ABSTRACT
OBJECTIVE: To analyse the Nutritional Knowledge Test (NKT) using Item Response Theory (ITR) analysis and to assess the construct validity of the Nutritional Knowledge Scale (NKTS) and its associations with adolescent food group consumption and nutritional biomarkers. DESIGN: Cross-sectional study. SETTING: Multicentre investigation conducted in ten European cities.ParticipantsAdolescents aged 12·5-17·5 years (n 3215) who completed over 75 % of the NKT. RESULTS: Factor analysis indicated that the NKT can be analysed with a one-dimensional model. Eleven out of twenty-three items from the NKT presented adequate parameters and were selected to be included in the NKTS. Nutrition knowledge was positively associated with consumption of fruits, cereals, dairy products, pulses, meat and eggs, and fish, as well as with blood concentrations of vitamin C, ß-carotene, n-3 fatty acids, holo-transcobalamin, cobalamin and folate; nutrition knowledge was negatively associated with intake of olives and avocado, alcohol and savoury snacks. CONCLUSIONS: The NKTS assessed nutritional knowledge adequately and it is proposed as a new tool to investigate this subject in future studies.
Subject(s)
Diet/statistics & numerical data , Health Knowledge, Attitudes, Practice , Nutrition Assessment , Adolescent , Child , Cross-Sectional Studies , Europe/epidemiology , Female , Humans , Male , Nutritional Status , Psychometrics/methods , Psychometrics/standardsABSTRACT
Dehydration is one of the main problems associated to endurance sports. In order to avoid the negative effects of dehydration athletes tend to drink well above their current needs. The negative effect of drinking too much fluid is hyponatremia. Hyponatremia is defined as a plasma sodium concentration lower than 135 mmol/L. Hyponatremia is the first cause of severe illness in ultraendurance sports and has been associated with sudden death. In this article, we analyze the causes, consequences, associated factors, therapeutic treatment and prevention of ultraendurance sports-associated hyponatremia. It is concluded that an adequate fluid ingestion is the best method to avoid hyponatremia. There is not conclusive data about the amount and necessity of sodium supplementation to avoid hyponatremia. However, it might be that it is not necessary to ingest additional sodium to prevent the development of hyponatremia in athletes who only partially replace their fluid losses during prolonged exercise.
Subject(s)
Exercise/physiology , Hyponatremia/etiology , Physical Endurance/physiology , Drinking , Female , Guidelines as Topic , Humans , Hyponatremia/diagnosis , Hyponatremia/drug therapy , Male , Sodium/administration & dosage , Sodium/deficiency , Sports/physiologyABSTRACT
La deshidratación es uno de los principales enemigos de los deportes de resistencia. Sin embargo, la ingesta excesiva de líquido con el objetivo de evitar dicha deshidratación, ha provocado en los últimos años numerosos casos de hiponatremia, especialmente en esfuerzos de extrema duración. La hiponatremia se define como la presentación de concentraciones de sodio en plasma por debajo de 135 mmol/L. Representa la primera causa de enfermedad severa en deportes de ultraresistencia, a lo que ha sido asociado numerosos casos de muerte súbita. Las extremadas exigencias físicas de este tipo de deportes de creciente popularidad, junto con el peligro potencial que supone para la salud del deportista, nos ha conducido al estudio profundo de las causas, consecuencias, factores asociados, abordaje terapéutico y prevención de la hiponatremia , tanto desde un punto de vista científico como práctico. La ingesta de la cantidad adecuada de líquido se presenta como el método más importante para prevenir su aparición. No está clara la cantidad idónea y/o necesidad de una suplementación de sodio en la bebida para evitar el desarrollo de hiponatremia y mejorar el rendimiento deportivo en pruebas de ultraresistencia. No obstante, parece ser que esta suplementación sólo sería útil en aquellos individuos que ingirieron una excesiva cantidad de líquido