ABSTRACT BACKGROUND: Physical activity (PA) practices seem to differ between weekdays and weekends and these pattern changes can affect body fat differently. However, previous studies did not assess the mediation effect of weekday and weekend PA on maintenance of body fat using sophisticated statistical models. OBJECTIVE: To analyze the mediation effect of PA during weekdays and weekends on maintenance of fat mass over a 12-month follow-up. DESIGN AND SETTING: Longitudinal cohort study (12 months) conducted at a public university in Presidente Prudente, Brazil. METHODS: A sample of 225 adults (117 females) was used. Body fatness and fat mass were assessed using dual-energy X-ray absorptiometry. PA levels were assessed using a pedometer. The statistical analysis consisted of paired-sample t tests, independent-sample t tests, Pearson correlations and mediation models. RESULTS: After 12 months, weekend PA had decreased while body composition indicators remained stable (without changes). The correlation between fat mass at baseline and follow-up was high for both sexes (men: 0.966; women: 0.941; P-value = 0.001 for both). Moreover, PA indices were inversely but moderately related to fat mass at baseline and follow-up. Lastly, weekend PA mediated the association between fat mass at baseline and follow-up (P-value < 0.05) by around 2% and 4%. CONCLUSION: Weekend PA mediated the association between fat mass at baseline and fat mass after one year of follow-up among these adults. Further studies are required to investigate the association between physical activity, body fat and other variables such as dietary patterns and sleep time.

Abstract AIM The aim of this longitudinal study was to analyze the relationship between sleep disorder and intima-media thickness. METHOD Baseline measurements included carotid intima-media thickness, assessed by an ultrasound device; questionnaires about sleep and other behavioral variables; physical activity was measured by pedometer; body fatness was estimated by Dual-Energy X-ray Absorptiometry; fasting glucose, lipid profile and C-reactive protein were collected. RESULTS The occurrence rate of sleep-related disorders was 47% (95%CI= 37.2%-56.7%). Carotid intima-media thickness was related to symptoms of insomnia (r= 0.328 [0.141 to 0.493]) and, after adjustments for potential confounders, the relationship between carotid intima-media thickness and insomnia remained statistically significant (β= 0.121 [95%CI= 0.017; 0.225]). CONCLUSIONS In young adults, sleep disorder was significantly related to premature increase in carotid intima-media thickness.

Abstract AIM To compare bone mass and body composition variables between adolescents engaged in high-impact sports and adults who were sedentary during early life. METHOD A cross-sectional study with 155 participants (64 adolescents and 91 adults) aged between 11 and 50 years old. Among the adults, history of sports was evaluated during face-to-face interviews, and information regarding the adolescents' training routines was provided by their coaches. Body composition was evaluated using Dual Energy X-Ray Absorptiometry which provided data about bone mineral density (BMD), bone mineral content (BMC), fat mass (FM), and free fat mass (FFM). RESULTS Adults who engaged in sports practice during early life had higher values of BMC (ES-r = 0.063), FFM (ES-r = 0.391), and lower values of FM (ES-r = 0.396) than sedentary adults. Higher values of BMC (ES-r = 0.063) and BMD in lower limbs (ES-r = 0.091) were observed in active adolescents. Adolescents engaged in sports and adults who were sedentary in early life presented similar values in all bone variables, FM, and FFM. CONCLUSIONS Sports involvement in early life is related to higher bone mass in adulthood. Adolescents engaged in sports presented similar bone mass to adults who had been sedentary in early life.

OBJETIVO: Analisar a ocorrência de distúrbios relacionados ao sono entre adultos de Presidente Prudente, São Paulo, bem como identificar suas associações com variáveis comportamentais, sociodemográficas e de estado nutricional. MÉTODOS: Após a seleção aleatória da amostra, foram realizadas entrevistas face a face com 743 adultos de ambos os sexos, residentes na cidade de Presidente Prudente, São Paulo. Foram aplicados questionários para análise de distúrbios relacionados ao sono, variáveis sociodemográficas (sexo, idade, etnia, escolaridade), comportamentais (atividade física no lazer, etilismo e tabagismo) e de estado nutricional. RESULTADOS: Foram observados distúrbios relacionados ao sono em 46,7% da amostra, com intervalo de confiança de 95% (IC95%) 43,1 - 50,2. Após a análise multivariada, foi observado que o sexo feminino, com odds ratio (OR) = 1,74 (IC95% 1,26 - 2,40), escolaridade (OR = 0,49; IC95% 0,28 - 0,82), sobrepeso (OR = 1,99; IC95% 1,39 - 2,85) e obesidade (OR = 2,90; IC95% 1,94 - 4,35) foram associados à ocorrência de distúrbios relacionados ao sono. CONCLUSÃO: É elevada a ocorrência de distúrbios de sono na amostra analisada, os quais foram mais frequentes em mulheres, pessoas de menor escolaridade e com sobrepeso e obesidade.

OBJECTIVE: To analyze the occurrence of sleep-related disorders among adults from Presidente Prudente, Brazil, as well as to identify associations with behavioral, socio-demographic and nutritional status variables. METHODS: After random selection of the sample, interviews were performed with 743 adults of both genders, living in Presidente Prudente, Brazil. Sleep-related disorders, demographic variables (sex, age, ethnicity and schooling), behavioral variables (leisure physical activity, alcohol consumption, and smoking) and nutritional status were analyzed by questionnaires. RESULTS: The prevalence of sleep-related disorders was 46.7%, with 95% confidence interval (95%CI) 43.1 - 50.2. In the multivariate analysis, female sex, with odds ratio (OR) 1.74 (95%CI 1.26 - 2.40), schooling (OR = 0.49; 95%CI 0.28 - 0.82), overweight (OR = 1.99; 95%CI 1.39 - 2.85) and obesity (OR = 2.90; 95%CI 1.94 - 4.35) were associated with sleep-related disorders. CONCLUSION: There is high occurrence of sleep-related disorders in this sample, which was associated with female sex, lower schooling, overweight and obesity.

OBJETIVO: Analisar a ocorrência de distúrbios relacionados ao sono entre adultos de Presidente Prudente, São Paulo, bem como identificar suas associações com variáveis comportamentais, sociodemográficas e de estado nutricional. MÉTODOS: Após a seleção aleatória da amostra, foram realizadas entrevistas face a face com 743 adultos de ambos os sexos, residentes na cidade de Presidente Prudente, São Paulo. Foram aplicados questionários para análise de distúrbios relacionados ao sono, variáveis sociodemográficas (sexo, idade, etnia, escolaridade), comportamentais (atividade física no lazer, etilismo e tabagismo) e de estado nutricional. RESULTADOS: Foram observados distúrbios relacionados ao sono em 46,7% da amostra, com intervalo de confiança de 95% (IC95%) 43,1 - 50,2. Após a análise multivariada, foi observado que o sexo feminino, com odds ratio (OR) = 1,74 (IC95% 1,26 - 2,40), escolaridade (OR = 0,49; IC95% 0,28 - 0,82), sobrepeso (OR = 1,99; IC95% 1,39 - 2,85) e obesidade (OR = 2,90; IC95% 1,94 - 4,35) foram associados à ocorrência de distúrbios relacionados ao sono. CONCLUSÃO: É elevada a ocorrência de distúrbios de sono na amostra analisada, os quais foram mais frequentes em mulheres, pessoas de menor escolaridade e com sobrepeso e obesidade.

OBJECTIVE: To analyze the occurrence of sleep-related disorders among adults from Presidente Prudente, Brazil, as well as to identify associations with behavioral, socio-demographic and nutritional status variables. METHODS: After random selection of the sample, interviews were performed with 743 adults of both genders, living in Presidente Prudente, Brazil. Sleep-related disorders, demographic variables (sex, age, ethnicity and schooling), behavioral variables (leisure physical activity, alcohol consumption, and smoking) and nutritional status were analyzed by questionnaires. RESULTS: The prevalence of sleep-related disorders was 46.7%, with 95% confidence interval (95%CI) 43.1 - 50.2. In the multivariate analysis, female sex, with odds ratio (OR) 1.74 (95%CI 1.26 - 2.40), schooling (OR = 0.49; 95%CI 0.28 - 0.82), overweight (OR = 1.99; 95%CI 1.39 - 2.85) and obesity (OR = 2.90; 95%CI 1.94 - 4.35) were associated with sleep-related disorders. CONCLUSION: There is high occurrence of sleep-related disorders in this sample, which was associated with female sex, lower schooling, overweight and obesity.

O objetivo do presente estudo foi desenvolver um snorquel (SNQ) de baixo custo para mensuração de parâmetros cardiorrespiratórios em natação. Para isso, a máscara do analisador de gases VO2000 (MASC) foi adaptada a um SNQ desenvolvido artesanalmente com espaço morto de 250ml. Oito participantes foram submetidos a dois testes incrementais (TI) em cicloergômetro utilizando a MASC e o SNQ. Os TI foram realizados até a exaustão voluntária e foram compostos por estágios de 3min com carga inicial e incrementos de 35W. Em ambas as situações, amostras gasosas foram coletadas em intervalos de 10s para determinação dos volumes de oxigênio (VO2), gás carbônico (VCO2), ventilatório (VE) e mensuração da freqüência cardíaca (FC). A comparação dos parâmetros cardiorrespiratórios (VO2, VE, VCO2 e FC) mensurados com o SNQ e a MASC foi realizada com o teste t de Student para amostras dependentes, enquanto que o teste de correlação de Pearson e a análise gráfica de Bland e Altman foram utilizados para verificar as associações e concordância entre parâmetros. Em todos os casos, o nível de significância foi de P < 0,05. A adequação das equações de correção para os valores provenientes do SNQ foi verificada pelos erros sistemáticos (bias), aleatórios (precisão) e acurácia (ac). Não foram observadas diferenças significativas entre os valores de VO2, VCO2 e FC obtidos com a MASC e SNQ. Os valores de VE mensurados com o SNQ foram significativamente superiores aos obtidos com a MASC. No entanto, todos os parâmetros apresentaram elevada concordância e coeficiente de correlação (0,88 a 0,97). Além disso, foram verificados reduzidos valores de bias (VO2 = 0,11L/min; VE = 4,11L/min; VCO2 = 0,54L/min; 8,87bpm), precisão (VO2 = 0,24L/min; VE = 11,02L/ min; VCO2 = 0,18L/min; 7,42bpm) e ac (VO2 = 0,27L/min; VE = 11,76L/min; VCO2 = 0,56L/min; 11,56bpm). Desse modo, pode-se concluir que o SNQ desenvolvido neste estudo possibilita a mensuração válida de parâmetros cardiorrespiratórios em natação.

The aim of the present study was to develop a snorkel (SNK) with low cost for cardio respiratory parameters measurement in swimming. So, a mask of gas analyzer VO2000 (MASK) was adapted to a SNQ developed by man craftwork form with dead space of 250 ml. Eight subjects were submitted to two incremental tests (IT) on cycloergometer using the MASK and the SNK. The IT(s) occurred until voluntary exhaustion and it was composed per stages of 3 min and with initial load and grade increment of 35 W. In both situations, gaseous samples were collected in intervals of 10 s for determination of the amount of oxygen (VO2), of carbonic gas (VCO2) and of ventilatory volume (VE); heart rate (HR) measurement was done with monitor frequency heart (Polar). The comparison of the cardiorespiratory parameters (VO2, VE, VCO2) and HR measured with a SNK and a MASK was performed with the Student's t test of dependent samples, while the Pearson's correlation test and graphic analyzer of Bland and Altman were performed to verify the associations and agreement among parameters. In all cases the level of significance was P < 0.05. The appropriate equations of the correction of values originating from SNK was verified by systematic error (bias), aleatory (precision) and accuracy (ac). It was not found significant differences among the values of VO2, VCO2 and HR obtained with the MASK and SNK. The values of VE measured with SNK were found significantly higher than the obtained with the MASK. However, all parameters presented high agreement and correlation (0.88 to 0.97). Besides, low values of bias (VO2 = 0.11 L/min; VE = 4.11 L/min; VCO2 = 0.54 L/min; 8.87 bpm), precision (VO2 = 0,24 L/min; VE = 11.02 L/min; VCO2 = 0,18 L/min; 7.42 bpm) and accuracy (VO2 = 0,27 L/min; VE = 11.76 L/min; VCO2 = 0.56 L/min; 11.56 bpm) were verified. Thereby, we could conclude that the SNK developed in this study allow a validate measurement of cardiorespiratory parameters in swimming.

A percepção subjetiva de esforço (PSE) é determinada de forma não invasiva e utilizada juntamente com a resposta lactacidêmica como indicadores de intensidade durante teste incremental. Em campo, especialmente na natação, há dificuldades nas coletas sanguíneas; por isso, utilizam-se protocolos alternativos para estimar o limiar anaeróbio. Assim, os objetivos do estudo foram: prescrever um teste incremental baseado na PSE (Borg 6-20) visando estimar os limiares metabólicos determinados por métodos lactacidêmicos [ajuste bi-segmentado (V LL), concentração fixa-3,5mM (V3,5mM) e distância máxima (V Dmáx)]; relacionar a PSE atribuída em cada estágio com a freqüência cardíaca (FC) e com parâmetros mecânicos de nado [freqüência (FB) e amplitude de braçada (AB)], analisar a utilização da escala 6-20 na regularidade do incremento das velocidades no teste e correlacionar os limiares metabólicos com a velocidade crítica (VC). Para isso, 12 nadadores (16,4 ± 1,3 anos) realizaram dois esforços máximos (200 e 400m); os dados foram utilizados para determinar a VC, velocidade de 400m (V400m) e a freqüência crítica de braçada (FCb); e um teste incremental com intensidade inicial baseada na PSE, respectivamente, 9, 11, 13, 15 e 17; sendo monitorados em todos os estágios a FC, lactacidêmia e os tempos de quatro ciclos de braçadas e das distâncias de 20m (parte central da piscina) e 50m. Posteriormente, foram calculadas as velocidades dos estágios, FB, AB, V LL, V3,5mM e V Dmáx. Utilizaram-se ANOVA e correlação de Pearson para análise dos resultados. Não foram encontradas diferenças entre VC, V Dmáx e V LL, porém a V3,5mM foi inferior às demais velocidades (P < 0,05). Correlações significativas (P < 0,05) foram observadas entre VC versus V400m, V Dmáx e V3,5mM; V400m versus V3,5mM e V Dmáx; V Dmáx versus V LL; e no teste incremental entre PSE versus velocidade, [Lac], FC, FB e AB (P < 0,05). Concluímos que a PSE é uma ferramenta confiável no controle da velocidade dos estágios durante teste incremental na natação.

The Rating of Perceived Exertion (RPE) is non-invasively determined and used together with lactacidemic analysis as indicator of intensity during incremental test. In field, especially in swimming, due to the difficulty of sample collection, alternative protocols have been used to estimate the anaerobic threshold. Thus, the study aims were: to prescribe one incremental test based on Borg's scale; to estimate metabolic thresholds determined through analysis lactate methods [settling bi-segmented (V LT), fixed concentration-3.5 mM (V3.5mM) and maximal distance (V Dmáx)]; to relate the RPE attributed in each stage with a heart rate (HR) and swimming mechanical parameters [stroke rate (SR), and stroke length (SL)]; to analyze the utilization of the Borg's scale in regularity of velocity increment in test and relate the metabolic thresholds with the critical velocity (CV). Twelve swimmers (16.4 ± 1.3 years old) were subjected to two maximal efforts (200 and 400 meters), the data was used to determine the CV, velocity in 400 meters (V400m) and critical stroke rate (CSR); and one incremental test with an initial intensity based in RPE, respectively, 9, 11, 13, 15 and 17; the HR, lactacidemia ([Lac]) and the times of four cycles strokes and the distances of 20 m and 50 m, were monitored in all stages. Subsequently, the velocity of the SR, SL, V LT, V3.5mM and V Dmáx stages were calculated. ANOVA and correlation of Pearson were used to analyze the results. Significant differences were not found among VC, V Dmáx and V LT, however the V3,5mM was lower than all velocities (P < 0.05). Significant relationships (P < 0.05) were found among VC versus V400m, V Dmáx, V3.5mM; V400m versus V3.5mM and V Dmáx; V Dmáx versus V LL; in incremental test among the RPE versus velocity, [Lac], HR, SR and SL (P < 0.05). Our conclusion was that RPE is a reliable tool for velocity control of stages during incremental test in swimming.

La Percepción Subjetiva del Esfuerzo (PSE) es determinada de forma no invasiva y utilizada juntamente con la respuesta lactacidémica como indicadores de intensidad durante un test de incremento. En campo, especialmente en la natación, hay dificultades en las colectas sanguíneas, por eso se utilizan protocolos alternativos para estimar el límite anaerobio. Así, los objetivos de este estudio fueron: prescribir un test adicional basado en la PSE (Borg 6-20) con el objetivo de estimar los límites metabólicos determinados por métodos lactacidémicos [ajuste bisegmentado (V LL), concentración fija-3,5 mM (V3,5mM) y distancia máxima (V Dmáx)]; relacionar la PSE atribuida en cada etapa con la frecuencia cardíaca (FC) y con los parámetros mecánicos de nado [frecuencia (FB) y amplitud de brazada (AB)], analizar la utilización de la escala 6-20 en la regularidad del incremento de velocidades en el test y correlacionar los límites metabólicos con la velocidad crítica (VC). Para esto, doce nadadores (16,4 ± 1,3 años) realizaron dos esfuerzos máximos (200 y 400 m), los datos fueron utilizados para determinar la VC, velocidad de 400 m (V400m) y la frecuencia crítica de brazada (FCb); y un test adicional con intensidad inicial basada en la PSE, respectivamente, 9, 11, 13, 15 y 17; siendo monitorizadas en todos las etapas la FC, lactacidemia y los tiempos de 4 ciclos de brazadas y las distancias de 20 m (parte central de la piscina) y 50 m. Posteriormente, se calcularon las velocidades de las etapas, FB, AB, V LL, V3,5mM y V Dmáx. Se utilizó ANOVA y correlación de Pearson para el análisis de los resultados. No se encontraron diferencias entre VC, V Dmáx y V LL, sin embargo la V3,5mM fue inferior a las demás velocidades (P < 0,05). Correlaciones significativas (P < 0,05) fueron observadas entre VC versus V400m, V Dmáx y V3,5mM; V400m versus V3,5mM y V Dmáx; V Dmáx versus V LL; y en el test adicional entre PSE versus velocidad, [Lac], FC, FB y AB (P < 0,05). Concluimos que la PSE es una herramienta confiable en el control de la velocidad de las etapas durante el test adicional en la natación.