The Reliability of Neuromuscular and Perceptual Measures Used to Profile Recovery, and the Time-Course of Such Responses Following Academy Rugby League Match-Play

In professional academy rugby league (RL) players, this two-part study examined; (A) the within- and between-day reliability of isometric mid-thigh pulls (IMTP), countermovement jumps (CMJ), and a wellness questionnaire (n = 11), and (B) profiled the responses with acceptable reliability (no between-trial differences and between-day coefficient of variation (CV) ≤10% and intraclass correlation coefficient (ICC) ≥0.8) for 120 h (baseline: −3, +24, +48, +72, +96, +120 h) following RL match-play (n = 10). In part A, force at 200, and 250 ms, and peak force (PF) demonstrated acceptable within- (CV%: 3.67–8.41%, ICC: 0.89–0.93) and between-day (CV%: 4.34–8.62%, ICC: 0.87–0.92) reliability for IMTP. Most CMJ variables demonstrated acceptable within-day reliability (CV%: 3.03–7.34%, ICC: 0.82–0.98), but only six (i.e., flight-time, PF, peak power (PP), relative PP, velocity at take-off (VTO), jump-height (JH)) showed acceptable between-day reliability (CV%: 2.56–6.79%, ICC: 0.83–0.91). Only total wellness demonstrated acceptable between-day reliability (CV%: 7.05%, ICC: 0.90) from the questionnaire. In part B, reductions of 4.75% and 9.23% (vs. baseline; 2.54 m∙s−1; 0.33 m) occurred at +24 h for CMJ VTO, and JH, respectively. Acceptable reliability was observed in some, but not all, variables and the magnitude and time-course of post-match responses were test and variable specific. Practitioners should therefore be mindful of the influence that the choice of recovery monitoring tool may have upon the practical interpretation of the data.

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Between-session reliability of performance and asymmetry variables obtained during unilateral and bilateral countermovement jumps in basketball players

PLoS ONE ◽

10.1371/journal.pone.0255458 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0255458

Author(s):

Alejandro Pérez-Castilla ◽

Amador García-Ramos ◽

Danica Janicijevic ◽

Gabriel Delgado-García ◽

Juan Carlos De la Cruz ◽

...

Keyword(s):

Peak Power ◽

Peak Velocity ◽

Jump Height ◽

Mean Power ◽

Basketball Players ◽

Performance Variables ◽

Velocity Peak ◽

Power Peak ◽

Force Velocity ◽

Acceptable Reliability

This study aimed to evaluate the between-session reliability of single-leg performance and asymmetry variables during unilateral and bilateral countermovement jumps (CMJ). Twenty-three basketball players completed two identical sessions which consisted of four unilateral CMJs (two with each leg) and two bilateral CMJs. Mean and peak values of force, velocity and power, impulse, and jump height were obtained separately for each leg using a dual force platform. All performance variables presented an acceptable reliability (CVrange = 4.05–9.98%) with the exceptions of jump height for the unilateral CMJs and mean power, peak velocity, peak power, and impulse for the left leg during the bilateral CMJ (CV≥11.0%). Nine out of 14 variables were obtained with higher reliability during the unilateral CMJ (CVratio≥1.16), and 4 out of 14 during the bilateral CMJ (CVratio≥1.32). Asymmetry variables always showed an unacceptable reliability (ICCrange = 0.15–0.64) and poor/slight levels of agreement in direction (Kapparange = -0.10 to 0.15) for the unilateral CMJ, while an acceptable reliability (ICCrange = 0.74–0.77) and substantial levels of agreement in direction (Kapparange = 0.65 to 0.74) were generally obtained for the bilateral CMJ. These results suggest that single-leg performance can be obtained with higher reliability during the unilateral CMJ, while the bilateral CMJ provides more consistent measures of inter-limb asymmetries.

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Quantifying Fatigue in the Rugby Codes: The Interplay Between Collision Characteristics and Neuromuscular Performance, Biochemical Measures, and Self-Reported Assessments of Fatigue

Frontiers in Physiology ◽

10.3389/fphys.2021.711634 ◽

2021 ◽

Vol 12 ◽

Author(s):

Mitchell Naughton ◽

Scott McLean ◽

Tannath J. Scott ◽

Dan Weaving ◽

Colin Solomon

Keyword(s):

Time Course ◽

Time Windows ◽

Rugby League ◽

Rugby Union ◽

Primary Role ◽

Match Play ◽

Neuromuscular Performance ◽

Objective Metrics ◽

The Hours ◽

Latent Structures

Locomotor and collision actions that rugby players complete during match-play often lead to substantial fatigue, and in turn, delays in recovery. The methods used to quantify post-match fatigue and recovery can be categorised as subjective and objective, with match-related collision characteristics thought to have a primary role in modulating these recovery measures. The aim of this review was to (1) evaluate how post-match recovery has been quantified in the rugby football codes (i.e., rugby league, rugby union, and rugby sevens), (2) to explore the time-course of commonly used measures of fatigue post-match, and (3) to investigate the relationships between game-related collisions and fatigue metrics. The available evidence suggests that upper-, and lower-body neuromuscular performance are negatively affected, and biomarkers of muscular damage and inflammation increase in the hours and days following match-play, with the largest differences being at 12–36 h post-match. The magnitude of such responses varies within and between neuromuscular performance (Δ ≤ 36%, n = 13 studies) and tissue biomarker (Δ ≤ 585%, n = 18 studies) measures, but nevertheless appears strongly related to collision frequency and intensity. Likewise, the increase in perceived soreness in the hours and days post-match strongly correlate to collision characteristics across the rugby football codes. Within these findings, there are specific differences in positional groups and recovery trajectories between the codes which relate to athlete characteristics, and/or locomotor and collision characteristics. Finally, based on these findings, we offer a conceptual model of fatigue which details the multidimensional latent structure of the load to fatigue relationship contextualised to rugby. Research to date has been limited to univariate associations to explore relationships between collision characteristics and recovery, and multivariate methods are necessary and recommended to account for the latent structures of match-play external load and post-match fatigue constructs. Practitioners should be aware of the typical time windows of fatigue recovery and utilise both subjective and objective metrics to holistically quantify post-match recovery in rugby.

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COMPARISON OF THREE DIFFERENT MEASUREMENT SYSTEMS TO ASSESS THE VERTICAL JUMP HEIGHT

Revista Brasileira de Medicina do Esporte ◽

10.1590/1517-869220202602185305 ◽

2020 ◽

Vol 26 (2) ◽

pp. 143-146

Author(s):

Jose Heredia-Jimenez ◽

Eva Orantes-Gonzalez

Keyword(s):

Numerical Integration ◽

Integration Method ◽

Intraclass Correlation ◽

Flight Time ◽

Force Platform ◽

Measurement Unit ◽

Maximum Height ◽

Jump Height ◽

Numerical Integration Method ◽

Gold Standard Method

ABSTRACT Introduction: The numerous instruments used to measure jump height use different technologies and calculations that can provide variable results. Objective: This study compared the countermovement jump (CMJ) height assessed with a wearable 3D inertial measurement unit (IMU), using flight time and the numerical integration method with a force platform and photocells. Methods: Forty CMJs were analysed, starting from an upright standing position with the hands placed on the waist. Twenty healthy volunteers completed 2 CMJs, which were simultaneously assessed using an IMU placed on the subject's sacrum, a force platform (considered the gold standard method) and photocells. The maximum height of each CMJ was measured. Results: The results showed a significant overestimation (p<0.001) in jump height for the IMU using the numerical integration method when compared to the force platform (+7 cm). Excellent intraclass correlation coefficients (ICCs) were obtained with the flight time equations for the different types of measurement equipment. Fair to good ICCs were obtained with the IMU using the numerical integration method and force platform. Conclusion: In conclusion, the jump height obtained with the IMU using the numerical integration method showed the poorest agreement compared to the force platform. Level of evidence III; Prospective comparative study.

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Correlation and Reliability of Two Field Tests for Vertical Jump Height

The Asian Journal of Kinesiology ◽

10.15758/ajk.2020.22.1.9 ◽

2020 ◽

Vol 22 (1) ◽

pp. 9-14 ◽

Cited By ~ 2

Author(s):

YongSuk Lee ◽

Kyeong Eun Min ◽

Jihong Park

Keyword(s):

High Reliability ◽

Pearson Correlation ◽

Vertical Jump ◽

Intraclass Correlation ◽

Field Tests ◽

Flight Time ◽

Whole Body ◽

Jump Height ◽

Vertical Jump Height ◽

Highly Correlated

OBJECTIVES This study established the relationship and reliability of vertical jump height measurements using both the jump-reach method and the flight-time method.METHODS Sixteen healthy subjects (13 males and 3 females, body mass index: 22.5 kg/m<sup>2</sup>) visited the laboratory twice with at least two days between visits. During each visit, they performed three successful trials of one- and two-legged maximal vertical jumps on a Vertec jump tester (the jump-reach method). Simultaneously, two digital cameras were videotaped, one for a whole body view and another for a view of the feet (240 frame rate and 1/1000 s shutter speed). Flight-times were measured using a free motion analysis software (Kinovea 0.8.15) and were then inserted into the formula h = t<sup>2 </sup>× 122.625 to calculate the height. To determine if the jump values from each method were correlated, average values from the three trials for both jump methods were analyzed using Pearson correlation and simple linear regression tests. To establish a within- and between-session reliability, the intraclass correlation coefficients (ICCs) were calculated.RESULTS Assessed vertical jump heights using the two methods were highly correlated with each other (r values ranged between 0.86 and 0.93 with p<0.0001 for all tests) and showed high reliability (ICC values ranged between 0.73 and 0.99 for all tests).CONCLUSIONS Vertical jump heights assessed by the two field tests were highly correlated and consistent. Although the flight-time method calculates less jump heights, the underestimated amount can be estimated by the established equations. We suggest that athletes and coaches use either technique in the field in consideration of advantages for each method.

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Physiological and perceptual responses to training and competition in elite female netball players

10.23889/suthesis.58707 ◽

2021 ◽

Author(s):

◽

Laurence Birdsey

Keyword(s):

Strength Training ◽

Power Output ◽

Peak Power ◽

Peak Velocity ◽

Training Session ◽

Peak Power Output ◽

Jump Height ◽

Match Play ◽

Neuromuscular Performance ◽

The Impact

Few studies have reported the physical demands of, and physiological responses to, training and competition in international netball players. This thesis set out to investigate this in female players via a series of studies. Study one characterised the playing demands of international match-play, and the physiological and perceptual responses to an international netball tournament. Mid-court performed at a higher Player LoadTM (mean difference ± standard deviation: 85.7% ± 49.6%), and internal intensity (mean heart rate: 3.7% ± 3.8%) than goal-based positions. Neuromuscular performance decreased after a single match (jump height: 4.0% ± 2.5%) whilst markers of muscle damage, soreness and perceived fatigue accumulated across the tournament. Study two characterised the physiological and perceptual responses to a regularly performed netball-training session. Neuromuscular performance was enhanced immediately post-exercise (Cohen’s d effect size, percent change: peak power output: 0.47, 5%), returned to baseline two hours post, and was reduced 24 h post-training (peak power output: 0.27, 3%; jump height: 0.39, 6%). Study three investigated the effect of training-session order. Performing netball prior to strength training resulted in enhanced neuromuscular performance two hours post-training (peak power output: 1.2, 5%; jump height: 1.2, 9%; peak velocity: 1.0, 3%), whilst strength followed by netball reduced neuromuscular performance at 20 h post (peak power output: 1.1, 4%; jump height: 1.4, 10%; peak velocity: 1.4, 4%). This thesis provides a detailed investigation in to the responses to netball training and competition, as well as the impact of training-session order on neuromuscular, perceptual and endocrine responses over 20 h. Training should be individualised to condition players for the positional-specific external and internal demands of international match-play. To optimise training performance, two hours post-training could be a more favourable time to perform explosive training than the following day, whilst technical netball training should precede strength training when both sessions are performed within the same training day.

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5 Examination of the relationship between changes in workload and changes in loaded countermovement jump during a rugby union season

British Journal of Sports Medicine ◽

10.1136/bjsm-2021-basemabs.5 ◽

2021 ◽

Vol 55 (16) ◽

pp. 941.3-942

Author(s):

Rob Strong ◽

Daniel West ◽

Joe Kupsarevic

Keyword(s):

Peak Power ◽

Rank Order ◽

Rugby Union ◽

Countermovement Jump ◽

Match Play ◽

Time To Peak ◽

Significant Relationships ◽

Flight Season ◽

Acute Changes ◽

The Relationship

BackgroundThe loaded countermovement jump (CMJ) is a variation on the normal CMJ (bodyweight-only), used routinely in sport settings as a measure of neuromuscular fatigue (NMF). Although commonplace, the CMJ variables that are most sensitive to NMF remain somewhat unclear.PurposeThe aim of this study was to examine the relationship between changes in workload and changes in the loaded CMJ; specifically, to determine its suitability for assessment of NMF.MethodsEighteen professional rugby union players performed loaded CMJ tests on seven occasions over the course of thirteen weeks, during an English top-flight season. Eight CMJ variables were measured, assessing different aspects of the CMJ. Workload was measured by GPS total distance and was the sum of the previous week’s data, recorded in on-field training and match-play. Spearman’s rank-order correlations were calculated to identify the relationship between changes in workload and changes in loaded CMJ variables.ResultsNo significant relationships were found between loaded CMJ variables and workload with no lag or workload lagged one week. Significant relationships were found between workload lagged 2 weeks and flight time/contact time (FT-CT; rs=-0.35; p=0.04) and time to peak power (TtPP; rs=0.35; p=0.05).ConclusionThis study suggests loaded CMJ is not a suitable test to monitor acute changes to NMF. However, results also indicate that FT-CT and TtPP, are associated with changes in workload lagged 2-weeks. Therefore, certain CMJ variables may prove useful to help prescribe alterations to athlete training plans following periods of heavy workload.

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The validity and reliability of a novel mobile app to measure agility performance in the physically active youth population

European Journal of Human Movement ◽

10.21134/eurjhm.2020.45.9 ◽

2020 ◽

Vol 45 ◽

pp. 85-92

Author(s):

Juan A. Escobar-Alvarez ◽

Rocio Carrasco ◽

Pedro R. Olivares ◽

Sebastián Feu ◽

Robinson Ramírez-Velez ◽

...

Keyword(s):

Correlation Analysis ◽

Confidence Interval ◽

Standard Error ◽

Low Cost ◽

Intraclass Correlation ◽

Mobile App ◽

Validity And Reliability ◽

Physically Active ◽

Youth Population ◽

Acceptable Reliability

Agility is a key component of physical fitness in adolescents. However, the measurement of this variable is usually complex, requiring high cost instruments and complex software. To test the validity and reliability of a novel iPhone app (Lap Tracker Auto-timer) to measure agility performance among adolescents. Twenty-four physically active adolescents (15.7 ± 2.3 years old) participated in two testing sessions (separated by 7 days). They performed three 4 x 10 m agility test trials measured by Photocell or the iPhone app. The correlation analysis revealed high validity (r = .92; 95% confidence interval [CI] = .88 – .95), with a standard error of the estimate of 0.56 s (p < 0.001). The coefficient of variation (CV; 0.09) and intraclass correlation coefficient (ICC; .93; 95% CI = .85 – .97) showed an acceptable reliability. This study demonstrated that the iPhone App Lap Tracker Auto-timer could be a valid, reliable and low-cost tool to evaluate agility performance in adolescents. However, more studies are required to guarantee the utility of this app.

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Can We Rely on Flight Time to Measure Jumping Performance or Neuromuscular Fatigue-Overload in Professional Female Soccer Players?

Applied Sciences ◽

10.3390/app10134424 ◽

2020 ◽

Vol 10 (13) ◽

pp. 4424

Author(s):

Estrella Armada-Cortés ◽

Javier Peláez Barrajón ◽

José Antonio Benítez-Muñoz ◽

Enrique Navarro ◽

Alejandro F. San Juan

Keyword(s):

Gold Standard ◽

Vertical Jump ◽

Intraclass Correlation ◽

Smartphone Application ◽

Flight Time ◽

Neuromuscular Fatigue ◽

Football Players ◽

Validity And Reliability ◽

Jumping Performance ◽

Significant Difference

The main purpose of this study was to compare the validity of the take-off velocity method (TOV) measured with a force platform (FP) (gold standard) versus the flight time method (FT) in a vertical jump to measure jumping performance or neuromuscular fatigue-overload in professional female football players. For this purpose, we used a FP and a validated smartphone application (APP). A total of eight healthy professional female football players (aged 27.25 ± 6.48 years) participated in this study. All performed three valid trials of a countermovement jump and squat jump and were measured at the same time with the APP and the FP. The results show that there is a lack of validity and reliability between jump height (JH) calculated through the TOV method with the FP and the FT method with the FP (r = 0.028, p > 0.84, intraclass correlation coefficient (ICC) = −0.026) and between the JH measured with the FP through the TOV method and the APP with the FT method (r = 0.116, p > 0.43, ICC = −0.094 (−0.314–0.157)). A significant difference between the JH measured through the TOV with the FP versus the APP (p < 0.05), and a trend between the JH obtained with the FP through the TOV and the FT (p = 0.052) is also shown. Finally, the JH with the FP through the FT and the APP did not differ (p > 0.05). The eta-squared of the one-way ANOVA was η2 = 0.085. It seems that only the TOV measured with a FP could guarantee the accuracy of the jump test in SJ+CMJ and SJ, so it is recommended that high-level sportswomen and men should be assessed with the FP through TOV as gold standard technology to ensure correct performance and/or fatigue-overload control during the sport season.

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Audio-Based System for Automatic Measurement of Jump Height in Sports Science

Sensors ◽

10.3390/s19112543 ◽

2019 ◽

Vol 19 (11) ◽

pp. 2543

Author(s):

Basilio Pueo ◽

Jose J. Lopez ◽

Jose M. Jimenez-Olmedo

Keyword(s):

High Speed ◽

Muscle Power ◽

Audio Signal ◽

Automatic Measurement ◽

Flight Time ◽

Systematic Bias ◽

Jump Height ◽

Random Errors ◽

Signal Processing Algorithm ◽

Sports Science

Jump height tests are employed to measure the lower-limb muscle power of athletic and non-athletic populations. The most popular instruments for this purpose are jump mats and, more recently, smartphone apps, which compute jump height through manual annotation of video recordings to extract flight time. This study developed a non-invasive instrument that automatically extracts take-off and landing events from audio recordings of jump executions. An audio signal processing algorithm, specifically developed for this purpose, accurately detects and discriminates the landing and take-off events in real time and computes jump height accordingly. Its temporal resolution theoretically outperforms that of flight-time-based mats (typically 1000 Hz) and high-speed video rates from smartphones (typically 240 fps). A validation study was carried out by comparing 215 jump heights from 43 active athletes, measured simultaneously with the audio-based system and with of a validated, commercial jump mat. The audio-based system produced nearly identical jump heights than the criterion with low and proportional systematic bias and random errors. The developed audio-based system is a trustworthy instrument for accurately measuring jump height that can be readily automated as an app to facilitate its use both in laboratories and in the field.

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A constant-load ergometer for measuring peak power output and fatigue

Journal of Applied Physiology ◽

10.1152/jappl.1988.65.5.2343 ◽

1988 ◽

Vol 65 (5) ◽

pp. 2343-2348 ◽

Cited By ~ 18

Author(s):

J. H. Williams ◽

W. S. Barnes ◽

J. F. Signorile

Keyword(s):

Power Output ◽

Peak Power ◽

Intraclass Correlation ◽

Average Power ◽

Load Cycle ◽

Constant Load ◽

Load Cell ◽

Peak Power Output ◽

Maximal Power Output ◽

Power Curves

A constant-load cycle ergometer was constructed that allows maximal power output to be measured for each one-half pedal revolution during brief, high-intensity exercise. To determine frictional force, an electronic load cell was attached to the resistance strap and the ergometer frame. Dead weights were attached to the strap's free end. Flywheel velocity was recorded by means of a magnetic switch and two magnets placed on the pedal sprocket. Pedaling resulted in magnetically activated switch closures, which produced two electronic pulses per pedal revolution. Pulses and load cell output were recorded (512 Hz), digitized, and stored on disk via microcomputer. Power output was later computed for each pair of adjacent pulses, representing average power per one-half pedal revolution. Power curves generated for each subject were analyzed for peak power output (the highest one-half pedal revolution average), time to peak power, power fatigue rate and index, average power, and total work. Thirty-eight males performed two 15-s tests separated by 15 min (n = 16) or 48 h (n = 22). Peak power output ranged from 846.0 to 1,289.1 W. Intraclass correlation analysis revealed high test-retest reliability for all parameters recorded on the same or different days (R = 0.91-0.97). No significant differences (P greater than 0.05) were noted between parameter means of the first and second tests. These results indicate that the ergometer described provides a means for conveniently and reliably assessing short-term power output and fatigue.

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