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1.
Br J Sports Med ; 50(10): 590-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26614761

RESUMO

BACKGROUND: Injury and illness surveillance in the aquatic disciplines has been conducted during the FINA World Championships and Olympic Games. The development of an aquatic-specific injury and illness surveillance system will improve the quality of the data collected and the development of preventive measures. Our ultimate objective is to enhance aquatic athlete health and performance. OBJECTIVE: The objective was to refine the injury and illness surveillance protocols to develop aquatic-specific definitions of injury and illness; define aquatic-specific injury location and causation; better describe overuse injuries; regard pre-existing and recurrent injuries; more accurately define aquatic athlete exposures and develop a protocol to capture out-of-competition aquatic athlete health parameters. METHODS: FINA compiled an Injury and Illness Surveillance Expert Working Group comprised of international experts to review the scientific literature in the field. A consensus meeting was convened to provide an opportunity for debate, following which recommendations were collated. RESULTS: Aquatic-specific injury and illness surveillance protocols covering both the in-competition and out-of-competition time periods were developed. Definitions for all relevant variables were outlined, and documentation forms for athletes and for clinicians were proposed. Recommendations for the implementation of an injury and illness surveillance system for FINA are presented. CONCLUSION: The FINA consensus authors recommend ongoing in-competition and out-of-competition surveillance to determine injury and illness trends over time. The implementation of the definitions and methodology outlined in this paper will improve the accuracy and value of injury and illness surveillance, and provide important information for injury prevention.


Assuntos
Natação/lesões , Traumatismos em Atletas/diagnóstico , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/prevenção & controle , Consenso , Previsões , Humanos , Prontuários Médicos , Recidiva , Projetos de Pesquisa , Medicina Esportiva/métodos , Medicina Esportiva/tendências , Índices de Gravidade do Trauma
2.
Scand J Med Sci Sports ; 26(5): 564-71, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-25944058

RESUMO

The objective of this study was to estimate the incidence and prevalence of injury and illness among elite junior tennis players. A cohort of 73 players (11-14 years) in the 2012-2013 Dutch national high-performance program was followed for 32 weeks; all participants completed the study. The OSTRC Questionnaire on Health Problems was used to record self-reported injuries and illnesses and to record training and match exposure. Main outcome measures were average prevalence of overuse injury and illness and incidence density of acute injury. On average, players practiced 9.1 h/week (SD 0.6; range 2.3-12.0) and had 2.2 h of match play (SD 0.6; range 2.3-12.0). During the course of the study, 67 players reported a total of 187 health problems. The average weekly prevalence of all health problems was 21.3% (95% CI: 19.2-22.9), of which 12.1% (95% CI: 10.9-13.3) constituted overuse injuries and 5.8% (95% CI: 4.6-6.9) illnesses. The incidence of acute injuries was 1.2/1000 h of tennis play (95% CI: 0.7-1.7). The high occurrence of overuse injuries among elite junior tennis players suggests that an early focus on preventative measures is warranted, with a particular focus on the monitoring and management of workload.


Assuntos
Transtornos Traumáticos Cumulativos/epidemiologia , Gastroenteropatias/epidemiologia , Infecções Respiratórias/epidemiologia , Tênis/lesões , Doença Aguda , Adolescente , Traumatismos do Tornozelo/epidemiologia , Criança , Feminino , Gastroenteropatias/microbiologia , Virilha/lesões , Humanos , Incidência , Masculino , Países Baixos/epidemiologia , Prática Psicológica , Prevalência , Estudos Prospectivos , Autorrelato , Fatores de Tempo
4.
Br J Sports Med ; 49(18): 1164-73, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26069301

RESUMO

Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimise performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimise performance is to heat acclimatise. Heat acclimatisation should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimise dehydration during exercise. Following the development of commercial cooling systems (eg, cooling-vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organisers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimising the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events, for hydration and body cooling opportunities, when competitions are held in the heat.


Assuntos
Exercício Físico/fisiologia , Temperatura Alta , Esportes/fisiologia , Aclimatação/fisiologia , Desempenho Atlético/fisiologia , Bebidas , Regulação da Temperatura Corporal/fisiologia , Vestuário , Temperatura Baixa , Exercícios de Desaquecimento/fisiologia , Desidratação/prevenção & controle , Hidratação/métodos , Transtornos de Estresse por Calor/fisiopatologia , Transtornos de Estresse por Calor/prevenção & controle , Humanos , Medicina Esportiva/métodos
5.
Scand J Med Sci Sports ; 25 Suppl 1: 6-19, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25943653

RESUMO

Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimize performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimize performance is to heat acclimatize. Heat acclimatization should comprise repeated exercise-heat exposures over 1-2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimize dehydration during exercise. Following the development of commercial cooling systems (e.g., cooling vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organizers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimizing the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events for hydration and body cooling opportunities when competitions are held in the heat.


Assuntos
Aclimatação/fisiologia , Comportamento de Ingestão de Líquido/fisiologia , Exercício Físico/fisiologia , Transtornos de Estresse por Calor/prevenção & controle , Temperatura Alta/efeitos adversos , Esportes/fisiologia , Desempenho Atlético/fisiologia , Regulação da Temperatura Corporal/fisiologia , Desidratação/complicações , Desidratação/prevenção & controle , Desidratação/terapia , Hidratação , Transtornos de Estresse por Calor/etiologia , Transtornos de Estresse por Calor/terapia , Humanos
6.
Br J Sports Med ; 43(12): 893-7, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19900956

RESUMO

BACKGROUND: The reported incidence, severity and nature of injuries sustained in tennis vary considerably between studies. While some of these variations can be explained by differences in sample populations and conditions, the main reasons are related to differences in definitions and methodologies employed in the studies. OBJECTIVE: This statement aims to review existing consensus statements for injury surveillance in other sports in order to establish definitions, methods and reporting procedures that are applicable to the specific requirements of tennis. DESIGN: The International Tennis Federation facilitated a meeting of 11 experts from seven countries representing a range of tennis stakeholders. Using a mixed methods consensus approach, key issues related to definitions, methodology and implementation were discussed and voted on by the group during a structured 1-day meeting. Following this meeting, two members of the group collaborated to produce a draft statement, based on the group discussions and voting outcomes. Three revisions were prepared and circulated for comment before the final consensus statement was produced. RESULTS: A definition of medical conditions (injuries and illnesses) that should be recorded in tennis epidemiological studies and criteria for recording the severity and nature of these conditions are proposed. Suggestions are made for recording players' baseline information together with recommendations on how medical conditions sustained during match play and training should be reported. CONCLUSIONS: The definitions and methodology proposed for recording injuries and illnesses sustained during tennis activities will lead to more consistent and comparable data being collected. The surveillance procedures presented here may also be applicable to other racket sports.


Assuntos
Doenças Musculoesqueléticas/epidemiologia , Doenças do Sistema Nervoso/epidemiologia , Dermatopatias/epidemiologia , Tênis/lesões , Doença Aguda , Exercício Físico/fisiologia , Feminino , Humanos , Incidência , Masculino , Recidiva
7.
Br J Sports Med ; 42(11): 868-71, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18344386

RESUMO

OBJECTIVE: To assess possible ergogenic properties of corticosteroid administration. DESIGN: A balanced, double-blind, placebo-controlled design was used. PARTICIPANTS: 28 well-trained cyclists and rowers. INTERVENTION: 4 weeks' daily inhalation of 800 microg budesonide or placebo. MAIN OUTCOME MEASUREMENTS: The subjects performed three incremental cycle ergometer tests until exhaustion, before and after 2 and 4 weeks of placebo or budesonide administration, to measure maximal power output (W(max)). Once a week they filled in a profile of mood state (POMS) questionnaire. RESULTS: There was no significant difference in W(max) between the placebo (376 (SD 25) W) and the corticosteroid group (375 (36) W) during the preintervention test, and there were no significant changes in either group after 2 and 4 weeks of intervention. No effect of the intervention on mood state was found. CONCLUSION: 4 weeks of corticosteroid or placebo inhalation in healthy, well-trained athletes did not affect maximal power output or mood state. Hence no ergogenic properties of 4 weeks' corticosteroid administration could be demonstrated, which corroborates previous studies of short-term corticosteroid administration.


Assuntos
Desempenho Atlético/fisiologia , Broncodilatadores/uso terapêutico , Budesonida/uso terapêutico , Resistência Física/efeitos dos fármacos , Administração por Inalação , Adulto , Método Duplo-Cego , Teste de Esforço , Humanos , Masculino , Resistência Física/fisiologia , Adulto Jovem
9.
Br J Sports Med ; 40(6): 507-11; discussion 511-2, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16720886

RESUMO

BACKGROUND: Creatine supplementation is popular among tennis players but it is not clear whether it actually enhances tennis performance. OBJECTIVES: To examine the effects of creatine supplementation on tennis specific performance indices. METHODS: In a randomised, double blind design, 36 competitive male tennis players (24 creatine, mean (SD) age, 22.5 (4.9) years; 12 placebo, 22.8 (4.8) years) were tested at baseline, after six days of creatine loading, and after a maintenance phase of four weeks (14 creatine, 10 placebo). Serving velocity (10 serves), forehand and backhand velocity (three series of 5x8 strokes), arm and leg strength (bench press and leg press), and intermittent running speed (three series of five 20 metre sprints) were measured. RESULTS: Compared with placebo, neither six days nor five weeks of creatine supplementation had a significant effect on serving velocity (creatine: +2 km/h; placebo: +2 km/h, p = 0.90); forehand velocity (creatine: +4 km/h; placebo: +4 km/h, p = 0.80), or backhand velocity (creatine: +3 km/h; placebo: +1 km/h, p = 0.38). There was also no significant effect of creatine supplementation on repetitive sprint power after 5, 10, and 20 metres, (creatine 20 m: -0.03 m/s; placebo 20 m: +0.01 m/s, p = 0.18), or in the strength of the upper and lower extremities. CONCLUSIONS: Creatine supplementation is not effective in improving selected factors of tennis specific performance and should not be recommended to tennis players.


Assuntos
Creatina/administração & dosagem , Tênis/fisiologia , Adolescente , Adulto , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Masculino , Análise e Desempenho de Tarefas , Resultado do Tratamento
10.
Br J Sports Med ; 40(5): 378, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16632563
11.
Br J Sports Med ; 40(5): 387-91; discussion 391, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16632566

RESUMO

This review focuses on the characteristics of tennis players during match play and provides a greater insight into the energy demands of tennis. A tennis match often lasts longer than an hour and in some cases more than five hours. During a match there is a combination of periods of maximal or near maximal work and longer periods of moderate and low intensity activity. Match intensity varies considerably depending on the players' level, style, and sex. It is also influenced by factors such as court surface and ball type. This has important implications for the training of tennis players, which should resemble match intensity and include interval training with appropriate work to rest ratios.


Assuntos
Tênis/fisiologia , Metabolismo Energético/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/análise , Ácido Láctico/metabolismo , Masculino , Consumo de Oxigênio/fisiologia , Educação Física e Treinamento/métodos , Resistência Física/fisiologia , Descanso/fisiologia , Fatores de Tempo
12.
Br J Sports Med ; 40(5): 415-23, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16632572

RESUMO

A systematic search of published reports was carried out in three electronic databases from 1966 on to identify relevant articles relating to tennis injuries. There were 39 case reports, 49 laboratory studies, 28 descriptive epidemiological studies, and three analytical epidemiological studies. The principal findings of the review were: first, there is a great variation in the reported incidence of tennis injuries; second, most injuries occur in the lower extremities, followed by the upper extremities and then the trunk; third, there have been very few longitudinal cohort studies that investigated the association between risk factors and the occurrence of tennis injuries (odds ratios, risk ratios, hazard ratios); and fourth, there were no randomised controlled trials investigating injury prevention measures in tennis. More methodologically sound studies are needed for a better understanding of risk factors, in order to design useful strategies to prevent tennis injuries.


Assuntos
Tênis/lesões , Adolescente , Adulto , Idoso , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/prevenção & controle , Criança , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Distribuição por Sexo
13.
Br J Sports Med ; 40(5): 464-8; discussion 468, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16632582

RESUMO

Concerns have long existed over the participation of adolescent athletes in professional sports. In 2004, the Sony Ericsson WTA Tour (WTA Tour) commissioned a Professional Development Advisory Panel (PDAP) to evaluate the WTA Tour's age eligibility rule (AER) and professional development programmes (PDPs) for female tennis players since their inception in 1995. More than 75% of the 628 respondents supported the principles of the AER, and 90% indicated a need for PDPs. Statistical analysis of WTA Tour players' careers found that premature retirements (players leaving the Tour at or before age 21) decreased significantly from 7% before the AER to less than 1% afterward, and median career length increased by 43%. The PDAP recommends that the WTA Tour continues a phased-in, developmentally appropriate AER, enhances the PDPs, and works with other sport governing bodies to coordinate rules and programmes at earlier ages to aid the transition of adolescents into adult sports.


Assuntos
Mobilidade Ocupacional , Tênis/educação , Adolescente , Fatores Etários , Feminino , Humanos , Estudos Longitudinais , Masculino
14.
J Sci Med Sport ; 6(1): 28-39, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12801208

RESUMO

The purpose of the study was to specify the changes in blood glucose concentrations in the course of repeated tournament and practice matches, and to quantify the Incidence of hypoglycaemia in elite tennis players. The study consisted of two parts. In the first, 147 tournament players completed a questionnaire about the incidence of hypoglycaemic symptoms during repeated tennis matches. In the second part of the study, the players participated in two subsequent matches (one singles match followed by a doubles) under (T) tournament (n = 57) and (P) practice (n = 20) conditions. Of the 147 players consulted, 94 (63.9%) reported experiences with hypoglycaemic symptoms during a tennis tournament (n = 80) and/or tennis practice (n = 62). The warm-up period for the second match day was identified as the most sensitive point for the occurrence of hypoglycaemic symptoms (n = 29), compared to the final stages of the first (n = 11) or second match (n = 7). Under both practice and tournament conditions, a significant (p < 0.01) drop in blood glucose concentration was found during the warm-up period for the second match per day (T: from 5.8 +/- 1.4 mmol x L(-1) to 4.3 +/- 0.8 mmol x L(-1) and P: from 5.4 +/- 1.1 mmol x L(-1) to 4.1 +/- 1.5 mmol x L(-1)). In conclusion, precautions should be taken to prevent a sudden drop in blood glucose concentration and hypoglycaemic symptoms during the early stages of a player's second tennis match in one day.


Assuntos
Glicemia/análise , Tênis/fisiologia , Adulto , Alemanha/epidemiologia , Homeostase , Humanos , Hipoglicemia/epidemiologia , Incidência , Ácido Láctico/sangue , Masculino , Resistência Física/fisiologia
15.
Eur J Appl Physiol ; 85(1-2): 27-33, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11513317

RESUMO

The purpose of the study was to compare selected physiological responses during singles tennis match play and continuous running at a similar mean oxygen uptake (VO2). The study consisted of two main parts, which were separated by 1 week. In the first part, 12 nationally ranked senior tennis players [six females and six males; 47.2 (6.6) years old and 47.0 (5.4) years old, respectively] each completed a 2-h singles tennis match (TE). Mean VO2 during TE [23.1 (3.1) ml.kg(-1). min(-1) for the women and 25.6 (2.8) ml.kg(-1).min(-1) for the men] was measured by a portable spirometry-telemetry system and corresponded to 56% (women) or 54% (men) of their respective maximum VO2. In the second part, the relative VO2 data measured during TE were used to set a similar workload during a 2-h treadmill run at a constant level (RU). At the measured time points, heart rate [140.1 (15.5) beats.min(-1) vs 126.4 (15.1) beats. min(-1)], lactate concentration [1.53 (0.65) mmol.l(-1) vs 1.01 (0.38) mmol.l(-1)] and glucose concentration [5.45 (0.84) mmol.l(-1) vs 4.34 (0.56) mmol.l(-1)] in capillary blood, as well as the respiratory exchange ratio [0.93 (0.03) vs 0.88 (0.03)], were higher (P<0.05) in TE compared to RU. Serum concentrations of free fatty acids increased (P < 0.05) during both work loads [from 0.25 (0.15) mmol.l(-1) to 1.31 (0.44) mmol.l(-1) in TE and from 0.22 (0.17) mmol.l(-1) to 1.24 (0.35) mmol.l(-1) in RU]. Post-exercise urine concentrations of epinephrine [0.17 (0.14) micromol.l(-1) vs 0.08 (0.04) micromol.l(-1)] and norepinephrine [1.27 (0.59) micromol.l(-1) vs. 0.55 (0.33) micromol.l(-1)] were higher in TE (P<0.05). These results indicate a stronger metabolic emphasis on glycolysis and glycogenolysis and an overall enhanced sympathoadrenal activity during tennis match play compared to continuous running exercise at a similar mean VO2.


Assuntos
Consumo de Oxigênio/fisiologia , Esforço Físico/fisiologia , Corrida/fisiologia , Tênis/fisiologia , Adulto , Glicemia , Epinefrina/urina , Ácidos Graxos não Esterificados/sangue , Feminino , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Norepinefrina/urina , Resistência Física/fisiologia , Espirometria , Telemetria
16.
J Sports Sci ; 19(4): 235-42, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11311021

RESUMO

The aim of this study was to assess the effect of the recovery duration in intermittent training drills on metabolism and coordination in sport games. Ten nationally ranked male tennis players (age 25.3+/-3.7 years, height 1.83+/-0.8 m, body mass 77.8+/-7.7 kg; mean +/- sx) participated in a passing-shot drill (baseline sprint with subsequent passing shot) that aimed to improve both starting speed and stroke quality (speed and precision). Time pressure for stroke preparation was individually adjusted by a ball-machine and corresponded to 80% of maximum running speed. In two trials (T10, T15) separated by 2 weeks, the players completed 30 strokes and sprints subdivided into 6 x 5 repetitions with a 1 min rest between series. The rest between each stroke-and-sprint lasted either 10 s (T10) or 15 s (T15). The sequence of both conditions was randomized between participants. Post-exercise blood lactate concentration was significantly elevated in T10 (9.04+/-3.06 vs 5.01+/-1.35 mmol x l(-1), P < 0.01). Running time for stroke preparation (1.405+/-0.044 vs 1.376+/-0.045 s, P < 0.05) and stroke speed (106+/-12 vs 114+/-8 km x h(-1), P < 0.05) were significantly decreased in T10, while stroke precision - that is, more target hits (P < 0.1) and fewer errors (P < 0.05) - tended to be higher. We conclude that running speed and stroke quality during intermittent tennis drills are highly dependent on the duration of recovery time. Optimization of training efficacy in sport games (e.g. combined improvement of conditional and technical skills) requires skilful fine-tuning of monitoring guidelines.


Assuntos
Educação Física e Treinamento/métodos , Corrida/fisiologia , Tênis/fisiologia , Adulto , Análise de Variância , Humanos , Ácido Láctico/sangue , Masculino
17.
Circulation ; 101(3): 336-44, 2000 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-10645932

RESUMO

BACKGROUND: It has been postulated that depending on the type of exercise performed, 2 different morphological forms of athlete's heart may be distinguished: a strength-trained heart and an endurance-trained heart. Individual studies have not tested this hypothesis satisfactorily. METHODS AND RESULTS: The hypothesis of divergent cardiac adaptations in endurance-trained and strength-trained athletes was tested by applying meta-analytical techniques with the assumption of a random study effects model incorporating all published echocardiographic data on structure and function of male athletes engaged in purely dynamic (running) or static (weight lifting, power lifting, bodybuilding, throwing, wrestling) sports and combined dynamic and static sports (cycling and rowing). The analysis encompassed 59 studies and 1451 athletes. The overall mean relative left ventricular wall thickness of control subjects (0.36 mm) was significantly smaller than that of endurance-trained athletes (0.39 mm, P=0.001), combined endurance- and strength-trained athletes (0.40 mm, P=0.001), or strength-trained athletes (0.44 mm, P<0.001). There was a significant difference between the 3 groups of athletes and control subjects with respect to left ventricular internal diameter (P<0. 001), posterior wall thickness (P<0.001), and interventricular septum thickness (P<0.001). In addition, endurance-trained athletes and strength-trained athletes differed significantly with respect to mean relative wall thickness (0.39 versus 0.44, P=0.006) and interventricular septum thickness (10.5 versus 11.8 mm, P=0.005) and showed a trend toward a difference with respect to posterior wall thickness (10.3 versus 11.0 mm, P=0.078) and left ventricular internal diameter (53.7 versus 52.1 mm, P=0.055). With respect to cardiac function, there were no significant differences between athletes and control subjects in left ventricular ejection fraction, fractional shortening, and E/A ratio. CONCLUSIONS: Results of this meta-analysis regarding athlete's heart confirm the hypothesis of divergent cardiac adaptations in dynamic and static sports. Overall, athlete's heart demonstrated normal systolic and diastolic cardiac functions.


Assuntos
Coração/anatomia & histologia , Medicina Esportiva , Adulto , Coração/fisiologia , Humanos , Masculino , Educação Física e Treinamento , Resistência Física
18.
Heart ; 81(6): 612-7, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10336920

RESUMO

OBJECTIVE: To examine the correlation between heart rate variability and left ventricular mass in cyclists with an athlete's heart. METHODS: Left ventricular mass and diastolic function were determined at rest and myocardial high energy phosphates were quantified at rest and during atropine-dobutamine stress in 12 male cyclists and 10 control subjects, using magnetic resonance techniques. Ambulatory 24 hour ECG recordings were obtained, and time and frequency domain heart rate variability indices were computed. RESULTS: In the cyclists, the mean of all RR intervals between normal beats (meanNN), the SD of the RR intervals, and their coefficient of variation were significantly greater than in control subjects (p < 0.01, p < 0.01, and p < 0.05, respectively). For cyclists and control subjects, only meanNN correlated with left ventricular mass (r = 0.48, p = 0.038). The heart rate variability indices that correlated with functional or metabolic variables were: meanNN v E/A peak (the ratio of peak early and peak atrial filling rate) (r = 0.48, p = 0.039); the root mean square of successive differences in RR intervals among successive normal beats v E/A area (ratio of peak early and peak atrial filling volume) (r = 0.48, p = 0.040); percentage of successive RR intervals differing by more than 50 ms v the phosphocreatine to ATP ratio at rest (r = 0.54, p = 0. 017); and the SD of the average RR intervals during all five minute periods v the phosphocreatine to ATP ratio during stress (r = 0.60, p = 0.007). CONCLUSIONS: Highly trained cyclists have increased heart rate variability indices, reflecting increased cardiac vagal control compared with control subjects. Left ventricular mass has no major influence on heart rate variability, but heart rate variability is significantly correlated with high energy phosphate metabolism and diastolic function.


Assuntos
Ciclismo/fisiologia , Frequência Cardíaca/fisiologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Adulto , Estudos de Casos e Controles , Eletrocardiografia Ambulatorial , Hemodinâmica/fisiologia , Humanos , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Fosfatos/metabolismo
20.
Circulation ; 97(7): 666-72, 1998 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-9495302

RESUMO

BACKGROUND: The question of whether training-induced left ventricular hypertrophy in athletes is a physiological rather than a pathophysiological phenomenon remains unresolved. The purpose of the present study was to detect any abnormalities in cardiac function in hypertrophic hearts of elite cyclists and to examine the response of myocardial high-energy phosphate metabolism to high workloads induced by atropine-dobutamine stress. METHODS AND RESULTS: We studied 21 elite cyclists and 12 healthy control subjects. Left ventricular mass, volume, and function were determined by cine MRI. Myocardial high-energy phosphates were examined by 31P magnetic resonance spectroscopy. There were no significant differences between cyclists and control subjects for left ventricular ejection fraction (59+/-5% versus 61+/-4%), left ventricular cardiac index (3.4+/-0.4 versus 3.4+/-0.4 L x min(-1) x m[-2]), peak early filling rate (562+/-93 versus 535+/-81 mL/s), peak atrial filling rate (315+/-93 versus 333+/-65 mL/s), ratio of early and atrial filling volumes (3.0+/-1.0 versus 2.6+/-0.6), mean acceleration gradient of early filling (5.2+/-1.4 versus 5.8+/-1.9 L/s2), mean deceleration gradient of early filling(-3.1 +/- 0.9 versus -3.2 +/- 0.7 L/s2), mean acceleration gradient of atrial filling (3.6+/-1.8 versus 4.5+/-1.7 L/s2), and atrial filling fraction (0.23+/-0.06 versus 0.26+/-0.04, respectively). Cyclists and control subjects showed similar decreases in the ratio of myocardial phosphocreatine to ATP measured with 31P magnetic resonance spectroscopy during atropine-dobutamine stress (1.41+/-0.20 versus 1.41+/-0.18 at rest to 1.21+/-0.20 versus 1.16+/-0.13 during stress, both P=NS). CONCLUSIONS: Left ventricular hypertrophy in cyclists is not associated with significant abnormalities of cardiac function or metabolism as assessed by MRI and spectroscopy. These observations suggest that training-induced left ventricular hypertrophy in cyclists is predominantly a physiological phenomenon.


Assuntos
Trifosfato de Adenosina/análise , Ciclismo , Dobutamina , Hemodinâmica , Hipertrofia Ventricular Esquerda/fisiopatologia , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Miocárdio/metabolismo , Fosfocreatina/análise , Adaptação Fisiológica , Adulto , Antropometria , Atropina/farmacologia , Diástole , Átrios do Coração , Humanos , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/metabolismo , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo , Consumo de Oxigênio/efeitos dos fármacos , Volume Sistólico , Sístole , Função Ventricular Esquerda
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