Modelling 5-km Running Performance on Level and Hilly Terrains in Recreational Runners.

Incline and level running on treadmills have been extensively studied due to their different cardiorespiratory and biomechanical acute responses. However, there are no studies examining the performance determinants of outdoor running on hilly terrains. We aimed to investigate the influence of anthropometrics, muscle strength, and cardiorespiratory and gait spatiotemporal parameters during level (0%) and inclined (+7%) running on performance in level and hilly 5-km races. Twenty male recreational runners completed two 5-km outdoor running tests (0% vs. +7% and −7%), and two submaximal (10 km·h−1) and incremental treadmill tests at 0 and 7% slopes, after complete laboratory evaluations. The velocity at maximal oxygen consumption (VO2max) evaluated at 7% incline and level treadmill running were the best performance predictors under both hilly (R2 = 0.72; p < 0.05) and level (R2 = 0.85; p < 0.01) conditions, respectively. Inclusion of ventilatory and submaximal heart rate data improved the predictive models up to 100%. Conversely, none of the parameters evaluated in one condition contributed to the other condition. The spatiotemporal parameters and the runners' strength levels were not associated to outdoor performances. These results indicate that the vVO2max evaluated at similar slopes in the lab can be used to predict 5-km running performances on both level and hilly terrains.

Tempo de aceleração na via de saída do ventrículo direito: correlação com a função diastólica do ventrículo esquerdo, sexo e idade / Right ventricular outflow tract acceleration time: correlation with left ventricular diastolic function, sex, and age

Fundamento: O tempo de aceleração na artéria pulmonar (TAP) pode ser utilizado para avaliação da hipertensão pulmonar na análise da função diastólica do ventrículo esquerdo. Objetivo: Avaliar se existe correlação entre o valor do tempo de aceleração na artéria pulmonar e parâmetros da função diastólica do ventrículo esquerdo em indivíduos com função sistólica do ventrículo esquerdo preservada e de acordo com sexo, idade e fatores de risco cardiovasculares. Métodos: Estudo observacional, transversal. Foram selecionados 119 pacientes (59 mulheres; 49,6%). Os indivíduos foram submetidos ao ecocardiograma transtorácico incluindo os valores de tempo de aceleração na artéria pulmonar; ondas E e A e relação E/A ao Doppler espectral do influxo mitral; ondas e' septal, e' lateral e relação E/e' ao Doppler tecidual do anel mitral; pressão sistólica na artéria pulmonar e volume atrial esquerdo. Resultados: No sexo feminino, foi encontrada correlação positiva (coeficiente de correlação de Spearman) entre o valor do tempo de aceleração na artéria pulmonar e e' lateral (coeficiente de correlação de Spearman de 0,47; p=0,002), relação E/A (coeficiente de correlação de Spearman de 0,32; p=0,04) e e' septal (coeficiente de correlação de Spearman de 0,36; p=0,023) e uma correlação negativa entre o valor do tempo de aceleração na artéria pulmonar e pressão sistólica na artéria pulmonar (coeficiente de correlação de Spearman de -0,43; p=0,034). No sexo masculino, não foi encontrada correlação significativa. Foram encontrados menores valores de tempo de aceleração na artéria pulmonar em mulheres com hipertensão arterial sistêmica quando comparadas a mulheres sem hipertensão arterial sistêmica (0,13±0,03 segundos versus 0,16±0,03 segundos; p = 0,015). Conclusão: O presente estudo mostrou correlação significativa dos valores do TAP com alguns parâmetros da função diastólica do ventrículo esquerdo apenas no sexo feminino, sendo que mulheres hipertensas apresentaram menores valores de TAP. (AU)

Background: Pulmonary artery acceleration time (PAAT) can be used as a parameter in the evaluation of pulmonary hypertension and aids left ventricular diastolic function (LVDF) analyses. Objective: To assess whether there is a correlation between PAAT and LVDF parameters in individuals with a preserved left ventricular systolic function and by sex, age, and cardiovascular risk factors. Method: Observational cross-sectional study. One hundred nineteen patients were selected (59 women [49.6%]). The subjects underwent transthoracic echocardiography including measurements of PAAT, E and A waves and E/A ratio, e' septal and e' lateral waves and E/e' ratio, pulmonary artery systolic pressure (PASP), and left atrial volume. Results: In female patients, a positive correlation (Spearman's correlation coefficient ­ Spearman correlation coefficient [SCC]) was found between the PAAT value and the lateral e' (SCC, 0.47; p = 0.002), with the E/A ratio (SCC, 0.32; p = 0.04), and with septal e' (SCC, 0.36; p = 0.023), and a negative correlation between PAAT and PASP (SCC, -0.43; p = 0.034). In men, no correlation was found between PAAT. and any parameters. Lower PAAT values were found in women with systemic arterial hypertension (hypertension) than in women without hypertension (0.13 ± 0.03 s versus 0.16 ± 0.03 s; p = 0.015). Conclusion: The present study showed a significant correlation between PAAT and some LVDF parameters in female patients only. Hypertension was correlated with lower PAAT values in women. (AU)

The Entrainment Frequency of Cardiolocomotor Synchronization in Long-Distance Race Emerges Spontaneously at the Step Frequency.

In forced conditions, where the heart rate and step frequency have been matched, cardiolocomotor synchronization (CLS) has been recognized. However, knowledge about the occurrence of CLS and its triggers in sports gesture in real contexts is little known. To address this gap, the current study tested the hypothesis that CLS in running spontaneous conditions would emerge at entrainment bands of muscle activation frequencies associated with a freely chosen step frequency. Sixteen male long-distance runners undertook treadmill assessments running ten three-minute bouts at different speeds (7, 7.5, 8, 9, 10, 11, 12, 13, 14, and 15 km⋅h-1). Electrocardiography and surface electromyography were recorded simultaneously. The center frequency was the mean of the frequency spectrum obtained by wavelet decomposition, while CLS magnitude was determined by the wavelet coherence coefficient (WCC) between the electrocardiography and center frequency signals. The strength of CLS affected the entrainment frequencies between cardiac and muscle systems, and for WCC values greater than 0.8, the point from which we consider the emerging CLS, the entrainment frequency was between 2.7 and 2.8 Hz. The CLS emerged at faster speeds (13-15 km⋅h-1) most prevalently but did not affect the muscle activation bands. Spontaneous CLS occurred at faster speeds predominantly, and the entrainment frequencies matched the locomotor task, with the entrainment bands of frequencies emerging around the step frequencies (2.7-2.8 Hz). These findings are compatible with the concept that interventions that determine optima conditions of CLS may potentiate the benefits of the cardiac and muscle systems synchronized in distance runners.

Tempo de provas curtas e volume de treinamento como preditores do desempenho de maratona / Short-time race time and training volume as predictors of Marathon performance / Tiempo de pruebas cortas y volumen de entrenamiento como predictores del rendimiento de Maratón

Resumo Além das determinantes fisiológicas, o desempenho em maratonas é influenciado por características antropométricas, de treinamento e de experiência dos atletas. O objetivo do estudo foi investigar a associação desses fatores com o desempenho de maratonistas brasileiros. Um questionário foi aplicado nos dois dias anteriores à Maratona Internacional de Porto Alegre. Dentre os achados, os atletas de menor índice de massa corporal foram mais rápidos e o desempenho em provas de 5 e 21 km apresentou correlações altas com o desempenho (r = 0,76 e r = 0,81, p < 0,01). Isso sugere que corredores mais rápidos na maratona são mais rápidos em provas de distâncias menores. Além disso, índices como experiência anterior e distância dos treinos longos não foram bons preditores do desempenho para maratona.

Abstract Not only physiological variables, but anthropometric, training and experience characteristics influence marathon performance. The aim of this study was to investigate the correlation of those factors on Brazilian marathoners performance. A questionnaire was applied in the two days prior to the International Porto Alegre Marathon. Mainly, athletes with lower body mass index were faster on the race, and performance at 5 km and 21 km have high correlations with marathon performance (r=0.76 and r=0.81, p<0.01), suggesting that the fastest runners in the marathon are faster over shorter distances. In addition, indices like previous experience and long session distances were not good performance predictors for marathoners.

Resumen Además de los determinantes fisiológicos, el rendimiento en maratones está influenciado por las características antropométricas, el entrenamiento y la experiencia de los atletas. El objetivo del estudio fue investigar la asociación de estos factores con el rendimiento de los corredores de maratón brasileños. Se aplicó un cuestionario en los dos días antes de la Maratón Internacional de Porto Alegre. Entre los hallazgos, los atletas con menor índice de masa corporal fueron más rápidos, y el rendimiento en las pruebas de 5 y 21 km están altamente correlacionados con el rendimiento (r = 0,76 yr = 0,81, p <0,01), lo que sugiere que los corredores más rápidos en la maratón son más rápidos en pruebas de distancias más cortas. Además, los índices tales como la experiencia previa y la distancia de entrenamientos largos no fueron buenos indicadores de rendimiento para la maratón.

Nephrolithiasis in pediatric patients: metabolic and anatomical investigation.

UNLABELLED: Metabolic disorders are frequently observed in pediatric patients with renal lithiasis. OBJECTIVES: Study the metabolic and anatomical alterations and perform the chemical analysis of stones found in children with nephrolithiasis in our region. METHODS: A retrospective study on 158 children with evidence of recent renal stone formation was performed. One hundred and nine children concluded the metabolic study. Laboratory investigation consisted in two samples of 24-hour urine for calcium, uric acid, citrate, oxalate, sodium and creatinine; qualitative cystinuria, urinary pH following 12-hour fasting and water restriction, urine culture and chemical analysis when the stones were available. Renal imaging techniques included, at least, renal ultrasound and excretory urogram. RESULTS: A cause for nephrolithiasis was identified in 96.3% of children. The main metabolic alteration was hypercalciuria (73.4%). Chemical analysis of stones showed calcium oxalate in 90.9% of the cases. Anatomical alterations were found in 18.0% of the investigated cases and the most frequently found alteration was pyelo-ureteral duplication (28.6%). CONCLUSIONS: Hypercalciuria was the most frequently found disorder and pyelo-ureteral duplication was the most common anatomical alteration; moreover, calcium oxalate was the most frequent chemical constituent. The present study showed the characteristics of pediatric patients with nephrolithiasis in our region.

Nefrolitíase em pacientes pediátricos: investigação metabólica e anatômica / Nephrolithiasis in pediatric patients: metabolic and anatomical investigation

Desordens metabólicas são frequentes em pacientes com nefrolitíase pediátrica. OBJETIVOS: Estudar as alterações metabólicas e anatômicas e a análise química dos cálculos encontrados em pacientes da nossa região. MÉTODOS: Este é um estudo retrospectivo em 158 crianças com evidência de formação recente de cálculos, destes apenas 109 concluíram a investigação metabólica. A investigação laboratorial consistiu de duas amostras de urina de 24 horas com dosagem de cálcio, ácido úrico, citrato, oxalato, sódio e creatinina, cistinúria qualitativa, pH urinário seguido de 12 horas de jejum e restrição hídrica, cultura da urina e análise química quando os cálculos foram disponíveis. As técnicas de imagem incluíram ultrassonografia do trato urinário e urografia excretora. RESULTADOS: Em 96,3 por cento das crianças alguma causa foi detectada. A principal alteração metabólica encontrada foi a hipercalciúria (73,4 por cento). Análise química dos cálculos mostrou oxalato de cálcio em 90,9 por cento dos casos. Alterações anatômicas foram encontradas em 18,0 por cento dos pacientes investigados, e a mais frequente foi a duplicação pieloureteral (28,6 por cento). CONCLUSÕES:Hipercalciúria foi a desordem mais encontrada, a alteração anatômica mais comum foi a duplicação pieloureteral e oxalato de cálcio foi o constituinte químico mais frequente. Este trabalho serviu para o conhecimento das características dos pacientes pediátricos portadores de nefrolitíase em nossa região.

Metabolic disorders are frequently observed in pediatric patients with renal lithiasis. OBJECTIVES: Study the metabolic and anatomical alterations and perform the chemical analysis of stones found in children with nephrolithiasis in our region. METHODS: A retrospective study on 158 children with evidence of recent renal stone formation was performed. One hundred and nine children concluded the metabolic study. Laboratory investigation consisted in two samples of 24-hour urine for calcium, uric acid, citrate, oxalate, sodium and creatinine; qualitative cystinuria, urinary pH following 12-hour fasting and water restriction, urine culture and chemical analysis when the stones were available. Renal imaging techniques included, at least, renal ultrasound and excretory urogram. RESULTS: A cause for nephrolithiasis was identified in 96.3 percent of children. The main metabolic alteration was hypercalciuria (73.4 percent). Chemical analysis of stones showed calcium oxalate in 90.9 percent of the cases. Anatomical alterations were found in 18.0 percent of the investigated cases and the most frequently found alteration was pyelo-ureteral duplication (28.6 percent). CONCLUSIONS: Hypercalciuria was the most frequently found disorder and pyelo-ureteral duplication was the most common anatomical alteration; moreover, calcium oxalate was the most frequent chemical constituent. The present study showed the characteristics of pediatric patients with nephrolithiasis in our region.