elite-standard soccer referees with those of the players from the same match. Match analysis data were collected (Prozone® Leeds, UK) for 18 elite-standard soccer referees (age 26–49 years) on FA Premier League matches during the 2008/09 English FA Premier League season (236 observations). Running categories for referees and players were as follows: total distance covered (m); high-speed running distance (speed >19.8 km · h?1); and sprinting distance (speed >25.2 km · h?1). Analysis of the distance–time regression coefficients revealed no differences between the referees' and players' within-match rates of change for total distance covered (?0.594 ± 0.394 vs. ?0.713 ± 0.269 m · min?1; P = 0.104), high-speed running (?0.039 ± 0.077 vs. ?0.059 ± 0.030 m · min?1; P = 0.199), and sprinting (?0.003 ± 0.039 vs. ?0.021 ± 0.017 m · min?1; P = 0.114). In addition, there were no differences between across-season rates of change for total distance (–26.756 ± 40.434 vs. ?20.031 ± 25.502 m per match day; P = 0.439) and sprinting (–9.662 ± 7.564 vs. ?8.589 ± 4.351 m per match day; P = 0.542). These results show that elite-standard soccer referees' intensities of exercise during match-play are interrelated with those of the players and thus demonstrate that referees are able to keep pace with the players during FA Premier League matches.  相似文献   

2.
Abstract

The aim of this study was to assess the validity (Study 1) and reliability (Study 2) of a novel intermittent running test (Carminatti's test) for physiological assessment of soccer players. In Study 1, 28 players performed Carminatti's test, a repeated sprint ability test, and an intermittent treadmill test. In Study 2, 24 players performed Carminatti's test twice within 72 h to determine test–retest reliability. Carminatti's test required the participants to complete repeated bouts of 5 × 12 s shuttle running at progressively faster speeds until volitional exhaustion. The 12 s bouts were separated by 6 s recovery periods, making each stage 90 s in duration. The initial running distance was set at 15 m and was increased by 1 m at each stage (90 s). The repeated sprint ability test required the participants to perform 7 × 34.2 m maximal effort sprints separated by 25 s recovery. During the intermittent treadmill test, the initial velocity of 9.0 km · h?1 was increased by 1.2 km · h?1 every 3 min until volitional exhaustion. No significant difference (P > 0.05) was observed between Carminatti's test peak running velocity and speed at VO2max (v-VO2max). Peak running velocity in Carminatti's test was strongly correlated with v-VO2max (r = 0.74, P < 0.01), and highly associated with velocity at the onset of blood lactate accumulation (r = 0.63, P < 0.01). Mean sprint time was strongly associated with peak running velocity in Carminatti's test (r = ?0.71, P < 0.01). The intraclass correlation was 0.94 with a coefficient of variation of 1.4%. In conclusion, Carminatti's test appears to be avalid and reliable measure of physical fitness and of the ability to perform intermittent high-intensity exercise in soccer players.  相似文献   

3.
ABSTRACT

Purpose: The association between an overlooked classical Lactate Threshold (LT), named “Minimum Lactate Equivalent” (LEmin), with Maximal Lactate Steady State (MLSS) has been recently described with good MLSS prediction results in endurance-trained runners. This study aimed to determine the applicability of LEmin to predict MLSS in lower aerobic-conditioned individuals compared to well-established blood lactate-related thresholds (BLTs). Method: Fifteen soccer players [velocity at MLSS (MLSSV) 13.2 ± 1.0 km·h?1; coefficient of variation (CV) 7.6%] conducted a submaximal discontinuous incremental running test to determine BLTs and 3–6 constant velocity running tests to determine MLSSV. Results: LEmin did not differ from conventional LTs (p > .05) and was 24% lower than MLSS (p < .001; ES: 3.26). Among LTs, LEmin best predicted MLSSV (r = 0.83; p < .001; SEE = 0.59 km·h?1). There was no statistical difference between MLSS and estimated MLSS using LEmin prediction formula (p = .99; ES: 0.001). Mean bias and limits of agreement were 0.00 ± 0.58 km·h?1 and ±1.13 km·h?1, respectively. LEmin best predicted MLSSV (r = 0.92; p < .001; SEE = 0.54 km·h?1) in the pooled data of soccer players and endurance-trained runners of the previous study (n = 28; MLSSV range 11.2–16.5 km·h?1; CV 9.8%). Conclusion: Results support LEmin to be one of the best single predictors of MLSS. This study is the sole study providing specific operational regression equations to estimate the impractical gold standard MLSSV in soccer players by means of a BLT measured during a submaximal single-session test.  相似文献   

4.
Abstract

As with other match analysis systems, ProZone® uses an absolute speed threshold to identify running speeds at “high-intensity”. In this study, we examined the use of an individualized high-intensity speed threshold based on the speed at the second ventilatory threshold (VT2speed) for assessment of the distance run at high-intensity during matches. Ten professional soccer players completed a maximal treadmill test to determine VT2speed. Match data were identified by means of the ProZone® match analysis system. The distances run at high-intensity during matches were calculated using the default value (19.8 km · h?1) and VT2speed. Differences between VT2speed and the default were analysed using a non-parametric median sign test. The distances run at high-intensity were compared with a paired t-test. The median VT2speed was 15 km · h?1 (range 14–16 km · h?1), which was less than the default (P < 0.01). Mean distance run at high-intensity based on the default and VT2speed was 845 m (s = 296) and 2258 m (s = 707), respectively [mean difference 1413 m; P < 0.001 (95% CI: 1037–1789 m)]. The high-intensity running speeds based on the second ventilatory threshold are substantially less than that used as the default within the ProZone® match analysis system, thus the distance run at high-intensity can be substantially underestimated.  相似文献   

5.
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6.
Abstract

In this study, we investigated the age-related differences in repeated-sprint ability and blood lactate responses in 134 youth football players. Players from the development programme of a professional club were grouped according to their respective under-age team (U-11 to U-18). Following familiarization, the participants performed a repeated-sprint ability test [6 × 30-m sprints 30 s apart, with active recovery (2.0–2.2 m · s?1) between sprints]. The test variables were total time, percent sprint decrement, and post-test peak lactate concentration. Total time improved from the U-11 to U-15 age groups (range 33.15 ± 1.84 vs. 27.25 ± 0.82 s), whereas no further significant improvements were evident from U-15 to U-18. No significant differences in percent sprint decrement were reported among groups (range 4.0 ± 1.0% to 5.5 ± 2.1%). Post-test peak lactate increased from one age group to the next (range 7.3 ± 1.8 to 12.6 ± 1.6 mmol · l?1), but remained constant when adjusted for age-related difference in body mass. Peak lactate concentration was moderately correlated with sprint time (r = 0.70, P > 0.001). Our results suggest that performance in repeated-sprint ability improves during maturation of highly trained youth football players, although a plateau occurs from 15 years of age. In contrast to expectations based on previous suggestions, percent sprint decrement during repeated sprints did not deteriorate with age.  相似文献   

7.
Abstract

This study examined the influence of the regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and the endurance performance. Sixteen non-competitive, recreational female runners performed a discontinuous incremental treadmill test. The initial speed was set at 7 km · h?1, and increased every 3 min by 1 km · h?1 with a 30-s rest between the stages used for earlobe capillary blood sample collection. Lactate-speed data were fitted by an exponential-plus-constant and a third-order polynomial equation. The lactate threshold was determined for both regression equations, using all the coordinates, excluding the first and excluding the first and second initial points. Mean speed of a 10-km road race was the performance index (3.04 ± 0.22 m · s?1). The exponentially-derived lactate threshold had a higher correlation (0.98 ≤ r ≤ 0.99) and smaller standard error of estimate (SEE) (0.04 ≤ SEE ≤ 0.05 m · s?1) with performance than the polynomially-derived equivalent (0.83 ≤ r ≤ 0.89; 0.10 ≤ SEE ≤ 0.13 m · s?1). The exponential lactate threshold was greater than the polynomial equivalent (P < 0.05). The results suggest that the exponential lactate threshold is a valid performance index that is independent of the initial intensity of the incremental test and better than the polynomial equivalent.  相似文献   

8.
Purpose: Correlations between fatigue-induced changes in exercise performance and maximal rate of heart rate (HR) increase (rHRI) may be affected by exercise intensity during assessment. This study evaluated the sensitivity of rHRI for tracking performance when assessed at varying exercise intensities. Method: Performance (time to complete a 5-km treadmill time-trial [5TTT]) and rHRI were assessed in 15 male runners following 1 week of light training, 2 weeks of heavy training (HT), and a 10-day taper (T). Maximal rate of HR increase (measured in bpm·s?1) was the first derivative maximum of a sigmoidal curve fit to HR data recorded during 5 min of running at 8 km·h?1 (rHRI8km·h?1), and during subsequent transition to 13 km·h?1 (rHRI8–13km·h?1) for a further 5 min. Results: Time to complete a 5-km treadmill time-trial was likely slower following HT (effect size ± 90% confidence interval = 0.16 ± 0.06), and almost certainly faster following T (–0.34 ± 0.08). Maximal rate of HR increase during 5 min of running at 8 km·h?1 and rHRI8–13km·h?1 were unchanged following HT and likely increased following T (0.77 ± 0.45 and 0.66 ± 0.62, respectively). A moderate within-individual correlation was found between 5TTT and rHRI8km·h?1 (r value ± 90% confidence interval = –.35 ± .32). However, in a subgroup of athletes (n = 7) who were almost certainly slower to complete the 5TTT (4.22 ± 0.88), larger correlations were found between the 5TTT and rHRI8km·h?1 (r = –.84 ± .22) and rHRI8–13km·h?1 (r = –.52 ± .41). Steady-state HR during rHRI assessment in this group was very likely greater than in the faster subgroup (≥ 1.34 ± 0.86). Conclusion(s): The 5TTT performance was tracked by both rHRI8km·h?1 and rHRI8–13km·h?1. Correlations between rHRI and performance were stronger in a subgroup of athletes who exhibited a slower 5TTT. Individualized workloads during rHRI assessment may be required to account for varying levels of physical conditioning.  相似文献   

9.
Abstract The aim of this study was to determine sprint profiles of professional female soccer players and evaluate how various speed thresholds impact those outcomes. Seventy-one professional players competing in full matches were assessed repeatedly during 12 regular season matches using a Global Positioning System (GPS). Locomotion ≥18?km?·?h(-1) was defined as sprinting and each event was classified into: Zone 1: 18.0-20.9?km· h(-1); Zone 2: 21.0-22.9?km?·?h(-1); Zone 3: 23.0-24.9?km?·?h(-1) and Zone 4: >25?km?·?h(-1). Outcomes included: duration (s), distance (m), maximum speed (km?·?h(-1)), duration since previous sprint (min) and proportion of total sprint distance. In total 5,019 events were analysed from 139 player-matches. Mean sprint duration, distance, maximum speed and time between sprints were 2.3?±?1.5?s, 15.1?±?9.4?m, 21.8?±?2.3?km· h(-1), and 2.5?±?2.5?min, respectively. Mean sprint distances were 657?±?157, 447?±?185, and 545?±?217?m for forwards, midfielders and defenders, respectively (P?≤?0.046). Midfielders had shorter sprint duration (P = 0.023), distance (P?≤?0.003) and maximum speed (P?相似文献   

10.
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11.
Abstract

The aim of this study was to assess the extent to which measures derived from the new FIFA referees’ fitness tests can be used to monitor a referee's match-related physical capacity. Match-analysis data were collected (Prozone®, Leeds, UK) from 17 soccer referees for 5.0 (s = 1.7) FA Premier League matches per referee during the first 4 months of the 2007–08 season. Physical match performance categories included total distance covered, high-intensity running distance (speed >5.5 m · s?1), and sprinting distance (>7.0 m · s?1). The two tests were a 6 × 40-m sprint test and a 150-m interval test. Heart rate demand was correlated with total match distance covered (r = ?0.70, P = 0.002) and high-intensity running (r = ?0.57, P = 0.018) in the interval test. The fastest 40-m sprint was related to total distance covered (r = ?0.69, P = 0.002), high-intensity running (r = ?0.76, P < 0.001), and sprinting distance (r = ?0.75, P = 0.001), while mean time for the 40-m sprints was related to total distance covered (r = ?0.70, P = 0.002), high-intensity running (r = ?0.77, P < 0.001), and sprinting distance (r = ?0.77, P < 0.001). The referees who recorded the best interval-test heart rate demand and fastest 40-m time produced the best physical match performances. However, only the sprint test and in particular the fastest 40-m time had appropriate construct validity for the physical assessment of soccer referees.  相似文献   

12.
Abstract

Twenty-four players from the 1st/2nd (elite) and 24 players from the 3rd/4th (non-elite) university football teams were recruited to evaluate the Loughborough Soccer Passing Test (LSPT) and Loughborough Soccer Shooting Test (LSST) as tools to assess soccer skill. The LSPT requires players to complete 16 passes as quickly as possible. The LSST requires players to pass, control, and shoot the ball to targets on a full-sized goal. Participants completed two main trials each separated by at least one day. During both trials, the participants were given practice efforts before recording the mean of the next two (LSPT) or 10 (LSST) attempts as the performance score. For the LSPT, the mean time taken, added penalty time, and overall performance time were less in the elite players (elite: 43.6 s, s = 3.8; non-elite: 52.5 s, s = 7.4; P = 0.0001). For the LSST, there was no difference in the mean points scored per shot between groups (elite: 1.34, s = 0.46; non-elite: 1.28, s = 0.53). However, the elite players had higher mean shot speed (elite: 80 km · h?1, s = 4.5; non-elite: 74 km · h?1, s = 4.2; P < 0.0001) and performed each shot sequence faster (elite: 7.87 s, s = 0.29; non-elite: 8.07 s, s = 0.35; P = 0.037) than the non-elite players. Performance on both tests was more repeatable in elite players. In conclusion, the LSPT and LSST are valid and reliable protocols to assess differences in soccer skill performance.  相似文献   

13.
This investigation assessed whether prior heavy resistance exercise would improve the repeated sprint performance of 16 trained youth soccer players (Age 17.05 ± 0.65 years; height 182.6 ± 8.9 cm; body mass 77.8 ± 8.2 kg). In session 1, individual 1 repetition max was measured utilising a squat movement. In sessions 2 and 3, participants performed a running-based repeated anaerobic sprint test with and without prior heavy resistance exercise of 91% of their 1 repetition max. Times were recorded for each of the 6 sprints performed in the repeated sprint test and summed to provide total time. T-tests compared the two exercise conditions via differences in corresponding sprint times and total time. Analysis revealed significantly reduced total time with use of heavy resistance exercise (33.48 (±1.27) vs. 33.59 (±1.27); P = 0.01). Sprints 1 (P = 0.05) and 2 (P = 0.02) were also faster in the heavy resistance exercise condition (5.09 (±0.16) vs. 5.11 (±0.16) and 5.36 (±0.24) vs. 5.45 (±0.26) seconds respectively) although no other differences were shown. Findings demonstrate improved sprint times of trained adolescent soccer players after heavy resistance exercise although benefits appear not as sustained as in adult participants.  相似文献   

14.
Abstract

The aim of the present study was to compare, in 36 highly trained under-15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n = 115 player-files). Total distance and distance covered >16 km h–1 (D > 16 km h?1) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen’s d for MSS: 0.5–1.0, likely to almost certain) and match running performances (D > 16 km h?1: 0.2–0.5, possibly to likely) than their younger, less mature and/or smaller teammates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures versus match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players’ maturity status when assessing their on-field playing performance.  相似文献   

15.
Abstract

The aims of this study were twofold: (1) to characterize repeated high-intensity movement activity profiles of a professional soccer team in official match-play; and (2) to inform and verify the construct validity of tests commonly used to determine repeated-sprint ability in soccer by investigating the relationship between the results from a test of repeated-sprint ability and repeated high-intensity performance in competition. High-intensity running performance (movement at velocities >19.8 km · h?1 for a minimum of 1 s duration) was measured in 20 players using computerized time–motion analysis. Performance in 80 French League 1 matches was analysed. In addition, 12 of the 20 players performed a repeated-sprint test on a non-motorized treadmill consisting of six consecutive 6 s sprints separated by 20 s passive recovery intervals. In all players, most consecutive high-intensity actions in competition were performed after recovery durations ≥61 s, recovery activity separating these efforts was generally active in nature with the major part of this spent walking, and players performed 1.1 ± 1.1 repeated high-intensity bouts (a minimum of three consecutive high-intensity bouts with a mean recovery time ≤20 s separating efforts) per game. Players reporting lowest performance decrements in the repeated-sprint ability test performed more high-intensity actions interspersed by short recovery times (≤20 s, P < 0.01 and ≤30 s, P < 0.05) compared with those with higher decrements. Across positional roles, central-midfielders performed more high-intensity actions separated by short recovery times (≤20 s) and spent a larger proportion of time running at higher intensities during recovery periods, while fullbacks performed the most repeated high-intensity bouts (statistical differences across positional roles from P < 0.05 to P < 0.001). These findings have implications for repeated high-intensity testing and physical conditioning regimens.  相似文献   

16.
Abstract

Movement patterns in elite men’s soccer have been reported in depth, but less research exists for women’s soccer. Aims of the study were to identify the movement profiles of elite women soccer players in international competition and examine the effect the level of opposition, based on Federation Internationale de Football Association (FIFA) rankings, had on the physical demands of the game. MinimaxX athlete tracking devices were used by 15 players during 13 international matches against opponent teams of varying ability. Total distance covered averaged 9292 ± 175 m. There was a decrease in high-intensity running (HIR) in the 60- to 75-min and 75- to 90-min periods compared to the 0- to 15-min period of 22.4% and 26.1%, respectively (P = 0.022, P = 0.004) although sprint distances remained unchanged across game periods. HIR distances covered were significantly greater for midfielders versus defenders, while defenders had lower sprinting compared to both midfielders and attackers. Stronger opponents elicited less HIR and greater low-speed activity (LSA) compared to playing teams of similar or lower ranking. These results are important to coaches to prepare players for international competition and show the differing demands required depending on the ability of the opponents.  相似文献   

17.
The aim of this study was to determine whether gait cycle characteristics are associated with running economy in elite Kenyan runners. Fifteen elite Kenyan male runners completed two constant-speed running sets on a treadmill (12 km ·h?1 and 20 km ·h?1). VO2 and respiratory exchange ratio values were measured to calculate steady-state oxygen and energy cost of running. Gait cycle characteristics and ground contact forces were measured at each speed. Oxygen cost of running at different velocities was 192.2 ± 14.7 ml· kg?1· km?1 at 12 km· h?1 and 184.8 ± 9.9 ml· kg?1· km?1 at 20 km· h?1, which corresponded to a caloric cost of running of 0.94 ± 0.07 kcal ·kg?1·km?1 and 0.93 ± 0.07 kcal· kg?1· km?1. We found no significant correlations between oxygen and energy cost of running and biomechanical variables and ground reaction forces at either 12 or 20 km· h?1. However, ground contact times were ~10.0% shorter (very large effect) than in previously published literature in elite runners at similar speeds, alongside an 8.9% lower oxygen cost (very large effect). These results provide evidence to hypothesise that the short ground contact times may contribute to the exceptional running economy of Kenyan runners.  相似文献   

18.
Abstract

Low energy availability [(energy intake – exercise expenditure)/kg lean body mass], a component of the Female Athlete Triad, has been associated with menstrual disturbances and low bone mass. No studies have examined the energy availability of athletes across a season. The purpose of this study was to assess the prevalence of, and what contributes to, low energy availability in Division I female soccer players across a season. Nineteen participants aged 18–21 years (mean [Vdot]O2max: 57.0 ± 1.0 mL · kg?1 · min?1) were studied during the pre, mid, and post season. Mean energy availability was overall lowest at mid season, and lower at mid than post season (35.2 ± 3.7 vs. 44.5 ± 3.7 kcal · kg?1 lean body mass, P = 0.009). Low energy availability (<30 kcal · kg?1 lean body mass) was observed in 5/19 (26.3%), 5/15 (33.3%), and 2/17 (11.8%) of participants during the pre, mid, and post season. Dietary energy intake was lower mid (P = 0.008) and post season (P = 0.022) than it was pre season (pre: 2794 ± 233 kcal · day?1; mid: 2208 ± 156 kcal · day?1; post: 2161 ± 143 kcal · day?1). Exercise energy expenditure decreased significantly (P ≤ 0.001) over time (pre: 819 ± 57 kcal · day?1; mid: 642 ± 26 kcal · day?1; post: 159 ± 28 kcal · day?1). Low energy availability was due to lower dietary energy intake at lunch during pre season (P = 0.014) and during lunch and dinner during mid season (P ≤ 0.030). Energy availability was inversely related to body dissatisfaction (r = ?0.62, P = 0.017) and drive for thinness (r = ?0.55, P = 0.041) during mid season. Although most Division I female soccer players are not at risk for low energy availability, a concerning proportion exhibited low energy availability at pre or mid season. Further studies are needed to explore strategies to prevent and monitor low energy availability in these athletes.  相似文献   

19.
The purpose of this study was to ascertain the typical metabolic power characteristics of elite men’s hockey, and whether changes occur within matches and throughout an international tournament. National team players (n = 16), divided into 3 positional groups (strikers, midfielders, defenders), wore Global Positioning System devices in 6 matches. Energetic (metabolic power, energy expenditure) and displacement (distance, speed, acceleration) variables were determined, and intensity was classified utilising speed, acceleration and metabolic power thresholds. Midfielder’s average metabolic power (11.8 ± 1.0 W · kg?1) was similar to strikers (11.1 ± 1.3 W · kg?1) and higher than defenders (10.8 ± 1.2 W · kg?1, P = 0.001). Strikers (29.71 ± 3.39 kJ · kg?1) expended less energy than midfielders (32.18 ± 2.67 kJ · kg?1, P = 0.014) and defenders (33.23 ± 3.96 kJ · kg?1, P < 0.001). Energetic variables did not change between halves or across matches. Across all positions, over 45% of energy expenditure was at high intensity (>20 W · kg?1). International hockey matches are intense and highly intermittent; however, intensity is maintained throughout matches and over a tournament. In isolation, displacement measures underestimate the amount of high-intensity activity, whereas the integration of instantaneous speed and acceleration provides a more comprehensive assessment of the demands for variable-speed activity typically occurring in hockey matches.  相似文献   

20.
Muscle glycogen is the predominant energy source for soccer match play, though its importance for soccer training (where lower loads are observed) is not well known. In an attempt to better inform carbohydrate (CHO) guidelines, we quantified training load in English Premier League soccer players (n = 12) during a one-, two- and three-game week schedule (weekly training frequency was four, four and two, respectively). In a one-game week, training load was progressively reduced (P < 0.05) in 3 days prior to match day (total distance = 5223 ± 406, 3097 ± 149 and 2912 ± 192 m for day 1, 2 and 3, respectively). Whilst daily training load and periodisation was similar in the one- and two-game weeks, total accumulative distance (inclusive of both match and training load) was higher in a two-game week (32.5 ± 4.1 km) versus one-game week (25.9 ± 2 km). In contrast, daily training total distance was lower in the three-game week (2422 ± 251 m) versus the one- and two-game weeks, though accumulative weekly distance was highest in this week (35.5 ± 2.4 km) and more time (P < 0.05) was spent in speed zones >14.4 km · h?1 (14%, 18% and 23% in the one-, two- and three-game weeks, respectively). Considering that high CHO availability improves physical match performance but high CHO availability attenuates molecular pathways regulating training adaptation (especially considering the low daily customary loads reported here, e.g., 3–5 km per day), we suggest daily CHO intake should be periodised according to weekly training and match schedules.  相似文献   

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