On-Ice Physical Demands of World-Class Women's Ice Hockey: From Training to Competition

Identifying Key Training Load and Intensity Indicators in Ice Hockey Using Unsupervised Machine Learning

To identify key training load (TL) and intensity indicators in ice hockey, practice, and game data were collected using a wearable 200-Hz accelerometer and heart rate (HR) recording throughout a four-week (29 days) competitive period (23 practice sessions and 8 competitive games in 17 elite Danish players (n = 427 observations). Within-individual correlations among accelerometer- (total accelerations [Acctot], accelerations >2 m·s-2 [Acc2], total accelerations [Dectot], decelerations <- 2 m·s-2 [Dec2]), among HR-derived (time >85% maximum HR [t85%HRmax], Edwards' TL and modified training impulse) TL indicators, and between acceleration- and HR-derived TL parameters were large to almost perfect (r = 0.69-0.99). No significant correlations were observed between accelerometer- and HR-derived intensity indicators. Three between- and two within-components were found. The K-means++ cluster analysis revealed five and four clusters for between- and within-loadings, respectively. The least Euclidean distance from their centroid for each cluster was reported by session-duration, Acctot, Dec2, TRIMPMOD, %t85HRmax for between-loadings, whereas session-duration, Acc2, t85HRmax and Dec2/min for within-loadings. Specific TL or intensity variables might be relevant to identify similar between-subject groups (e.g. individual player, playing positions), or temporal patterns (e.g. changes in TL or intensity over time). Our study provides insights about the redundancy associated with the use of multiple TL and intensity variables in ice hockey.

Determinants of fast attack performance on match outcome in the elite women's ice hockey

The primary objective of this study was to discern the determinants affecting the ice hockey game based on the performance of the fast attack between the winning and losing teams. Data from the women's ice hockey games at the Beijing 2022 Winter Olympics (n = 28) were used. A total of 2011 fast attacks were recorded, which included winning team 1156 times and losing team 855 times. 29 variables from nine categories were involved and analysed using chi-square tests, univariate tests and binary logistic regression. As a result, that fast attack performance varies between winning and losing teams, Effective Offensive Play. Scoring Analysis of the 2005 World Championships and the 2006 Olympics, INT, DZ, OZ, one-timer, dekes, shooting zone 1, shooting zone 3, shooting zone 4, SOG, SG%, 2nd period, PK, are key variables in distinguishing the winner and loser (P<0.05). The predictive model shows that shooting zone 4 (OR = 0.824), one-timer (OR = 1.255), 2nd period (OR = 1.193), SOG (OR = 1.230), and SG% (OR = 1.170) are determining factors of game outcomes. The current information has important practical applications as it allows coaches and players to improve the tactical strategy and offensive efficiency of the game.

Analysis of Sleep, Nocturnal Physiology, and Physical Demands of NCAA Women's Ice Hockey Across a Championship Season

ABSTRACT

Merrigan, JJ, Stone, JD, Kraemer, WJ, Friend, C, Lennon, K, Vatne, EA, and Hagen, JA. Analysis of sleep, nocturnal physiology, and physical demands of NCAA women's ice hockey across a championship season. J Strength Cond Res 38(4): 694-703, 2024-The aims of this study were to evaluate the (a) relationships between daily physical demands and nighttime sleep, heart rate (HR), and heart rate variability (HRV); (b) weekly changes in physical demands and sleep; and (c) differences among positions and between training and competition during a competitive season in National Collegiate Athletic Association (NCAA) women's ice hockey. Twenty-five NCAA Division I women's ice hockey athletes wore a sensor at night to monitor sleep quantity or quality (e.g., time asleep and sleep efficiency) and physiology (e.g., HR and HRV). During training and competitions (31 regular season and 7 postseason), athletes wore performance monitoring systems to assess workload demands (e.g., training impulse and TRIMP). As internal workload (TRIMP, Time >80% of HRmax, Average HR) during training or competition increased, nocturnal HRV decreased, HR increased, and Sleep Duration, Sleep Score, and Readiness Score decreased that night. Across the season, athletes experienced lower HRV, but exhibited longer sleep durations. Training Distance, Duration, Time >80% HRmax, Average HR, and TRIMP decreased, whereas competition Total Distance, Duration, and TRIMP increased across weeks throughout the season. There were differences across positions and season blocks when evaluating these data at the mesocycle level. Athletes slept longer before competition compared with training, but physiological data did not differ. Competitions had greater physiological demands than training. We speculate that the increased focus on sleep hygiene, as evidenced by the increase in sleep over the season, may have served as a recovery aid to combat physiological stress of accumulated demands of competitions that increased over time into postseason tournaments.

Investigating the Relevance of Maximal Speed and Acceleration in Varsity-Level Female Ice Hockey Players

PURPOSE

To characterize and compare female ice hockey players' peak skating speed and acceleration ability during linear sprints and gameplay. We also sought to quantify the time spent at various speeds and the frequency of accelerations at different thresholds during games.

METHODS

Seventeen varsity-level female ice hockey players (20 [1.4] y, 68.9 [4.9] kg, 167.6 [4.7] cm) participated in an on-ice practice session (performing 3 × 40-m linear sprints) and 4 regular-season games while being monitored using a local positioning system. Speed and acceleration were recorded from the sprint and within-game monitoring. Time on ice spent in relative skating speed zones and the frequency of accelerations at different intensities were recorded.

RESULTS

Players' greatest peak speeds (29.5 [1.3] vs 28.3 [1.1] km/h) and accelerations (4.39 [0.48] vs 3.34 [0.36] m/s2) reached during gameplay were higher than those reached in linear sprinting (both P < .01). Peak in-game values were moderately predicted by linear sprint values for speed (r = .69, P < .01) but not for acceleration (r < .01, P = .95). Players spent little time at near-peak linear sprint speeds (≥80% [22.7 km/h], ∼3% time on ice; ≥90% [25.5 km/h], <1% of time on ice) during gameplay. However, 26% to 35% of accelerations recorded during the 4 games were ≥90% of linear sprint acceleration.

CONCLUSIONS

Although skating speed may be advantageous in specific game situations, our results suggest that players spend little time at near-maximal speeds while accelerating frequently during games. This warrants further investigation of direction changes, skating transitions, repeated sprints, and other determinant variables potentially related to on-ice success and the implementation of training strategies to improve repeated acceleration or qualities beyond maximal skating speed.

Reliability and validity of an indoor local positioning system for measuring external load in ice hockey players

This study determined the reliability and validity of a Kinexon local positioning system (LPS) for measuring external load in ice hockey players during an on-ice session. Fourteen ice hockey players (25.1 y, 78.6 kg, 176.9 cm) wore two LPS sensors to examine the inter-sensor reliability of the LPS during an on-ice session, and LPS speed and acceleration were measured during 40 m linear on-ice sprints and compared to a previously validated robotic sprint device to examine LPS accuracy. The coefficient of variation (CV), standard error of measurement (SEM), and intra-class correlation coefficient (ICC) were calculated for each LPS measure. Pearson's correlations, simple linear regressions, and Bland-Altman plots were used to test the agreement and relationship between the two systems. Statistical significance was determined at p < 0.05. The majority of LPS measures were reliable (CV < 10% and ICC > 0.9) when comparing the two sensors worn by each player. Peak speed, speed at 5 m, and 0-5 m acceleration were all comparable to those reported by the robotic sprint device, with nearly perfect (peak speed and 0-5 m acceleration) and very large (speed at 5 m) magnitudes of correlation and mean biases <0.5 km/hr for speed measures and <0.01 m/s² for acceleration. The present results demonstrate that the Kinexon LPS is reliable and accurate for investigating on-ice external load in ice hockey players when sensors are consistently secured on the back of the players' shoulder pads.

A Framework for the Standardization of Game Analysis in Ice Hockey

BACKGROUND

Compared with other major global team sports such as football or basketball, ice hockey has received considerably less attention in sport-science research. However, the research focus on ice hockey performance is growing rapidly. Unfortunately, despite the growing interest in ice hockey, among the little research that has been conducted there are inconsistencies in terminology and methodology in the study of physiology and performance during games. The need for systematic and standardized reporting of study methodology is vital, as a lack of methodological detail or methodological inconsistencies make it impossible to replicate published studies, and alterations in the methodologies used can influence the measured demands imposed on players. Accordingly, this prohibits the ability of coaches to generate game-replicating training programs, decreasing the application of research findings to practice. In addition, a lack of methodological detail or methodological inconsistencies can result in incorrect conclusions being made from research.

PURPOSE

In this invited commentary, we aim to increase awareness regarding the current standard of methodological reporting in ice hockey game-analysis research. In addition, we have developed a framework for the standardization of game analysis in ice hockey in order to allow for greater replication in future research and to increase the application of published findings to practice.

CONCLUSIONS

We implore researchers in the field to consult the Ice Hockey Game Analysis Research Methodological Reporting Checklist in order to adopt a detailed reporting standard of methodologies in future work to help improve the applicability of research outcomes.

Sleep in German female youth national ice hockey athletes

Background

Adequate sleep is of great importance in recovering from and preparing for training and competition.

Objective

This study aimed to investigate subjective sleep quality and daytime sleepiness of the German women’s junior national ice hockey team before and after a training camp immediately preceding the World Championship Division IA tournament.

Materials and methods

Twenty athletes (16.40 ± 0.68 years) completed German paper–pencil versions of the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale (ESS) before the training camp (T1, day 1) and on the final day of the training camp (T2, day 7).

Results

Paired t-tests indicated a significant decrease in PSQI global scores from pre- to post-training camp assessments (t = 2.33, p = 0.031, df = 19), with a medium effect size (d = 0.52). Regarding ESS global scores, results of the paired t-test indicated no significant pre- to post-training camp differences (t = 0.67, p = 0.510, df = 19) and the effect size was trivial (d = 0.15). Mean scores were reduced for both PSQI (T1 = 5.90 ± 2.36, T2 = 4.65 ± 2.18) and ESS (T1 = 9.00 ± 3.58, T2 = 8.60 ± 4.04) after the training camp. When analyzed according to the position of the players, no statistically significant intergroup differences were found.

Conclusion

This study underlines the need for monitoring and screening youth athletes’ sleep before special sports events in order to identify a potential need for intervention as early as possible, to prevent serious consequences for athletes’ performance capability and well-being.

Local Positioning System-Derived External Load of Female and Male Varsity Ice Hockey Players During Regular Season Games

Purpose

The purposes of this study were to quantify the external load for female and male varsity ice hockey players during regular season games using a local positioning system (LPS), compare LPS-derived external load between sexes and positions, and compare skating distances in absolute and relative speed zones.

Methods

Data were collected for 21 female (7 defense, 14 forwards; 20.0 ± 1.4 yrs., 69.1 ± 6.7 kg, 167.1 ± 5.4 cm) and 25 male (8 defense, 17 forwards; 21.9 ± 1.1 yrs., 85.9 ± 5.4 kg, 181.1 ± 5.2 cm) varsity ice hockey players. Measures included skating distance (total, and in absolute and relative speed zones), peak skating speed, peak acceleration and deceleration, accumulative acceleration load, and number of accelerations, decelerations, turns, skating transitions, direction changes, and impacts.

Results

Female and male players had a high external load during games, with average peak skating speeds >28 km/h and average skating distances >4.4 km. Most LPS-derived measures showed greater external load in males than females (p < 0.05). Forwards skated further at higher speeds compared to defense in both sexes (p < 0.001). Skating distances were significantly different when comparing absolute and relative speed zones (p < 0.001), with absolute speed zones potentially overestimating skating at very slow, very fast, and sprint speeds and underestimating skating at slow and moderate speeds.

Conclusion

This was the first study to measure external load in female ice hockey players with a LPS. Both female and male varsity players had high external loads during games, with forwards having greater external load at higher intensities and defense having greater external load at lower intensities. Sex and positional differences outline the importance of individualized athlete monitoring.

Simulated Game-Based Ice Hockey Match Design (Scrimmage) Elicits Greater Intensity in External Load Parameters Compared With Official Matches

Objective

A limited number of studies have explored the external load experienced in indoor sports such as ice hockey, and few the link between training and match performance. As a paucity exists within this topic, this study explored whether a simulated match design (i.e., scrimmage) could be representative of official match demands and elicit similar external loads as in official matches in a group of elite youth male ice hockey players.

Methods

A total of 26 players were monitored during eight official and four simulation matches using a Local Positioning System. Total distance, max velocity, slow (0–10.9 km/h), moderate (11–16.9 km/h), high (17.0–23.9 km/h), and sprint (>24 km/h) speed skating distance, distance per min, PlayerLoad^TM, PlayerLoad^TM per min, high-intensity events (HIEs) (>2.5 m/s⁻²), acceleration (ACCs), decelerations (DECs), and change of directions (CODs) were extracted from the tracking devices. A two-level regression analysis was conducted to compare the difference between match types when controlling for time on ice, match day, and position.

Results

Between match-type results showed a credible difference in all variables except max velocity and ACCs. Distance per min was 27.3% higher during simulation matches and was explained by a 21.3, 24.1, and 14.8% higher distance in sprint-, high-, and moderate speed skating distance, while slow speed-skating distance was 49.2% lower and total distance only trivially different from official to simulation matches. Total PlayerLoad^TM was 11.2% lower, while PlayerLoad^TM per min was 8.5% higher during simulation matches. HIEs, CODs, and DECs were 10.0, 11.9, and 22.3% higher during simulation matches.

Conclusion

The simulated match design is related to official match demands with comparable match-time, playing time, number of shifts, and shift duration. However, simulation matches provoked a higher external load output compared with official matches, possibly explained by a more continuous movement design. A game-based simulation match design can therefore be utilized when match-related actions at high intensity are warranted.

Carbohydrate Mouth-Rinsing Improves Overtime Physical Performance in Male Ice Hockey Players During On-Ice Scrimmages

Purpose

This randomized, double-blind, crossover study examined the effects of mouth-rinsing (MR) with a carbohydrate (CHO) vs. a placebo (PLA) solution on external and internal loads in hydrated ice hockey players during regulation and overtime (OT) periods of an on-ice scrimmage.

Methods

Twelve skilled male hockey players (22.6 [3.4] years, 178.9 [4.7] cm, 84.0 [6.5] kg) played three 20-min regulation periods and one 12-min OT period of small-sided 3-on-3 scrimmage. Skaters repeated 2 min shift and rest intervals. Participants mouth rinsed with 25 mL of CHO or PLA solution approximately every 10 min for a total of 7 rinses. A local positioning system (LPS) tracked external load variables including speed, distance, acceleration, and deceleration. Internal load was monitored with heart rate (HR) sensors and a rating of perceived exertion (RPE).

Results

During regulation play, both the conditions developed similar fatigue, with significantly decreased high-intensity distance, average speed and decelerations, and increased RPE, from period 1 to 2 and 3. In OT, CHO MR increased the distance skated at high-intensity (224 [77], 185 [66] m, p = 0.042), peak speed (24.6 [1.6], 23.7 [1.3] km·h⁻¹, p = 0.016), number of sprints (1.9 [1.2], 1.2 [0.9], p = 0.011), and decreased distance skated at slow speed (300 [33], 336 [47], p = 0.034) vs. PLA MR. OT RPE was similar between the two conditions in spite of more work done in CHO MR.

Conclusions

CHO MR may be a valuable practice to protect against decrements in external load with increased playing time in ice hockey, and possibly allows athletes to perform more work relative to perceived levels of exertion.

Internal Load of Male Varsity Ice Hockey Players During Training and Games Throughout an Entire Season

PURPOSE

The purpose of this study was to quantify the internal load of male varsity ice hockey players, using both sessional rating of perceived exertion (sRPE) and the heart rate-derived physiological measure of training impulse (TRIMP), during training sessions and competitions throughout an entire season.

METHODS

Twenty-seven male varsity ice hockey players (22.1 [1.1] y, 85.9 [5.4] kg, 181.3 [5.1] cm) were included in this longitudinal prospective cohort study.

RESULTS

The internal load was significantly higher (P < .001) for games (sRPE: 403 [184] arbitrary units [AU], TRIMP: 98 [59] AU) compared with training sessions (sRPE: 281 [130] AU, TRIMP: 71 [35] AU). The regular season had the highest internal load compared with the preseason and postseason. There was evidence of microcycle periodization with training sessions several days prior to game days having the highest internal load (both sRPE and TRIMP) and tapering down as the subsequent training sessions approached game day. For positional comparisons, the goalies had higher sRPE (346 [151] AU, P < .001) and TRIMP (99 [64] AU, P < .001) compared with defense (sRPE: 295 [130] AU, TRIMP: 65 [29] AU) and forwards (sRPE: 264 [123] AU, TRIMP: 70 [30] AU) for training sessions, but no significant differences were present for competitions. Finally, there was an overall moderate and statistically significant relationship between the sRPE and TRIMP internal load measures (r = .434, P < .001).

CONCLUSIONS

Internal load was greater during competitions versus training sessions in male varsity ice hockey players, and the microcycle assessment demonstrated that training sessions were tailored to game day. Mesocycle assessment revealed the highest internal loads during the regular season due to dense game scheduling and a short season.

Weekly Training Load in Elite Male Ice Hockey: Practice Versus Competition Demands

PURPOSE

The aim of this study was to compare training load (TL) between practice and games across in-season microcycles in elite Danish male ice hockey.

METHODS

Practice sessions and game data were collected using a wearable 200-Hz accelerometer, heart rate (HR) recording, and rating of perceived exertion (RPE) throughout 23 practice sessions and 8 competitive games (n = 427 files) and examined in relation to the number of days before the game (game day minus).

RESULTS

Total accelerations, accelerations >2 m·s-2 (Acc2), total decelerations, decelerations less than -2 m·s-2 (Dec2), time >85% maximum heart rate (t85HRmax), Edwards TL, modified training impulse (TRIMPMOD), session-RPE, peak HR (HRpeak), and RPE were greater during competition than during practice (r = .19-.91; P < .05), whereas total accelerations per minute and total decelerations per minute were lower (r = .27-.36; P < .001). Acc2, t85HRmax, Edwards TL and TRIMPMOD, % t85HRmax, mean HR (HRmean), and RPE progressively decreased toward game day (r = .13-.63; P < .001). Positive correlations were found between Acc2, Dec2, Acc2 per minute, and Dec2 per minute during practice and during competition (r = .66-.84; P < .001).

CONCLUSIONS

Evident within-week decreases in internal TL but not external TL were observed as the game day approached. Day-to-day variations were more pronounced in HR- and RPE-based parameters than accelerations and decelerations. Finally, the amount of intense accelerations and decelerations performed during practice was associated to the amount performed during competition, whereas physiological and perceptual demands showed no such relationship.

Internal Load of Female Varsity Ice Hockey Players During Training and Games During a Season

This study quantified internal load, using sessional rating of perceived exertion (sRPE) and heart-rate derived training impulse (TRIMP), of female varsity ice hockey players throughout a season. Twenty-four female (19.8±1.4 yr, 68.0±6.9 kg) varsity ice hockey players participated in this prospective cohort study. Internal load was captured using sRPE and TRIMP for each on-ice session. Internal load was significantly higher (p<0.05) for games (sRPE: 324±202 AU, TRIMP: 95±60 AU) compared to training (sRPE: 248±120 AU, TRIMP: 68±32 AU). Overall, goalies had a higher internal load than forwards (sRPE and TRIMP) and defence (TRIMP), with no differences between forwards and defence. Micro-cycle periodization was present, with training sessions several days prior to game days having the highest internal load (sRPE and TRIMP) and tapering down as subsequent training sessions approached game day. For the meso-cycle assessment, for both training and competition combined, the post-season sRPE was greater than the pre-season (p=0.002) and regular season (p<0.001). Lastly, the association between sRPE and TRIMP, revealed a large, statistically significant relationship (r=0.592, p<0.001). Internal load was greater during competitions, training sessions and subsequent internal loads suggested prioritization around game days, the post-season phase demanded the highest internal load and there was a strong correlation between sRPE and TRIMP.

Associations between Testing and Game Performance in Ice Hockey: A Scoping Review

BACKGROUND

Despite the exhaustive body of literature on the demands of ice hockey, less is known about the relationships between functional performance testing protocols (on ice and off ice) and performance in a game situation. The objective of this review is to provide an overview of these associations.

METHODS

This review aims to identify on- and off-ice testing currently used in the scientific literature and their possible transfer to game performance as well as identifying research gaps in this field.

RESULTS

The 17 selected studies showed that off-ice and on-ice fitness test results can be modestly transferred to the player's selection as well as global and advanced performance indicators.

CONCLUSION

This review of the literature reinforces the importance of strength and conditioning coaches administering previously validated fitness tests. Regarding the academic research, it is also proposed to use performance markers that are directly related to the players' on-ice performance to represent more accurately the relationship between the players' fitness level and their work output. Three research gaps were also identified in relation to targeted populations, choice of performance markers and data measurement methods.

Impact of Preceding Workload on Team Performance in Collegiate Men's Ice Hockey

ABSTRACT

Neeld, KL, Peterson, BJ, Dietz, CC, Cappaert, TA, and Alvar, BA. Impact of preceding workload on team performance in collegiate men's ice hockey. J Strength Cond Res 35(8): 2272-2278, 2021-Although the workload-injury relationship has received ample research attention, the relationship between prior workload and performance in team sport remains poorly understood. The purpose of this study was to determine if preceding workloads influence competition performance in men's ice hockey. On-ice workload data were collected from all players on a NCAA Division I men's ice hockey team for 2 consecutive seasons. Training and match workloads were characterized using 7 variables (player load, skating load, explosive efforts, high force strides, player load·min-1, skating load·min-1, and average stride force·lb-1). Team performance was calculated as the difference between the subject and opposing teams' shots on goal. Nine separate ANCOVAs were performed to assess the effect of workload across quartiles of 5 different time spans (1,3,5,7 and 28 days), and low, typical, and high zones of 4 time ratios (1/28, 3/28, 5/28, and 7/28) days) on team shot differential, accounting for season quarter and rank differential between the subject and opposing team. Alpha was set a priori to 0.05. Of all workload measures included in each analysis, only 7-day high force strides (p < 0.01, eta2 = 0.72), and 7-day player load·min-1 (p < 0.05, eta2 = 0.50) had a significant effect on shot differential. Measures of skating intensity in the week preceding competition have the largest impact on team performance. These results can be used by performance coaches to examine tests of speed, power, strength, and conditioning to identify potential limiting factors to high-intensity skating, design training programs with specific need-based emphases, and make recommendations for weekly management of high-intensity skating loads.

Use of Rating of Perceived Exertion-Based Training Load in Elite Ice Hockey Training and Match-Play

ABSTRACT

Rago, V, Vigh-Larsen, JF, Deylami, K, Muschinsky, A, and Mohr, M. Use of rating of perceived exertion-based training load in elite ice hockey training and match-play. J Strength Cond Res XX(X): 000-000, 2020-Training load (TL) based on the subjective rating of perceived exertion (RPE) may be a useful athlete monitoring alternative when wearable technology is unavailable. The aim of this study was to examine the validity of RPE-based TL monitoring in elite ice hockey. A male ice hockey team (n = 18) was monitored using a 200-Hz accelerometer, heart rate (HR) and RPE (0-10 scale), throughout a 4-week competitive period (n = 309 individual observations). Session-RPE (RPE × duration) averaged 244.8 ± 135.2 and 728.6 ± 150.9 arbitrary units (AU) during practice sessions and during official games, respectively. The smallest worthwhile change was 19.8 AU. Within-individual correlations between session-RPE and total accelerations >0.5 m·s-2 (Acctot), accelerations >2 m·s-2 (Acc2), total decelerations >-0.5 m·s-2 (Dectot), decelerations < -2 m·s-2 (Dec2), time > 85% maximum HR, Edwards' TL, and modified training impulse were very large (r = 0.70-0.89; p < 0.001). In addition, correlations between RPE and measures of exercise intensity (Acctot per min, Acc2 per min, Dectot per min, mean HR, and peak HR) were small (r = 0.02-0.29; p < 0.05) except for Dec2 being unclear (p = 0.686). Differences in intensity parameters between RPE range (easy to very hard, 2-7 AU) were small (r = 0.22-0.31; p < 0.05). The session-RPE method can be used as a global indicator of TL in ice hockey. Specific ranges of time-motion and HR intensity variables can be demarcated between RPE categories (easy to very hard; 2-7 AU). Accounting for training volume (session-RPE) more accurately reflects objective methods of TL based on accelerative efforts and HR, than the RPE score (based on the perception of the intensity).

Validation of Wearable Sensors during Team Sport-Specific Movements in Indoor Environments

The aim of this study was to determine possible influences, including data processing and sport-specific demands, on the validity of acceleration measures by an inertial measurement unit (IMU) in indoor environments. IMU outputs were compared to a three-dimensional (3D) motion analysis (MA) system and processed with two sensor fusion algorithms (Kalman filter, KF; Complementary filter, CF) at temporal resolutions of 100, 10, and 5 Hz. Athletes performed six team sport-specific movements whilst wearing a single IMU. Mean and peak acceleration magnitudes were analyzed. Over all trials (n = 1093), KF data overestimated MA resultant acceleration by 0.42 ± 0.31 m∙s⁻² for mean and 4.18 ± 3.68 m∙s⁻² for peak values, while CF processing showed errors of up to 0.57 ± 0.41 m∙s⁻² and −2.31 ± 2.25 m∙s⁻², respectively. Resampling to 5 Hz decreased the absolute error by about 14% for mean and 56% for peak values. Still, higher acceleration magnitudes led to a large increase in error. These results indicate that IMUs can be used for assessing accelerations in indoor team sports with acceptable means. Application of a CF and resampling to 5 Hz is recommended. High-acceleration magnitudes impair validity to a large degree and should be interpreted with caution.

On-Ice Measures of External Load in Relation to Match Outcome in Elite Female Ice Hockey

The aim of this study is to investigate the differences between select on-ice measures using inertial movement sensors based on match outcome, and to determine changes in player movements across three periods of play. Data were collected during one season of competition in elite female ice hockey players (N = 20). Two-factor mixed effects ANOVAs for each skating position were performed to investigate the differences in match outcome, as well as differences in external load measures during the course of a match. For match outcome, there was a small difference for forwards in explosive ratio (p = 0.02, ES = 0.26) and percentage high force strides (p = 0.04, ES = 0.50). When viewed across three periods of a match, moderate differences were found in skating load (p = 0.01, ES = 0.75), explosive efforts (p = 0.04, ES = 0.63), and explosive ratio (p = 0.002, ES = 0.87) for forwards, and in PlayerLoad (p = 0.01, ES = 0.70), explosive efforts (p = 0.04, ES = 0.63), and explosive ratio (p = 0.01, ES = 0.70) for defense. When examining the relevance to match outcome, external load measures associated with intensity appear to be an important factor among forwards. These results may be helpful for coaches and sport scientists when making decisions pertaining to training and competition strategies.