We compared the accuracy of 2 GPS systems with different sampling rates for the determination of distances covered at high-speed and metabolic power derived from a combination of running speed and acceleration. 8 participants performed 56 bouts of shuttle intermittent running wearing 2 portable GPS devices (SPI-Pro, GPS-5?Hz and MinimaxX, GPS-10?Hz). The GPS systems were compared with a radar system as a criterion measure. The variables investigated were: total distance (TD), high-speed distance (HSR>4.17?m·s(-1)), very high-speed distance (VHSR>5.56?m·s(-1)), mean power (Pmean), high metabolic power (HMP>20?W·kg(-1)) and very high metabolic power (VHMP>25?W·kg(-1)). GPS-5?Hz had low error for TD (2.8%) and Pmean (4.5%), while the errors for the other variables ranged from moderate to high (7.5-23.2%). GPS-10?Hz demonstrated a low error for TD (1.9%), HSR (4.7%), Pmean (2.4%) and HMP (4.5%), whereas the errors for VHSR (10.5%) and VHMP (6.2%) were moderate. In general, GPS accuracy increased with a higher sampling rate, but decreased with increasing speed of movement. Both systems could be used for calculating TD and Pmean, but they cannot be used interchangeably. Only GPS-10?Hz demonstrated a sufficient level of accuracy for quantifying distance covered at higher speeds or time spent at very high power.
To quantify the seasonal training load completed by professional soccer players of the English Premier League.
Thirty players were sampled (using GPS, heart rate, and rating of perceived exertion [RPE]) during the daily training sessions of the 2011-12 preseason and in-season period. Preseason data were analyzed across 6×1-wk microcycles. In-season data were analyzed across 6×6-wk mesocycle blocks and 3×1-wk microcycles at start, midpoint, and end-time points. Data were also analyzed with respect to number of days before a match.
Typical daily training load (ie, total distance, high-speed distance, percent maximal heart rate [%HRmax], RPE load) did not differ during each week of the preseason phase. However, daily total distance covered was 1304 (95% CI 434-2174) m greater in the 1st mesocycle than in the 6th. %HRmax values were also greater (3.3%, 1.3-5.4%) in the 3rd mesocycle than in the first. Furthermore, training load was lower on the day before match (MD-1) than 2 (MD-2) to 5 (MD-5) d before a match, although no difference was apparent between these latter time points.
The authors provide the 1st report of seasonal training load in elite soccer players and observed that periodization of training load was typically confined to MD-1 (regardless of mesocycle), whereas no differences were apparent during MD-2 to MD-5. Future studies should evaluate whether this loading and periodization are facilitative of optimal training adaptations and match-day performance.
The aim of the current study was to identify the external-training-load markers that are most influential on session rating of perceived exertion (RPE) of training load (RPE-TL) during elite soccer training.
Twenty-two elite players competing in the English Premier League were monitored. Training-load data (RPE and 10-Hz GPS integrated with a 100-Hz accelerometer) were collected during 1892 individual training sessions over an entire in-season competitive period. Expert knowledge and a collinearity r < .5 were used initially to select the external training variables for the final analysis. A multivariate-adjusted within-subjects model was employed to quantify the correlations of RPE and RPE-TL (RPE × duration) with various measures of external training intensity and training load.
Total high-speed-running (HSR; >14.4 km/h) distance and number of impacts and accelerations >3 m/s2 remained in the final multivariate model (P < .001). The adjusted correlations with RPE were r = .14, r = .09, and r = .25 for HSR, impacts, and accelerations, respectively. For RPE-TL, the correlations were r = .11, r = .45, and r = .37, respectively.
The external-load measures that were found to be moderately predictive of RPE-TL in soccer training were HSR distance and the number of impacts and accelerations. These findings provide new evidence to support the use of RPE-TL as a global measure of training load in elite soccer. Furthermore, understanding the influence of characteristics affecting RPE-TL may help coaches and practitioners enhance training prescription and athlete monitoring.
High-speed running (>5 m · s?¹) is commonly reported in men's rugby union and sevens; however, the appropriateness of using the same speed threshold for Women's Rugby Sevens players is unclear, and likely underestimates the degree of high-intensity exercise completed by female players. The aim of this study was to establish, for international Women's Rugby Sevens players, a physiologically defined threshold - speed at the second ventilatory threshold (VT(2peed)) - for the analysis of high-intensity running, using mean and individualised thresholds. Game movement patterns (using 5 Hz GPS) of 12 international Women's Rugby Sevens players (23.5 ± 4.9 ears, 1.68 ± 0.04 m, 68.2 ± 7.7 kg; mean ± s) were collected at an international tournament. Seven of these players also completed a treadmill VO(2max) test to estimate VT(2speed). Compared to the mean VT(2speed) threshold (3.5 m · s?¹), the industry-used threshold of 5 m · s?¹ underestimated the absolute amount of high-intensity running completed by individual players by up to 30%. Using an individualised threshold, high-intensity running could over- or underestimating high-intensity running by up to 14% compared to the mean VT(2peed) threshold. The use of individualised thresholds provides an accurate individualised assessment of game demands to inform the prescription of training.
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.
With adolescent sport increasingly challenged by mismatches in size, new strategies are important to maximize participation. The objectives were to (1) improve the understanding of mismatches in physical size, speed and power in adolescent rugby union players, (2) explore associations between size and performance with demographic, playing-history, and injury profiles, and (3) explore the applicability of existing criteria for age/body mass-based dispensation (playing-down) strategies.
Four hundred and eighty-five male community rugby union players were recruited from three Australian states selected to represent community-based U12, U13, U14 and U15 players. Body mass, stature, speed (10, 30, and 40?m sprints) and lower-leg power (relative peak power and relative peak force) were measured. Independent student t-tests, linear regressions and Chi square analyses were undertaken.
Mean values in age groups for size, speed and power masked considerable overlap in the ranges within specific age groups of adolescent rugby players. Only a small proportion of players (approximately 5%) shared the highest and lowest tertiles for speed, relative peak power and body mass. Physical size was not related to injury. The mean body mass of current community rugby union players was above the 75th percentile on normative growth-charts.
The notion that bigger, faster, and more powerful characteristics occur simultaneously in adolescent rugby players was not supported in the present study. Current practices in body mass-based criteria for playing down an age group lack a sufficient evidence for decision-making. Dispensation solely based on body mass may not address mismatch in junior rugby union.
The physical and technical responses of experienced (?5 years) and less experienced (1–4 years) elite Australian Football (AF) players were compared following the most intense passages of match-play.
Descriptive cohort study.
Time–motion analyses were performed using global positioning systems (MinimaxX S4, Catapult Innovations, Melbourne, Australia) on one elite AF team during 13 matches. The global positioning data were categorised into total distance, low-speed activity (0–2.78?m?s?1), moderate-speed running (2.79–4.14?m?s?1) and high-speed running (?4.15?m?s?1) distances. A standardised 5-point technical coding criteria was used to rate the number and quality of skill involvements during match-play.
Following the most intense 3-min running period the experienced players covered greater distances at high-speeds in match quarters two (effect size, ES?=?0.42?±?0.30) and three (ES?=?0.38?±?0.33) than their less experienced counterparts. Compared with less experienced players, experienced players performed more skill involvements during the second quarter (ES?=?0.42?±?0.33) and fourth quarter peak 3-min bouts of exercise intensity (ES?=?0.40?±?0.30) and quarter one (ES?=?0.49?±?0.29) and three subsequent periods (ES?=?0.33?±?0.20).
Less experienced players exhibited greater reductions in physical and technical performance following peak periods of match-play. These findings suggest that training may require a greater emphasis on developing the ability of less experienced players to maintain physical performance and gain possession of the football following intense periods of match-play.