External Load of Flamenco Zap-3 Footwork Test: Use of PlayerLoad Concept with Triaxial Accelerometry

The intense footwork required in flamenco dance may result in pain and injury. This study aimed to quantify the external load of the flamenco Zapateado-3 (Zap-3) footwork via triaxial accelerometry in the form of PlayerLoad (PL), comparing the difference in external loads at the fifth lumbar vertebra (L5), the seventh cervical vertebra (C7) and the dominant ankle (DA), and to explore whether the speed, position, axis and proficiency level of the flamenco dancer affected the external load. Twelve flamenco dancers, divided into professional and amateur groups, completed a 15-s Zap-3 footwork routine at different speeds. Triaxial accelerometry sensors were positioned at the DA, L5 and C7 and were utilized to calculate the total PlayerLoad (PLTOTAL), uniaxial PlayerLoad (PLUNI) and uniaxial contributions (PL%). For both PLTOTAL and PLUNI, this study identified significant effects of speed and position (p < 0.001), as well as the interaction between speed and position (p ≤ 0.001), and at the DA, values were significantly higher (p < 0.001) than those at C7 and L5. Significant single axis and group effects (p < 0.001) and effects of the interactions between the position and a single axis and the group and speed (p ≤ 0.001) were also identified for PLUNI. Medial-lateral PL% represented a larger contribution compared with anterior-posterior PL% and vertical PL% (p < 0.001). A significant interaction effect of position and PL% (p < 0.001) also existed. In conclusion, the Zap-3 footwork produced a significant external load at different positions, and it was affected by speed, axis and the proficiency level of the flamenco dancer. Although the ankle bears the most external load when dancing the flamenco, some external load caused by significant vibrations is also borne by the lumbar and cervical vertebrae.

A Comparison of the External and Internal Demands Imposed during Conditioning Training and Match-Play in Semi-Professional and Development Female Netball Players

This case series, team-based study aimed to compare the demands imposed during conditioning training and match-play in netball players. Female netball players competing at semi-professional (n = 9, age: 22.2 ± 3.8 years) and development (n = 9, age: 22.3 ± 2.9 years) levels had their internal (rating of perceived exertion (RPE)) and external (relative PlayerLoad (PL) in total and in the forwards, sideways, and vertical vectors) loads measured during conditioning-based training sessions and matches in a season. Demand variables were compared between conditioning and match-play across all players and according to position in each playing level. Conditioning training imposed higher relative PL in total and in each vector compared to match-play in semi-professional and development players (small to large effects). In contrast, RPE was significantly (p = 0.006) higher during match-play than conditioning training in semi-professional and development players (medium effects). Furthermore, according to playing position, significantly higher relative PL variables were evident during conditioning training than match-play in wing attack and goalkeeper semi-professional players and in goal attack, goal shooter, goal keeper, and goal defence development players. These results suggest conditioning training practices elicit adequate external intensities but inadequate internal intensities relative to match-play across positions in semi-professional and development netball players.

Impact of Match Type on Exercise Volume and Intensity of Semi-Professional Basketball Referees During a Competitive Season

Identification of the exercise volume and intensity of basketball referees, across competitive match types based on competition sex and level, would assist in developing appropriate training regimes. Purpose: The aims of this study were to quantify and compare the exercise volume and intensity encountered by semiprofessional basketball referees during different match types across a competitive season. Method: Sixteen referees participated and were monitored for absolute and relative PlayerLoad (PL) using microsensors during 25 semiprofessional matches (12 men's, 13 women's, 17 regular season, eight playoff). Comparisons between match types (men's vs. women's; regular season vs. playoff) were examined via independent t-tests or Mann-Whitney U tests, and repeated measures ANOVA with the magnitude of differences calculated via effect size. Results: Referees experienced an absolute PL of ~365 arbitrary units (AU) per match that was similar for men's, women's, regular season, and playoff matches during a competitive season. Relative PL was significantly greater (5.35 ± 0.82 vs. 4.26 ± 0.59 AU.min^-1, p < .001, effect size = 1.57) during women's matches with a greater proportion of each quarter and match spent within PL band 2 compared to men's matches (11.6 ± 2.2 vs. 8.8 ± 1.4%, p < .001, effect size = 1.53), likely due to a reduced number of referees officiating. Minimal differences existed between the regular season and playoff matches for absolute PL, relative PL, and proportion of quarter/match time within PL bands. Conclusion: The current study confirmed that referees experienced considerable exercise volume and intensity per match during a competitive season with these influenced primarily by referee configuration. The current results provide crucial information to develop effective training regimes for referees during a competitive season.

Relationship Between External and Internal Load Measures in Youth Beach Handball

PURPOSE

Assessing the relationship between external load (EL) and internal load (IL) in youth male beach handball players.

METHODS

A total of 11 field players from the Lithuanian U17 beach handball team were monitored across 14 training sessions and 7 matches. The following EL variables were assessed by means of inertial movement units: PlayerLoad™, accelerations, decelerations, changes of direction, and jumps and total of inertial movements. IL was assessed objectively and subjectively using the summated heart rate zones and training load calculated via session rating of perceived exertion, respectively. Spearman correlations (ρ) were used to assess the relationship between EL and IL. The interindividual variability was investigated using linear mixed models with random intercepts with IL as dependent variable, PlayerLoad™ as the independent variable, and players as random effect.

RESULTS

The lowest significant (P < .05) relationship was for high jumps with objective (ρ = .56) and subjective (ρ = .49) IL. The strongest relationship was for PlayerLoad™ with objective (ρ = .9) and subjective (ρ = .84) IL. From the linear mixed model, the estimated SD of the random intercepts was 19.78 arbitrary units (95% confidence interval, 11.75-33.31); SE = 5.26, and R2 = .47 for the objective IL and 6.03 arbitrary units (95% confidence interval, 0.00-7330.6); SE = 21.87; and R2 = .71 for the subjective IL.

CONCLUSIONS

Objective and subjective IL measures can be used as a monitoring tool when EL monitoring is not possible. Coaches can predict IL based on a given EL by using the equations proposed in this study.

Assessing the External Load Associated With High-Intensity Activities Recorded During Official Basketball Games

Load monitoring in basketball is fundamental to develop training programs, maximizing performance while reducing injury risk. However, information regarding the load associated with specific activity patterns during competition is limited. This study aimed at assessing the external load associated with high-intensity activities recorded during official basketball games, with respect to different (1) activity patterns, (2) playing positions, and (3) activities performed with or without ball. Eleven male basketball players (six backcourt, five frontcourt, age: 20.5 ± 1.1 years, stature: 191.5 ± 8.7 cm, body mass: 86.5 ± 11.3 kg; experience: 8.5 ± 2.4 years) competing in the Lithuanian third division were recruited for this study. Three in-season games were assessed via time-motion analysis and microsensors. Specifically, the high-intensity activities including sprints, high-intensity specific movements (HSM) and jumps were identified and subsequently the external load [PlayerLoad™ (PL) and PlayerLoad™/min (PL/min)] of each activity was determined. Linear mixed models were used to examine differences in PL, PL/min and mean duration between activity pattern, playing positions and activities performed with or without ball. Results revealed PL was lower in jumps compared to sprints [p < 0.001, effect size (ES) = 0.68] and HSMs (p < 0.001, ES = 0.58), while PL/min was greater in sprints compared to jumps (p = 0.023, ES = 0.22). Jumps displayed shorter duration compared to sprints (p < 0.001, ES = 1.10) and HSMs (p < 0.001, ES = 0.81), with HSMs lasting longer than sprints (p = 0.002, ES = 0.17). Jumps duration was longer in backcourt than frontcourt players (p < 0.001, ES = 0.33). When considering activity patterns combined, PL (p < 0.001, ES = 0.28) and duration (p < 0.001, ES = 0.43) were greater without ball. Regarding HSMs, PL/min was higher with ball (p = 0.036, ES = 0.14), while duration was longer without ball (p < 0.001, ES = 0.34). The current findings suggest that external load differences in high-intensity activities exist among activity patterns and between activities performed with and without ball, while no differences were found between playing positions. Practitioners should consider these differences when designing training sessions.

The Influence of Playing Surface on the Loading Response to Soccer-Specific Activity

CONTEXT

The influence of playing surface on injury risk in soccer is contentious, and contemporary technologies permit an in vivo assessment of mechanical loading on the player.

OBJECTIVE

To quantify the influence of playing surface on the PlayerLoad elicited during soccer-specific activity.

DESIGN

Repeated measures, field-based design.

SETTING

Regulation soccer pitches.

PARTICIPANTS

Fifteen amateur soccer players (22.1 [2.4] y), injury free with ≥6 years competitive experience.

INTERVENTIONS

Each player completed randomized order trials of a soccer-specific field test on natural turf, astroturf, and third-generation artificial turf. GPS units were located at C7 and the mid-tibia of each leg to measure triaxial acceleration (100 Hz).

MAIN OUTCOME MEASURES

Total accumulated PlayerLoad in each movement plane was calculated for each trial. Ratings of perceived exertion and visual analog scales assessing lower-limb muscle soreness were measured as markers of fatigue.

RESULTS

Analysis of variance revealed no significant main effect for playing surface on total PlayerLoad (P = .55), distance covered (P = .75), or postexercise measures of ratings of perceived exertion (P = .98) and visual analog scales (P = .61). There was a significant main effect for GPS location (P < .001), with lower total loading elicited at C7 than mid-tibia (P < .001), but with no difference between limbs (P = .70). There was no unit placement × surface interaction (P = .98). There was also a significant main effect for GPS location on the relative planar contributions to loading (P < .001). Relative planar contributions to loading in the anterioposterior:mediolateral:vertical planes was 25:27:48 at C7 and 34:32:34 at mid-tibia.

CONCLUSIONS

PlayerLoad metrics suggest that playing surface does not influence mechanical loading during soccer-specific activity (not including tackling). Clinical reasoning should consider that PlayerLoad magnitude and axial contributions were sensitive to unit placement, highlighting opportunities in the objective monitoring of load during rehabilitation.

Workload Differences Between Training Drills and Competition in Elite Netball

PURPOSE

To examine potential differences in internal and external workload variables between playing positions and between training drills and games within an elite netball team during training and competition.

METHODS

Nine elite female netballers were monitored during 15 games and all training sessions over 28 weeks. Workload variables assessed were relative PlayerLoad (PL per minute), accelerations, decelerations, jumps, changes of direction, high-intensity events, medium-intensity events, low-intensity events, PL in a forward direction, PL in a sideways direction, PL in a vertical direction, and summated heart-rate zones using heart-rate monitors and inertial measurement units.

RESULTS

Conditioning and match play during training were the only drills that matched or exceeded game workloads. Workloads during small-sided games were lower than game workloads for all variables. In games, goalkeeper, goal attack, and goal shooter had a greater frequency of jumps compared with other positions. Midcourt positions had a greater frequency of low-intensity events in a game.

CONCLUSIONS

Workloads during small-sided games were lower than game workloads across all external and internal variables; therefore, netball staff should modify these small-sided games if they wish them to develop game-based qualities. Specific game workload variables indicate that there are differences within some positional groups; coaches need to be aware that positional groupings may fail to account for differences in workload between individual playing positions.

No Influence of Prematch Subjective Wellness Ratings on External Load During Elite Australian Football Match Play

PURPOSE

To determine whether there is an association between external match load and contextual factors on subjective wellness in the days before and after Australian Rules football match play.

METHODS

A total of 34 elite male Australian football players completed a subjective wellness questionnaire in the days leading into the match (-3, -2, and -1 d), the day of (match day), and the days after each match (+3, +2, and +1 d). Players subjectively rated each item (mood, energy, stress, leg heaviness, muscle soreness, sleep quality, hours slept, and total wellness [a sum of the total response score]) on a visual analog scale ranging from 1 to 10, with 1 representing the negative end of the continuum. External load during competitive matches was quantified using accelerometer-derived PlayerLoad, and running activity was quantified using global positioning system technology across 2 competitive seasons. The relationships between perceptions of wellness (within-individual z score), external match load, and contextual factors (match result, match location, and between-matches recovery duration) were analyzed using linear mixed models.

RESULTS

Mixed-effect linear models revealed trivial effects of match-day wellness z score on subsequent external match load metrics. Match result (win) and PlayerLoad in the anteroposterior vector (au·min-1) were associated with an increased (estimate ± SE: 0.30 ± 0.13 z score) and reduced subjective wellness (-0.15 ± 0.06 z score), respectively.

CONCLUSION

The results of this study suggest that prematch perceived wellness does not relate to external match load in elite Australian football players. The between-matches microcycle length appears to be sufficient to restore perceived wellness to values that do not affect the subsequent external match loads.

Relationships Between External- and Internal-Workload Variables in an Elite Female Netball Team and Between Playing Positions

PURPOSE

To examine relationships between external- and internal-workload variables in an elite female netball team, with consideration of positional differences.

METHODS

Nine elite female netball athletes had their weekly workloads monitored across their preseason and competition phases of a season. Internal workload was determined using summated heart-rate (HR) zones and session ratings of perceived exertion (sRPE), whereas external workload was determined using inertial movement units and included absolute PlayerLoad (PL), relative PL (PL per minute), accelerations (ACCEL), decelerations (DECEL), jumps, changes of direction (COD), high-intensity events, medium-intensity events, low-intensity events, PL in the forward direction, PL in the sideways direction, and PL in the vertical direction. Relationships between external- and internal-workload variables in the team and relative to playing position were examined.

RESULTS

Across the team, the strongest external workloads that correlated with summated HR zones were PL (r = .65), COD (r = .64), ACCEL (r = .61), and DECEL (r = .61). The strongest external workloads that correlated with sRPE were COD (r = .79), followed by jumps (r = .76), ACCEL (r = .75), and DECEL (r = .75). For all positions, except-goal shooter, the strongest correlation was between PL and sRPE (r = .88-.94). In the goal-shooter position, the strongest correlation was between summated HR zones and DECEL (r = .89).

CONCLUSIONS

The inertial movement unit-derived external-workload variables are strongly related to common internal-workload variables. In particular, COD and sRPE appear to provide a good monitoring combination of external and internal training loads for elite netball players.

Submaximal Cricket Fast Bowling Offers a Disproportionate Reduction in Loading Versus Performance: An Alternative Workload Intervention

CONTEXT

Cricket fast bowlers are particularly susceptible to lumbar spine loading and injury. Quantitative analysis of technique typically involves laboratory-based biomechanical systems with limited ecological validity, whereas contemporary developments in global positioning satellite microtechnologies facilitate an on-field evaluation of loading.

OBJECTIVE

To quantify the influence of submaximal bowling from reduced approach lengths on performance and loading.

DESIGN

Repeated-measures, field-based design.

SETTING

Regulation cricket pitch.

PARTICIPANTS

A total of 12 male cricket academy fast bowlers (18.7 [0.7] y), injury free with ≥3 years of competitive experience.

INTERVENTIONS

Each bowler wore 2 global positioning satellite units placed at C7 and L4 to measure triaxial acceleration (100 Hz). Bowlers completed an over (6 deliveries) from a randomized 3-, 6-, 9-, and 12-stride approach.

MAIN OUTCOME MEASURES

Ball speed was recorded as the performance measure, with PlayerLoad in the anteroposterior, mediolateral, and vertical planes also calculated for each delivery length.

RESULTS

In ball speed, there was a significant main effect for delivery length (P = .02), with a 3-stride approach eliciting significantly less ball speed than a 9-stride (P = .03) or 12-stride (P = .002) approach. In loading, there was a significant main effect for delivery length (P < .001) in the anteroposterior, mediolateral, and vertical planes, with loading increasing linearly as a function of delivery strides. The 6-stride approach elicited a 44% reduction in loading, with a disproportionately small 3.5% decrease in performance. There was a significant main effect for global positioning satellite location (P ≤ .023) in all planes, with L4 eliciting greater loading than C7.

CONCLUSIONS

A submaximal 6-stride approach yielded the optimum balance between reduced loading and performance inhibition. Reduced delivery length, therefore, offers an alternative to reduced overs in reducing loading in young bowlers and might also have practicable value in the rehabilitation of bowlers postinjury.

The Influence of Soccer Playing Surface on the Loading Response to Ankle (P)Rehabilitation Exercises

CONTEXT

Contemporary synthetic playing surfaces have been associated with an increased risk of ankle injury in the various types of football. Triaxial accelerometers facilitate in vivo assessment of planar mechanical loading on the player.

OBJECTIVE

To quantify the influence of playing surface on the PlayerLoad elicited during footwork and plyometric drills focused on the mechanism of ankle injury.

DESIGN

Repeated-measures, field-based design.

SETTING

Regulation soccer pitches.

PARTICIPANTS

A total of 15 amateur soccer players (22.1 [2.4] y), injury free with ≥6 years competitive experience.

INTERVENTIONS

Each player completed a test battery comprising 3 footwork drills (anterior, lateral, and diagonal) and 4 plyometric drills (anterior hop, inversion hop, eversion hop, and diagonal hop) on natural turf (NT), third-generation artificial turf (3G), and AstroTurf. Global positioning system sensors were located at C7 and the mid-tibia of each leg to measure triaxial acceleration (100 Hz).

MAIN OUTCOME MEASURES

PlayerLoad in each axial plane was calculated for each drill on each surface and at each global positioning system location.

RESULTS

Analysis of variance revealed a significant main effect for sensor location in all drills, with PlayerLoad higher at mid-tibia than at C7 in all movement planes. AstroTurf elicited significantly higher PlayerLoad in the mediolateral and anteroposterior planes, with typically no difference between NT and 3G. In isolated inversion and eversion hopping trials, the 3G surface also elicited lower PlayerLoad than NT.

CONCLUSIONS

PlayerLoad magnitude was sensitive to unit placement, advocating measurement with greater anatomical relevance when using microelectromechanical systems technology to monitor training or rehabilitation load. AstroTurf elicited higher PlayerLoad across all planes and drills and should be avoided for rehabilitative purposes, whereas 3G elicited a similar mechanical response to NT.

External Workload Can Be Anticipated During 5 vs. 5 Games-Based Drills in Basketball Players: An Exploratory Study

This study determined whether external workload could be anticipated during 5 vs. 5 games-based drills in basketball. Thirteen semi-professional, male basketball players were monitored during 5 vs. 5 training drills across the season. External workload was determined using PlayerLoad™ (AU∙min-1). The reference workload for each drill was calculated across all sessions, using bootstrapping. The bootstrap mean workload and 95% confidence intervals (CI) were then calculated for session 1, sessions 1-2, and continued for remaining sessions (1-3, 1-4, etc.), and were compared with those of the reference workload. The minimum sessions to anticipate workload for each drill was identified when the first normative value fell within ±5% or ±10% of the reference workload 95% CI. The minimum sessions were then tested to determine the accuracy to which workload could be anticipated. Three to four sessions were needed to anticipate workload within ±5%, while 2-3 sessions were needed to anticipate workload within ±10%. External workload was anticipated in 0-55% of future sessions using an error range of ±5%, and in 58-89% of sessions using an error range of ±10%. External workload during 5 vs. 5 games-based drills can be anticipated in most sessions using normative values established during a short-term monitoring period with an error range of ±10%.

Associations Between Two Athlete Monitoring Systems Used to Quantify External Training Loads in Basketball Players

Monitoring external training load (eTL) has become popular for team sport for managing fatigue, optimizing performance, and guiding return-to-play protocols. During indoor sports, eTL can be measured via inertial measurement units (IMU) or indoor positioning systems (IPS). Though each device provides unique information, the relationships between devices has not been examined. Therefore, the purpose of this study was to assess the association of eTL between an IMU and IPS used to monitor eTL in team sport. Retrospective analyses were performed on 13 elite male National Collegiate Athletic Association (NCAA) Division I basketball players (age: 20.2 ± 1.2 years, height: 201.1 ± 7.6 cm, mass: 96.8 ± 8.8 kg) from three practices during the off-season training phase. A one-way analysis of variance was used to test differences in eTL across practices. Pearson’s correlation examined the association between the Distance traveled during practice captured by IPS compared to PlayerLoad (PL), PlayerLoad per Minute (PL/Min), 2-Dimensional PlayerLoad (PL^2D), 1-Dimensional PlayerLoad Forward (PL^1D-FWD), Side (PL^1D-SIDE), and Up (PL^1D-UP) captured from the IMU. Regression analyses were performed to predict PL from Distance traveled. The eTL characteristics during Practice 1: PL = 420.4 ± 102.9, PL/min = 5.8 ± 1.4, Distance = 1645.9 ± 377.0 m; Practice 2: PL = 472.8 ± 109.5, PL/min = 5.1 ± 1.2, Distance = 1940.0 ± 436.3 m; Practice 3: PL = 295.1 ± 57.8, PL/min = 5.3 ± 1.0, Distance = 1198.2 ± 219.2 m. Significant (p ≤ 0.05) differences were observed in PL, PL^2D, PL^1D-FWD, PL^1D-SIDE, PL^1D-UP, and Distance across practices. Significant correlations (p ≤ 0.001) existed between Distance and PL parameters (Practice 1: r = 0.799–0.891; Practice 2: r = 0.819–0.972; and Practice 3: 0.761–0.891). Predictive models using Distance traveled accounted for 73.5–89.7% of the variance in PL. Significant relationships and predictive capacities exists between systems. Nonetheless, each system also appears to capture unique information that may still be useful to performance practitioners regarding the understanding of eTL.

Joint Hypermobility as a Predictor of Mechanical Loading in Dancers

CONTEXT

Dance requires the performance of complex movements that may exceed normal anatomical range. However, in hypermobile individuals, this may have implications for injury and performance.

OBJECTIVES

The aim of the study was to investigate the efficacy of the Beighton score (BS) in predicting mechanical loading in dancers in hypermobile and nonhypermobile dancers with consideration of accelerometer placement and lumbar flexion hypermobility.

DESIGN

Cohort study, clinical measurement.

SETTING

University.

PARTICIPANTS

A total of 34 dancers had their joint hypermobility assessed by the BS. Participants completed the Dance Aerobic Fitness Test with a global positioning device incorporating a triaxial accelerometer located at the cervico-thoracic junction (C7) and one at the midbelly of the gastrocnemius.

MAIN OUTCOME MEASURES

Accelerometry data were used to calculate PlayerLoad total, PlayerLoad medial-lateral, PlayerLoad anterior-posterior, and PlayerLoad vertical. Physiological response was measured via heart rate and fatigue response by rate of perceived exertion.

RESULTS

The total BS was a poor predictor of all mechanical loading directions with PlayerLoad anterior-posterior C7 (r = .15) and PlayerLoad total lower limb (r = .20) the highest values. Multiple linear regression was a better predictor with values of C7 (r = .43) and lower limb (r = .37). No significant difference existed between hypermobile and nonhypermobile subjects for mechanical loading values for all stages of the Dance Aerobic Fitness Test and for heart rate and fatigue responses.

CONCLUSIONS

The BS is not a good predictor of mechanical loading which is similar in hypermobile and nonhypermobile dancers for all levels of the Dance Aerobic Fitness Test. Mechanical loading and fatigue responses are similar between hypermobile and nonhypermobile dancers.

Accelerometer detected lateral sway during a submaximal running test correlates with endurance exercise performance in elite Australian male cricket players

OBJECTIVE

To identify whether movement patterns during a standardized submaximal running test (SSRT), assessed by accelerometry, were associated with improvements in endurance exercise performance.

DESIGN

A retrospective analysis of data collected from the 2018-2019 Australian cricket preseason.

METHODS

Thirty-nine high-performance male cricket players were studied (25±3 years, 82±6kg, 183±6cm). SSRT was performed monthly prior to a two kilometre (km) running time trial (2kmTT). SSRT involved running between markers, positioned twenty metres apart, for three minutes. Foot strikes were timed to a metronome (154beats/min) to elicit a running speed of ˜eight km/h. Triaxial accelerometers were worn in vests on the upper back and used to assess PlayerLoad medio-lateral vector (PL1D_side%), vertical vector (PL1D_up%) and anterior-posterior vector (PL1D_fwd%) were assessed.

RESULTS

2kmTT performance improved over the study period (p<0.05). PlayerLoad vectors during the first minute of SSRT were not related to 2kmTT performance (p>0.23). During the second and third minutes there were positive associations between 2kmTT (run time) and PL1D_side% (SSRT_2min, β 2.12, p<0.03, 95% CI: 0.22-4.01; SSRT3_min, β 2.30, p<0.03, 95% CI:0.32-4.29), but not PL1D_up% (SSRT_2min, β -0.15, p=0.77, 95% CI: -1.13-0.83; SSRT_3min, β -0.15, p=0.77, 95% CI: -1.11-0.87) or PL1D_fwd% (SSRT_2min, β -0.45, p=0.42, 95% CI: -1.49-0.62; SSRT_3min, B-0.45, p=0.40, 95% CI: -1.51-0.60).

CONCLUSION

Assessment of PL1D_side% during the second or third minutes of SSRT may inform how an athlete's endurance exercise performance is responding to changes in training load.

Working Overtime: The Effects of Overtime Periods on Game Demands in Basketball Players

PURPOSE

To quantify and compare internal and external workloads in regular and overtime games and examine changes in relative workloads during overtime compared with other periods in overtime games in male basketball players.

METHODS

Starting players for a semiprofessional male basketball team were monitored during 2 overtime games and 2 regular games (nonovertime) with similar contextual factors. Internal (rating of perceived exertion and heart-rate variables) and external (PlayerLoad and inertial movement analysis variables) workloads were quantified across games. Separate linear mixed-models and effect-size analyses were used to quantify differences in variables between regular and overtime games and between game periods in overtime games.

RESULTS

Session rating-of-perceived-exertion workload (P = .002, effect size 2.36, very large), heart-rate workload (P = .12, 1.13, moderate), low-intensity change-of-direction events to the left (P = .19, 0.95, moderate), medium-intensity accelerations (P = .12, 1.01, moderate), and medium-intensity change-of-direction events to the left (P = .10, 1.06, moderate) were higher during overtime games than during regular games. Overtime periods also exhibited reductions in relative PlayerLoad (first quarter P = .03, -1.46, large), low-intensity accelerations (first quarter P = .01, -1.45, large; second quarter P = .15, -1.22, large), and medium-intensity accelerations (first quarter P = .09, -1.32, large) compared with earlier periods.

CONCLUSIONS

Overtime games disproportionately elevate perceptual, physiological, and acceleration workloads compared with regular games in starting basketball players. Players also perform at lower external intensities during overtime periods than earlier quarters during basketball games.

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

PURPOSE

To compare on-ice external and internal training loads in world-class women's ice hockey during training and competition.

METHODS

On-ice training loads were collected during 1 season from 25 world-class ice hockey players via wearable technology. A total of 105 on-ice sessions were recorded, which consisted of 61 training sessions and 44 matches. Paired and unpaired t tests compared training and competition data between and across playing positions.

RESULTS

For training data, there was a difference between positions for PlayerLoad (P < .001, effect size [ES] = 0.32), PlayerLoad·minute-1 (P < .001, ES = 0.55), explosive efforts (P < .001, ES = 0.63), and training impulse (P < .001, ES = 0.48). For the competition data, there were also differences between positions for PlayerLoad (P < .001, ES = 0.26), PlayerLoad·minute-1 (P < .001, ES = 0.38), explosive efforts (P < .001, ES = 0.64), and training impulse (P < .001, ES = 1.47). Similar results were found when positions were viewed independently; competition had greater load and intensity across both positions for PlayerLoad, training impulse, and explosive efforts (P < .001, ES = 1.59-2.98) and with PlayerLoad·minute-1 (P = .016, ES = 0.25) for the defense.

CONCLUSIONS

There are clear differences in the volume and intensity of external and internal workloads between training and competition sessions. These differences were also evident when comparing the playing positions, with defense having lower outputs than forwards. These initial results can be used to design position-specific drills that replicate match demands for ice hockey athletes.

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.

Differences in PlayerLoad and pitch type in collegiate baseball players

PlayerLoad is derived from a tri-axial accelerometer device and is a measure of an athlete's external training load. Tri-axial accelerometers (Optimeye S5, Catapult Sports, Melbourne, Australia) were worn by 25 collegiate pitchers during a pitching session. Pitches included fastballs, curve balls, sliders, and changeups. Peak and sum PlayerLoad were calculated for fastballs, curve balls, sliders, and changeups. Statistical analysis included paired t-tests (p < 0.01) and effect size indexes (ESI). Peak and sum PlayerLoad were higher for fastballs compared to changeups (N = 20; ESI_peak = 0.47, p= 0.001 and ESI_Sum = 0.13, p = 0.001, respectively). Peak and sum PlayerLoad were not different comparing fastball to curveball (N = 12; ESI_peak = 0.24, p = 0.050 and ESI_Sum<0.01, p = 0.106) and fastball to slider (N = 12; ESI_peak = 0.32, p = 0.088 and ESI_Sum = 0.02, p = 0.221). Fastball velocity (37.1 ± 2.1 m/s) differed from the changeup (33.8 ± 1.9 m/s; p < 0.001), curveball (32.2 ± 1.2; p < 0.001), and slider (33.8 ± 1.3 m/s; p < 0.001). Pitching workload may differ based on pitch type. Pitch counts may not capture true player fatigue due to variability in stresses resulting from different pitch types.

The Validity of External:Internal Training Load Ratios in Rested and Fatigued Soccer Players

PURPOSE

To examine the relationship of external:internal training load ratios with fitness and assess the impact of fatigue.

METHOD

Ten soccer players performed a lactate threshold test followed by two soccer simulations (BEAST90mod) 48 h apart. Recovery (TQR) and muscle soreness (DOMS) was measured before each trial. Internal Training load (TL) (iTRIMP) and external load total distance (TD), high intensity distance (HID), PlayerLoad™ (PL) mean metabolic power (MMP) high metabolic power distance (HP) were collected for each trial and external:internal ratios produced. The relationships between ratios and velocity at lactate threshold (vLT) and velocity at Onset of Blood Lactate Accumulation (vOBLA) were examined in both trials along with changes in ratios.

RESULTS

Total Quality of Recovery and DOMS showed large changes. There were trivial to large decreases in TL from trial 1 to 2. Moderate increases in ratios for TD:iTRIMP, PL:iTRIMP and MMP:iTRIMP were seen but only small/trivial for HP:iTRIMP and HID:iTRIMP. In rested conditions all ratios show large relationships with vLT and vOBLA. However vLT vs. HID:iTRIMP; PL:iTRIMP; HP:iTRIMP and vOBLA vs. TD:iTRIMP; PL:iTRIMP; MMP:iTRIMP became weaker under fatigue.

CONCLUSIONS

Acute changes in the ratios have implications forthe use of ratios as fitness measures but also as indicators of fatigue.