Anthropometric measurements and body composition of selected national athletes

This study was conducted to determine the anthropometric measurements and body composition of selected national athletes. A total of 84 male athletes from 10 different types of sports and 24 female athletes from 5 types of sports were studied. The height and body weight of subjects were measured using the SEGA weighing balance with height attachment. Skinfold thickness measurements were taken using the Harpenden Calipers at 4 sites (biceps, triceps, subscapular and suprailiac). Percentage of body fat was calculated from the sum of 4 measurements of skinfold thickness. Based on body mass index (BMI), most of the male (68 subjects or 81%) and female (19 subjects or 79%) athletes were classified as normal. The percentage average body fat for both male and female athletes were 13.8 ± 4.5% and 24.7 ± 5.3%, respectively. The male and female athletes also had lower percentage of body fat when compared to non-athletes, however these athletes had slightly higher percentage of body fat when compared to those in selected countries.     

Energy expenditure and requirements in aging humans.

Although physical activity is frequently recommended for the elderly individual, its influence on energy intake and energy expenditure is unclear. The use of indirect calorimetry techniques and stable isotopes make it possible to examine the effects of physical activity on total daily energy expenditure and its components. In this review, the influence of physical activity on adaptive changes in energy intake, daily energy expenditure, resting metabolic rate and the energy expenditure of physical activity during nonexercising time was examined. Recent findings show that moderate physical activity can increase resting metabolic rate and energy intake in the elderly. Vigorous exercise, however, did not increase total daily energy expenditure because of a compensatory decline in physical activity during nonexercising time. These findings should prompt investigators to re-examine the influence of different levels of endurance exercise on total daily energy expenditure in an attempt to maximize the energy expending properties of physical exercise in older persons. A second objective was to examine the current status of methodology to predict energy requirements in older persons. Current recommendations for energy lack specificity and have not considered the influence of physical activity and body composition. Energy needs of older persons need to be re-examined based on the measurement of total daily energy expenditure. It will then be important to identify biological markers of total daily energy expenditure that take into account the variation in physical activity and body composition.     

Energy expenditure and protein requirements after traumatic injury.

Traumatic injury induces hypermetabolism. The degree of hypermetabolism can be variable, depending on the type of injury, the degree of inflammation, body composition, age, and treatment regimens. To estimate metabolic rate in some types of injury, predictive equations have been published. Some of these equations have been tested in validation studies. For other types of injury, equations do not exist. Some expert panels have recommended measuring in lieu of estimating metabolic rate, though studies have not been performed to determine whether clinical outcome is affected by the method used to determine energy requirements. Traumatically injured patients are usually catabolic, but protein needs after traumatic injury continue to be debated. Some suggest that 1.5 g protein per kg body weight is adequate and that any additional protein is simply oxidized, adding to the nitrogen load to be excreted. Alternately, protein intake >2.0 g/kg body weight increases the absolute rate of body protein synthesis, and achievement of nitrogen balance has been associated with survival. Thus, provision of high-protein feeding to achieve nitrogen balance might be worthwhile, even if that balance is achieved at the cost of additional nitrogen production.     

Energy requirements during pregnancy based on total energy expenditure and energy deposition

BACKGROUND: Energy requirements during pregnancy remain controversial because of uncertainties regarding maternal fat deposition and reductions in physical activity. OBJECTIVE: This study was designed to estimate the energy requirements of healthy underweight, normal-weight, and overweight pregnant women and to explore energetic adaptations to pregnancy. DESIGN: The energy requirements of 63 women [17 with a low body mass index (BMI; in kg/m(2)), 34 with a normal BMI, and 12 with a high BMI] were estimated at 0, 9, 22, and 36 wk of pregnancy and at 27 wk postpartum. Basal metabolic rate (BMR) was measured by calorimetry, total energy expenditure (TEE) by doubly labeled water, and activity energy expenditure (AEE) as TEE - BMR. Energy deposition was calculated from changes in body protein and fat. Energy requirements equaled the sum of TEE and energy deposition. RESULTS: BMR increased gradually throughout pregnancy at a mean (+/-SD) rate of 10.7 +/- 5.4 kcal/gestational week, whereas TEE increased by 5.2 +/- 12.8 kcal/gestational week, which indicated a slight decrease in AEE. Energy costs of pregnancy depended on BMI group. Although total protein deposition did not differ significantly by BMI group (mean for the 3 groups: 611 g protein), FM deposition did (5.3, 4.6, and 8.4 kg FM in the low-, normal-, and high-BMI groups; P = 0.02). Thus, energy costs differed significantly by BMI group (P = 0.02). In the normal-BMI group, energy requirements increased negligibly in the first trimester, by 350 kcal/d in the second trimester, and by 500 kcal/d in the third trimester. CONCLUSION: Extra energy intake is required by healthy pregnant women to support adequate gestational weight gain and increases in BMR, which are not totally offset by reductions in AEE.     

Energy expenditure and substrate oxidation predict changes in body fat in children

BACKGROUND: The hypothesis that alterations in energy metabolism predict body fat gain is controversial. OBJECTIVE: The aim of this study was to determine which components of energy metabolism were most important in predicting fat gain in children aged 10.8 +/- 0.6 y. DESIGN: A 2-y longitudinal study to examine whether components of energy metabolism are predictors of body fat gain was conducted in 114 preadolescent African American and white children aged 9-11 y by measuring total daily energy expenditure on the basis of doubly labeled water (DLW), resting metabolic rate, the thermic effect of food, energy expended in physical activity, and substrate oxidation after a meal. The primary endpoint was the 2-y change in percentage body fat (%BF). RESULTS: Individual variables of energy metabolism predicted up to 7% of the variance in changes in %BF over the 2-y interval in the whole group. Predictors of change in body fatness tended to be sex and race specific. Protein oxidation during a test meal explained a significant portion of the variance in change in %BF in the overall group and in nearly all of the subgroups. Multivariate prediction models accounted for 10-41% of the variance in change in %BF. Tanner stage at 2-y follow-up was highly predictive of change in body fatness and improved the overall prediction, accounting for 24-62% of the variance in change in %BF in those groups in which Tanner entered the model. CONCLUSION: This study provides evidence that total daily energy expenditure, resting metabolic rate, substrate oxidation, and total energy intake are predictors of gain in body fatness during late childhood in boys and girls.     

Energy expenditure and dietary intake during high-volume and low-volume training periods among male endurance athletes

The primary purpose of this study was to examine dietary intake in endurance-trained athletes during a week of high-volume and a week of low-volume training while measuring exercise energy expenditure (EEE), resting metabolic rate (RMR), and nonexercise activity thermogenesis (NEAT). In addition, compliance with current American College of Sports Medicine/American Dietetic Association nutrition and performance recommendations for macronutrients was evaluated. Energy expenditure and dietary intake were measured in 15 male endurance athletes during 2 nonconsecutive weeks resembling a high-volume and a low-volume training period. Anthropometric measurements were taken and percentage body fat was determined at the beginning and end of each week of training. Total daily energy expenditure (TDEE) was calculated by summing RMR, NEAT, and EEE. Dietary intake was assessed with an online food-frequency questionnaire completed at the end of each week of data collection. Despite significant differences between TDEE and energy intake, no difference in body composition between the beginning and end of either week of training was observed, suggesting underreporting of caloric intake. Further, no changes in total caloric intake or macronutrient intake occurred even though TDEE increased significantly during the high-volume training. Reported carbohydrate intake (4.5?g·kg(-1)) and fiber intake (25?g·day(-1)) were below recommendations, whereas fat intake (1.3?g·kg(-1)) was slightly above recommendations. In summary, no short-term dietary adjustments occurred in response to differences in training regimen. Because these athletes were generally consuming a Western diet, they may have required some support to achieve desirable intakes for health and performance.     

Energy requirements and energy expenditure of lean and overweight women, measured by indirect calorimetry

To estimate the energy requirement of lean and overweight women, 29 lean (body weight, 59 +/- 1 kg; means +/- SEM) and 18 overweight (94 +/- 5 kg) women consumed a weight-maintenance diet for 8 d. The final 80 h were spent in a whole-body indirect calorimeter. Actual metabolizable energy intake (ME) was measured by analyzing food, feces, and urine. Mean ME was 8.88 +/- 0.13 MJ/d (2123 +/- 30 kcal/d) (lean) and 10.12 +/- 0.29 MJ/d (2419 +/- 70 kcal/d) (overweight). Mean 24-h energy expenditure (24hEE) of the lean (8.58 +/- 0.13 MJ or 2052 +/- 32 kcal) was lower than that of the overweight (10.70 +/- 0.45 MJ or 2558 +/- 108 kcal; p less than 0.001) women. Energy balance was close to zero in both groups. Therefore, 24hEE was used as an estimation of energy requirement. Multiple-regression analysis showed body weight to be the best single predictor of 24hEE. Our data may be useful for prediction of energy requirements of women (aged 20-50 yr) in normal life.     

Energy expenditure of nonexercise activity

BACKGROUND: We found recently that changes in nonexercise activity thermogenesis (NEAT) mediate resistance to weight gain with overfeeding in sedentary adults. A potentially important, yet seldom investigated, component of NEAT is the energy expenditure of fidgeting-like activities. OBJECTIVE: Our goal was to measure changes in energy expenditure with fidgeting-like activities. DESIGN: Energy expenditure was measured in 24 subjects (17 women and 7 men x+/- SD body weight: 76 +/- 21 kg) while recumbent at rest, sitting motionless, standing motionless, partaking of self-selected fidgeting-like movements while seated and while standing, and walking on a treadmill at 1.6, 3.2, and 4.8 km/h (1, 2, and 3 mph). Measurements were performed by using a high-precision, indirect calorimeter connected to the subject via a transparent, lightweight facemask that enabled almost unrestricted movement. RESULTS: Compared with metabolic rate in the supine position (5.4 +/- 1.5 kJ/min), energy expenditure increased while sitting motionless by 4 +/- 6%, while fidgeting while seated by 54 +/- 29% (P: < 0.0001), while standing motionless by 13 +/- 8% (P: < 0.0001), while fidgeting while standing by 94 +/- 38% (P: < 0.0001), while walking at 1.6 km/h by 154 +/- 38% (P: < 0.0001), while walking at 3.2 km/h by 202 +/- 45% (P: < 0.0001), and while walking at 4.8 km/h by 292 +/- 81% (P: < 0.0001). There was a significant, positive correlation between changes in energy expenditure and body weight for fidgeting-like activities while standing (r = 0.43, P: = 0.02) but not while seated. CONCLUSIONS: There is marked variance between subjects in the energy expenditure associated with self-selected fidgeting-like activities. The thermogenic potential of fidgeting-like and low-grade activities is sufficiently great to substantively contribute to energy balance.     

Energy expenditure of rats subjected to long-term food restriction

Food restriction, even when expressed per unit of metabolic mass, leads to energy conservation as seen by decreased oxygen consumption. The objective of the present study was to verify whether the energy conservation mechanism reduces energy expenditure for as long as food restriction lasts or whether a return to basal level may occur without realimentation, mainly in mildly food-restricted rats. Wistar rats were brought to the laboratory on weaning. They were then assigned to control group that received ad libitum food intake, R 10 and R 20 groups that received 90 and 80%, respectively, of the food eaten by control group and R M group that received an amount of food enough only to keep body weight. The food restriction period lasted for 3 months and was followed by another month during which all groups received ad libitum food intake. The results showed that even in animals subjected to mild food restriction (10%) there was a sustained decrease in oxygen consumption that lasted until refeeding of the animals. The results led to the conclusion that the energy conservation mechanism is active from little food restriction until more stronger levels of restriction, in a proportional manner, and the decreased energy expenditure is maintained during the whole food restriction period.     

Energy expenditure of rats subjected to long-term food restriction

Food restriction, even when expressed per unit of metabolic mass, leads to energy conservation as seen by decreased oxygen consumption. The objective of the present study was to verify whether the energy conservation mechanism reduces energy expenditure for as long as food restriction lasts or whether a return to basal level may occur without realimentation, mainly in mildly food-restricted rats. Wistar rats were brought to the laboratory on weaning. They were then assigned to control group that received ad libitum food intake, R10 and R20 groups that received 90 and 80%, respectively, of the food eaten by control group and RM group that received an amount of food enough only to keep body weight. The food restriction period lasted for 3 months and was followed by another month during which all groups received ad libitum food intake. The results showed that even in animals subjected to mild food restriction (10%) there was a sustained decrease in oxygen consumption that lasted until refeeding of the animals. The results led to the conclusion that the energy conservation mechanism is active from little food restriction until more stronger levels of restriction, in a proportional manner, and the decreased energy expenditure is maintained during the whole food restriction period.     

Energy requirements derived from total energy expenditure and energy deposition during the first 2 y of life

BACKGROUND: Current recommendations for energy intake of children are derived from observed intakes. Deriving energy requirements on the basis of energy expenditure and deposition is scientifically more rational than is using the observational approach and is now possible with data on total energy expenditure (TEE), growth, and body composition. OBJECTIVES: The objectives of this study were 1) to define energy requirements during the first 2 y of life on the basis of TEE and energy deposition; 2) to test effects of sex, age, and feeding mode on energy requirements; and 3) to determine physical activity. DESIGN: TEE, sleeping metabolic rate, anthropometry, and body composition were measured in 76 infants. TEE was measured with doubly labeled water, sleeping metabolic rate with respiratory calorimetry, and body composition with a multicomponent model. RESULTS: Total energy requirements were 2.23, 2.59, 2.97, 3. 38, 3.72, and 4.15 MJ/d at 3, 6, 9, 12, 18, and 24 mo, respectively. Energy deposition (in MJ/d) decreased significantly over time (P: = 0.001) and was lower in breast-fed than in formula-fed infants (P: = 0.01). Energy requirements were approximately 80% of current recommendations. Energy requirements differed by age (P: = 0.001), feeding group (P: = 0.03), and sex (P: = 0.03). Adjusted for weight or fat-free mass and fat mass, energy requirements still differed by feeding group but not by age or sex. Temperament and motor development did not affect TEE. CONCLUSION: The TEE and energy-deposition data of these healthy, thriving children provide strong evidence that current recommendations for energy intake in the first 2 y of life should be revised.     

Ability of the actiwatch accelerometer to predict free-living energy expenditure in young children

OBJECTIVE: To determine whether activity counts obtained with the Actiwatch monitor are associated with total expenditure and body composition in young children. RESEARCH METHODS AND PROCEDURES: Actiwatch activity monitors were tested in 29 children 4 to 6 years old under field conditions over eight days. Total energy expenditure (TEE) was assessed with the doubly labeled water (DLW) technique. Correlation analyses were used to identify variables related to energy expenditure and percentage body fat. Multiple linear regression analyses were used to examine the variance in TEE and percentage body fat explained by activity counts after adjusting for relevant covariates. RESULTS: Both average total daily activity counts (658,816 +/- 201,657) and the pattern of activity were highly variable among subjects. TEE was significantly related to lean body mass (r = 0.45) and age (r = 0.48; p < 0.05 for both). Activity counts alone were not associated with TEE. In multiple linear regression analyses, TEE was independently associated with only lean body mass. Percentage fat mass was independently associated with body weight, being a girl, and being white, but not with average total activity counts. DISCUSSION: Activity counts obtained with the Actiwatch under free-living conditions do not reflect TEE in 4- to 6-year-old children and are not correlated with percentage fat mass. Therefore, average total activity counts obtained with the Actiwatch may be of limited value in identifying children at risk for becoming obese.     

Antioxidant requirements of endurance athletes: implications for health

This review discusses studies investigating the effects of antioxidant supplementation on exercise-induced oxidative stress with a focus on the health implications. The aim is to determine antioxidant requirements for endurance athletes. Overall, differences in methodology make it difficult to compare the relatively small number of published studies on this topic. The types of studies needed to more adequately assess the health effects of antioxidant supplements in athletes (long-term interventions with hard end points) have not been done. Therefore, there is currently insufficient evidence to recommend antioxidant supplements for endurance athletes.