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1.
J Strength Cond Res ; 37(11): e601-e608, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37883408

RESUMO

ABSTRACT: Redshaw, AS, Carrick-Ranson, G, Bennett, H, Norton, KI, and Walker, A. Effect of aging on movement quality in Australian urban firefighters. J Strength Cond Res 37(11): e601-e608, 2023-Adequate levels of movement quality (MQ) are required to safely perform occupational tasks in physically demanding and hazardous professions such as firefighting. Although it is well established that MQ deteriorates with age in population studies, there is conflicting evidence in older tactical populations. This study sought to examine the relationship between age and MQ in Australian urban firefighters. The impact of physical activity, injury history, and body mass index on MQ were also explored. The MQ of 324 professional Australian urban firefighters was assessed using MovementSCREEN MQ assessment tool. Scores of whole-body MQ ranged from 35.3 to 82.6 (0-100 scale), with a mean score of 59.2 ± 10.0. There was a moderate, negative association between MQ and age (r = -0.500; p ≤ 0.001), with those older than 50 years of age having significantly lower scores of MQ than their younger counterparts (p ≤ 0.001). Secondary analysis found that higher body mass index (r = -0.285; p ≤ 0.001), lower habitual physical activity levels (r = 0.165; p ≤ 0.003), and the presence of any musculoskeletal injury in the previous 12 months (p = 0.016) had significant negative effects on composite MQ. Firefighters older than 50, obese, and engaging in low levels of physical activity should be considered a high priority for functional strength training interventions to maintain adequate MQ throughout their careers.


Assuntos
Bombeiros , Treinamento Resistido , Humanos , Idoso , Austrália , Envelhecimento , Índice de Massa Corporal , Movimento
2.
J Sports Sci Med ; 19(1): 78-83, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32132830

RESUMO

The aim of this study was to evaluate the influence of contextual factors on game styles in professional soccer. Interactions between styles and different playing venues, opposition quality, total match goals, and competing styles, were investigated using logistic regression and odds ratios. Game styles were characterised using the moments of play framework where three distinct styles have been identified: Style 1 - moderate strength in defence; Style 2 - dominance in transition, and Style 3 - strength in attacking phases of play. Results revealed that when playing at home against teams identified by Style 1, teams were more likely to play Style 2 (p < 0.05) or Style 3 (p < 0.001). Against top 10 opposition, teams were less likely to play Style 3 compared to either Style 1 (p < 0.001) or Style 2 (p < 0.001). Regardless of venue, teams were more likely to play Style 3 against bottom 10 sides compared to either Style 1 (p < 0.001) or Style 2 (p < 0.001), suggesting a hierarchical order between contextual factors. Competing game styles significantly impacted total match goals scored, whilst match results were also influenced by game style combinations. Overall, this study showed the significant effects of various contextual variables on game styles played by teams in the EPL.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Futebol/fisiologia , Inglaterra , Humanos , Destreza Motora/fisiologia
3.
J Sports Sci Med ; 19(3): 508-516, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32874103

RESUMO

The aim of this investigation was to compare the changes in endurance running performance and physiological variables after a four-week period of high intensity interval training (HIIT) in either running or cycling in female athletes. Fourteen recreational female runners (age = 42 10 yr, height = 1.67 0.06 m, body mass = 61.6 10.4 kg, body mass index (BMI) = 22.2 3.4 kg.m-2) were randomly allocated to one of two HIIT training groups: running (HIITrun) or cycling (HIITbike). Each group performed two HIIT sessions per week for 4 weeks, which consisted of 6 x 2 min at 95% of maximal heart rate (HRmax) and 4 x 1 min all out efforts. Maximal oxygen consumption (VO2max) in treadmill running increased significantly after the HIITrun (p < 0.01, ES = 0.6) but remained unchanged in HIITbike. However, HIITbike improved average velocity in a 10 km running time trial (TTrun) (p < 0.05, ES = -0.4), whereas, no changes were found for the HIITrun group. Analysing the first and last HIIT sessions, for HIITrun only the average rate of perceived exertion (RPEav) increased significantly, whereas, performance variables such as average heart rate (HRav) and average pace (paceav) remained unchanged. HIITbike enhanced significantly the average speed of HIIT sets (speedav) and the peak power output (PPO) of the session, as well as, the RPEav and delayed onset muscle soreness immediately after HIIT session (DOMSpost) were increased significantly. A regime of HIIT in cycling may evoke increases in female recreational runners' power, which may be related with improvements in a 10 km TTrun independent of changes in aerobic capacity. This may be advantageous in order to avoid overuse running related injuries.


Assuntos
Ciclismo/fisiologia , Treinamento Intervalado de Alta Intensidade/métodos , Resistência Física/fisiologia , Corrida/fisiologia , Adulto , Creatina Quinase/sangue , Feminino , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Pessoa de Meia-Idade , Fadiga Muscular/fisiologia , Mialgia/metabolismo , Mialgia/fisiopatologia , Consumo de Oxigênio , Percepção/fisiologia , Esforço Físico/fisiologia
4.
J Sports Sci ; 37(24): 2806-2817, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31500505

RESUMO

The aim of this trial was to compare an eight-week individual movement quality versus traditional resistance training intervention on movement quality and physical performance. Forty-six trained adults were randomised to a movement quality-focused training (MQ) or a traditional resistance training (TRAD) group, and performed two individualised training sessions per week, for 8 weeks. Session-RPE (sRPE) was obtained from each session. Measures of movement quality (MovementSCREEN and Functional Movement Screen (FMS)) and physical performance were performed pre- and post-intervention. All measures improved significantly in both groups (3-14.5%, p = <0.005). The between-group difference in MovementSCREEN composite score was not statistically significant (0.3, 95% CI -3.4, 4.1, p = 0.852). However, change in FMS composite was significantly greater in MQ (1.3, 95% CI 0.8, 1.8, p < 0.001). There were no significant between-group differences in physical performance (p = 0.060-0.960). The mean sRPE was significantly lower in MQ (5.25, SD 1.2) compared to TRAD (6.6 SD 1.0, p = <0.001). Thus, although movement quality scores were not distinctly greater in the MQ group, a movement quality specific intervention caused comparable improvements in physical performance compared to traditional resistance training but at lower perceived training intensity.


Assuntos
Destreza Motora , Movimento , Desempenho Físico Funcional , Treinamento Resistido , Adulto , Feminino , Humanos , Masculino , Força Muscular , Músculo Esquelético/fisiologia , Adulto Jovem
5.
J Therm Biol ; 65: 16-20, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28343570

RESUMO

Heat acclimation over consecutive days has been shown to improve aerobic-based performance. Recently, it has been suggested that heat training can improve performance in a temperate environment. However, due to the multifactorial training demands of athletes, consecutive-day heat training may not be suitable. The current study aimed to investigate the effect of brief (8×30min) intermittent (every 3-4 days) supplemental heat training on the second lactate threshold point (LT2) in temperate and hot conditions. 21 participants undertook eight intermittent-day mixed-intensity treadmill exercise training sessions in hot (30°C; 50% relative humidity [RH]) or temperate (18°C; 30% RH) conditions. A pre- and post-incremental exercise test occurred in temperate (18°C; 30% RH) and hot conditions (30°C; 50% RH) to determine the change in LT2. The heat training protocol did not improve LT2 in temperate (Effect Size [ES]±90 confidence interval=0.10±0.16) or hot (ES=0.26±0.26) conditions. The primary finding was that although the intervention group had a change greater than the SWC, no statistically significant improvements were observed following an intermittent eight day supplemental heat training protocol comparable to a control group training only in temperate conditions. This is likely due to the brief length of each heat training session and/or the long duration between each heat exposure.


Assuntos
Aclimatação , Ácido Láctico/sangue , Corrida , Adulto , Teste de Esforço , Feminino , Temperatura Alta , Humanos , Masculino , Pessoa de Meia-Idade , Resistência Física
6.
J Strength Cond Res ; 31(10): 2903-2919, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28614164

RESUMO

Multicomponent movement assessment tools have become commonplace to measure movement quality, proposing to indicate injury risk and performance capabilities. Despite popular use, there has been no attempt to compare the components of each tool reported in the literature, the processes in which they were developed, or the underpinning rationale for their included content. As such, the objective of this systematic review was to provide a comprehensive summary of current movement assessment tools and appraise the evidence supporting their development. A systematic literature search was performed using PRISMA guidelines to identify multicomponent movement assessment tools. Commonalities between tools and the evidence provided to support the content of each tool was identified. Each tool underwent critical appraisal to identify the rigor in which it was developed, and its applicability to professional practice. Eleven tools were identified, of which 5 provided evidence to support their content as assessments of movement quality. One assessment tool (Soccer Injury Movement Screen [SIMS]) received an overall score of above 65% on critical appraisal, with a further 2 tools (Movement Competency Screen [MCS] and modified 4 movement screen [M4-MS]) scoring above 60%. Only the MCS provided clear justification for its developmental process. The remaining 8 tools scored between 40 and 60%. On appraisal, the MCS, M4-MS, and SIMS seem to provide the most practical value for assessing movement quality as they provide the strongest reports of developmental rigor and an identifiable evidence base. In addition, considering the evidence provided, these tools may have the strongest potential for identifying performance capabilities and guiding exercise prescription in athletic and sport-specific populations.


Assuntos
Teste de Esforço/métodos , Teste de Esforço/normas , Movimento/fisiologia , Humanos , Reprodutibilidade dos Testes
7.
J Sports Sci ; 32(20): 1874-1880, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24786319

RESUMO

Abstract Movement patterns in elite men's soccer have been reported in depth, but less research exists for women's soccer. Aims of the study were to identify the movement profiles of elite women soccer players in international competition and examine the effect the level of opposition, based on Federation Internationale de Football Association (FIFA) rankings, had on the physical demands of the game. MinimaxX athlete tracking devices were used by 15 players during 13 international matches against opponent teams of varying ability. Total distance covered averaged 9292 ± 175 m. There was a decrease in high-intensity running (HIR) in the 60- to 75-min and 75- to 90-min periods compared to the 0- to 15-min period of 22.4% and 26.1%, respectively (P = 0.022, P = 0.004) although sprint distances remained unchanged across game periods. HIR distances covered were significantly greater for midfielders versus defenders, while defenders had lower sprinting compared to both midfielders and attackers. Stronger opponents elicited less HIR and greater low-speed activity (LSA) compared to playing teams of similar or lower ranking. These results are important to coaches to prepare players for international competition and show the differing demands required depending on the ability of the opponents.

8.
J Law Med ; 21(4): 826-44, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25087365

RESUMO

The Australian Fitness Industry Risk Management (AFIRM) Project was set up to explore the operation of rules and regulations for the delivery of safe fitness services. This article summarises the results of recent focus group research and a national survey of risk management practices by the AFIRM Project. Our focus group research in four States identified the following most important concerns: (1) the competency of fitness professionals; (2) the effectiveness of pre-exercise screening and the management of de-conditioned clients; (3) poor supervision of fitness service users and incorrect use of equipment; (4) fitness trainers failing to remain within their scope of practice; (5) equipment misuse (as distinct from incorrect use); and (6) poor fitness training environments. This information was then used to develop 45 specific items for a questionnaire that was disseminated throughout the fitness industry. The survey, which is the largest ever conducted in the Australian fitness industry (n = 1,178), identified similar concerns. Our research indicates that efforts to improve risk management in the fitness industry should focus, first and foremost, on the development and monitoring of safety policy, and improvements in the education and training of fitness instructors to ensure that they can incorporate risk management practices.


Assuntos
Exercício Físico , Indústrias , Gestão de Riscos/legislação & jurisprudência , Adolescente , Adulto , Idoso , Austrália , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Competência Profissional , Segurança/legislação & jurisprudência , Inquéritos e Questionários , Ferimentos e Lesões/prevenção & controle , Adulto Jovem
9.
Phys Sportsmed ; 42(4): 14-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25419884

RESUMO

BACKGROUND: Health/fitness facilities are popular venues for physical activity, where increasingly more individuals at risk of cardiovascular events exercise to achieve positive health outcomes. The aim of our study was to analyze cardiac emergency preparedness in health/fitness facilities in Queensland, Australia. DESIGN: Cross-sectional survey of health/fitness facilities in Queensland. METHODS: A risk management questionnaire was administered over 7 months, July 2009 to January 2010, using an online or paper-based version. The data are presented as the proportion of survey respondents giving specific responses to questionnaire items related to cardiac emergency preparedness, especially the provision of automated external defibrillators (AEDs). RESULTS: Fifty-two health/fitness facility managers responded to the survey. Most of the surveyed facilities conducted pre-activity screening (92%). Of those with a written emergency plan (79%), only 37% physically rehearsed their emergency response systems at regular intervals. Ninety-five percent of the facilities had fitness employees with a current first aid/cardiopulmonary resuscitation certificate and training. Of the 10 (19%) facilities with an on-site AED, only 6 had staff qualified to use the AED in an emergency, and only 6 had the AED as part of a public access defibrillator program. CONCLUSION: This is the first study to report that cardiac emergency preparedness is not optimal in the health/fitness facilities in Australia. Development of policies and procedures for training health/fitness professionals in emergency procedures is needed to minimize the risk when exercise-induced cardiac events occur at health/fitness facilities.


Assuntos
Serviços Médicos de Emergência/estatística & dados numéricos , Academias de Ginástica , Instalações de Saúde , Austrália , Reanimação Cardiopulmonar , Defesa Civil , Serviços Médicos de Emergência/organização & administração , Humanos
10.
Work ; 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38552128

RESUMO

BACKGROUND: Firefighting is recognised as a physically demanding occupation involving exposure to hazardous environments and activities. An aging workforce combined with the age-related decline in physical fitness may result in increased future workers' compensation expenditure for fire service organisations. OBJECTIVE: The objective of this research was to investigate the costs associated with musculoskeletal sprain and strain injury and the impacts of age and injury location on Workers' Compensation claims submitted by professional urban firefighters. METHODS: Claim rates, direct costs, and days lost were extracted from a professional Fire Service organisation's workers' compensation claim database for financial years between 2011 to 2018. RESULTS: The mean cost per claim increased with age, with a mean claim cost of the 60-70-year-old group over 10 times more than the 20-29-year-old group. The mean days lost per claim were also higher for claims submitted by firefighters aged over 50. CONCLUSIONS: Older firefighters miss more workdays when injured and are associated with increased claims costs, particularly those in the 60-70-year group. With an aging workforce, Fire Service organisations must implement appropriate management and prevention strategies to reduce the potential risks associated with an aging workforce.

11.
Popul Health Metr ; 11(1): 23, 2013 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-24299001

RESUMO

BACKGROUND: The South Australian Department of Health has administered the Active Australia Survey triennially since 1998 to assess physical activity levels in the South Australian adult population. Survey findings may reflect the impact of health messages on the population and provide evidence to inform public health policy.This study analyzed the data from the South Australian Active Australia Surveys from 1998 to 2010 to quantify trends in the physical activity patterns of the total population and groups within the population over this period. METHODS: The study used a retrospective analysis of the SA Health Active Australia Surveys of 1998, 2001, 2004, 2007, and 2010. Data were age-adjusted to the Australian 2001 Population Census. Proportions reporting sufficient physical activity for health benefits (≥ 150 min/week) were calculated by year of survey, and according to the following variables: gender, age group, area, educational level, income bracket, and body mass index (BMI). Population proportions statistics were used to determine the significance of the changes in levels of physical activity between 1998 and 2010. RESULTS: The main finding was a significant increase in the overall proportion of the population reporting sufficient physical activity. However, the changes were not uniform across categories. Differences in proportions reporting sufficient physical activity appear to have narrowed within the categories of gender and BMI but have widened within the categories of educational level and income bracket. Changes were relatively consistent across age and geographic location. CONCLUSIONS: The results suggest that government programs to increase engagement in regular physical activity have been effective in some groups within the total population. They provide strong evidence to support the need for better ways of increasing physical activity levels and thus improving health outcomes for disadvantaged groups in the South Australian population.

12.
J Sports Sci ; 31(1): 97-103, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22974317

RESUMO

This study measured the relative rates of change of the three human energy systems across a 30-year age range. A cross-section of highly trained masters cyclists (n = 156 males and 17 females; 35-64 years) were tested for maximal cycling performance. There were 50 (29%) track sprint cyclists and the remaining (71%) were predominantly road cycling specialists. A 10 s peak power test measured anaerobic power, a 30 s test measured anaerobic capacity, and a progressive test to volitional fatigue was used to determine peak aerobic power. Participants' exercise patterns were recorded using a physical activity recall questionnaire. Linear regression showed significant changes in anaerobic performance with aging. Peak anaerobic power (W · kg⁻¹) declined at a rate (mean ± SEE) of 8.1 ± 4.1% per decade (P < 0.0001) and anaerobic capacity (kJ · kg⁻¹) declined at 8.0 ± 3.3% per decade (P < 0.0001). Peak aerobic power [W · kg⁻¹] did not change significantly with age [-1.8 ± 1.5% per decade (P = 0.218)]. This cross-sectional study showed performance of the two anaerobic energy systems declined significantly across the age spectrum with no change in aerobic capacity.


Assuntos
Envelhecimento , Limiar Anaeróbio , Desempenho Atlético , Ciclismo , Exercício Físico , Resistência Física , Esforço Físico , Adulto , Fatores Etários , Atletas , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Inquéritos e Questionários
13.
JAMA Netw Open ; 6(8): e2328633, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37566413

RESUMO

Importance: Concussions are common in sports. Return-to-play protocols can be enhanced by objective biometrics. Objective: To characterize temporal changes of headpulse, a digital biometric, in athletes with sports-related concussion; to explore the association of unstructured physical activity with headpulse changes. Design, Setting, and Participants: This cohort study included headpulse measurements from players in the highest level of amateur Australian Rules Football in South Australia. Analysis included feasibility and validation phases, with the feasibility cohort recruited between August 5, 2021, and September 10, 2021, and the validation cohort recruited between May 5, 2022, and September 3, 2022. Data were analyzed October 2022 through January 2023. Interventions: Cranial accelerometry detected micromovements of the head following cardiac contraction (what we have described as "headpulse"). Headpulse was serially recorded for 1 month in concussed individuals. Main Outcomes and Measures: Headpulse waveforms underwent frequency transformation analysis per prespecified algorithm. Result Z scores were calculated. Headpulse Z scores exceeding 2 (2 SDs from control means) met an abnormality threshold. Headpulse sensitivity, timing, and duration of change were determined. Results: A total of 59 control and 43 concussed individuals (44 total concussions; 1 control also concussed, 1 concussed individual injured twice) provided headpulse measurements. The feasibility cohort (all male) included 17 control (median [IQR] age, 23 [19-28] years) and 15 concussed individuals (median [IQR] age, 21 [19-23] years). The validation cohort included 25 female (median [IQR] age, 21 [20-22] years) and 17 male (median [IQR] age, 26 [23-29] years) control individuals, and 8 female (median [IQR] age, 28 [20-31] years) and 20 male (median [IQR] age, 21 [19-23] years) concussed individuals. Headpulse reached abnormality threshold in 26 of 32 concussed individuals (81%; 9% on day 0, 50% by day 2, 90% by day 14). Headpulse alterations lasted 14 days longer than symptoms and were exacerbated by return-to-play or unsupervised physical activity. Conclusions and Relevance: In this study of 101 amateur Australian Rules Football athletes, the digital headpulse biometric was evaluated in 44 sports-related concussions. Compared with controls, new headpulse changes occurred after concussion; this objective metric may complement return-to-play protocols.


Assuntos
Concussão Encefálica , Humanos , Masculino , Feminino , Adulto Jovem , Adulto , Estudos de Coortes , Austrália/epidemiologia , Concussão Encefálica/diagnóstico , Atletas , Biometria
14.
J Pharmacol Toxicol Methods ; 121: 107266, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36963703

RESUMO

INTRODUCTION: Characterization of the incidence of spontaneous arrhythmias to identify possible drug-related effects is often an important part of the analysis in safety pharmacology studies using telemetry. METHODS: A retrospective analysis in non-clinical species with and without telemetry transmitters was conducted. Electrocardiograms (24 h) from male and female beagle dogs (n = 131), Göttingen minipigs (n = 108) and cynomolgus non-human primates (NHP; n = 78) were analyzed. RESULTS: Ventricular tachycardia (VT) was observed in 3% of the dogs but was absent in minipigs and NHPs. Ventricular fibrillation (VF) was not observed in the 3 species. Ventricular premature beats (VPBs) were more frequent during daytime and atrioventricular blocks (AVBs) were more frequent at night in all species. A limited number of animals exhibited a high arrhythmia frequency and there was no correlation between animals with higher frequency of an arrhythmia type and the frequency of other arrythmias in the same animals. Clinical chemistry or hematology parameters were not different with or without telemetry devices. NHP with a transmural left ventricular pressure (LVP) catheter exhibited a greater incidence of VPBs and PJCs compared to telemetry animals without LVP. DISCUSSION: All species were similar with regards to the frequency of ventricular ectopic beats (26-46%) while the dog seemed to have more frequent junctional complexes and AVB compared to NHP and minipigs. Arrhythmia screening may be considered during pre-study evaluations, to exclude animals with abnormally high arrhythmia incidence.


Assuntos
Arritmias Cardíacas , Telemetria , Animais , Cães , Suínos , Masculino , Feminino , Porco Miniatura , Incidência , Estudos Retrospectivos , Eletrocardiografia
15.
BMC Public Health ; 12: 851, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-23043381

RESUMO

BACKGROUND: The activitystat hypothesis proposes that when physical activity or energy expenditure is increased or decreased in one domain, there will be a compensatory change in another domain to maintain an overall, stable level of physical activity or energy expenditure. To date, there has been no experimental study primarily designed to test the activitystat hypothesis in adults. The aim of this trial is to determine the effect of two different imposed exercise loads on total daily energy expenditure and physical activity levels. METHODS: This study will be a randomised, multi-arm, parallel controlled trial. Insufficiently active adults (as determined by the Active Australia survey) aged 18-60 years old will be recruited for this study (n=146). Participants must also satisfy the Sports Medicine Australia Pre-Exercise Screening System and must weigh less than 150 kg. Participants will be randomly assigned to one of three groups using a computer-generated allocation sequence. Participants in the Moderate exercise group will receive an additional 150 minutes of moderate to vigorous physical activity per week for six weeks, and those in the Extensive exercise group will receive an additional 300 minutes of moderate to vigorous physical activity per week for six weeks. Exercise targets will be accumulated through both group and individual exercise sessions monitored by heart rate telemetry. Control participants will not be given any instructions regarding lifestyle. The primary outcome measures are activity energy expenditure (doubly labeled water) and physical activity (accelerometry). Secondary measures will include resting metabolic rate via indirect calorimetry, use of time, maximal oxygen consumption and several anthropometric and physiological measures. Outcome measures will be conducted at baseline (zero weeks), mid- and end-intervention (three and six weeks) with three (12 weeks) and six month (24 week) follow-up. All assessors will be blinded to group allocation. DISCUSSION: This protocol has been specifically designed to test the activitystat hypothesis while taking into account the key conceptual and methodological considerations of testing a biologically regulated homeostatic feedback loop. Results of this study will be an important addition to the growing literature and debate concerning the possible existence of an activitystat. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12610000248066.


Assuntos
Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Atividade Motora/fisiologia , Projetos de Pesquisa , Adolescente , Adulto , Austrália , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
16.
Int J Sports Physiol Perform ; 17(2): 170-175, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34560664

RESUMO

PURPOSE: Modeling intermittent work capacity is an exciting development to the critical power model with many possible applications across elite sport. With the Skiba 2 model validated using subelite participants, an adjustment to the model's recovery rate has been proposed for use in elite cyclists (Bartram adjustment). The team pursuit provides an intermittent supramaximal event with which to validate the modeling of W' in this population. METHODS: Team pursuit data of 6 elite cyclists competing for Australia at a Track World Cup were solved for end W' values using both the Skiba 2 model and the Bartram adjustment. Each model's success was evaluated by its ability to approximate end W' values of 0 kJ, as well as a count of races modeled to within a predetermined error threshold of ±1.840 kJ. RESULTS: On average, using the Skiba 2 model found end W' values different from zero (P = .007; mean ± 95% confidence limit, -2.7 ± 2.0 kJ), with 3 out of 8 cases ending within the predetermined error threshold. Using the Bartram adjustment on average resulted in end W' values that were not different from zero (P = .626; mean ± 95% confidence limit, 0.5 ± 2.5 kJ), with 4 out of 8 cases falling within the predetermined error threshold. CONCLUSIONS: On average, the Bartram adjustment was an improvement to modeling intermittent work capacity in elite cyclists, with the Skiba 2 model underestimating the rate of W' recovery. In the specific context of modeling team pursuit races, all models were too variable for effective use; hence, individual recovery rates should be explored beyond population-specific rates.


Assuntos
Ciclismo , Futebol , Austrália , Teste de Esforço , Humanos , Consumo de Oxigênio
17.
Sci Rep ; 12(1): 19803, 2022 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-36396735

RESUMO

Landscape evolution is driven by tectonics, climate and surface denudation. In New Zealand, tectonics and steep climatic gradients cause a dynamic landscape with intense chemical weathering, rapid soil formation, and high soil losses. In this study, soil, and elemental redistribution along two adjacent hillslopes in East Otago, New Zealand, having different landscape settings (ridge versus valley) are compared to identify soil weathering and erosion dynamics. Fallout radionuclides (239+240Pu) show that over the last ~ 60 years, average soil erosion rates in the valley (~ 260 [t km-2 year-1]) are low compared to the ridge (~ 990 [t km-2 year-1]). The ridge yields up to 26% lower soil weathering intensity than the topographical-protected valley. The lowest soil weathering intensity is found at both hilltop positions, where tors (residual rocks) are present and partially disintegrate. The soil weathering intensity increases with distance from tors, suggesting that tors rejuvenate the chemical weathering signature at the hilltop positions with fresh material. The inversed and decreasing weathering degree with all soil depth indicates that the fresh mineral contribution must be higher at the soil surface than at the bedrock weathering front. Higher erosion rates at the exposed ridge may be partially attributed to wind, consistent with rock abrasion of tors, and low local river sediment yields (56 [t km-2 year-1]). Thus, the East Otago spatial patterns of soil chemistry and erosion are governed by tor degradation and topographic exposure.


Assuntos
Solo , Tempo (Meteorologia) , Nova Zelândia , Rios
18.
Int J Behav Nutr Phys Act ; 8: 133, 2011 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-22136578

RESUMO

BACKGROUND: Increases in chronic illness due to sedentary lifestyles and poor metabolic fitness have led to numerous intervention strategies to promote physical activity (PA). This paper describes the methodological strategies of two short-term PA interventions. Outcome measures reported are PA adherence and compliance rates during the intervention and at 3, 6 and 12-month follow-up. METHODS: The 40-day interventions were: a pedometer-based walking program (n = 251) and a group-based intensive program (n = 148). There was also an active control group (n = 135). Intervention subjects were prescribed PA each day and required to record all activity sessions (pedometer steps or energy expenditure from heart rate monitors). RESULTS: Compliance (≥ 150 min/wk PA) was highest post-intervention (81.1% and 64.5% for the group and pedometer subjects, respectively) and then progressively decreased across the 12-month follow-up period (final compliance rates were 53.5% and 46.6%, respectively) although they remained significantly higher than pre-intervention rates (zero %). There was significantly higher adherence to 6 months (75.0% and 64.9%), and compliance to 3 months (64.9% and 51.0%), for group versus pedometer subjects. The active control group maintained the highest adherence and compliance rates across the study. CONCLUSIONS: The group-based program resulted in higher adherence and compliance rates post-intervention although both types of interventions showed long-term effectiveness to increase activity patterns.


Assuntos
Exercício Físico/fisiologia , Comportamento Sedentário , Caminhada/fisiologia , Adolescente , Adulto , Metabolismo Energético , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente
19.
Sports Med Open ; 7(1): 28, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33913061

RESUMO

BACKGROUND: There is extensive research investigating the match demands of players in the Australian Football League (AFL). OBJECTIVE: This systematic literature review and meta-regression sought to analyse the evolution of in-game demands in AFL matches from 2005 to 2017, focusing on the relationship between volume and intensity. METHODS: A systematic search of Ovid MEDLINE, Embase, Emcare, Scopus, SPORTDiscus, and Cochrane Library databases was conducted. Included studies examined the physical demands of AFL matches utilising global positioning system (GPS) technology. Meta-regression analysed the shift in reported volume (total distance and total match time) and intensity (metres per minute [m.min-1], sprint duration and acceleration) metrics for overall changes, across quarters and positional groups (forwards, nomadics and defenders) from 2005 to 2017 inclusive and for each year between 2005 and 2007, 2007 and 2010, 2010 and 2012, and 2012 and 2015/2017 breakpoints. RESULTS: Distance (p = 0.094), m.min-1 (p = 0.494), match time (p = 0.591), time over 18 km·h-1 (p = 0.271), and number of accelerations greater than 4 km·h-1 (p = 0.498) and 10 km·h-1 (p = 0.335) in 1 s did not change from 2005 to 2017. From 2005 to 2007 volume decreased (- 6.10 min of match time; p = 0.010) and intensity increased (6.8 m.min-1 increase; p = 0.023). Volume and intensity increased from 2007 to 2010, evidenced by increases in total distance (302 m; p = 0.039), time over 18 km·h-1 (0.31 min; p = 0.005), and number of accelerations greater than 4 km·h-1 (41.1; p = 0.004) and 10 km·h-1 (3.6; p = 0.005) in 1 s. From 2010 to 2012, intensity decreased, evidenced by reductions in metres per minute (- 4.3; p = 0.022), time over 18 km·h-1 (- 0.93 min; p < 0.001), and number of accelerations greater than 4 km·h-1 (- 104.4; p < 0.001) and 10 km·h-1 (- 8.3; p < 0.001) in 1 s, whilst volume stabilised with no changes in distance (p = 0.068) and match time (p = 0.443). From 2012 to 2015/2017 volume remained stable and intensity increased with time over 18 km·h-1 (0.27 min; p = 0.008) and number of accelerations greater than 4 km·h-1 (31.6; p = 0.016) in 1 s increasing. CONCLUSIONS: Changes in volume and intensity of AFL match demands are defined by discrete periods from 2007 to 2010 and 2010 to 2012. The interaction of rule and interpretation changes and coaching strategies play a major role in these evolutionary changes. In turn, modified game styles impact player game demands, training, and selection priorities. Standardisation and uniformity of GPS data reporting is recommended due to inconsistencies in the literature.

20.
Int J Sports Physiol Perform ; 15(1): 68-72, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31034296

RESUMO

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.

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