Metabolic power and energy expenditure in an international men's hockey tournament

High-Intensity Running During International Male Field Hockey Involves Frequent Changes of Direction and Repeated Accelerations but Seldom Reaches Sprint Velocities

ABSTRACT

Goods, PS, Appleby, B, Scott, BR, Peeling, P, and Galna, B. High-intensity running during international male field hockey involves frequent changes of direction and repeated accelerations but seldom reaches sprint velocities. J Strength Cond Res 38(11): 1933-1940, 2024-The aim of this investigation was to quantify the characteristics of high-intensity running in international male field hockey. Player movement data were collected through wearable player tracking devices across 3 tournaments (17 matches) from 27 members of the Australian male field hockey team (totaling 266 player matches). Active duration (minute), high-intensity efforts (>2.5 m·s -2 for >1 second), repeated high-intensity efforts (≥3 efforts with ≤45-second recovery between efforts), and sprints (>7 m·s -1 ) were extracted and aggregated for each player match. The duration, distance, mean and peak speed, mean change of direction and straightness for each high-intensity effort, and peak deceleration at the conclusion of each effort were calculated. Mixed-effects models were used to estimate the mean for each outcome (fixed effect), with random intercepts modeled for player and match. On average, players completed 42.2 high-intensity efforts and 2.1 sprints per match. High-intensity efforts were short (3.61 seconds, 12.9 m), failed to reach high velocities (average peak velocity: 4.8 m·s -1 ), and involved frequent changes of direction (56% of efforts were not straight). There were 4.7 bouts of repeated high-intensity efforts per player, per match (comprising 3.8 efforts, with 3.53 seconds per effort separated by 16.2-second recovery). Last, we also found that 29% of high-intensity efforts involved a high-speed deceleration (>3.5 m·s -2 ), and these occurred frequently when in conjunction with a >45° (86%) or >90° (89%) change of direction. We recommend practitioners focus on developing players' ability to repeatedly accelerate, decelerate, and change direction over short distances and adopt testing and monitoring programs that assess these qualities.

Energetics (and Mechanical Determinants) of Sprint and Shuttle Running

Unsteady locomotion (e. g., sprints and shuttle runs) requires additional metabolic (and mechanical) energy compared to running at constant speed. In addition, sprints or shuttle runs with relevant speed changes (e. g., with large accelerations and/or decelerations) are typically short in duration and, thus, anaerobic energy sources must be taken into account when computing energy expenditure. In sprint running there is an additional problem due to the objective difficulty in separating the acceleration phase from a (necessary and subsequent) deceleration phase.In this review the studies that report data of energy expenditure during sprints and shuttles (estimated or actually calculated) will be summarized and compared. Furthermore, the (mechanical) determinants of metabolic energy expenditure will be discussed, with a focus on the analogies with and differences from the energetics/mechanics of constant-speed linear running.

Wearable Sensors and the Evaluation of Physiological Performance in Elite Field Hockey Players

Sports performance tracking has gained a lot of interest and widespread use in recent years, especially in elite and sub-elite sports. This makes it possible to improve the effectiveness of training, to calibrate and balance workloads according to real energy expenditure, and to reduce the likelihood of injuries due to excessive physical stress. In this context, the aim of this review was to map the scientific literature on wearable devices used in field hockey, evaluating their characteristics and the available evidence on their validity in measuring physiological and movement parameters. A systematic investigation was carried out by employing five electronic databases and search terms that incorporated field hockey, wearables, and performance analysis. Two independent reviewers conducted assessments of the 3401 titles and abstracts for inclusion, and at the end of the screening process, 102 full texts were analyzed. Lastly, a total of 23 research articles that specifically concentrated on field hockey were incorporated. The selected papers dealt with performance monitoring (6 papers), technical analysis and strategy game (6), injury prevention (1), and physiological measurements (10). To appraise the quality of the evaluations, the Oxford quality scoring system scale was employed. The extraction of information was carried out through the utilization of the participants, intervention, comparison, and outcomes (PICOS) format. The analysis encompassed research studies that implemented wearable devices during training and competitive events. Among elite field hockey competitions, GPS units were identified as the predominant wearable, followed by heart rate monitors. The intraclass correlation coefficient (ICC) related to wearable devices showed reasonably high between-trial ICCs ranging from 0.77 to 0.99. The utilization of wearable devices in field hockey primarily centers around the measurement of player activity profiles and physiological demands. The presence of discrepancies in sampling rates and performance bands makes it arduous to draw comparisons between studies. Nevertheless, this analysis attested to the fact that wearable devices are being employed for diverse applications in the realm of field hockey.

Metabolic power in the men's European handball championship 2020

PURPOSE

To ascertain the typical metabolic power characteristics of elite handball players of different positions, and whether changes occur within matches.

METHODS

414 elite male handball players were included. During all 65 matches of the EURO 2020, local positioning system data were collected, yielding 1853 datasets. Field players were categorised into six positional groups: centre backs (CB), left/right wings (LW/RW), left/right backs (LB/RB) and pivots (P). Metabolic power, total energy expenditure, high-power energy, and the equivalent distance index were calculated. We used linear mixed models with players as random and positions as fixed effects models. Intensity models adjusted for time-dependency by incorporating the duration of play.

RESULTS

LW/RW spent most time on the court, expanded most total energy, and most relative energy per kg body weight in the high-intensity categories. CB played at the highest mean metabolic power (7.85 W/kg; CI_95% [7.67, 8.03]). Playing intensity decreased by 2.5% (0.2 kJ/kg/s; CI_95% [0.17, 0.23]) per 10 min played.

CONCLUSION

Positional differences in metabolic power parameters exist. In general, wing players had the highest volume and CB the highest intensity of match-play. Analysis of metabolic intensity in handball should take position and players' time on the court into account.

Physical preparation of the Australian national male field hockey team exceeded the movement demands of the Tokyo 2020 Olympic Games tournament

This investigation explored differences in the pre-tournament preparation period relative to the movement demands of the Tokyo 2020 Olympic Games for the Australian male field-hockey team. Movement data was collected over 7 months prior to and during the 13-day Olympic tournament. Duration, distance (total; >80% individual peak velocity; >5 m.s^-1), high-speed decelerations (>3.5 m.s^-2), and total accelerations and decelerations (>2.5 m.s^-2) were measured during each running-based session. A 13-day moving sum was calculated for each variable and compared to a player-specific "worst-case scenario" (WCS) for intra-tournament total movement demands. Summed 13-day movement demands exceeded the WCS for 6-58% of the preparation period across variables, for the entire squad. During the tournament, midfielders covered significantly greater sprint distance than Defenders (+84%,p = 0.020), with no other positional differences found. Greater variation in tournament movement demands was observed between players for accelerations, decelerations, and high-speed distance (CV = 19-46%) compared to duration and distance (CV = 4-9%). In conclusion, physical preparation exposed athletes to movement demands which surpassed WCS. Additionally, gross measures of training volume (duration and distance) are more generalisable to a squad; however, additional metrics such as sprint distance and high-speed decelerations are needed to better define positional and individual movement demands, and therefore, should be monitored by practitioners.

Metabolic power and energy expenditure in the German Bundesliga

The aims of the study were to analyze metabolic power (MP) and MP derived parameters for different positions in the German Soccer Bundesliga and to evaluate if classification of high-intensity is more suited using the metabolic power approach instead of using traditional speed-based methods. 1,345 video match analysis (25 Hz) datasets from 380 players in 96 matches of the German first Bundesliga were gathered by an automatic player tracking system. Displacement (speed, acceleration, distance) and energetic (MP, energy expenditure) variables were determined. Intensity was classified utilizing conventional thresholds. Metabolic and running profiles were compared among six positional groups and between the halves of the match respectively (one-way ANOVA). Further, time spent, distance covered and energy expended at high speed (>15.5 km h-1) and high acceleration (>2 m s-2) were compared to those at high MP (>20 W kg-1) (one-way ANOVA) for evaluating if metabolic power is more suited to describe intensity in team sports. Main findings are that central-attacking midfielders (CAM) and central midfielders (CM) expended more energy (CAM: 59.8 ± 4.2 kJ kg-1; CM: 59.6 ± 3.6 kJ kg-1) and covered more distance (CAM: 11,494 ± 765 m; CM: 11,445 ± 638 m) than all other positions (p < 0.001). In the whole group of players, less time (t) and less energy were expended (EE) in high speed (t: 302 ± 84 s; EE: 10.1 ± 2.9 kJ kg-1) and at high acceleration zones (t: 147 ± 24 s; EE: 5.5 ± 1.2 kJ kg-1) when compared to high MP zone (t: 617 ± 141 s; EE: 20.0 ± 4.4 kJ kg-1) (p < 0.001). Furthermore, players covered more distance at high MP (2,464 ± 597 m) than at high speed (1,638 ± 458 m) and much less at high acceleration (359 ± 67 m) (p < 0.001). The higher activity profiles of CAM and CM compared to the other positions indicate the need for higher developed physiological performance in players of these positions. High intensity activities should be interpreted differently when using MP and displacement parameters as indicators of high intensity in soccer.

Microdosing Sprint Distribution as an Alternative to Achieve Better Sprint Performance in Field Hockey Players

Introduction: The implementation of optimal sprint training volume is a relevant component of team sport performance. This study aimed to compare the efficiency and effectiveness of two different configurations of within-season training load distribution on sprint performance over 6 weeks. Methods: Twenty male professional FH players participated in the study. Players were conveniently assigned to two groups: the experimental group (MG; n = 11; applying the microdosing training methodology) and the control group (TG; n = 9; traditional training, with players being selected by the national team). Sprint performance was evaluated through 20 m sprint time (T20) m and horizontal force−velocity profile (HFVP) tests before (Pre) and after (Post) intervention. Both measurements were separated by a period of 6 weeks. The specific sprint training program was performed for each group (for vs. two weekly sessions for MG and TG, respectively) attempting to influence the full spectrum of the F-V relationship. Results: Conditional demands analysis (matches and training sessions) showed no significant differences between the groups during the intervention period (p > 0.05). No significant between-group differences were found at Pre or Post for any sprint-related performance (p > 0.05). Nevertheless, intra-group analysis revealed significant differences in F0, Pmax, RFmean at 10 m and every achieved time for distances ranging from 5 to 25 m for MG (p < 0.05). Such changes in mechanical capabilities and sprint performance were characterized by an increase in stride length and a decrease in stride frequency during the maximal velocity phase (p < 0.05). Conclusion: Implementing strategies such as microdosed training load distribution appears to be an effective and efficient alternative for sprint training in team sports such as hockey.

A repeated shuttle sprint test with female and male international field hockey players is reliable and associated with single sprint but not intermittent endurance performance

Field hockey is a high-intensity intermittent team sport that has recently undergone a series of rule changes that have resulted in a greater demand for repeated high-intensity movements. Coaches and practitioners now require a reliable assessment of repeated accelerations, decelerations and changes of direction to assess these important match qualities. This investigation assessed the test-retest reliability of a novel 6x40m repeated shuttle sprint test (20m + 20m with a 180° turn) and its association with 40m straight line sprint and YoYo Intermittent Recovery Test performance in 28 International field hockey players (n = 14 females and n = 14 males). The sum of 6 sprint times (SUM) demonstrated ‘excellent’ (ICC = 0.94 and CV = 0.59%) and ‘good’ (ICC = 0.84 and CV = 0.75%) reliability in females and males, respectively. Best sprint time during the repeated shuttle sprint test also demonstrated suitable reliability to evaluate field hockey physical performance (ICC = 0.92 & 0.76, CV = 0.76% & 1.00% in females and males, respectively). SUM was significantly associated with 40 m straight line sprint performance in females (r = 0.90; p<0.001) and males (r = 0.92; p<0.001), but only a weak association was found with YoYo Intermittent Recovery Test performance for either group (r = 0.20; p = 0.495 & r = -0.19; p = 0.525 in females and males, respectively). In summary, field hockey testing batteries that include a repeated shuttle sprint test should consider including a test of intermittent endurance. Further, changes in SUM greater than 1.0% can be confidently interpreted by coaches and practitioners as a real change for both female and male elite field hockey players.

Techniques to derive and clean acceleration and deceleration data of athlete tracking technologies in team sports: A scoping review

The application of acceleration and deceleration data as a measure of an athlete's physical performance is common practice in team sports. Acceleration and deceleration are monitored with athlete tracking technologies during training and games to quantify training load, prevent injury and enhance performance. However, inconsistencies exist throughout the literature in the reported methodological procedures used to quantify acceleration and deceleration. The object of this review was to systematically map and provide a summary of the methodological procedures being used on acceleration and deceleration data obtained from athlete tracking technologies in team sports and describe the applications of the data. Systematic searches of multiple databases were undertaken. To be included, studies must have investigated full body acceleration and/or deceleration data of athlete tracking technologies. The search identified 276 eligible studies. Most studies (60%) did not provide information on how the data was derived and what sequence of steps were taken to clean the data. Acceleration and deceleration data were commonly applied to quantify and describe movement demands using effort metrics. This scoping review identified research gaps in the methodological procedures and deriving and cleaning techniques that warrant future research focussing on their effect on acceleration and deceleration data.

Effect of Changing Match Format from Halves to Quarters on the Performance Characteristics of Male University Field Hockey Players

The study examined whether the performance characteristics of male university field hockey players differed when the match format was 2 × 35 min halves compared to 2 × 2 × 17.5 min quarters. Thirty-five male university field hockey players (age 21.2 ± 3.0 years, height 1.81 ± 0.07 m, body mass 75.1 ± 8.9 kg), competing at national level in the UK, were monitored over 52 matches played across the 2018–2019 (2 × 35 min halves) and 2019–2020 (2 × 2 × 17.5 min quarters) seasons using 15 Hz Global Positioning System units and heart rate monitors. Total distance, high-speed running distance (≥15.5 km·h⁻¹), accelerations (≥2 m·s⁻¹), decelerations (≤−2 m·s⁻¹), average heart rate and percentage of time spent at >85% of maximum heart rate were recorded during both match formats. Two-level random intercept hierarchal models (Match—level 1, Player—level 2) suggested that the change in format from 2 × 35 min halves (2018–2019 season) to 2 × 2 × 17.5 min quarters (2019–2020 season) resulted in a reduction in total distance and high-speed running distance completed during a match (by 221 m and 120 m, respectively, both p < 0.001). As no significant cross-level interactions were observed (between season and half), the change from 35 min halves to 17.5 min quarters did not attenuate the reduced physical performance evident during the second half of matches (total distance: −235 m less in second half; high-speed running distance: −70 m less in second half; both p < 0.001). Overall, the findings suggest that the change in match format did alter the performance characteristics of male university field hockey players, but the quarter format actually reduced the total distance and high-speed running distance completed during matches, and did not attenuate the reduction in performance seen during the second half of matches.

Wearable Technologies in Field Hockey Competitions: A Scoping Review

The aim of this review is to investigate the common wearable devices currently used in field hockey competitions, and to understand the hockey-specific parameters these devices measure. A systematic search was conducted by using three electronic databases and search terms that included field hockey, wearables, accelerometers, inertial sensors, global positioning system (GPS), heart rate monitors, load, performance analysis, player activity profiles, and competitions from the earliest record. The review included 39 studies that used wearable devices during competitions. GPS units were found to be the most common wearable in elite field hockey competitions, followed by heart rate monitors. Wearables in field hockey are mostly used to measure player activity profiles and physiological demands. Inconsistencies in sampling rates and performance bands make comparisons between studies challenging. Nonetheless, this review demonstrated that wearable devices are being used for various applications in field hockey. Researchers, engineers, coaches, and sport scientists can consider using GPS units of higher sampling rates, as well as including additional variables such as skin temperatures and injury associations, to provide a more thorough evaluation of players’ physical and physiological performances. Future work should include goalkeepers and non-elite players who are less studied in the current literature.

The Quantification of Acceleration Events in Elite Team Sport: a Systematic Review

BACKGROUND

Wearable tracking devices are commonly utilised to quantify the external acceleration load of team sport athletes during training and competition. The ability to accelerate is an important attribute for athletes in many team sports. However, there are many different acceleration metrics that exist in team sport research. This review aimed to provide researchers and practitioners with a clear reporting framework on acceleration variables by outlining the different metrics and calculation processes that have been adopted to quantify acceleration loads in team sport research.

METHODS

A systematic review of three electronic databases (CINAHL, MEDLINE, SPORTDiscus), was performed to identify peer-reviewed studies that published external acceleration load in elite team sports during training and/or competition. Articles published between January 2010 and April 2020 were identified using Boolean search phrases in relation to team sports (population), acceleration/deceleration (comparators), and competition and/or training (outcome). The included studies were required to present external acceleration and/or deceleration load (of any magnitude) from able-bodied athletes (mean age ≥ 18 years) via wearable technologies.

RESULTS

A total of 124 research articles qualified for inclusion. In total, 113/124 studies utilised GPS/GNSS technology to outline the external acceleration load of athletes. Count-based metrics of acceleration were predominant of all metrics in this review (72%). There was a lack of information surrounding the calculation process of acceleration with 13% of studies specifying the filter used in the processing of athlete data, whilst 32% outlined the minimum effort duration (MED). Markers of GPS/GNSS data quality, including horizontal dilution of precision (HDOP) and the average number of satellites connected, were outlined in 24% and 27% of studies respectively.

CONCLUSIONS

Team sport research has predominantly quantified external acceleration load in training and competition with count-based metrics. Despite the influence of data filtering processes and MEDs upon acceleration, this information is largely omitted from team sport research. Future research that outlines acceleration load should present filtering processes, MEDs, HDOP, and the number of connected satellites. For GPS/GNSS systems, satellite planning tools should document evidence of available satellites for data collection to analyse tracking device performance. The development of a consistent acceleration filtering method should be established to promote consistency in the research of external athlete acceleration loads.

Volume and Intensity of Locomotor Activity in International Men's Field Hockey Matches Over a 2-Year Period

The locomotor demands of international men's field hockey matches were investigated across positions (DEF, MID, FWD) and playing quarters. Volume (i.e., total values) and intensity (i.e., relative to playing time) data were collected using 10-Hz GPS/100-Hz accelerometer units from the #11 world-ranked (WR) team, during 71 matches, against 24 opponents [WR 12 ± 11 (range, 1–60)]. Mean ± SD team total distance (TD) was 4,861 ± 871 m, with 25% (1,193 ± 329 m) “high-speed running” (>14.5 km h⁻¹) and 8% (402 ± 144 m) “sprinting” (>19.0 km h⁻¹). Reduced TD (range, −3 to 4%) and average speed (range, −3.4 to 4.7%) occurred through subsequent quarters, vs. Q1 (p < 0.05). A “large” negative relationship (r = −0.64) was found between playing duration and average speed. Positional differences (p < 0.05) were identified for all volume metrics including; playing duration (DEF, 45:50 ± 8:00 min; MID, 37:37 ± 7:12 min; FWD, 33:32 ± 6:22 min), TD (DEF, 5,223 ± 851 m; MID, 4,945 ± 827 m; FWD, 4,453 ± 741 m), sprinting distance (DEF, 315 ± 121 m; MID, 437 ± 144 m; FWD, 445 ± 129 m), and acceleration efforts (>2 m s⁻²; DEF, 48 ± 12; MID, 51 ± 11; FWD, 50 ± 14). Intensity variables similarly revealed positional differences (p < 0.05) but with a different pattern between positions; average speed (DEF, 115 ± 10 m min⁻¹; MID, 132 ± 10 m min⁻¹; FWD, 134 ± 15 m min⁻¹), sprinting (DEF, 7 ± 3 m min⁻¹; MID, 12 ± 4 m min⁻¹; FWD, 14 ± 4 m min⁻¹), and accelerations (DEF, 1.1 ± 0.3 n min⁻¹; MID, 1.4 ± 0.2 n min⁻¹; FWD, 1.5 ± 0.3 n min⁻¹). Physical outputs reduced across playing quarters, despite unlimited substitutions, demonstrating the importance of optimizing physical preparation prior to international competition. Volume and intensity data highlight specific positional requirements, with forwards displaying shorter playing durations but greater high-intensity activities than defenders.

A Comparison of Peak Intensity Periods across Male Field Hockey Competitive Standards

This investigation aimed to compare the international level peak intensity period of male field hockey players to those experienced during professional and amateur club hockey match play. Twenty-seven players from an international squad were monitored for all activity relating to field hockey over three seasons. The peak intensity period, of 3 min duration, was extracted from match play files for international and club matches. Club matches were categorised by league standard-professional vs. amateur. The output for the peak intensity period, within positions, was compared using linear mixed models (LMMs) and post hoc pairwise comparisons. Significance levels were set as p < 0.05 and Cohen's d was utilised for effect sizes. Competition level had a main effect on relative total distance (p < 0.05) and significant interaction effects were found between competition level and position (p < 0.05). Midfielders competing in amateur leagues and international match play completed less relative total distance than those who compete in professional leagues (-47.88 m/min, p < 0.05), (-46.06 m/min, p < 0.05) with large effect sizes reported. No other position displayed significant differences for peak periods. Match play in professional leagues provide opportunities for midfielders to experience peak intensity periods of a greater magnitude than international match play.

Area per player in small-sided games to replicate the external load and estimated physiological match demands in elite soccer players

The current study determined the area-per-player during small- or large-sided games with or without goalkeeper that replicates the relative (m·min^-1) total distance, high-intensity running distance, sprint distance and metabolic power covered during official matches. Time-motion analysis was performed on twenty-five elite soccer-players during 26 home-matches. A total of 2565 individual samples for SSGs using different pitch sizes and different number of players were collected and classified as SSGs with (SSG-G) or without goalkeeper (SSG-P). A between-position comparison was also performed. The area-per-player needed to replicate the official match demands was largely higher in SSG-G vs SSG-P for total distance [187±53 vs 115±35 m², effect size (ES): 1.60 95%CI 0.94/2.21], high-intensity running distance [262±72 vs 166±39 m², ES: 1.66(0.99/2.27)] and metabolic power [177±42 vs 94±40, ES: 1.99(1.31/2.67)], but similar for sprint distance [(316±75 vs 295±99 m², ES: 0.24(-0.32/0.79)] with direction of larger area-per-player for sprint distance > high-intensity running > total distance ≌ metabolic power for both SSG-G and SSG-P. In SSG-G, forwards required higher area-per-player than central-defenders [ES: 2.96(1.07/4.35)], wide-midfielders [ES: 2.45(0.64/3.78)] and wide-defenders [ES: 3.45(1.13/4.99)]. Central-midfielders required higher area-per-player than central-defenders [ES: 1.69(0.20/2.90)] and wide-midfielders [ES: 1.35(-0.13/2.57)]. In SSG-P, central defenders need lower area-per-player (ES: -6.01/-0.92) to overall replicate the match demands compared to all other positions. The current results may be used to gain knowledge of the SSGs relative to the match demands. This imply manipulating SSGs using higher or lower ApP, the presence of the goalkeeper or design specific rules to increase or decrease the position-specific demands with respect to the desired external load outcomes.

Reliability and Validity of Maximal Mean and Critical Speed and Metabolic Power in Australian Youth Soccer Players

The reliability and validity of maximal mean speed (MMS), maximal mean metabolic power (MMPmet), critical speed (CS) and critical metabolic power (CPmet) were examined throughout the 2016-2017 soccer National Youth League competitions. Global positioning system (GPS) data were collected from 20 sub-elite soccer players during a battery of maximal running tests and four home matches. A symmetric moving average algorithm was applied to the instantaneous velocity data using specific time windows (1, 5, 10, 60, 300 and 600 s) and peak values were identified. Additionally, CS and CP¬met values calculated from match data were compared to CS and CPmet values determined from previously validated field tests to assess the validity of match values. Intra-class correlation (one-way random absolute agreement) scores ranged from 0.577 to 0.902 for speed, and from 0.701 to 0.863 for metabolic power values. Coefficients of variation (CV) ranged from good to moderate for speed (4-6%) and metabolic power (4-8%). Only CS and CPmet values were significantly correlated (r = 0.842; 0.700) and not statistically different (p = 0.066; 0.271) to values obtained in a shuttle-running critical test. While the present findings identified match-derived MMS, MMPmet, CS and CPmet to be reliable, only CS and CPmet derived from match play were validated to a CS field test that required changes in speed and direction rather than continuous running. This suggests that both maximal mean and critical speed and metabolic power analyses could be alternatives to absolute distance and speed in the assessment of match running performance during competitive matches.

Physical Demands of Elite Women's Ultimate Frisbee Between Halves and Across Matches in an International Tournament

Palmer, JA, Landers, G, Buttfield, A, and Polglaze, T. Physical demands of elite women's Ultimate Frisbee between halves and across matches in an international tournament. J Strength Cond Res XX(X): 000-000, 2020-To quantify the physical match demands of elite women's Ultimate Frisbee across a tournament, elite female Ultimate players (N = 9) from the Australian Under 24 Women's team wore global positioning system units in all 12 matches of the 2018 Under 24 World Championship competition. Temporal, displacement, and energetic parameters were obtained. Distribution of activity above and below a generic speed threshold (12.42 km·h) and its equivalent metabolic power value (16.02 W·kg) were determined. Players spent 12:44 ± 6:41 min:s on the field, covered 1,559 ± 741 m and expended 8.95 ± 4.21 kJ·kg during a match. The mean stint duration was 2:00 ± 0:48 min:s, mean bench duration was 13:25 ± 7:05 min:s, and work-to-recovery ratio was 0.22 ± 0.11. Players performed 57 ± 27 high-speed runs per match and 45 ± 20 high-accelerations. Mean match speed was 127 ± 18 m·min, mean metabolic power was 12.2 ± 1.7 W·kg, and mean intermittency index was 1.24 ± 0.04. No differences were found between halves for any parameters. Compared with the first 4 matches, the last 4 matches were shorter and more intense (p < 0.05). At the international level, Ultimate is an intense and highly intermittent sport, characterized by brief playing stints interspersed with long periods of recovery, which allow playing intensity to be maintained throughout a match and elevated in the latter stages of a tournament. The information gained from this research can be used to guide the creation of Ultimate-specific conditioning programs for elite female players.

Metabolic power in hurling with respect to position and halves of match-play

The current investigation compared the metabolic power and energetic characteristics in team sports with respect to positional lines and halves of match-play. Global positioning system (GPS) technology data were collected from 22 elite competitive hurling matches over a 3-season period. A total of 250 complete match-files were recorded with players split into positional groups of full-back; half-back; midfield; half-forward; full-forward. Raw GPS data were exported into a customized spreadsheet that provided estimations of metabolic power and speed variables across match-play events (average metabolic power [P_met], high metabolic load distance [HMLD], total distance, relative distance, high-speed distance, maximal speed, accelerations, and deceleration). P_met, HMLD, total, relative and high-speed distance were 8.9 ± 1.6 W·kg^-1, 1457 ± 349 m, 7506 ± 1364 m, 107 ± 20 m·min^-1 and 1169 ± 260 m respectively. Half-backs, midfielders and half-forwards outperformed full-backs (Effect Size [ES] = 1.03, 1.22 and 2.07 respectively), and full-forwards in P_met (Effect Size [ES] = 1.70, 2.07 and 1.28 respectively), and HMLD (full-backs: ES = -1.23, -1.37 and -0.84 respectively, and full-forwards: ES = -1.77, -2.00 and -1.38 respectively). Half-backs (ES = -0.60), midfielders (ES = -0.81), and half-forwards (ES = -0.74) experienced a second-half temporal decrement in HMLD. The current investigation demonstrates that metabolic power may increase our understanding of the match-play demands placed on elite hurling players. Coaches may utilize these findings to construct training drills that replicate match-play demands.

High-Intensity Acceleration and Deceleration Demands in Elite Team Sports Competitive Match Play: A Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND

The external movement loads imposed on players during competitive team sports are commonly measured using global positioning system devices. Information gleaned from analyses is employed to calibrate physical conditioning and injury prevention strategies with the external loads imposed during match play. Intense accelerations and decelerations are considered particularly important indicators of external load. However, to date, no prior meta-analysis has compared high and very high intensity acceleration and deceleration demands in elite team sports during competitive match play.

OBJECTIVE

The objective of this systematic review and meta-analysis was to quantify and compare high and very high intensity acceleration vs. deceleration demands occurring during competitive match play in elite team sport contexts.

METHODS

A systematic review of four electronic databases (CINAHL, MEDLINE, SPORTDiscus, Web of Science) was conducted to identify peer-reviewed articles published between January 2010 and April 2018 that had reported higher intensity (> 2.5 m·s-2) accelerations and decelerations concurrently in elite team sports competitive match play. A Boolean search phrase was developed using key words synonymous to team sports (population), acceleration and deceleration (comparators) and match play (outcome). Articles only eligible for meta-analysis were those that reported either or both high (> 2.5 m·s-2) and very high (> 3.5 m·s-2) intensity accelerations and decelerations concurrently using global positioning system devices (sampling rate: ≥ 5 Hz) during elite able-bodied (mean age: ≥ 18 years) team sports competitive match play (match time: ≥ 75%). Separate inverse random-effects meta-analyses were conducted to compare: (1) standardised mean differences (SMDs) in the frequency of high and very high intensity accelerations and decelerations occurring during match play, and (2) SMDs of temporal changes in high and very high intensity accelerations and decelerations across first and second half periods of match play. Using recent guidelines recommended for the collection, processing and reporting of global positioning system data, a checklist was produced to help inform a judgement about the methodological limitations (risk of detection bias) aligned to 'data collection', 'data processing' and 'normative profile' for each eligible study. For each study, each outcome was rated as either 'low', 'unclear' or 'high' risk of bias.

RESULTS

A total of 19 studies met the eligibility criteria, comprising seven team sports including American Football (n = 1), Australian Football (n = 2), hockey (n = 1), rugby league (n = 4), rugby sevens (n = 3), rugby union (n = 2) and soccer (n = 6) with a total of 469 male participants (mean age: 18-29 years). Analysis showed only American Football reported a greater frequency of high (SMD = 1.26; 95% confidence interval [CI] 1.06-1.43) and very high (SMD = 0.19; 95% CI - 0.42 to 0.80) intensity accelerations compared to decelerations. All other sports had a greater frequency of high and very high intensity decelerations compared to accelerations, with soccer demonstrating the greatest difference for both the high (SMD = - 1.74; 95% CI - 1.28 to - 2.21) and very high (SMD = - 3.19; 95% CI - 2.05 to - 4.33) intensity categories. When examining the temporal changes from the first to the second half periods of match play, there was a small decrease in both the frequency of high and very high intensity accelerations (SMD = 0.50 and 0.49, respectively) and decelerations (SMD = 0.42 and 0.46, respectively). The greatest risk of bias (40% 'high' risk of bias) observed across studies was in the 'data collection' procedures. The lowest risk of bias (35% 'low' risk of bias) was found in the development of a 'normative profile'.

CONCLUSIONS

To ensure that elite players are optimally prepared for the high-intensity accelerations and decelerations imposed during competitive match play, it is imperative that players are exposed to comparable demands under controlled training conditions. The results of this meta-analysis, accordingly, can inform practical training designs. Finally, guidelines and recommendations for conducting future research, using global positioning system devices, are suggested.

Classification of Intensity in Team Sport Activity

PURPOSE

This study aimed to assess the efficacy of critical metabolic power derived from variable-speed movement for classifying intensity in team sport activity.

METHODS

Elite male hockey players (n = 12) completed a series of time trials (100 yards, 400 yards, 1500 yards) and a 3-min all-out test to derive both critical speed (CS) and critical power (CP). Heart rate (HR), blood lactate, and rating of perceived exertion were measured during each protocol. Participants (n = 10) then played two competitive hockey matches. Time spent greater than 85% of maximum HR was compared with time spent above CS (from the time trials) and CP (from the 3-min test).

RESULTS

Between protocols, there was a moderate and nonsignificant association for CS (r = 0.359, P = 0.252) and a very large association for CP (r = 0.754, P = 0.005); the association was very large for peak HR (r = 0.866, P < 0.001), large for blood lactate (r = 0.506, P = 0.093), and moderate for rating of perceived exertion (rho = 0.441, P = 0.152). Time trials produced higher CS (4.3 vs 2.0 m·s, P < 0.001) and CP (18.3 vs 10.5 W·kg, P < 0.001) values than did the 3-min test. In matches, there was a very large association between time spent above 85% of maximum HR and time spent above both CS (r = 0.719, P < 0.001) and CP (r = 0.867, P < 0.001). This relationship was stronger for CP compared with CS (Z = 3.29, P = 0.0007).

CONCLUSIONS

Speed is not an appropriate parameter for the classification of team sport activity comprising continual changes in speed and direction; however, critical metabolic power derived from variable-speed activity seems useful for this purpose.

Metabolic Power: A Step in the Right Direction for Team Sports

The ability of the "metabolic power" model to assess the demands of team-sport activity has been the subject of some interest-and much controversy-in team-sport research. Because the cost of acceleration depends on the initial speed and the costs of acceleration and deceleration are not "equal and opposite," changes in speed must be accounted for when evaluating variable-speed locomotion. The purpose of this commentary is to address some of the misconceptions regarding "metabolic power," acknowledge its limitations, and highlight some of the benefits that energetic analysis offers over alternative approaches to quantifying the demands of team sports.

Effect of Prior Fatiguing Sport-Specific Exercise on Field Hockey Passing Ability

PURPOSE

To evaluate the effect of multiple sets of repeated-sprint-ability (RSA)-induced fatigue on subsequent passing-skill performance in field hockey players.

METHODS

A total of 10 elite U-21 (under-21) male field hockey players performed 5 sets of a combination of RSA test (6 × 20 m, 20 s of passive recovery) followed by a 1-min passing-skill test (passing reception with subsequent passes at a predesigned target). Data on fastest sprint time and cumulated sprint time for RSA test; total number of balls played, targeted, and passing accuracy (number of balls targeted/total number of balls played) for passing-skill test; heart rate (HR), blood lactate concentration (BLa), and rating of perceived exertion (RPE)  were collected throughout the protocol.

RESULTS

RSA performance was significantly impaired from set 1 to set 5 (fastest sprint time +4.1%, P < .001; cumulated sprint time +2.3%, P < .01). For a similar average number of balls played (12.8 [1.4]) during each set, number of balls targeted (-1.7%, P < .05) and passing accuracy (-3.1%, P < .05) decreased up to the third set before reimproving over the last 2 sets. Psychophysiological responses (HR, BLa, and RPE) progressively increased (P < .05) toward protocol cessation. The decrease in passing accuracy with increasing RSA cumulated sprint time was fitted to a 2nd-order polynomial function (r2 = .94, P < .05).

CONCLUSION

Multiple-set RSA-induced fatigue was accompanied by passing-skill adjustment variation, suggesting a complex interaction between physiological and psychological/cognitive function to preserve passing skill under fatigued condition.

Positional Comparisons in the Impact of Fatigue on Movement Patterns in Hockey

PURPOSE

To examine the influence of the match period on the movement patterns of hockey players according to their playing positions under the introduction of quarters (QTRs).

METHODS

Sixteen subelite-level Spanish National League male hockey players participated in the study (age: 25.5 [2.9] y; body mass: 74.6 [5.5] kg). Global positioning system devices were used to monitor players' running performance during 17 competitive matches (113 match-play profiles). Only players who played for at least 85% of the game were analyzed. Players were placed into 3 position categories: backs, midfielders, and forwards.

RESULTS

Moderate to large differences in relative total distance were found between midfielders and both backs and forwards in all QTRs (effect size [ES]: 0.4-1.2). ES for total distance was moderate for midfielders when compared with backs during the first QTR (moderate ES: 0.7). Midfielders and forwards covered more distance (m and m·min^-1) in high-velocity zones than backs (ES: 0.6). Acceleration activities (n·min^-1) at moderate and high intensities decreased in all groups across QTRs with moderate to very large ES (ES: 0.4-1.4). Relative sprinting distance decreased in backs (ES: 0.8). Backs had fewer repeated-sprint bouts (n and n·min^-1) as the game progressed (ES: 1.0).

CONCLUSIONS

During competitive match play, a degree of positional variation can be observed across QTRs. The relative distance and the number of accelerations and decelerations at moderate and high intensity decreased across QTRs. No between-QTRs differences in high-speed activity were reported.