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1.
Curr Sports Med Rep ; 20(7): 359-365, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34234091

RESUMO

ABSTRACT: This article discusses the "bidirectional" relationship between inflammatory bowel disease (IBD) and physical activity. Intestinal symptoms and extraintestinal manifestations of IBD negatively impact a patient's ability to participate in sports. IBD also impacts athletic performance via its effects on muscle mass, muscle function, bone density, and fatigue. Surveys of IBD patients consistently show that IBD interferes with athletic participation. While IBD negatively affects physical activity, there is growing evidence that physical activity can be beneficial for IBD patients. Prospective studies have revealed that structured physical activities may positively influence inflammatory markers, disease activity, muscle strength, bone density, fatigue, stress, anxiety, and quality of life. This suggests that physical activity may be a simple and safe adjuvant therapy for IBD patients. Future studies assessing the optimal activity regimen are warranted. Finally, a cohort of professional athletes with IBD are described for the first time - football players in the National Football League.


Assuntos
Atletas , Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Doenças Inflamatórias Intestinais/fisiopatologia , Esportes/fisiologia , Ansiedade/terapia , Densidade Óssea/fisiologia , Eritema Nodoso/etiologia , Fadiga/fisiopatologia , Futebol Americano/fisiologia , Futebol Americano/estatística & dados numéricos , Humanos , Doenças Inflamatórias Intestinais/complicações , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/prevenção & controle , Artropatias/classificação , Artropatias/etiologia , Músculo Esquelético/fisiologia , Desempenho Físico Funcional , Pioderma Gangrenoso/etiologia , Qualidade de Vida , Esclerite/etiologia , Dermatopatias/etiologia , Estresse Fisiológico/fisiologia , Uveíte/etiologia
2.
J Sci Med Sport ; 24(8): 793-799, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34112612

RESUMO

OBJECTIVES: To examine, 1) optimal structure of break periods to mitigate physiological heat strain during rugby league play (Stage 1); and ii) effectiveness of three different cooling strategies applied during breaks (Stage 2). DESIGN: Counter-balanced crossover design. METHODS: In 37 °C, 50% RH, 11 males completed six simulated 80-min (two 40-min halves) rugby league matches on a treadmill with different break structures: regular game (RG) (12-min halftime), 1-min or 3-min "quarter-time" breaks halfway through each half with a 12-min halftime break (R1C and R3C), a 20-min halftime break (EH), or 1-min or 3-min quarter-time breaks with a 20-min halftime break (E1C and E3C) [Stage 1]. Nine participants completed Stage 2, which assessed the application of either ice towels (ICE), an electric fan (FAN) or a misting fan (MST) during breaks in the E3C protocol which, in Stage 1, prevailed as the optimal break structure. RESULTS: Stage 1: Irrespective of quarter-time break duration, reductions in rectal temperature (-0.24 °C ±â€¯0.24) and heart rate (-61 ±â€¯10 bpm) during the halftime break were greater with a 20-min compared to a 12-min break (-0.08 ±â€¯0.13 °C, p = 0.005; -55 ±â€¯-9 bpm, p = 0.021). Stage 2: End-game rises in rectal temperature were smaller (p < 0.006) in MST (1.41 ±â€¯0.22 °C), FAN (1.55 ±â€¯0.36 °C) and ICE (1.60 ±â€¯0.21 °C) than in CON (1.80 ±â€¯0.39 °C). The end-halftime heart rate was lower (p < 0.001) in ICE (89 ±â€¯13 bpm), MST (90 ±â€¯10 bpm) and FAN (92 ±â€¯13 bpm) than in CON (99 ±â€¯18 bpm). CONCLUSIONS: Combining an extended halftime period and quarter-time breaks with MST application is the optimal cooling strategy for rugby league players in hot, humid conditions.


Assuntos
Regulação da Temperatura Corporal , Crioterapia/métodos , Futebol Americano/fisiologia , Transtornos de Estresse por Calor/prevenção & controle , Resposta ao Choque Térmico , Temperatura Alta , Estudos Cross-Over , Frequência Cardíaca , Humanos , Umidade , Gelo , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Descanso , Sensação Térmica , Fatores de Tempo
3.
PLoS One ; 16(5): e0251970, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34029340

RESUMO

Movement, positioning and coordination of player formations is a key aspect for the performance of teams within field-based sports. The increased availability of player tracking data has given rise to numerous studies that focus on the relationship between simple descriptive statistics surrounding team formation and performance. While these existing approaches have provided a high-level a view of team-based spatial formations, there is limited research on the nature of collective movement across players within teams and the establishment of stable collective states within game play. This study draws inspiration from the analysis of collective movement in nature, such as that observed within schools of fish and flocking birds, to explore the existence of collective states within the phases of play in soccer. Order parameters and metrics describing group motion and shape are derived from player movement tracks to uncover the nature of the team's collective states and transitions. This represents a unique addition to the current body of work around the analysis of player movement in team sports. The results from this study demonstrate that sequences of ordered collective behaviours exist with relatively rapid transitions between highly aligned polar and un-ordered swarm behaviours (and vice-versa). Defensive phases of play have a higher proportion of ordered team movement than attacking phases, indicating that movements linked with attacking tactics, such as player dispersion to generate passing and shooting opportunities leads to lower overall collective order. Exploration within this study suggests that defensive tactics, such as reducing the depth or width to close passing opportunities, allows for higher team movement speeds and increased levels of collective order. This study provides a novel view of player movement by visualising the collective states present across the phases of play in football.


Assuntos
Desempenho Atlético/fisiologia , Comportamento Competitivo/fisiologia , Futebol Americano/fisiologia , Futebol/fisiologia , Adulto , Entropia , Humanos , Masculino , Movimento/fisiologia , Esportes/fisiologia
4.
J Sports Sci ; 39(14): 1633-1660, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33956579

RESUMO

Small-sided games is a commonly used training method to develop technical, tactical and physical qualities concurrently. However, a review of small-sided games in rugby football codes (e.g. rugby union, rugby league) is not available. This systematic review aims to investigate the acute responses and chronic adaptations of small-sided games within rugby football codes considering the constraints applied. Four electronical databases were systematically searched until August 2020. Acute and chronic studies investigating rugby football codes small-sided games, with healthy amateur and professional athletes were included. Twenty studies were eventually included: 4 acute and 1 chronic in rugby union, 13 acute and 2 chronic in rugby league. Acute studies investigated task and individual constraints. Chronic studies showed that small-sided games would be an effective training method to improve physical performance. Current research in rugby football codes is heavily biased towards investigating how manipulating constraints can affect the physical characteristics of small-sided games, with limited literature investigating the effect on technical skills, and no studies investigating tactical behaviour. Future research is needed to evidence the effects of constraint manipulation on technical and tactical behaviour of rugby football players in small-sided games, in addition to physical characteristics.


Assuntos
Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Humanos
5.
Nutrients ; 13(5)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919043

RESUMO

BACKGROUND: Previous research has reported that elite Gaelic football players' carbohydrate (CHO) intakes are sub-optimal, especially, in the lead up to competitive matches. Despite clear decrements in running performance across elite Gaelic football matches, there are no studies that have investigated nutrition interventions on match-related Gaelic football performance. The aim of this study was to determine whether a higher-CHO diet in line with sports nutrition guidelines can improve Gaelic football-related performance compared to lower CHO intakes previously observed in Gaelic footballers. METHODS: Twelve Gaelic football players completed a Gaelic football simulation protocol (GFSP) on two occasions after consuming a high-CHO diet (7 g·kg-1) (HCHO) or an energy-matched lower-CHO diet (3.5 g·kg-1) (L-CHO) for 48 h. Movement demands and heart rate were measured using portable global positioning systems devices. Countermovement jump height (CMJ) and repeated-sprint ability (RSA) were measured throughout each trial. Expired respiratory gases were collected throughout the trial using a portable gas analyser. Blood samples were taken at rest, half-time, and post-simulation. RESULTS: There was no significant difference in total distance (p = 0.811; η2 = 0.005) or high-speed running distance (HSRD) covered between both trials. However, in the second half of the HCHO trial, HSRD was significantly greater compared to the second half of the LCHO trial (p = 0.015). Sprint distance covered during GFSP was significantly greater in HCHO (8.1 ± 3.5 m·min-1) compared with LCHO (6.4 ± 3.2 m·min-1) (p = 0.011; η2 = 0.445). RSA performance (p < 0.0001; η2 = 0.735) and lower body power (CMJ) (p < 0.0001; η2 = 0.683) were significantly greater during the HCHO trial compared to LCHO. Overall CHO oxidation rates were significantly greater under HCHO conditions compared to LCHO (3.3 ± 0.5 vs. 2.7 ± 0.6 g·min-1) (p < 0.001; η2 = 0.798). Blood lactate concentrations were significantly higher during HCHO trial versus LCHO (p = 0.026; η2 = 0.375). There were no significant differences in plasma glucose, non-esterified fatty acids (NEFAs), and glycerol concentration between trials. In both trials, all blood metabolites were significantly elevated at half-time and post-trial compared to pre-trial. CONCLUSION: These findings indicate that a higher-CHO diet can reduce declines in physical performance during simulated Gaelic football match play.


Assuntos
Desempenho Atlético/fisiologia , Carboidratos da Dieta/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Futebol Americano/fisiologia , Corrida/fisiologia , Glicemia/metabolismo , Ingestão de Energia , Frequência Cardíaca/fisiologia , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Metaboloma , Oxirredução , Respiração/efeitos dos fármacos , Especificidade por Substrato/efeitos dos fármacos , Adulto Jovem
6.
J Sports Sci ; 39(16): 1850-1859, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33840362

RESUMO

This study investigated the variability in the worst-case scenario (WCS) and suggested a framework to improve the definition and guide further investigation. Optical tracking data from 26 male players across 38 matches were analysed to determine the WCS for total distance, high-speed running (>5.5 m.s-1) and sprinting (>7.0 m.s-1) using a 3-minute rolling window. Position, total output, previous epoch, match half, time of occurrence, classification of starter vs substitute, and minutes played were modelled as selected contextual factors hypothesized to have associations with the WCS. Linear mixed effects models were used to account for cross-sectional observations and repeated measures. Unexplained variance remained high (total distance R2 = 0.53, high-speed running R2 = 0.53 and sprinting R2 = 0.40). Intra-individual variability was also high (total distance CV = 4.6-8.2%; high-speed CV = 15.6-37.8% and Sprinting CV = 21.1-76.4%). The WCS defined as the maximal physical load in a given time-window, produces unstable metrics lacking context, with high variability. Furthermore, training drills targetting this metric concurrently across players may not have representative designs and may underprepare athletes for complete match demands and multifaceted WCS scenarios. Using WCS as benchmarks (reproducing similar physical activity for training purposes) is conceptually questionable.


Assuntos
Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Corrida/fisiologia , Adulto , Estudos Transversais , Sistemas de Informação Geográfica , Humanos , Masculino , Estudos Retrospectivos , Adulto Jovem
7.
J Sport Health Sci ; 10(1): 91-98, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33518018

RESUMO

OBJECTIVE: To determine which intrinsic and extrinsic exertional heat illness (EHI) risk factors exist in youth American football players and observe perceptual and physiological responses of players during events (games and practices). METHODS: Cross-sectional cohort study observing 63 youth football players, varying in position. Independent variables were league (weight-restricted (WR, n = 27) and age-restricted (AR, n = 36)) and event type. Dependent variables were anthropometrics, work-to-rest ratio, and wet bulb globe temperature. Descriptive variables included preparticipation examination and uniform configuration. A subset of 16 players participated in physiological variables (heart rate and gastrointestinal temperature). Data collection occurred on 7 AR and 8 WR nonconsecutive practices and the first 3 games of the season. RESULTS: Mean values for anthropometric variables were higher (p < 0.05) in the AR league than the WR league. Work time (χ2 (1,111) = 4.232; p = 0.039) and rest time (χ2 (1,111) = 43.41; p < 0.001) were significantly greater for games, but ratios were significantly higher for practices (χ2 (1,111) = 40.62; p < 0.001). The majority of events (77%) observed were in black and red flag wet bulb globe temperature risk categories. A total of 57% of the players had a preparticipation examination, and up to 82% of events observed were in full uniforms. Individual gastrointestinal temperature and heart rate responses ranged widely and no players reached critical thresholds. CONCLUSION: Extrinsic (disproportionate work ratios, environmental conditions) and intrinsic (higher body mass index) EHI risk factors exist in youth football. Certain risk factors may be influenced by event and league type. National youth football organizations need to create thorough guidelines that address EHI risk factors for local leagues to adopt.


Assuntos
Temperatura Corporal/fisiologia , Futebol Americano/fisiologia , Frequência Cardíaca/fisiologia , Transtornos de Estresse por Calor/etiologia , Adolescente , Fatores Etários , Estatura , Índice de Massa Corporal , Superfície Corporal , Peso Corporal , Distribuição de Qui-Quadrado , Criança , Meio Ambiente , Trato Gastrointestinal/fisiologia , Humanos , Masculino , Descanso , Fatores de Risco , Sudeste dos Estados Unidos , Esportes de Equipe , Fatores de Tempo , Trabalho , Esportes Juvenis
8.
J Sports Sci ; 39(13): 1445-1451, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33596782

RESUMO

The study examined the utility of surrogate measures of athletic performance to determine locomotor qualities (maximal aerobic velocity and peak velocity) in elite Australian Football (AF). 29 professional AF players undertook aerobic fitness (3km time-trial [TT] and 30-15 Intermittent Fitness Test [30-15 IFT]) and peak velocity (PV; 50 m maximal sprints using 10Hz GPS) assessments in pre-season. Characteristics of TT performance (mean velocity, 500m and 1km splits) were compared with a surrogate for maximal aerobic velocity (MAV; 80% of 30-15 IFT final velocity). PVs derived from sprint tests were compared to those attained in AF matches (10 Hz GPS). Higher Pearson correlations were observed between MAV versus the fastest 500m (r = 0.74) and 1km (r = 0.75) of the 3km TT, but they were not superior to mean velocity (r = 0.72; p ≥ 0.30) which also demonstrated the lowest bias (p ≤ 0.01) and equivalent typical errors (0.16-0.17 m.s-1). Peak velocity was higher across match observations (0.28, CI: ± 0.17 m.s -1, p = 0.017) versus sprint tests. There was no impact of playing position on the determination of locomotor qualities using surrogate measures of locomotor qualities. Locomotor qualities can be determined practically using 10Hz GPS devices during 3km time-trials and competitive matches (assuming appropriate signal quality), without additional fitness assessments.


Assuntos
Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Locomoção/fisiologia , Corrida/fisiologia , Austrália , Teste de Esforço , Sistemas de Informação Geográfica , Humanos
9.
J Sports Sci ; 39(sup1): 132-139, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33541213

RESUMO

This study examined the relationship between proximal arm strength and mobility performance in wheelchair rugby (WR) athletes and examined whether a valid structure for classifying proximal arm strength impairment could be determined. Fifty-seven trained WR athletes with strength impaired arms and no trunk function performed six upper body isometric strength tests and three 10 m sprints in their rugby wheelchair. All strength measures correlated with 2 m and 10 m sprint times (r ≥ -0.43; p ≤ 0.0005) and were entered into k-means cluster analyses with 4-clusters (to mirror the current International Wheelchair Rugby Federation [IWRF] system) and 3-clusters. The 3-cluster structure provided a more valid structure than both the 4-cluster and existing IWRF system, as evidenced by clearer differences in strength (Effect sizes [ES] ≥ 1.0) and performance (ES ≥ 1.1) between adjacent clusters and stronger mean silhouette coefficient (0.64). Subsequently, the 3-cluster structure for classifying proximal arm strength impairment would result in less overlap between athletes from adjacent classes and reduce the likelihood of athletes being disadvantaged due to their impairment. This study demonstrated that the current battery of isometric strength tests and cluster analyses could facilitate the evidence-based development of classifying proximal arm strength impairment in WR.


Assuntos
Braço/fisiologia , Futebol Americano/fisiologia , Movimento/fisiologia , Força Muscular/fisiologia , Paratletas , Estudo de Prova de Conceito , Adulto , Ataxia/classificação , Ataxia/fisiopatologia , Desempenho Atlético/fisiologia , Análise por Conglomerados , Feminino , Futebol Americano/classificação , Humanos , Contração Isométrica/fisiologia , Masculino , Paratletas/classificação , Valores de Referência , Traumatismos da Medula Espinal/complicações , Esportes para Pessoas com Deficiência/fisiologia , Cadeiras de Rodas
10.
J Sports Sci ; 39(sup1): 91-98, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33593245

RESUMO

This study aims were twofold: (1) to evaluate the construct validity of the Repetitive Movement Test (RMT) a novel test developed for Wheelchair Rugby classification which evaluates arm coordination impairment at five joints - shoulder, elbow, forearm, wrist and fingers - and (2), pending sufficiently positive results, propose objective minimum impairment criteria (MIC). Forty-two WR athletes with an eligible coordination impairment, and 20 volunteers without impairment completed the RMT and two clinically established coordination tests: the finger-nose test (FNT) and the spiral test (ST). Coordination deduction (CD), an ordinal observational coordination scale, currently used in WR classification, was obtained. Spearman-rank correlation coefficients (SCC) between RMT and ST (0.40 to 0.67) and between RMT and CD (0.31 to 0.53) generally supported RMT construct validity, SCC between RMT and FNT were lower (0.12-0.31). When the scores on ST, FNT and RMT from the sample of WR players were compared with the scores from volunteers without impairment, 93.5% to 100% of WR players had scores > 2SD below the mean of volunteers without impairment on the same test. In conclusion, RMT at the elbow, forearm, wrist and fingers have sufficient construct validity for use in WR. MIC were recommended with ST and RMT.


Assuntos
Braço/fisiopatologia , Ataxia/fisiopatologia , Futebol Americano/fisiologia , Articulações/fisiopatologia , Esportes para Pessoas com Deficiência/fisiologia , Adolescente , Adulto , Ataxia/classificação , Desempenho Atlético , Estudos de Casos e Controles , Estudos Transversais , Articulação do Cotovelo/fisiopatologia , Feminino , Articulações dos Dedos/fisiopatologia , Futebol Americano/classificação , Antebraço , Humanos , Masculino , Pessoa de Meia-Idade , Paratletas , Desempenho Psicomotor/fisiologia , Amplitude de Movimento Articular/fisiologia , Reprodutibilidade dos Testes , Articulação do Ombro/fisiopatologia , Esportes para Pessoas com Deficiência/classificação , Estatísticas não Paramétricas , Articulação do Punho/fisiologia , Adulto Jovem
11.
J Sci Med Sport ; 24(8): 756-762, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33558190

RESUMO

OBJECTIVES: To determine the effect of heat acclimatisation (HA) training on blood profile and resting cardiac function in elite athletes with spinal cord injury (SCI). DESIGN: Quasi-experimental. METHODS: Eleven athletes (10m, 1f) with SCI (C5-T3) completed a five-day isothermic HA protocol whereby gastrointestinal temperature (Tc) was elevated to and maintained at ∼38.5 degrees Celsius (°C) via intermittent exercise for sixty minutes each day. Blood samples were collected pre- and post-HA to determine changes in plasma volume (PV). Doppler ultrasound of the left-ventricular outflow tract and 2-d speckle tracking echocardiography were performed in a subset of athletes (n=5) to determine changes in indices of resting left-ventricular function and mechanics, respectively. RESULTS: Ten athletes were successfully able to raise and maintain Tc to 38.5°C. There was a non-significant increase in PV with HA training (ΔPV%: 3.0±5.4%, p=0.086). Following HA, resting HR decreased (63±4 pre-HA vs. 58±5 bpm post-HA, p=0.020), velocity time integral (21.4±2.7 vs. 23.7±3.0cm, p=0.045) and stroke volume increased (64.8±7.6 vs. 70.2±10.5mL, p=0.055). CONCLUSIONS: Our findings suggest a short-term HA protocol in athletes with SCI is safe and may induce beneficial changes in indices of resting left-ventricular function - however results are highly individualized. Future studies on HA in athletes with SCI should focus on determining mechanisms of adaptation and performance outcomes.


Assuntos
Aclimatação , Desempenho Atlético/fisiologia , Hemodinâmica , Temperatura Alta , Traumatismos da Medula Espinal/fisiopatologia , Esportes para Pessoas com Deficiência/fisiologia , Adulto , Feminino , Futebol Americano/fisiologia , Frequência Cardíaca , Humanos , Masculino , Volume Plasmático , Volume Sistólico , Fatores de Tempo , Função Ventricular Esquerda
12.
J Sports Sci ; 39(14): 1585-1593, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33583340

RESUMO

This study aimed to investigate the influence of chronological age and maturation status on sprint acceleration characteristics in junior Australian football (AF) players. Biological maturity of 109 subjects was assessed and subjects were grouped according to predicted years from peak height velocity (PHV) (pre-, mid-, and post-PHV) and chronological age (13 years, 14 years, and 15 years). A one-way multivariate analysis of variance and magnitude-based decisions were used to determine between-group differences. Instantaneous velocity was measured during two maximal 30m sprints via radar gun with the velocity-time data used to derive the force, velocity, and power characteristics. Chronologically, the greatest differences were observed between the 13 and 14 year old groups with the latter group producing likely greater relative maximum power (Pmax) (ES[effect size]=0.44) and theoretical maximal velocity (V0) (ES=0.49). The post-PHV group likely demonstrated a greater ability to apply force at faster velocity (V0; ES=0.59) and orient the force in a horizontal direction (Drf%; ES=-0.49) than the mid-PHV group. No differences in relative theoretical maximal force (F0) were observed between groups. Considering the findings, practitioners should aim to improve relative lower limb strength through heavy sled push or sled pulls and traditional strength training exercises to improve relative F0.


Assuntos
Desenvolvimento do Adolescente/fisiologia , Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Corrida/fisiologia , Aceleração , Adolescente , Fatores Etários , Austrália , Fenômenos Biomecânicos , Humanos , Cinética
13.
J Sports Sci ; 39(14): 1594-1601, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33629651

RESUMO

This study examined possible predictors of upper respiratory tract symptom (URTS) episodes in elite rugby union and league players (n = 51) during intensive pre-season training. Baseline saliva and blood samples were collected in the first week of pre-season training for analysis of salivary secretory immunoglobulin A (SIgA) and cytomegalovirus. Thereafter, SIgA, URTS, internal training load and self-reported wellness data were repeatedly measured throughout a 10-week pre-season training period. Univariate frailty model analysis, which included 502 observations, was performed for each rugby code for the following independent predictor variables: SIgA concentration, internal training load, total wellness, sleep quantity, sleep quality and stress. Rugby union and league players experienced a similar number of URTS episodes; however, predictors of URTS episodes differed between the codes. No biomarkers or self-reported measures significantly predicted URTS risk in rugby union players, while reductions in self-reported total wellness (HR: 0.731, p = 0.004) and sleep quality (HR: 0.345, p = 0.001) predicted increased URTS risk in rugby league players. The findings from this study highlight that factors influencing URTS risk are perhaps sport specific and this may be attributed to different sporting demands and/or different management of players by team-practitioners.


Assuntos
Citomegalovirus/isolamento & purificação , Futebol Americano/fisiologia , Imunoglobulina A Secretora/metabolismo , Condicionamento Físico Humano/fisiologia , Infecções Respiratórias/epidemiologia , Adulto , Biomarcadores/metabolismo , Estudos de Coortes , Humanos , Incidência , Masculino , Nova Zelândia/epidemiologia , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
14.
Sci Rep ; 11(1): 1844, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33469159

RESUMO

Sickle cell trait (SCT) is a risk factor of collapse and sudden death in athletes. We conducted a longitudinal study to determine the hematological responses and hydration status in NCAA Division I American football players with SCT. The study took place over 2 years with 6 SCT and 6 position-matched controls (CON) in year 1; and 4 SCT and 4 CON in year 2. In year 2, three of the four SCT players were recruited and re-enrolled with new position-matched controls (total sample data = 10 SCT and 10 CON). Blood samples were taken at three visits: pre-camp, post-camp, and post-season to examine hemoglobin variants, complete blood counts, and chemistry panel 26. Hydration status was assessed by measuring body weight change, urine specific gravity, and urine and sweat electrolyte concentrations during the pre-season training camp. All SCT players were confirmed to have SCT (HbS = 37.9 ± 2.4%) and had greater red cell distribution width (RDW) compared to CON across all visits. Serum uric acid was higher in SCT (7.3 ± 1.0 mg/dL) compared to CON (6.1 ± 0.6 mg/dL; p = 0.001). Furthermore, serum creatine kinase levels were greater in SCT (1617.0 ± 1034.8 IU/L) at pre-camp compared to CON (1037.4 ± 602.8 IU/L; p = 0.03). SCT players exhibited lower pre- and post-practice urine electrolytes and urine specific gravity (SCT pre: 1.019 ± 0.005 vs. CON pre: 1.026 ± 0.008 p < 0.001; SCT post: 1.020 ± 0.005 vs. CON post: 1.030 ± 0.008 p < 0.01), whereas sweat sodium concentrations were higher in SCT players (55.4 ± 13.6 mmol/L) compared to CON (45.5 ± 10.6 mmol/L; p < 0.001). Given the evidence, greater uric acid and CPK levels in SCT players compared to CON may be an early indicator of altered kidney function and muscle damage, which could be added into NCAA guidelines for surveillance among SCT players. Consistent education and reinforcement of the importance of adequate fluid balance during exercise are critical for both SCT and CON players.


Assuntos
Anemia Falciforme/fisiopatologia , Futebol Americano/fisiologia , Estado de Hidratação do Organismo , Esportes , Adolescente , Anemia Falciforme/sangue , Biomarcadores/sangue , Estudos de Casos e Controles , Creatina Quinase/sangue , Taxa de Filtração Glomerular , Humanos , Masculino , Estados Unidos , Equilíbrio Hidroeletrolítico/fisiologia , Adulto Jovem
15.
J Sports Med Phys Fitness ; 61(5): 636-644, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33472345

RESUMO

BACKGROUND: This study aimed to describe the physical fitness characteristics of semi-professional rugby union (RU) players using VO2max (mL. min-1. kg-1), knee peak torque (PT), mean power (MP), hamstring: quadriceps (H:Q) ratio and basic anthropometrics characteristics and to compare backs and forwards across these same characteristics. METHODS: VO2max and ventilatory threshold (VT) as a percentage of VO2max were measured using the Bruce protocol maximal graded test. Knee strength test PT, MP and H:Q were analyzed using the isokinetic dynamometer test. Basic anthropometrics measures were obtained by measures of body mass, height (from Tanita Body Composition Analysis; Tanita Corp., Tokyo, Japan). While fat mass was measured using skinfold thicknesses taking from different body parts. Twenty-five semi-professional players aged (26.3±0.9 years) from the same team were recruited for the study. Mean experimental values from maximal graded test and isokinetic dynamometer test were analyzed using t-tests from the SigmaStat 3.11 program (Systat Software Inc., San Jose, CA, USA). RESULTS: The results showed that forwards were significant taller (P=0.036), heavier (P=0.01), with greater fat mass (P=0.001) than backs. Backs had a greater VO2max (P=0.02) than forwards. With forwards having a greater (P=0.01) eccentric H PT. CONCLUSIONS: This study presents important information for players and athletic coordinators as to the differences between backs and forwards across physiological and strength measures. This information can greatly inform the individualized training protocol and preparation of current and future players across different positions and different levels.


Assuntos
Aptidão Cardiorrespiratória , Comportamento Competitivo/fisiologia , Futebol Americano/fisiologia , Joelho/fisiologia , Força Muscular , Adulto , Limiar Anaeróbio , Estatura , Índice de Massa Corporal , Estudos Transversais , Teste de Esforço , Músculos Isquiossurais/fisiologia , Humanos , Masculino , Consumo de Oxigênio , Músculo Quadríceps/fisiologia , Pregas Cutâneas , Torque
16.
J Sports Med Phys Fitness ; 61(5): 687-692, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33472346

RESUMO

BACKGROUND: Body composition is frequently measured by sports, fitness, and healthcare professionals. Dual-Energy X-ray Absorptiometry (DXA) analysis is a validated measurement of body composition and is considered a criterion or "gold-standard" measurement. However, due to long scan times, accessibility and cost, conducting DXA scans on larger athletes (i.e., football players) is difficult. Hence fitness professionals, notably strength and conditioning coaches, typically use other methods to measure body composition. The aim of this study was to assess the accuracy of the Bioelectrical Impedance Analysis (BIA) and Integrative Body Composition (IBC) techniques to DXA body fat percent (BF%) in collegiate American Football players. METHODS: Participants performed all three modes of body composition measurement: DXA, BIA (BIA-A [athlete]and BIA-NA [non-athlete modes]), and IBC, on the same day during early morning hours in a fasted state. RESULTS: The BF% measured via all methods significantly correlated with BF% measured via DXA (i.e., BIA-A [P<0.001, r=0.903], BIA-NA [P<0.001, r=0.891], and IBC [P<0.001, r=0.867]). However, values obtained via BIA-A (athlete) (P<0.001) and IBC (P<0.001) methods under predicted BF%. CONCLUSIONS: BIA and IBC can be used as an alternative to DXA for measuring BF% in American Football players. The BIA-A and IBC under predicted BF% compare to DXA, therefore, a correction formula can be utilized by coaches and athletes to predict BF% more accurately compared to IBC and BIA-A methods in American Football players.


Assuntos
Absorciometria de Fóton , Distribuição da Gordura Corporal/métodos , Impedância Elétrica , Futebol Americano/fisiologia , Jejum , Humanos , Masculino , Estados Unidos , Universidades , Adulto Jovem
17.
Scand J Med Sci Sports ; 31(5): 1078-1085, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33421195

RESUMO

The value of echocardiography in the screening of athletes in addition to the electrocardiogram is debated and still unclear. 336 rugby players in French professional divisions (Top 14, Pro D2) were prospectively assessed with electrocardiogram and echocardiography. 75% were Caucasian, 16.4% Pacific Islanders, and 8.6% Afro-Caribbean. Six (1.8%) players had electrocardiogram abnormalities, exclusively negative T waves. Twenty-one (6.25%) of them had abnormal echocardiography findings: one possible early hypertrophic cardiomyopathy, one anomalous origin of coronary artery, two left ventricular dilatations, one isolated bicuspid aortic valve, two aortic regurgitations, and 14 ascending aortic dilatations. The median aortic diameter was modestly correlated with age: 32 mm [23-48] in players aged ≤25 years vs 33.5 mm [24-50] in those aged >25 years (P = 0.02, correlation coefficient -.01). This tendency increased with cumulative hours of weight training: 34 mm [24-50] in forwards vs 32 mm [25-44] in backs (P = 0.01); and ethnicity, with Pacific Islanders having higher values in both raw data and body surface area or height-indexed data than Afro-Caribbeans and Caucasians: 34 [25-50] vs 32 [27-48] and 33 [23-49] mm (P = 0.017); 15 [12.2-21] vs 14.8 [11-19.9] and 14.8 [10-20.9] mm/m2 (P < 0.0001); 18.5 [14-25] mm/m vs 17.4 [14.8-25] mm/m and 17.6 [12.2-25.3] mm/m (P = 0.0125). In a population of professional rugby players, echocardiography was contributive. The main anomaly was aortic dilatation (14/336, 4.2%). While this is proportionally much higher than in other sports, the cutoffs need to be defined more precisely by including the criterion of ethnicity, as is already the case for electrocardiography.


Assuntos
Aorta/diagnóstico por imagem , Aorta/patologia , Dilatação Patológica/diagnóstico por imagem , Ecocardiografia , Futebol Americano/fisiologia , Adulto , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/etnologia , Comportamento Competitivo/fisiologia , Anomalias dos Vasos Coronários/diagnóstico por imagem , Anomalias dos Vasos Coronários/etnologia , Dilatação Patológica/etnologia , Eletrocardiografia , França , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/etnologia , Humanos , Masculino , Estudos Prospectivos , Treinamento de Força , Adulto Jovem
18.
J Sports Sci ; 39(12): 1339-1347, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33404378

RESUMO

This study aimed to identify the predictive capacity of wellness questionnaires on measures of training load using machine learning methods. The distributions of, and dose-response between, wellness and other load measures were also examined, offering insights into response patterns. Data (n= 14,109) were collated from an athlete management systems platform (Catapult Sports, Melbourne, Australia) and were split across three sports (cricket, rugby league and football) with data analysis conducted in R (Version 3.4.3). Wellness (sleep quality, readiness to train, general muscular soreness, fatigue, stress, mood, recovery rating and motivation) as the dependent variable, and sRPE, sRPE-TL and markers of external load (total distance and m.min-1) as independent variables were included for analysis. Classification and regression tree models showed high cross-validated error rates across all sports (i.e., > 0.89) and low model accuracy (i.e., < 5% of variance explained by each model) with similar results demonstrated using random forest models. These results suggest wellness items have limited predictive capacity in relation to internal and external load measures. This result was consistent despite varying statistical approaches (regression, classification and random forest models) and transformation of wellness scores. These findings indicate practitioners should exercise caution when interpreting and applying wellness responses.


Assuntos
Nível de Saúde , Aprendizado de Máquina , Condicionamento Físico Humano/fisiologia , Condicionamento Físico Humano/psicologia , Esportes/fisiologia , Esportes/psicologia , Inquéritos e Questionários , Afeto , Críquete/fisiologia , Críquete/psicologia , Árvores de Decisões , Fadiga/diagnóstico , Futebol Americano/fisiologia , Futebol Americano/psicologia , Sistemas de Informação Geográfica , Humanos , Motivação , Mialgia/diagnóstico , Percepção/fisiologia , Esforço Físico/fisiologia , Análise de Regressão , Sono/fisiologia , Futebol/fisiologia , Futebol/psicologia , Estresse Psicológico/diagnóstico , Dispositivos Eletrônicos Vestíveis
19.
J Sci Med Sport ; 24(6): 592-596, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33386238

RESUMO

OBJECTIVES: This study investigated the effects of induced mental fatigue on the performance of Australian football (AF) specific skills amongst amateur AF players. DESIGN: Randomised cross over trial. METHODS: Twenty-five amateur AF players performed a series of standardised tests from the Australian Football League (AFL) Draft Combine after completing a 30-min Stroop test (mental fatigue condition) or 30-min control condition. The AFL Draft Combine tests included the standing vertical jump test, running vertical jump test, agility test, 20m sprint, Matthew Lloyd clean hands test, Brad Johnson goal kicking test and a Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1) test. RESULTS: The Stroop test score decreased during the Stroop test (first five trials: mean=84.7, SD=3.5; last five trials: mean=82.2, SD=5.0, p=0.03). The Yo-Yo IR1 test (mental fatigue: median=920m, IQR=400; control: median=1040m, IQR=760; p=0.03) and Brad Johnson goalkicking test (mental fatigue: median=19.0, IQR=5.0; control: median=25.0, IQR=10.0, p=0.048) were negatively affected by mental fatigue. No other Draft Combine tests demonstrated a negative affect from mental fatigue. CONCLUSIONS: Mental fatigue had a detrimental influence on the performance of AF specific skills. The findings may have implications for AF players who are required to sustain attention and concentration for prolonged periods before and during matches.


Assuntos
Desempenho Atlético/fisiologia , Futebol Americano/fisiologia , Fadiga Mental/fisiopatologia , Resistência Física , Desempenho Físico Funcional , Teste de Stroop/estatística & dados numéricos , Austrália , Cognição/fisiologia , Estudos Cross-Over , Humanos , Masculino , Destreza Motora , Movimento/fisiologia , Futebol/fisiologia , Fatores de Tempo , Adulto Jovem
20.
Med Sci Sports Exerc ; 53(5): 918-927, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33394896

RESUMO

PURPOSE: This investigation examined the longitudinal changes and interrelationships of salivary and self-report monitoring measures across a professional football season. METHODS: Measures were collected biweekly from 18 senior professional male players across a 6-wk preseason and eight 5-wk in-season mesocycles and analyzed using a linear mixed-effects model. RESULTS: Analysis identified a small (P = 0.003) cross-season suppression of salivary immunoglobulin A, small reductions to salivary α-amylase (P = 0.047) and salivary cortisol (P = 0.007), and trivial changes to salivary testosterone (P > 0.05). The testosterone/cortisol ratio typically responded inversely to changes in player workload. Self-report measures of fatigue (P = 0.030), sleep quality (P = 0.003), and muscle soreness (P = 0.005) improved (ES = small) across the first half of the season. Fatigue and sleep measures were most consistently related to hormonal measures (R2 = 0.43-0.45). For these relationships, increases in cortisol were associated with compromised self-report responses, whereas increases in testosterone/cortisol were associated with improved responses. Nonlinear relationships were identified for fatigue with immunoglobulin A (P = 0.017; ES = trivial) and testosterone (P = 0.012; ES = trivial), for sleep quality with testosterone (P < 0.001; ES = trivial), for muscle soreness with testosterone (P = 0.012; ES = trivial), and for the self-report inventory sum with testosterone (P = 0.027; ES = trivial). For these relationships, self-report responses were optimal at mean immunoglobulin A and testosterone levels, and very low levels (-2 SD) exerted the most compromising effects. CONCLUSIONS: Players can experience a chronic cross-season suppression of mucosal immunity. Salivary immunoglobulin A, testosterone, cortisol, and testosterone/cortisol measures relate to self-report measures of fatigue, sleep quality, and muscle soreness. In-season reductions in testosterone, cortisol, and testosterone/cortisol or increases in cortisol among elite football players could be used to indicate the need for reduced workload, which might lead to improved well-being.


Assuntos
Futebol Americano/fisiologia , Hidrocortisona/análise , Imunoglobulina A Secretora/análise , Saliva/química , alfa-Amilases Salivares/análise , Testosterona/análise , Adulto , Biomarcadores/análise , Fadiga/metabolismo , Humanos , Imunidade nas Mucosas , Masculino , Mialgia/metabolismo , Saliva/imunologia , Estações do Ano , Autorrelato , Sono/fisiologia , Carga de Trabalho
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