Quantifying External Load in Australian Football Matches and Training Using Accelerometers

2013 ◽  
Vol 8 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Luke J. Boyd ◽  
Kevin Ball ◽  
Robert J. Aughey
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
External Load ◽  
Percentage Change ◽  
Accelerometer Data ◽  
Elite Group ◽  
Australian Football ◽  
And Training

Purpose:To describe the external load of Australian football matches and training using accelerometers.Methods:Nineteen elite and 21 subelite Australian footballers wore accelerometers during matches and training. Accelerometer data were expressed in 2 ways: from all 3 axes (player load; PL) and from all axes when velocity was below 2 m/s (PLSLOW). Differences were determined between 4 playing positions (midfielders, nomadics, deeps, and ruckmen), 2 playing levels (elite and subelite), and matches and training using percentage change and effect size with 90% confidence intervals.Results:In the elite group, midfielders recorded higher PL than nomadics and deeps did (8.8%, 0.59 ± 0.24; 34.2%, 1.83 ± 0.39 respectively), and ruckmen were higher than deeps (37.2%, 1.27 ± 0.51). Elite midfielders, nomadics, and ruckmen recorded higher PLSLOW than deeps (13.5%, 0.65 ± 0.37; 11.7%, 0.55 ± 0.36; and 19.5%, 0.83 ± 0.50, respectively). Subelite midfielders were higher than nomadics, deeps, and ruckmen (14.0%, 1.08 ± 0.30; 31.7%, 2.61 ± 0.42; and 19.9%, 0.81 ± 0.55, respectively), and nomadics and ruckmen were higher than deeps for PL (20.6%, 1.45 ± 0.38; and 17.4%, 0.57 ± 0.55, respectively). Elite midfielders, nomadics, and ruckmen recorded higher PL (7.8%, 0.59 ± 0.29; 12.9%, 0.89 ± 0.25; and 18.0%, 0.67 ± 0.59, respectively) and PLSLOW (9.4%, 0.52 ± 0.30; 11.3%, 0.68 ± 0.25; and 14.1%, 0.84 ± 0.61, respectively) than subelite players. Small-sided games recorded the highest PL and PLSLOW and were the only training drill to equal or exceed the load from matches across positions and playing levels.Conclusion:PL differed between positions, with midfielders the highest, and between playing levels, with elite higher. Differences between matches and training were also evident, with PL from small-sided games equivalent to or higher than matches.

scholarly journals Comparison of Agility Demands of Small-Sided Games in Elite Australian Football

2013 ◽  
Vol 8 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Michael J. Davies ◽  
Warren Young ◽  
Damian Farrow ◽  
Andrew Bahnert
Keyword(s):  
Effect Size ◽  
Accelerometer Data ◽  
Triaxial Accelerometer ◽  
Notational Analysis ◽  
Australian Football League ◽  
Australian Football

Purpose:To compare the agility demands of 4 small-sided games (SSGs) and evaluate the variability in demands for elite Australian Football (AF).Methods:Fourteen male elite Australian Football League (AFL) players (mean ± SD; 21.7 ± 3.1 y, 189.6 ± 9.0 cm, 88.7 ± 10.0 kg, 39.4 ± 57.1 games) completed 4 SSGs of 3 × 45-s bouts each with modified designs. Video notational analysis, GPS at 5 Hz, and triaxial accelerometer data expressed the external player loads within games. Three comparisons were made using a paired t test (P < .05), and magnitudes of differences were reported with effect size (ES) statistics.Results:Reduced area per player (increased density) produced a small increase in total agility maneuvers (SSG1, 7.2 ± 1.3; SSG2, 8.8 ± 4.1), while a large 2D player load was accumulated (P < .05, ES = 1.22). A reduction in players produced a moderate (ES = 0.60) total number of agility maneuvers (SSG 3, 11.3 ± 6.1; SSG 2, 8.3 ± 3.6); however, a greater variability was found. The implementation of a 2-handed-tag rule resulted in a somewhat trivial decline (P > .05, ES = 0.16) in agility events compared with normal AFL tackling rules (SSG 2, 8.3 ± 3.6; SSG 4, 7.8 ± 2.6).Conclusions:SSG characteristics can influence agility-training demand, which can vary considerably for individuals. Coaches should carefully consider SSG design to maximize the potential to develop agility for all players.

Increased High-Intensity Activity in Elite Australian Football Finals Matches

2011 ◽  
Vol 6 (3) ◽  
pp. 367-379 ◽  
Author(s):  
Robert J. Aughey
Keyword(s):  
Confidence Intervals ◽  
Physical Condition ◽  
Effect Size ◽  
High Velocity ◽  
High Intensity ◽  
Anecdotal Evidence ◽  
Total Distance ◽  
Competitive Season ◽  
Australian Football

Background:Australian football (AF) is a highly intermittent sport, requiring athletes to accelerate hundreds of times with repeated bouts of high-intensity running (HIR). Players aim to be in peak physical condition for finals, with anecdotal evidence of increased speed and pressure of these games.Purpose:However, no data exists on the running demands of finals games, and therefore the aim of this study was to compare the running demands of finals to regular season games with matched players and opponents.Methods:Player movement was recorded by GPS at 5 Hz and expressed per period of the match (rotation), for total distance, high-intensity running (HIR, 4.17-10.00 m·s-1) and maximal accelerations (2.78-10.00 m·s–2). All data was compared for regular season and finals games and the magnitude of effects was analyzed with the effect size (ES) statistic and expressed with confidence intervals.Results:Each of the total distance (11%; ES: 0.78 ± 0.30), high-intensity running distance (9%; ES: 0.29 ± 0.25) and number of maximal accelerations (97%; ES: 1.30 ± 0.20) increased in finals games. The largest percentage increases in maximal accelerations occurred from a commencement velocity of between 3–4 (47%; ES: 0.56 ± 0.21) and 4–5 m·s-1 (51%; ES: 0.72 ± 0.26), and with <19 s between accelerations (53%; ES: 0.63 ± 0.27).Conclusion:Elite AF players nearly double the number of maximal accelerations in finals compared with regular season games. This large increase is superimposed on requirements to cover a greater total distance and spend more time at high velocity during finals games. Players can be effectively conditioned to cope with these increased demands, even during a long competitive season.

scholarly journals External Load Variations Between Medium- and Large-Sided Soccer Games: Ball Possession Games vs Regular Games with Small Goals

2019 ◽  
Vol 70 (1) ◽  
pp. 191-198 ◽  
Author(s):  
Filipe Manuel Clemente ◽  
Gibson Moreira Praça ◽  
Sarah da Glória Teles Bredt ◽  
Cornelis M. I. van der Linden ◽  
Jaime Serra-Olivares
Keyword(s):  
Effect Size ◽  
External Load ◽  
Training Load ◽  
Soccer Players ◽  
Accelerometer Data ◽  
Load Variations ◽  
Total Distance ◽  
Professional Soccer ◽  
Possession Condition

Abstract This study compared external load variations between 5 vs 5 and 10 vs 10 sided game formats played under two conditions: (i) a ball possession game with two floaters, and (ii) a regular game with goalkeepers and small goals. Twenty-two professional soccer players participated in this study: four central defenders, four wide defenders, nine central midfielders, three wide forwards, and three strikers. Total distance (TD), running distance (RD), sprinting distance (SD), number of sprints (NS), and player’s training load (PL) were recorded by GPS units. Within-format analyses revealed very likely large increases in TD (20.0%, [9.2; 31.9]; effect size (ES): 1.48, [0.71; 2.25]) and RD (130.9%, [20.2; 343.7]; ES: 1.32, [0.29; 2.35]) during the regular game when compared to the ball possession game in the 5 vs 5 format. In the 10 vs 10 format, large increases in TD (27.9%, [17.7; 39.1]; ES: 3.54, [2.34; 4.74]) and PL (27.4%, [12.6; 44.1]; ES: 2.46, [1.20; 3.72]) were observed in the regular condition when compared to the ball possession condition. Between-formats analyses revealed that, in the 10 vs 10 format, when compared to the 5 vs 5 format, RD was very likely larger (123.5%, [33.7; 273.7]), as was SD (195.8%, [20.5; 626.2]). However, very likely large decreases in PL were observed in the 10 vs 10 format (-19.6%; [-29.4; -8.3]) in the ball possession condition. Unclear differences were revealed based on variations in external load variables between formats in the regular condition. Smaller formats reduce the area available for running and sprinting and, thus, may be more adequate for increasing player’s training load (based on accelerometer data).

scholarly journals Physical Demands in Three Different Basketball Competitions Played By the Same Under-18 Players

2021 ◽  
Vol 10 (2) ◽  
pp. 59-64
Author(s):  
Hugo Salazar ◽  
◽  
Franc Garcia ◽  
Luka Svilar ◽  
Julen Castellano ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
High Intensity ◽  
External Load ◽  
Training Process ◽  
Physical Demands ◽  
Cohen’S D ◽  
Basketball Coaches ◽  
Cohen's D

The goal of this study was to compare the physical demands of the same team in three different basketball com- petitions (EBA league (EBA), U18 regional league (U18L), and a U18 international tournament (U18T)) during the same season. Data from eleven U18 players (age: 16.92 ± 0.67 years) were collected using inertial movement units. As external load variables, Player Load (PL), accelerations (ACC), decelerations (DEC), changes of direction (COD), and jumps (JUMP) were expressed in their total (t) and high intensity (h) values. The analysis of variances (ANOVA) and effect size (ES, Cohen’s d) with their respective 90% confidence intervals were applied to identify differences between the competitions. U18T showed the highest values in PL, tACC, tDEC, hDEC, tCOD, tJUMP, and hJUMP (small to moderate ES). However, the hACC and hCOD values were greater in EBA (small ES) than in U18L and U18T. In conclusion, all three competitions presented different external load demands for the same group of players. This data could help basketball coaches to optimize the training process based on the competition in which their team plays. Furthermore, data could also indicate the most suitable competition for players’ development.

Australian Football Player Work Rate: Evidence of Fatigue and Pacing?

2010 ◽  
Vol 5 (3) ◽  
pp. 394-405 ◽  
Author(s):  
Robert J. Aughey
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
High Intensity ◽  
Football Player ◽  
Team Sport ◽  
Work Rate ◽  
Low Intensity ◽  
Maximal Acceleration ◽  
Pacing Strategies ◽  
Australian Football

Previous research has suggested elite Australian footballers undertake pacing strategies to preserve high intensity activity later in matches. However, this research used GPS with slow sample rates, did not express performance relative to minutes played during games and used lowly ranked players.Methods:Therefore in this study movement was recorded by GPS at 5 Hz. Running performance was expressed per period of the match (rotation) divided into low-intensity activity (LIA, 0.10 to 4.17 m⋅s–1); high-intensity running (HIR, 4.17 to 10.00 m⋅s–1) and maximal accelerations (2.78 to 10.00 m⋅s–2). All data were expressed relative to the first period of play in the match and the magnitude of effects was analyzed with the effect size (ES) statistic and expressed with confidence intervals.Results:The total and LIA distance covered by players did not change by a practically important magnitude during games (ES< 0.20). High intensity running was reduced in both rotations of the second quarter, Q3R2 and both rotations of the fourth quarter (ES -0.30 ± 0.14; -0.42 ± 0.14; -0.30 ± 0.14; -0.42 ± 0.14; and -0.48 ± 0.15 respectively). Maximal acceleration performance was reduced in Q1R2, and each rotation of the second half of matches.Conclusion:When expressed per minute of game time played, total distance and low intensity activity distance are not reduced by a practically important magnitude in AF players during a match. These data are therefore inconsistent with the concept of team sport players pacing their effort during matches. However, both high intensity running and maximal accelerations are reduced later in games, indicative of significant fatigue in players.

scholarly journals Comparison between Continuous and Fractionated Game Format on Internal and External Load in Small-Sided Games in Soccer

2020 ◽  
Vol 17 (2) ◽  
pp. 405 ◽  
Author(s):  
Luís Branquinho ◽  
Ricardo Ferraz ◽  
Bruno Travassos ◽  
Mário C. Marques
Keyword(s):  
Confidence Intervals ◽  
External Load ◽  
Continuous Method ◽  
Soccer Players ◽  
Professional Soccer ◽  
Game Format ◽  
Physical Impact ◽  
Mean Differences ◽  
External Loads

This study aimed to identify the effects of continuous and fractionated game formats on internal and external load in small-sided games in soccer. Twenty male professional soccer players participated in the study performing the same exercise (5 vs. 5 players) continuously (1 × 24 min) and in a repeated/fractioned manner (2 × 12 min, 4 × 6 min, and 6 × 4 min). A comparison between playing conditions was assessed by means of standardized mean differences calculated with combined variance and respective confidence intervals of 90%. The limits for the statistics were 0.2, trivial; 0.6, small; 1.2, moderate; 2.0, large; and >2.0, very large. The results indicate that the use of the continuous method seems to present the tendency of less physical impact on the internal and external loads compared to the fractionated method. In addition, the higher number of exercise repetitions in the fractionated method was found to increase the external load compared to the continuous method. This study showed that application of small-sided games by the fractionated method tends to result in higher training loads.

Abstract 3789: Nessun Dorma : Have the Risks of Rosiglitazone been Exaggerated?

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
George A Diamond ◽  
Sanjay Kaul
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Cardiovascular Death ◽  
Sensitivity Analyses ◽  
Odds Ratios ◽  
True Effect Size ◽  
Index Study ◽  
The Stability

Background A highly publicized meta-analysis of 42 clinical trials comprising 27,844 diabetics ignited a firestorm of controversy by charging that treatment with rosiglitazone was associated with a “…worrisome…” 43% greater risk of myocardial infarction ( p =0.03) and a 64% greater risk of cardiovascular death ( p =0.06). Objective The investigators excluded 4 trials from the infarction analysis and 19 trials from the mortality analysis in which no events were observed. We sought to determine if these exclusions biased the results. Methods We compared the index study to a Bayesian meta-analysis of the entire 42 trials (using odds ratio as the measure of effect size) and to fixed-effects and random-effects analyses with and without a continuity correction that adjusts for values of zero. Results The odds ratios and confidence intervals for the analyses are summarized in the Table . Odds ratios for infarction ranged from 1.43 to 1.22 and for death from 1.64 to 1.13. Corrected models resulted in substantially smaller odds ratios and narrower confidence intervals than did uncorrected models. Although corrected risks remain elevated, none are statistically significant (*p<0.05). Conclusions Given the fragility of the effect sizes and confidence intervals, the charge that roziglitazone increases the risk of adverse events is not supported by these additional analyses. The exaggerated values observed in the index study are likely the result of excluding the zero-event trials from analysis. Continuity adjustments mitigate this error and provide more consistent and reliable assessments of true effect size. Transparent sensitivity analyses should therefore be performed over a realistic range of the operative assumptions to verify the stability of such assessments especially when outcome events are rare. Given the relatively wide confidence intervals, additional data will be required to adjudicate these inconclusive results.

Using confidence intervals to estimate the response of salmon populations (Oncorhynchus spp.) to experimental habitat alterations

2005 ◽  
Vol 62 (12) ◽  
pp. 2716-2726 ◽  
Author(s):  
Michael J Bradford ◽  
Josh Korman ◽  
Paul S Higgins
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
Null Hypothesis ◽  
Statistical Power ◽  
Habitat Restoration ◽  
Coho Salmon ◽  
Fish Habitat ◽  
Monitoring Program ◽  
Considerable Uncertainty ◽  
Monitoring Programs

There is considerable uncertainty about the effectiveness of fish habitat restoration programs, and reliable monitoring programs are needed to evaluate them. Statistical power analysis based on traditional hypothesis tests are usually used for monitoring program design, but here we argue that effect size estimates and their associated confidence intervals are more informative because results can be compared with both the null hypothesis of no effect and effect sizes of interest, such as restoration goals. We used a stochastic simulation model to compare alternative monitoring strategies for a habitat alteration that would change the productivity and capacity of a coho salmon (Oncorhynchus kisutch) producing stream. Estimates of the effect size using a freshwater stock–recruit model were more precise than those from monitoring the abundance of either spawners or smolts. Less than ideal monitoring programs can produce ambiguous results, which are cases in which the confidence interval includes both the null hypothesis and the effect size of interest. Our model is a useful planning tool because it allows the evaluation of the utility of different types of monitoring data, which should stimulate discussion on how the results will ultimately inform decision-making.

scholarly journals Robust Confidence Intervals for Effect Size in the Two-Group Case

2005 ◽  
Vol 4 (2) ◽  
pp. 353-371 ◽  
Author(s):  
H. J. Keselman ◽  
James Algina ◽  
Katherine Fradette
Keyword(s):  
Confidence Intervals ◽  
Effect Size ◽  
Group Case

scholarly journals Uncertainty Measures for Economics Journal Impact Factors

2013 ◽  
Vol 51 (1) ◽  
pp. 173-189 ◽  
Author(s):  
David I Stern
Keyword(s):  
Impact Factor ◽  
Confidence Intervals ◽  
Standard Error ◽  
Impact Factors ◽  
Elite Group ◽  
Economics Journal ◽  
Uncertainty Measures ◽  
Economics Journals ◽  
The Impact ◽  
Journal Impact

Academic economists appear to be intensely interested in rankings of journals, institutions, and individuals. Yet there is little discussion of the uncertainty associated with these rankings. To illustrate the uncertainty associated with citations-based rankings, I compute the standard error of the impact factor for all economics journals with a five-year impact factor in the 2011 Journal Citations Report. I use these to derive confidence intervals for the impact factors as well as ranges of possible rank for a subset of thirty journals. I find that the impact factors of the top two journals are well defined and set these journals apart in a clearly defined group. An elite group of 9–11 mainstream journals can also be fairly reliably distinguished. The four bottom ranked journals are also fairly clearly set apart. For the remainder of the distribution, confidence intervals overlap and rankings are quite uncertain. (JEL A14)

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