The Assessment of Total Energy Expenditure During a 14-day 'In-Season' Period of Professional Rugby League Players Using the Doubly Labelled Water Method

Peer reviewed

Predictive validity of three ActiGraph energy expenditure equations for children

Purpose: This Study evaluated the predictive validity of three previously published ActiGraph energy expenditure (EE) prediction equations developed for children and adolescents. Methods: A total of 45 healthy children and adolescents (mean age: 13.7 +/- 2.6 yr) completed four 5-min activity trials (normal walking. brisk walking, easy running, and fast running) in ail indoor exercise facility. During each trial, participants were all ActiGraph accelerometer oil the right hip. EE was monitored breath by breath using the Cosmed K4b(2) portable indirect calorimetry system. Differences and associations between measured and predicted EE were assessed using dependent t-tests and Pearson correlations, respectively. Classification accuracy was assessed using percent agreement, sensitivity, specificity, and area under the receiver operating characteristic (ROC) curve, Results: None of the equations accurately predicted mean energy expenditure during each of the four activity trials. Each equation, however, accurately predicted mean EE in at least one activity trial. The Puyau equation accurately predicted EE during slow walking. The Trost equation accurately predicted EE during slow running. The Freedson equation accurately predicted EE during fast running. None of the three equations accurately predicted EE during brisk walking. The equations exhibited fair to excellent classification accuracy with respect to activity intensity. with the Trost equation exhibiting the highest classification accuracy and the Puyau equation exhibiting the lowest. Conclusions: These data suggest that the three accelerometer prediction equations do not accurately predict EE on a minute-by-minute basis in children and adolescents during overground walking and running. The equations maybe, however, for estimating participation in moderate and vigorous activity.

Fast and efficient : Postnatal growth and energy expenditure in an Arctic-breeding waterbird, the Red-throated Loon (Gavia stellata)

Peer reviewed

Using Doubly-Labeled Water to Measure Energy Expenditure in an Important Small Ectotherm Drosophila melanogaster

Open Access funded by Wellcome Trust for University College London (UCL) authors. Acknowledegements Funding for this work was provided by the Wellcome Trust (MDWP, LP). John Speakman was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB13030000) a 1000 talents professorship. We are grateful to Peter Thomson and Paula Redman for technical assistance with isotope analysis

Shaving increases daily energy expenditure in free-living root voles

Funding This study was supported by the Polish Ministry of Science and Higher Education grant NN304349335 to P.A.S. J.R.S. was supported by a 1000 talents professorship of the Chinese government.

Effects of a 12-week aerobic exercise intervention on eating behaviour, food cravings and 7-day energy intake and energy expenditure in inactive men

This study examined effects of 12 weeks of moderate-intensity aerobic exercise on eating behaviour, food cravings and weekly energy intake and expenditure in inactive men. Eleven healthy men (mean ± SD: age, 26 ± 5 years; body mass index, 24.6 ± 3.8 kg/m2; maximum oxygen uptake, 43.1 ± 7.4 mL/kg/min) completed the 12-week supervised exercise programme. Body composition, health markers (e.g. blood pressure), eating behaviour, food cravings and weekly energy intake and expenditure were assessed before and after the exercise intervention. There were no intervention effects on weekly free-living energy intake (p=0.326, d=-0.12) and expenditure (p=0.799, d=0.04), or uncontrolled eating and emotional eating scores (p>0.05). However, there was a trend with a medium effect size (p=0.058, d=0.68) for cognitive restraint to be greater after the exercise intervention. Total food cravings (p=0.009, d=-1.19) and specific cravings of high-fat foods (p=0.023, d=-0.90), fast-food fats (p=0.009, d=-0.71) and carbohydrates/starches (p=0.009, d=-0.56) decreased from baseline to 12 weeks. Moreover, there was a trend with a large effect size for cravings of sweets (p=0.052, d=-0.86) to be lower after the exercise intervention. In summary, 12 weeks of moderate-intensity aerobic exercise reduced food cravings and increased cognitive restraint, however, these were not accompanied by changes in other eating behaviours and weekly energy intake and expenditure. The results indicate the importance of exercising for health improvements even when reductions in body mass are modest.

Patterns of sedentary behavior : insights from observational and experimental studies on body composition and energy expenditure

It is recognized that sedentary behavior (SB) has deleterious effects on numerous health outcomes and it appears that physiological mechanisms underlying these harms are distinct from the ones explaining moderate-to-vigorous physical activity (MVPA) benefits. Sedentary behavior represents a large portion of human’s life and is increasing with technological development. A new current of opinion supports the idea that the manner SB is accumulated plays an important role. This dissertation presents six research studies conducted under the scope of SB. In the methodological area, the first study highlighted the magnitude of potential errors in estimating SB and its patterns from common alternative methods (accelerometer and heart rate monitor) compared to ActivPAL. This study presented the accelerometer as a valid method at a group level. Two studies (2 and 5) were performed in older adults (the most sedentary group in the population) to test the associations for SB patterns with abdominal obesity using accelerometry. The findings showed positive graded associations for prolonged sedentary bouts with abdominal obesity and showed that those who interrupted SB more frequently were less likely to present abdominal obesity. Therefore, public health recommendations regarding breaking up SB more often are expected to be relevant. The associations between sedentary patterns and abdominal obesity were independent of MVPA in older adults. However, the low MVPA in this group makes it unclear whether this independent relationship still exists if highly active persons are analysed. Study 3 inovates by examining the association of SB with body fatness in highly trained athletes and found SB to predict total fat mass and trunk fat mass, independently of age and weekly training time. Study 4 also brings novelty to this research field by quantifying the metabolic and energetic cost of the transition from sitting to standing and then sitting back down (a break), informing about the modest energetic costs (0.32 kcal·min−1). Finally, from a successful multicomponent pilot intervention to reduce and break up SB (study 6), an important behavioral resistance to make more sit/stand transitions despite successfully reducing sitting time (~ 1.85 hours·day-1) was found, which may be relevant to inform future behavioral modification programs. The present work provides observational and experimental evidence on the relation for SB patterns with body composition outcomes and energy regulation that may be relevant for public health interventions.

Evaluation of nutritional status and energy expenditure in athletes

El ejercicio físico continuo conduce al atleta a mantener un equilibrio inestable entre la ingesta dietética, el gasto de energía y las exigencias adicionales de un alto grado de actividad física. Por lo tanto, una evaluación precisa del estado nutricional es esencial para optimizar el rendimiento, ya que afecta a la salud, la composición corporal, y la recuperación del atleta. Aspectos específicos como tipo de deporte, especialidad o posición de juego, programa de entrenamiento y calendario de competiciones, la categoría, objetivos específicos, que difieran de la población en general, deben ser tenidos en cuenta. La evaluación bioquímica nos puede dar una idea general del estado nutricional, del perfil lipídico, del funcionamiento de hígado o riñón, de si la dieta es demasiado alta en proteínas o grasas, así como las posibles deficiencias nutricionales y la necesidad de suplementación. La cineantropometría deportiva tiene gran utilidad ya que permite la evaluación de la masa corporal, altura, longitud, diámetro, perímetro y pliegues cutáneos, donde la información se procesa mediante la aplicación de diferentes ecuaciones, obteniendo información sobre el somatotipo, la composición corporal y la proporcionalidad de las distintas partes del cuerpo. Para poder dar una orientación nutricional adecuada, las necesidades de energía de los atletas deben ser conocidas. Si la medición objetiva no es posible, existen tablas que incluyen los requerimientos de energía teóricamente establecidos para diferentes deportes. La evaluación dietética debe incluir información sobre el consumo de alimentos y nutrientes para establecer la relación entre la dieta, el estado de salud y el rendimiento del atleta. Por otro lado, un estado adecuado de hidratación en los atletas es esencial para mantener un rendimiento óptimo. Se debe valorar específicamente la ingesta de líquidos por parte del deportista. La deshidratación puede causar efectos nocivos en la salud de los atletas. Como no existe un método “gold standard”, la gravidez y el color de la orina son los métodos más extendidos para analizar el estado de hidratación. Hay consenso en que la combinación de diferentes métodos asegura una captura efectiva de datos para la valoración nutricional del deportista que permitirá proceder a la intervención dietética y nutricional.

AD-HOC principles of minimum energy expenditure as corollaries of the constructal law the cases of river basins and human vascular systems

In a recent paper [1] Reis showed that both the principles of extremum of entropy production rate, which are often used in the study of complex systems, are corollaries of the Constructal Law. In fact, both follow from the maximization of overall system conductivities, under appropriate constraints. In this way, the maximum rate of entropy production (MEP) occurs when all the forces in the system are kept constant. On the other hand, the minimum rate of entropy production (mEP) occurs when all the currents that cross the system are kept constant. In this paper it is shown how the so-called principle of "minimum energy expenditure" which is often used as the basis for explaining many morphologic features in biologic systems, and also in inanimate systems, is also a corollary of Bejan's Constructal Law [2]. Following the general proof some cases namely, the scaling laws of human vascular systems and river basins are discussed as illustrations from the side of life, and inanimate systems, respectively.

Low-fat oxidation may be a factor in obesity among men with schizophrenia

Objective: Obesity associated with atypical antipsychotic medications is an important clinical issue for people with schizophrenia. The purpose of this project was to determine whether there were any differences in resting energy expenditure (REE) and respiratory quotient (RQ) between men with schizophrenia and controls. Method: Thirty-one men with schizophrenia were individually matched for age and relative body weight with healthy, sedentary controls. Deuterium dilution was used to determine total body water and subsequently fat-free mass (FFM). Indirect calorimetry using a Deltatrac metabolic cart was used to determine REE and RQ. Results: When corrected for FFM, there was no significant difference in REE between the groups. However, fasting RQ was significantly higher in the men with schizophrenia than the controls. Conclusion: Men with schizophrenia oxidised proportionally less fat and more carbohydrate under resting conditions than healthy controls. These differences in substrate utilisation at rest may be an important consideration in obesity in this clinical group.