Perceptions of lung function surveillance in urban firefighters.

BACKGROUND AND OBJECTIVE: Workplace health and safety (WHS) is an important responsibility falling on both employers and employees and is most effective when the perspectives of all stakeholders are considered. This study aimed to explore the facilitators and barriers to a voluntary workplace lung function surveillance program from the perspective of urban firefighters and describe their perceptions of its value. METHODS: Using a qualitative, descriptive methodology, firefighters who had participated in a longitudinal lung function surveillance study were invited to participate in semi-structured interviews. Purposeful, maximum variation sampling was used to achieve diversity in those firefighters invited to participate. We used inductive content analysis to identify themes. RESULTS: Interviews with 15 firefighters identified 3 main themes: (i) practical experience of surveillance (administration, communication, workplace culture change, convenience, acceptability, and appeal); (ii) value of surveillance (lung health efficacy and control, social support, workplace management support/motivations, contribution to global firefighter health); and (iii) contribution of surveillance to health (occupational risk, relevance in the context of total health, workability, and fitness and future value). CONCLUSION: Practical and psychosocial facilitators and barriers to providing lung function surveillance in the fire service were identified. In addition to the personal benefits of detecting adverse lung health and allowing for medical intervention, factors known to positively influence firefighter workplace wellbeing, such as providing peace of mind, feedback on good work practices, motivation to utilize control measures, management commitment to health, and providing data to assist with global knowledge were valued aspects of longitudinal lung function surveillance.

Oxygen uptake and heart rate responses to 4 weeks of RPE-guided handcycle training.

PURPOSE: To investigate the efficacy of using Ratings of Perceived Exertion (RPE) to prescribe and regulate a 4-week handcycle training intervention. METHODS: Thirty active adults, untrained in upper body endurance exercise, were divided into three groups to complete a 4-week intervention: (i) RPE-guided training (n = 10; 2 female), (ii) power output (PO)-guided (n = 10; 2 female) training, or (iii) non-training control (n = 10; 4 female). Training groups performed three sessions of handcycling each week. Oxygen uptake ([Formula: see text]), heart rate (HR), and Feeling Scale (FS) rating were collected during training sessions. RPE-guided training was performed at RPE 13. PO-guided training was matched for percentage of peak PO per session, based upon that achieved by the RPE-guided training group. RESULTS: There were no differences in percentage of peak [Formula: see text] (66 ± 13% vs 61 ± 9%, p = 0.22), peak HR (75 ± 8% vs 71 ± 6%, p = 0.11) or FS rating (1.2 ± 1.9 vs 0.8 ± 1.6, p = 0.48) between RPE- and PO-guided training, respectively. The average coefficient of variation in percentage of peak HR between consecutive training sessions was 2.8% during RPE-guided training, and 3.4% during PO-guided training. CONCLUSION: Moderate-vigorous intensity handcycling exercise can be prescribed effectively using RPE across a chronic training intervention, suggesting utility for practitioners in a variety of rehabilitation settings.

Ratings of perceived exertion from a submaximal 20-m shuttle run test predict peak oxygen uptake in children and the test feels better.

PURPOSE: To determine the validity and test-retest reliability of using ratings of perceived exertion (RPE) elicited during a submaximal 20-m Shuttle Run Test (20mSRT) to predict VO2peak in children and investigate acute affective responses. METHODS: Twenty-five children (14 boys; age, 12.8 ± 0.7 years; height, 162.0 ± 9.3 cm; mass, 49.9 ± 7.7 kg) completed four exercise tests (GXT, 2 submaximal 20mSRT, maximal 20mSRT). The Eston-Parfitt RPE scale was used, and affect was measured with the Feeling Scale. Submaximal 20mSRT were terminated upon participants reporting RPE7. The speed-RPE relationship from the submaximal 20mSRTs was extrapolated to RPE9 and 10 to predict peak speed and then used to estimate VO2peak. RESULTS: Repeated measures ANOVA to examine the validity of using submaximal RPE to predict VO2peak resulted in a Gender main effect (boys = 46.7 ± 5.1 mL kg-1 min-1; girls = 42.0 ± 5.1 mL kg-1 min-1) and Method main effect (p < 0.01). There were significant differences between measured and estimated VO2peak from the maximal 20mSRT, but not between measured and estimated VO2peak at RPE9 and RPE10. Intraclass correlation analysis revealed excellent reliability (~ 0.9) between the two submaximal 20mSRTs. Significant differences (p < 0.05) in end-test affect were reported between submaximal and maximal trials in girls, but not in boys, with girls feeling less negative at the end of the submaximal trials. CONCLUSIONS: The results of this study provide evidence that RPE reported during a submaximal 20mSRT can be used to predict VO2peak accurately and reliably. In this study, the submaximal 20mSRT ending at RPE7, provided better predictions of VO2peak while minimising aversive end-point affect, especially in girls.

Longitudinal lung function in urban firefighters: A group-based multi-trajectory modelling approach.

BACKGROUND AND OBJECTIVE: Urban firefighters are routinely exposed to both physical and chemical hazards that can negatively impact lung health, but it is unclear if firefighters experience accelerated decline in spirometry parameters due to chronic exposure and acute insults. This study aimed to describe sub-groups of firefighters with differing spirometry trajectories and examine the relationship between the identified trajectories and demographic, lifestyle and occupational characteristics. METHODS: Data from six waves of the Respiratory Function Measurement and Surveillance for South Australian Metropolitan Fire Service Study (2007-2019) were used to identify spirometry parameter z-score trajectories, using group-based multi-trajectory modelling (GBMTM). Analysis of variance and chi-square statistics were used to assess trajectory group differences in baseline self-reported demographic, lifestyle and occupational characteristics. RESULTS: In the 669 included firefighters, we identified five trajectories for the combination of Forced Expiratory Volume in the first second z-score (FEV1 z), Forced Vital Capacity z-score (FVCz) and the ratio of FEV1 and FVC z-score (FEV1 /FVCz). There were three stable trajectories of low, average and very high lung function and two declining trajectories of average and high lung function. Analysis of subgroup characteristics revealed no significant differences between expected and actual group proportions for the occupational characteristics of years of service and respiratory protection use. Significant differences were seen in respiratory health and body mass index. CONCLUSION: GBMTM defined distinct, plausible spirometry trajectory sub-groups. Firefighter longitudinal spirometry trajectory group membership was associated with BMI and respiratory disease or symptoms but not with self-reported smoking history or occupational factors.

Maximal Fat Oxidation during Incremental Upper and Lower Body Exercise in Healthy Young Males.

The aim of this study is to determine the magnitude of maximal fat oxidation (MFO) during incremental upper and lower body exercise. Thirteen non-specifically trained male participants (19.3 ± 0.5 y, 78.1 ± 9.1 kg body mass) volunteered for this repeated-measures study, which had received university ethics committee approval. Participants undertook two incremental arm crank (ACE) and cycle ergometry (CE) exercise tests to volitional exhaustion. The first test for each mode served as habituation. The second test was an individualised protocol, beginning at 40% of the peak power output (POpeak) achieved in the first test, with increases of 10% POpeak until volitional exhaustion. Expired gases were recorded at the end of each incremental stage, from which fat and carbohydrate oxidation rates were calculated. MFO was taken as the greatest fat oxidation value during incremental exercise and expressed relative to peak oxygen uptake (%V˙O2peak). MFO was lower during ACE (0.44 ± 0.24 g·min-1) than CE (0.77 ± 0.31 g·min-1; respectively, p < 0.01) and occurred at a lower exercise intensity (53 ± 21 vs. 67 ± 18%V˙O2peak; respectively, p < 0.01). Inter-participant variability for MFO was greatest during ACE. These results suggest that weight loss programs involving the upper body should occur at lower exercise intensities than for the lower body.

Continuous Thermoregulatory Responses to a Mass-Participation 89-km Ultramarathon Road Race.

PURPOSE: To continuously measure body core temperature (Tc) throughout a mass-participation ultramarathon in subelite recreational runners to quantify Tc magnitude and the influence of aerobic fitness and body fat. METHODS: Twenty-three participants (19 men and 4 women; age 45 [9] y; body mass 72.0 [9.3] kg; body fat 26% [6%]; peak oxygen uptake 50 [6] mL·kg-1·min-1) had gastrointestinal temperature measured during an 89-km ultramarathon. Prerace-to-postrace changes in body mass, plasma sodium, and fluid and food recall quantified body water balance. RESULTS: In maximal environmental conditions of 26.3 °C and 53% humidity, 21 of the 23 participants finished in 10:28 (01:10) h:min while replacing 49% (27%) of sweat losses, maintaining plasma sodium (140 [3] mmol·L-1), and dehydrating by 4.1% (1.3%). Mean maximum Tc was 39.0 (0.5) (range 38.2-40.1 °C) with 90% of race duration ≤39.0 °C. Mean maximum ΔTc was 1.9 (0.9) (0.9-2.7 °C) with 95% of race duration ≤2.0 °C. Over 0 to 45 km, associations between ΔTc and peak oxygen uptake (positive) and body fat (negative) were observed. Over 58 to 89 km, associations between Tc and peak oxygen uptake (negative) and body fat (positive) were observed. CONCLUSIONS: Modest Tc responses were observed in recreational ultramarathon runners. Runners with higher levels of aerobic fitness and lower levels of body fat demonstrated the greatest changes in Tc during the first half of the race. Conversely, runners with lower levels of aerobic fitness and higher levels of body fat demonstrated the greatest absolute Tc in the final third of the race.

Prediction of elite athletes' performance by analysis of peak-performance age and age-related performance progression.

The aim of this study was to analyse age-related performance progression and peak-performance age (PPA) in elite track and field athletes and to use a model to predict peak performance. Best performances of world-class athletes from ages 14 to 15 y up to and including the last Olympic year (n = 798), all-time top lists (n = 444), and world record-holders (n = 43) were considered in all 22 disciplines for men and 21 disciplines for women. A discipline/sex-specified model was used by applying dynamic panel data methods to analyze the performance trends. Profile analysis showed that PPA of all-time top list throwers was higher than middle-distance runners (P < 0.001), distance runners (P < 0.05), and jumpers (P < 0.05) in men and higher (P < 0.05) than middle-distance runners in women. Olympic year top list athletes showed that PPA of women throwers was higher than sprinters (P < 0.001) and middle-distance runners (P < 0.05), and PPA of women distance runners was higher (P < 0.05) than sprinters. In both all-time (P < 0.05) and Olympic year (P < 0.05) top lists, the PPA of men race walkers was higher than middle-distance runners. Performance over the preceding 1-2 years (in all disciplines), height (in Long Jump Men; Long Jump Women; Triple Jump Men) and weight (in Discus Throwing Men) indices, respectively, are important (P < 0.05) for predicting future records with different coefficients in different disciplines. The models provide a useful tool for coaches to predict peak performance records and PPA of their athletes which may be of benefit with goal-setting and evaluation of performance progression at different ages in track and field athletics.

Player Profiling and Monitoring in Basketball: A Delphi Study of the Most Important Non-Game Performance Indicators from the Perspective of Elite Athlete Coaches.

BACKGROUND: Little is known about which indicators of performance elite athlete coaches (i.e., professional coaches who coach at the national or international levels) consider to be important for basketball. OBJECTIVE: Using a Delphi procedure, the aim of this study was to identify the non-game performance indicators elite athlete coaches consider to be important for the recruitment/selection of basketball players. METHODS: Ninety elite athlete coaches (basketball coaches (n = 71) and strength/conditioning coaches (n = 19) who coached men (n = 60), women (n = 23), or both (n = 7)), employed in 23 countries across six continents, participated in a three-round online Delphi survey. Round 1 asked coaches to identify the non-game performance indicators (i.e., measures other than game statistics) they currently used (or would like to use) for player recruitment/selection, with common indicators combined into single indicators. Round 2 asked coaches to rate the importance of each performance indicator using a Likert scale (range: 0 = no importance whatsoever to 10 = extremely important). Round 3 asked coaches to identify the single best test measure for each indicator rated ≥ 6 (i.e., important to extremely important) in Round 2. Results were reported descriptively. RESULTS: A total of 608 responses (344 after removal of duplicates) were reported in Round 1, which were collapsed into 35 indicators, all of which were rated as 'important' in Round 2. Psychological and game intelligence indicators were typically rated as very important to extremely important (i.e., median = 9), with physical fitness and movement skills typically rated as very important (i.e., median = 8). For most indicators, coach observation was identified as the best test measure, with unique objective performance/anthropometric tests identified for all physical fitness indicators. CONCLUSION: This study identified a range of psychological, game intelligence, physical fitness, and movement skill indicators that were considered by elite athlete coaches to be important to extremely important for the recruitment/selection of basketball players. These findings may inform the development of a basketball-specific test battery for recruiting/selecting and monitoring players.

Effect of Biological Maturation on Performance of the Athletic Ability Assessment in Australian Rules Football Players.

PURPOSE: To determine the effect of biological maturation on athletic movement competency as measured using the Athletic Ability Assessment-6. METHODS: Fifty-two junior Australian Rules football players were split into 3 groups based on proximity to peak height velocity, while 46 senior players were split into 2 groups based on playing status. The subjects completed the Athletic Ability Assessment-6 (inclusive of the overhead squat, double lunge, single-leg Romanian dead lift, push-up, and chin-up). All subjects were filmed and retrospectively assessed by a single rater. A 1-way analysis of variance and effect-size statistics (Cohen d) with corresponding 90% confidence intervals were used to describe between-groups differences in the component movement scores. The statistical significance was set a priori at P < .05. RESULTS: There were significant between-groups differences for all component movements (P < .05). Post hoc testing revealed that older, more mature subjects possessed greater competency in all movements except the overhead squat. The effect sizes revealed predominantly moderate to very large differences in competency between the senior and junior groups (range of d [90% confidence interval]: 0.70 [0.06 to 1.30] to 3.01 [2.18 to 3.72]), with unclear to moderate differences found when comparing the 3 junior groups (0.08 [-0.50 to 0.65] to 0.97 [0.22-1.61]). CONCLUSIONS: The findings suggest that biological maturation may be associated with changes in athletic movement competency in youth Australian Rules football players. Therefore, it is recommended that strength and conditioning coaches monitor maturity status when working with 12- to 15-y-old players. This can allow for a comparison of an individual's athletic movement competency to maturity-based standards and help guide developmentally appropriate training programs.

The Use of Ratings of Perceived Exertion in Children and Adolescents: A Scoping Review.

In adults, ratings of perceived exertion (RPE) can be used to predict maximal oxygen uptake, estimate time to exhaustion, assess internal training load and regulate exercise intensity. However, the utility of RPE in children is less researched and therefore, warrants investigation. The purpose of this scoping review is to map out the literature around the application of RPE specifically during aerobic exercise in paediatric populations. Seven bibliographic databases were systematically searched. Grey literature searching and pearling of references were also conducted. To be included for the review, studies were required to comply with the following: (1) participants aged ≤ 18 years asymptomatic of any injuries, disabilities or illnesses; (2) applied RPE in aerobic exercise, testing and/or training; (3) included at least one measure of exercise intensity; and (4) be available in English. The search identified 22 eligible studies that examined the application of RPE in children. These studies involved a total of 718 participants across ten different countries. Nine different types of RPE scales were employed. Overall, the application of RPE in paediatric populations can be classified into three distinct themes: prediction of cardiorespiratory fitness/performance, monitoring internal training loads, and regulation of exercise intensity. The utility of RPE in paediatric populations remains unclear due to the small body of available research and inconsistencies between studies. However, findings from the included studies in this scoping review may show promise. Further research focussing on child-specific RPE scales across various sports, subgroups, and in field-based settings is needed.

Physical Activity Intensity Cut-Points for Wrist-Worn GENEActiv in Older Adults.

Purpose: This study aims to (1) establish GENEActiv intensity cutpoints in older adults and (2) compare the classification accuracy between dominant (D) or non-dominant (ND) wrist, using both laboratory and free-living data. Methods: Thirty-one older adults participated in the study. They wore a GENEActiv Original on each wrist and performed nine activities of daily living. A portable gas analyzer was used to measure energy expenditure for each task. Testing was performed on two occasions separated by at least 8 days. Some of the same participants (n = 13) also wore one device on each wrist during 3 days of free-living. Receiver operating characteristic analysis was performed to establish the optimal cutpoints. Results: For sedentary time, both dominant and non-dominant wrist had excellent classification accuracy (sensitivity 0.99 and 0.97, respectively; specificity 0.91 and 0.86, respectively). For Moderate to Vigorous Physical Activity (MVPA), the non-dominant wrist device had better accuracy (ND sensitivity: 0.90, specificity 0.79; D sensitivity: 0.90, specificity 0.64). The corresponding cutpoints for sedentary-to-light were 255 and 375 g · min (epoch independent: 42.5 and 62.5 mg), and those for the light-to-moderate were 588 and 555 g · min (epoch-independent: 98.0 and 92.5 mg) for the non-dominant and dominant wrist, respectively. For free-living data, the dominant wrist device resulted in significantly more sedentary time and significantly less light and MVPA time compared to the non-dominant wrist.

Comparison of a Countermovement Jump Test and Submaximal Run Test to Quantify the Sensitivity for Detecting Practically Important Changes Within High-Performance Australian Rules Football.

PURPOSE: To determine the typical variation of variables from a countermovement jump (CMJ) test and a submaximal run test (SRT), along with comparing the sensitivity of each test for the detection of practically important changes within high-performance Australian rules football players. METHODS: A total of 23 professional and semiprofessional Australian rules football players performed 6 CMJs and three 8-second 50-m runs every 30 seconds (SRT), 7 days apart. Absolute and trial-to-trial reliability was represented as a coefficient of variation, CV (±90% confidence intervals). Test-retest reliability was examined using the magnitude of the difference (effect size [±90% confidence interval]) from week 1 to week 2. The smallest worthwhile change was calculated as 0.25 × SD. RESULTS: Good reliability (CVs = 6.6%-9.3%) was determined for all variables except eccentric displacement (CV = 12.8%), with no clear changes observed in any variables between week 1 and week 2. All variables from the SRT possessed a CV less than smallest worthwhile change, indicating an ability to detect practically important changes in performance. Only peak velocity from the CMJ test possessed a CV less than smallest worthwhile change, exhibiting a limitation of this test in detecting practically meaningful changes within this environment. CONCLUSIONS: The results suggest that while all variables possess acceptable reliability, a SRT might offer to be a more sensitive monitoring tool than a CMJ test within high-performance Australian rules football, due to its greater ability for detecting practically important changes in performance.

Hamstring injuries and Australian Rules football: over-reliance on Nordic hamstring exercises as a preventive measure?

Nordic hamstring exercises (NHE) are promoted as an evidence-based strategy for reducing the prevalence of hamstring injuries in football, with a number of studies showing a significant reduction in hamstring injury rates following implementation of a NHE-based program. However, most of the research to date has been undertaken in soccer with less research carried out in other football codes. Despite this lack of relevant evidence, NHE has recently become popular as a preventative measure in Australian Rules football (ARF) teams; however, hamstring injuries remain high. This paper reviews the literature associated with the use of NHE for ARF players and questions the appropriateness of this exercise approach as a preventative measure for hamstring injuries in this sport. When considering the use of a preventative exercise program, such as the NHE, the specific risks associated with the sporting activity should be considered and the evidence reviewed in light of this. Whilst NHE provides an easy way to do eccentric exercises, the movement does not replicate what is needed in the real world for ARF and should therefore be included in a hamstring injury prevention program in this code with caution.

The effects of fatigue on the running profile of elite team sport athletes. A systematic review and meta-analysis.

INTRODUCTION: With the underlying mechanisms of fatigue shown to be task-specific, gaining an understanding of changes within the running profile due to fatigue may provide a greater task-specific method for monitoring neuromuscular fatigue (NMF) in elite team sport athletes. This review aimed to identify, review and summarize the literature to understand the effects of fatigue on the running profile of elite team sport athletes. EVIDENCE ACQUISITION: MEDLINE, SPORTDiscus, EMBASE and CINAHL were searched. To manage heterogeneity in athlete characteristics and sport demands, studies were limited to elite male field/court team sports, in which changes in running, gait or stride characteristics were assessed. EVIDENCE SYNTHESIS: Thirteen studies were included in the analysis with changes in sprint time, kinematic variables; contact time, center of mass vertical displacement and vertical stiffness, GPS accelerometer vector variables; z and y, and mechanical parameters; velocity and V0, all shown to be sensitive measures of fatigue. Due to having at least three sets of data points, meta-analysis was run for sprint time, with results showing a significant increase immediately postexercise (effect size [ES]±95% confidence interval [CI]; 1.67±1.61, P=0.04), but no change 24 hours postexercise (ES±95% CI; 0.93±3.21, P=0.57). CONCLUSIONS: The findings indicate that fatigue has a negative impact on the running profile in elite team sport athletes, offering an alternative task-specific measure of monitoring NMF in this population. However, due to large discrepancies in protocols, future research is required to allow greater uniformity in variables and methods.

Inter- and Intra-rater Reliability of the Athletic Ability Assessment in Subelite Australian Rules Football Players.

Rogers, DK, McKeown, I, Parfitt, G, Burgess, D, and Eston, RG. Inter- and intra-rater reliability of the athletic ability assessment in subelite Australian rules football players. J Strength Cond Res 33(1): 125-138, 2019-The aim of this study was to determine the inter- and intra-rater rater reliability of the Athletic Ability Assessment (AAA) in subelite Australian Rules football (ARF) players. Eighteen male ARF players completed the AAA movement assessment (overhead squat, double lunge [left and right], single-leg Romanian deadlift [left and right], chin-up and push-up), on 2 occasions separated by 1 week. During the first movement assessment, players were filmed in the frontal and sagittal planes. Ten raters took part in the study (1 experienced rater and 9 novices) and were assigned in a quasirandom manner, to complete either (a) real-time assessment on 2 occasions, (b) real-time assessment on 1 occasion, or (c) video-based assessment on 2 occasions. When assessed in real-time, of the 7 component movements of the AAA, raters registered moderate or greater intrarater agreement on between 2 and 5 occasions. Intraclass correlation coefficients (ICCs) of between 0.50 and 0.61 for the AAA total score indicated poor real-time intrarater reliability for this variable. When assessed by video-recording, raters registered moderate or greater intrarater agreement on between 6 and 7 occasions. The ICC for total score ranged between 0.60 and 0.93. Overall poor interrater reliability was evident for AAA component movements regardless of whether it was assessed in real-time or from video. Findings suggest the AAA is most reliably used when assessed through video. It is recommended that if comparison between multiple raters is desired, a stringent training process be applied so that the interpretation of AAA scoring criteria is standardized across raters.

What is the effect of aerobic exercise intensity on cardiorespiratory fitness in those undergoing cardiac rehabilitation? A systematic review with meta-analysis.

OBJECTIVE: Assess the role of exercise intensity on changes in cardiorespiratory fitness (CRF) in patients with cardiac conditions attending exercise-based cardiac rehabilitation. DESIGN: Systematic review with meta-analysis. DATA SOURCES: MEDLINE, Embase, CINAHL, SPORTDiscus, PsycINFO and Web of Science. ELIGIBILITY CRITERIA FOR SELECTION: Studies assessing change in CRF (reported as peak oxygen uptake; V̇O2peak) in patients post myocardial infarction and revascularisation, following exercise-based cardiac rehabilitation. Studies establishing V̇O2peak via symptom-limited exercise test with ventilatory gas analysis and reported intensity of exercise during rehabilitation were included. Studies with mean ejection fraction <40% were excluded. RESULTS: 128 studies including 13 220 patients were included. Interventions were classified as moderate, moderate-to-vigorous or vigorous intensity based on published recommendations. Moderate and moderate-to-vigorous-intensity interventions were associated with a moderate increase in relative V̇O2peak (standardised mean difference±95% CI=0.94±0.30 and 0.93±0.17, respectively), and vigorous-intensity exercise with a large increase (1.10±0.25). Moderate and vigorous-intensity interventions were associated with moderate improvements in absoluteV̇O2peak (0.63±0.34 and 0.93±0.20, respectively), whereas moderate-to-vigorous-intensity interventions elicited a large effect (1.27±0.75). Large heterogeneity among studies was observed for all analyses. Subgroup analyses yielded statistically significant, but inconsistent, improvements in CRF. CONCLUSION: Engagement in exercise-based cardiac rehabilitation was associated with significant improvements in both absolute and relative V̇O2peak. Although exercise of vigorous intensity produced the greatest pooled effect for change in relative V̇O2peak, differences in pooled effects between intensities could not be considered clinically meaningful. REGISTRATION: Prospero CRD42016035638.

Relationships Between Model-Predicted and Actual Match-Play Exercise-Intensity Performance in Professional Australian Footballers During a Preseason Training Macrocycle.

PURPOSE: To assess and compare the validity of internal and external Australian football (AF) training-load measures for predicting preseason variation of match-play exercise intensity (MEI sim/min) using a variable dose-response model. METHODS: A total of 21 professional male AF players completed an 18-wk preseason macrocycle. Preseason internal training load was quntified using the session rating-of-perceived-exertion method (sRPE) and external load from satellite (as distance [Dist] and high-speed distance [HS Dist]) and accelerometer (Player Load [PL]) data. Using a training-impulse (TRIMPs) calculation, external load expressed in arbitrary units was represented as TRIMPsDist, TRIMPsHSDist, and TRIMPsPL. Preseason training load and MEI sim/min data were applied to a variable dose-response model, which provided estimates of MEI sim/min. Model estimates of MEI sim/min were correlated with actual measures from each match-play drill performed during the preseason macrocycle. Magnitude-based inferences (effect size [90% confidence interval]) were calculated to determine practical differences in the precision of MEI sim/min estimates using each of the internal- and external-load inputs. RESULTS: Estimates of MEI sim/min demonstrated very large and large associations with actual MEI sim/min with models constructed from external and internal training inputs (r [90% confidence interval]; TRIMPsDist .73 [.72-.74], TRIMPsPL .72 [.71-.73], and sRPESkills .67 [.56-.78]). There were trivial differences in the precision of MEI sim/min estimates between models constructed from TRIMPsDist and TRIMPsPL and between internal input methods. CONCLUSIONS: Variable dose-response models from multiple training-load inputs can predict the within-individual variation of MEI sim/min across an entire preseason macrocycle. Models informed by external training inputs (TRIMPsDist and TRIMPsPL) exhibited predictive power comparable to those of sRPESkills models.

A Novel Method of Assessment for Monitoring Neuromuscular Fatigue in Australian Rules Football Players.

Purpose: To compare the sensitivity of a submaximal run test (SRT) with a countermovement-jump test (CMJ) to provide an alternative method of measuring neuromuscular fatigue (NMF) in high-performance sport. Methods: A total of 23 professional and semiprofessional Australian rules football players performed an SRT and CMJ test prematch and 48 and 96 h postmatch. Variables from accelerometers recorded during the SRT were player load 1D up (vertical vector), player load 1D side (mediolateral vector), and player load 1D forward (anteroposterior vector). Meaningful difference was examined through magnitude-based inferences (effect size [ES]), with reliability assessed as typical error of measurements expressed as coefficient of variance. Results: A small decrease in CMJ height, ES -0.43 ± 0.39 (likely), was observed 48 h postmatch before returning to baseline 96 h postmatch. This was accompanied by corresponding moderate decreases in the SRT variables player load 1D up, ES -0.60 ± 0.51 (likely), and player load 1D side, ES -0.74 ± 0.57 (likely), 48 h postmatch before also returning to prematch baseline. Conclusion: The results suggest that in the presence of NMF, players use an alternative running profile to produce the same external output (ie, time). This indicates that changes in accelerometer variables during an SRT can be used as an alternative method of measuring NMF in high-performance Australian rules football and provides a flexible option for monitoring changes in the recovery phase postmatch.

Physiological and Perceived Exertion Responses during Exercise: Effect of ß-blockade.

PURPOSE: This study investigated the effect of ß-blockade on physiological and perceived exertion (RPE) responses during incremental treadmill exercise. METHODS: Sixteen healthy participants (n = 8 men; age, 25.3 ± 4.6 yr) performed a maximal treadmill exercise test after ingestion of 100 mg metoprolol or placebo, with a double-blind, randomized, and counterbalanced design. Heart rate (HR), ventilatory, and gas exchange variables were measured continuously, and participants reported RPE at the end of each minute. Physiological and RPE responses during each condition were compared at the ventilatory threshold (VT), respiratory compensation point, and at maximal exercise using repeated-measures ANOVA. Linear regression modeled relationships between perceived exertion and physiological variables. RESULTS: The HR and V˙O2 at the VT, respiratory compensation point, and maximal exercise were all significantly lower after ß-blockade (P < 0.05). However, when standardized to within condition peak values, differences were no longer significant. The RPE associated with VT was higher after ß-blockade (12.9 ± 1.0 vs 12.3 ± 1.2, P < 0.05) but lower at maximal exercise (19.1 ± 0.6 vs 19.4 ± 0.5, P < 0.05). Increases in RPE relative to HR were greater after ß-blockade and remained significant when expressed relative to peak HR. There was no difference in the growth of the relationship between RPE and V˙O2 across conditions, although the origin of the relationship was higher with ß-blockade. CONCLUSIONS: Although ß-blockade resulted in a significant reduction in exercising HR and V˙O2, the RPE for a given relative intensity remained unchanged. The relationship between RPE and V˙O2 was not affected by ß-blockade. The results provide evidence that RPE is a useful and reliable measure for exercise testing and prescription in patients prescribed ß-blockade therapy.