scholarly journals Energy balance, metabolism, hydration, and performance during strenuous hill walking: the effect of age

2002 ◽  
Vol 93 (2) ◽  
pp. 714-723 ◽  
Author(s):  
P. N. Ainslie ◽  
I. T. Campbell ◽  
K. N. Frayn ◽  
S. M. Humphreys ◽  
D. P. M. MacLaren ◽  
...  
Keyword(s):  
Energy Balance ◽  
Energy Expenditure ◽  
Cognitive Processing ◽  
Processing Time ◽  
Urine Osmolality ◽  
Nonesterified Fatty Acid ◽  
Jump Performance ◽  
Impaired Performance ◽  
And Performance ◽  
Effect Of Age

We aimed to examine the effect of age on energy balance, metabolism, hydration, and performance during 10 days of strenuous hill walking. Seventeen male subjects were divided into two groups according to their age. The nine subjects in group 1 constituted the younger group (age 24 ± 3 yr), whereas eight older subjects were in group 2 (age 56 ± 3 yr). Both groups completed 10 consecutive days of high-intensity hill walking. Mean (range) daily walking distances and ascent were 21 km (10–35 km) and 1,160 m (800–2,540 m), respectively. Energy intake was calculated from weighed food intake, and energy expenditure was measured by the doubly labeled water method. Blood and urine were sampled on alternative days to determine any changes in metabolism and hydration during the 10 days. Subjects also completed a battery of tests that included muscular strength (handgrip), jump performance, cognitive processing time, and flexibility. The younger group remained hydrated, whereas the older group became progressively dehydrated, indicated by a near twofold increase in urine osmolality concentration on day 11. This increased urine osmolality in the older group was highly correlated with impairment in vertical-jump performance ( r = −0.86; P < 0.05) and decreased cognitive processing time ( r = 0.79; P < 0.05). Despite energy expenditure of ∼21 MJ/day, body mass was well maintained in both groups. Both groups displayed a marked increase in fat mobilization, reflected in significantly lowered prewalk insulin concentrations and elevated postwalk glycerol and nonesterified fatty acid concentrations. Despite the dehydration and impaired performance in the older group, blood glucose concentrations were well maintained in both groups, probably mediated via the increased mobilization of fat.

Probability-Based and Measurement-Related Hypotheses With Full Restriction for Investigations by Means of Confirmatory Factor Analysis

Methodology ◽  
2011 ◽  
Vol 7 (4) ◽  
pp. 157-164
Author(s):  
Karl Schweizer
Keyword(s):  
Factor Analysis ◽  
Confirmatory Factor Analysis ◽  
Cognitive Processing ◽  
Latent Variables ◽  
Repeated Measures ◽  
Latent Variable ◽  
Model Fit ◽  
Repeated Measures Data ◽  
Confirmatory Factor ◽  
And Performance

Probability-based and measurement-related hypotheses for confirmatory factor analysis of repeated-measures data are investigated. Such hypotheses comprise precise assumptions concerning the relationships among the true components associated with the levels of the design or the items of the measure. Measurement-related hypotheses concentrate on the assumed processes, as, for example, transformation and memory processes, and represent treatment-dependent differences in processing. In contrast, probability-based hypotheses provide the opportunity to consider probabilities as outcome predictions that summarize the effects of various influences. The prediction of performance guided by inexact cues serves as an example. In the empirical part of this paper probability-based and measurement-related hypotheses are applied to working-memory data. Latent variables according to both hypotheses contribute to a good model fit. The best model fit is achieved for the model including latent variables that represented serial cognitive processing and performance according to inexact cues in combination with a latent variable for subsidiary processes.

Energy balance and performance assessment of PV systems installed at a positive-energy building (PEB) solar energy research centre

Solar Energy ◽  
2020 ◽  
Vol 212 ◽  
pp. 258-274
Author(s):  
C. Zomer ◽  
I. Custódio ◽  
S. Goulart ◽  
S. Mantelli ◽  
G. Martins ◽  
...  
Keyword(s):  
Energy Balance ◽  
Solar Energy ◽  
Performance Assessment ◽  
Research Centre ◽  
Positive Energy ◽  
Energy Research ◽  
Pv Systems ◽  
And Performance

Determinants of energy expenditure and energy balance.

Appetite ◽  
2007 ◽  
Vol 49 (1) ◽  
pp. 339 ◽  
Author(s):  
K.R. Westerterp
Keyword(s):  
Energy Balance ◽  
Energy Expenditure

scholarly journals The effect of breakfast on appetite regulation, energy balance and exercise performance

2015 ◽  
Vol 75 (3) ◽  
pp. 319-327 ◽  
Author(s):  
David J. Clayton ◽  
Lewis J. James
Keyword(s):  
Energy Balance ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Exercise Performance ◽  
Intervention Studies ◽  
Precise Determination ◽  
Positive Energy ◽  
Cross Sectional ◽  
Positive Energy Balance ◽  
The Impact

The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.

Role of thermogenesis in the regulation of energy balance in relation to obesity

1989 ◽  
Vol 67 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Jean Himms-Hagen
Keyword(s):  
Adipose Tissue ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Thermal Balance ◽  
Prominent Feature ◽  
Thermic Effect Of Food ◽  
Brown Adipose ◽  
Effect Of Food ◽  
Thermic Effect

Obligatory thermogenesis is a necessary accompaniment of all metabolic processes involved in maintenance of the body in the living state, and occurs in ail organs. It includes energy expenditure involved in ingesting, digesting, and processing food (thermic effect of food (TEF)). At certain life stages extra energy expenditure for growth, pregnancy, or lactation would also be obligatory. Facultative thermogenesis is superimposed on obligatory thermogenesis and can be rapidly switched on and rapidly suppressed by the nervous system. Facultative thermogenesis is important in both thermal balance, in which control of thermoregulatory thermogenesis (shivering in muscle, nonshivering in brown adipose tissue (BAT)) balances neural control of heat loss mechanisms, and in energy balance, in which control of facultative thermogenesis (exercise-induced in muscle, diet-induced thermogenesis (DIT) in BAT) balances control of energy intake. Thermal balance (i.e., body temperature) is much more stringently controlled than energy balance (i.e., body energy stores). Reduced energy expenditure for thermogenesis is important in two types of obesity in laboratory animals. In the first type, deficient DIT in BAT is a prominent feature of altered energy balance. It may or may not be associated with hyperphagia. In a second type, reduced cold-induced thermogenesis in BAT as well as in other organs is a prominent feature of altered thermal balance. This in turn results in altered energy balance and obesity, exacerbated in some examples by hyperphagia. In some of the hyperphagic obese animals it is likely that the exaggerated obligatory thermic effect of food so alters thermal balance that BAT thermogenesis is suppressed. In all obese animals, deficient hypothalamic control of facultative thermogenesis and (or) food intake is implicated.Key words: thermogenesis, brown adipose tissue, energy balance, obesity, cold, thermoregulation, diet.

Energy Balance and Energy Availability During a Selection Course for Belgian Paratroopers

2021 ◽  
Author(s):  
Patrick Mullie ◽  
Pieter Maes ◽  
Laurens van Veelen ◽  
Damien Van Tiggelen ◽  
Peter Clarys
Keyword(s):  
Physical Activity ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Metabolic Rate ◽  
Energy Intake ◽  
Rest Metabolic Rate ◽  
Negative Energy ◽  
Fat Free Mass ◽  
Negative Energy Balance ◽  
Energy Availability

ABSTRACT Introduction Adequate energy supply is a prerequisite for optimal performances and recovery. The aims of the present study were to estimate energy balance and energy availability during a selection course for Belgian paratroopers. Methods Energy expenditure by physical activity was measured with accelerometer (ActiGraph GT3X+, ActiGraph LLC, Pensacola, FL, USA) and rest metabolic rate in Cal.d−1 with Tinsley et al.’s equation based on fat-free mass = 25.9 × fat-free mass in kg + 284. Participants had only access to the French individual combat rations of 3,600 Cal.d−1, and body fat mass was measured with quadripolar impedance (Omron BF508, Omron, Osaka, Japan). Energy availability was calculated by the formula: ([energy intake in foods and beverages] − [energy expenditure physical activity])/kg FFM−1.d−1, with FFM = fat-free mass. Results Mean (SD) age of the 35 participants was 25.1 (4.18) years, and mean (SD) percentage fat mass was 12.0% (3.82). Mean (SD) total energy expenditure, i.e., the sum of rest metabolic rate, dietary-induced thermogenesis, and physical activity, was 5,262 Cal.d−1 (621.2), with percentile 25 at 4,791 Cal.d−1 and percentile 75 at 5,647 Cal.d−1, a difference of 856 Cal.d−1. Mean daily energy intake was 3,600 Cal.d−1, giving a negative energy balance of 1,662 (621.2) Cal.d−1. Mean energy availability was 9.3 Cal.kg FFM−1.d−1. Eleven of the 35 participants performed with a negative energy balance of 2,000 Cal.d−1, and only five participants out of 35 participants performed at a less than 1,000 Cal.d−1 negative energy balance level. Conclusions Energy intake is not optimal as indicated by the negative energy balance and the low energy availability, which means that the participants to this selection course had to perform in suboptimal conditions.

1154-P: Mediobasal Hypothalamic PACAP Is Essential for Energy Balance by Stimulating Energy Expenditure

Diabetes ◽  
2021 ◽  
Vol 70 (Supplement 1) ◽  
pp. 1154-P
Author(s):  
DAVID Q. JOHNSON ◽  
RASHMITA BASU ◽  
JONATHAN FLAK
Keyword(s):  
Energy Balance ◽  
Energy Expenditure

Achievement in School in Relation to Simultaneous and Sequential Cognitive Processes among Young Egyptian Students

1997 ◽  
Vol 84 (3_suppl) ◽  
pp. 1139-1148 ◽  
Author(s):  
Fadia Z. Elwan
Keyword(s):  
Cognitive Processing ◽  
Cognitive Processes ◽  
Sequential Analysis ◽  
School Achievement ◽  
Reading Scores ◽  
Sequential Processing ◽  
Simultaneous Synthesis ◽  
And Performance ◽  
The Relationship ◽  
Reading Decoding

The present study was designed to examine whether a relationship exists between scores on simultaneous and sequential cognitive processes, on one hand, and performance on the Reading Decoding and Arithmetic subtests of the Kaufman Assessment Battery for Children (K–ABC), on the other hand, using a sample of 170 Egyptian school children in Grades 1, 3, and 5. To examine the differential magnitudes of the relationship between scores for cognitive processing and school achievement a two by two (simultaneous × sequential) analysis of variance was calculated with reading decoding and arithmetic scores as dependent variables. The results indicated that cognitive processing, especially simultaneous synthesis, is related to arithmetic as well as decoding during reading. Scores on sequential processing were not significantly related to scores for decoding reading and may not be important as simultaneous processing for mathematical skills. The findings were interpreted in the context of the Arabic orthographic system and in view of the nature of the cognitive and mathematical tasks employed in this study.

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