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PubMed1989

Nutritional status and body composition of adolescent female gymnasts.

Nutritional status and body composition of 26 young female gymnasts (average age 12 years) were studied. The body fat percentage (15% of total body weight) is low, still consistent with an excellent health. The caloric intake is lower (1552 kcal/day) than that recommended for their age group, however it is still within the standard by body weight (43 kcal/kg). They show and insufficient assumption of carbohydrates (47.7%), mineral salts and vitamins, so that a more detailed alimentary information is required in order to avoid undesired consequences on sport performance and growth rate.

Body Composition↗

PubMedDate not supplied

Bioelectrical impedance vs air displacement plethysmography and dual-energy X-ray absorptiometry to determine body composition in patients with end-stage renal disease.

BACKGROUND: Patients with end-stage renal disease (ESRD) have significant shifts in fluid homeostasis that may impair measurements of body composition using methods based upon determinations of body water. Estimates of body water are fundamental for bioelectrical impedance analysis (BIA), which measures electrical resistance to estimate total body water and body composition. METHODS: BIA was compared with 2 other techniques: (1) air displacement plethysmography (ADP), which relies on measurements of body density to estimate body fat and fat-free masses; and (2) dual-energy x-ray absorptiometry (DXA), which depends on the relative attenuation of an x-ray beam to produce images of body fat and bone mineral. In study 1, BIA and ADP were performed on 38 ESRD patients (21 men and 17 women; age 51.3 +/- 2.2 years; weight 79.8 +/- 2.9 kg; body mass index [BMI] 27.4 +/- 0.9 kg/m2). In study 2, BIA and DXA were performed on 47 patients (22 men and 25 women; age 52.7 +/- 2.3 years; weight 73.6 +/- 2.9 kg; BMI 25.9 +/- 1.0 kg/m2). RESULTS: The ranges of percent body fat using BIA in studies 1 and 2 were from 7% to 57% and from 6% to 52%, respectively. Percent body fat measurements were significantly (p < .0001) correlated for BIA vs ADP (r = .74) and for BIA vs DXA (r = .84). Mean body fat as determined by BIA and ADP in study 1 was 31.8 +/- 2.0% and 36.3 +/- 1.8%* and by BIA and DXA in study 2 was 29.6 +/- 1.5% and 31.8 +/- 1.8%*, respectively (*p < .05 vs BIA). All 3 methods had similar variability associated with their measurements (coefficients of variation approximately 5%). The average body fat measured by BIA was less than ADP or DXA, regardless of gender or race. Furthermore, the variation was not greater at lower or higher body fat values. CONCLUSIONS: Body fat measurements using ADP and DXA were correlated with those using BIA across a relatively wide range of body fat levels in adults with ESRD. However, BIA appeared to underestimate body fat and overestimate fat-free mass, possibly because of increased measurements of body water. Because ADP is convenient and does not use body water content in determination of body density and body composition, it has very good potential as a relatively new technique to estimate percent body fat in adults with ESRD.

Absorptiometry, Photon↗

PubMed2004

The relationship between body composition and muscle power output in men and women with obesity.

In order to investigate the effect of gender, age and level of obesity on body composition and anaerobic power output, and to test the hypothesis that variation in body composition affects muscle power output in obesity, a cohort of 377 subjects (112 males and 265 females, aged 18-75 yr) with different levels of obesity [class IIII, body mass index (BMI) range: 30.6-60.3 kg m(-2)] was cross-sectionally investigated. Body composition was assessed with bioelectric impedance analysis (BIA), in standardized conditions and using obesity-specific prediction formulas. Lower limb anaerobic power output (W) was measured with a modification of the Margaria stair climbing test. In males, a similar increase in fat-free mass (FFM) and fat mass (FM) was observed as a function of BMI, while in females, FM increased more than FFM. In both genders, FFM significantly decreased as a function of age (p<0.001), but was higher in men of all ages. Similar patterns of variation were observed in W. A differently significant correlation between BMI and W was observed between men and women, and it was found by multivariate analysis of variance (MANOVA) that W was affected negatively by age (p<0.001) and positively by BMI (p<0.001) in males, while in females only age had a significant effect (p<0.001) but not BMI. A positive correlation (p<0.001) was detected between FFM and W, in both genders. W per unit body mass, the actual muscle power for rapid external work, was higher in men than in women of all groups, and decreased with age in both genders, but only in older women decreased significantly (p<0.01) depending on BMI. It is concluded that the gender-dependent pattern of variation in body composition may be an important determinant of the different motor limitations observed in men and women. Older women (> or =50 yr) with extreme obesity (class III) suffered from the most serious motor dysfunction within this obese cohort. This result may have important clinical relevance in the care of obesity.

Adult↗

PubMed1998

Bone mineral density and body composition before and during treatment with gonadotropin-releasing hormone agonist in children with central precocious and early puberty.

Major changes in bone mineral density (BMD) and body composition occur during puberty. In the present longitudinal study, we evaluated BMD and calculated volumetric BMD [bone mineral apparent density (BMAD)], bone metabolism, and body composition of children (32 girls and 2 boys) with central precocious and early puberty before and during treatment with GnRH agonist (GnRH). Patients were studied at baseline and during treatment for 6 months (n = 34), 1 yr (n = 33), and 2 yr (n = 16). Lumbar spine and total body BMD and body composition were measured with dual-energy x-ray absorptiometry. The variables were compared with age- and sex-matched reference values of the same population and expressed as SD score (SDS). Bone age was assessed. Serum calcium, phosphate, alkaline phosphatase, osteocalcin, the carboxyterminal propeptide of type I collagen (PICP), cross-linked telopeptide of collagen I (ICTP), 1,25 dihydroxyvitamin D and urinary hydroxyproline/creatinine, and calcium/ creatinine ratios were measured. Mean lumbar spine BMD SDS was significantly higher than zero at baseline (P < 0.02) and did not differ from normal, after 2 yr of treatment. Mean spinal BMAD SDS and total body BMD SDS were not significantly different from zero at baseline and had not changed significantly after 2 yr of treatment. During therapy, fat mass and percentage body fat SDS increased, whereas lean tissue mass SDS decreased. Mean lumbar spine BMD and BMAD and total body BMD SDS, calculated for bone age, were all lower than zero at baseline (BMD P < 0.001 and BMAD P < 0.05) and also after 2 yr treatment (respectively, P < 0.001, P < 0.05, and P < 0.01). Biochemical bone parameters were significantly higher than prepubertal values at baseline, and they decreased during treatment. In conclusion, patients with central precocious and early puberty had normal BMD for chronological age but low BMD for bone age, after 2 yr of treatment with GnRH. Bone turnover decreased during treatment. Changes in body composition resembled those seen in patients with GH deficiency.

Body Composition↗

PubMed2003

Body composition in aging: a biological perspective.

PURPOSE OF REVIEW: Changes in body composition accompany and predict medical and surgical risk; interventions may be considered. Aging affects body composition, particularly in reduction of the body cell mass. RECENT FINDINGS: The molecular biology of aging has become an active frontier of research in the past 30 years, with acceleration in the past decade. A review of the toxicities of reactive oxygen and nitrogen species, especially at the mitochondria, can now be studied at the molecular, genetic, and proteomic scales, in individual cell components and systems, with major implications for patient management, for planning therapeutic interventions, and for predicting future age spans. SUMMARY: The intersections between the clinical fields of endocrinology, nuclear medicine/radiology, and geriatrics, with the more fundamental fields of physiology, molecular biology, genetics, and proteomics are indicated.

Aged↗

PubMedDate not supplied

Validation of dual x-ray absorptiometry for body-composition assessment of rats exposed to dietary stressors.

Evidence of the validity and accuracy of dual x-ray absorptiometry (DXA) to measure soft-tissue composition of laboratory rats with altered body composition associated with nutritional perturbations is lacking. We compared DXA determinations made in prone and supine positions with measurements of chemical composition of 49 male, weanling Sprague-Dawley rats that were fed the basal AIN-93 growth diet, were fed the basal diet modified to contain 30% fat, were fasted for 2 d, were limit fed 6 g of the basal diet daily for 1 wk, or were treated with furosemide (10 mg/kg intraperitoneally 2 h before DXA). DXA produced similar estimates of body mass and soft-tissue composition in the prone and supine positions. DXA estimates of body composition were significantly correlated with reference composition values (R(2) = 0.371-0.999). DXA discriminated treatment effects on body mass, fat-free and bone-free mass, fat mass, and body fatness; it significantly underestimated body mass (1% to 2%) and fat-free and bone-free mass (3%) and significantly overestimated fat mass and body fatness (3% to 25%). The greatest errors occurred in treatment groups in which body mass was diminished and body hydration was decreased. These findings suggest that DXA can determine small changes in fat-free, bone-free mass in response to obesity and weight loss. Errors in DXA determination of fat mass and body fatness associated with extra corporeal fluid and dehydration indicate the need for revision of calculation algorithms for soft-tissue determination.

Absorptiometry, Photon↗

PubMed2006

Body composition and nutritional intake in children with chronic kidney disease.

The aim of this study was to assess body composition in children with chronic renal failure (CRF) and post renal transplantation (Tx), and to compare it to body mass index (BMI) and nutritional intake. Dietary assessment using 3-day diaries, total and regional body composition assessment by dual x-ray energy absorptiometry of 50 CRF children (29M, 21F), median age 8.9 yrs and 50 Tx children (32M, 18F), median age 12.9 yrs. BMI, percentage fat mass (%FM) and lean mass (LM) were corrected for height and expressed as SDS (HSDS). In both groups, BMIHSDS was lower than %FMHSDS and higher than LMHSDS (p<0.05). In the Tx group, there were associations on bivariate analysis between energy & protein intake and BMIHSDS & %FMHSDS (r,0.5, p<0.05), and between LMHSDS and protein intake (r,0.5, p<0.05). On multivariate analysis, there was an association between LMHSDS and time since transplantation (r,-0.4, p<0.05). Children in the CRF and Tx groups had a high percentage predicted trunk:leg FM ratio of 148% and 157%, respectively. Children with CRF and Tx have discordant body composition with a relatively high FM and low LM, which is not reflected by BMI. In addition, they appear to have an increased level of central adiposity that may predispose them to increased morbidity in later life.

Absorptiometry, Photon↗

PubMed1994

Estimation of body composition in Chinese and British men by ultrasonographic assessment of segmental adipose tissue volume.

It has been shown that ultrasonographic measurements can be used to predict body composition in adults. The purpose of this study was to assess the relationship between ultrasonograph and caliper (SKF) measurements of subcutaneous adipose tissue thickness in athletic Caucasian (English, E) and Asian (Chinese, C) men against estimates of body composition determined from hydrodensitometry (HYD). The usefulness of a proposed ultrasonographic method of estimating lean and fat proportions in the upper and lower limbs was also evaluated as a potential method of predicting body composition. Ultrasonography (US) was used to measure adipose and skin thickness at the following sites: biceps, triceps, subscapular, suprailiac, abdominal, pectoral, thigh and calf. Caliper measurements were also made at the above sites. Subcutaneous fat thickness and segmental radius were measured directly from the display screen of the ultrasonic scanner (Aloka 500 SD). By applying the geometry of a cone, the proximal and distal radii of the upper arm and upper leg were used to calculate the proportionate volumes of adipose tissue. The best correlations for US and SKF were obtained at the quadriceps, subscapular and pectoral sites for E (r = 0.96, 0.93 and 0.90, respectively) and at the quadriceps, calf and abdominal sites for C (r = 0.90, 0.81 and 0.75, respectively). The best ultrasonographic predictor of the percentage fat in both groups was the percentage adipose tissue volume in the upper leg (r = 0.83 and 0.79 for C and E, respectively). Stepwise multiple regression analysis indicated that the prediction of percentage fat was improved by the addition of the ultrasonographic abdomen measurement in both groups: Chinese sample: %fat = %fat(leg) (0.491) + US abdomen (0.337) + 0.95 ( R = 0.89, s.e.e. = 1.9%); English sample: %fat = %fat(leg) (0.435) + US abdomen (0.230) - 0.765 ( R = 0.80, s.e.e. = 3.6%). It is concluded that ultrasonographic measurements of subcutaneous adipose tissue and volumetric assessment of percentage adipose tissue in the thigh are useful estimates of body composition in athletic English and Chinese males.

Adipose Tissue↗

PubMed2003

Evaluation of two foot-to-foot bioelectrical impedance analysers to assess body composition in overweight and obese adolescents.

The objective of the present study was to determine the accuracy of two foot-to-foot (FF) bioelectrical impedance analysers (BIA) to assess body composition in overweight and obese adolescents, compared with dual-energy X-ray absorptiometry (DXA) and hand-to-foot (HF) BIA. Body composition was assessed in fifty-three overweight or obese adolescents (BMI 27.9 (SD 4.1) kg/m2; aged 13-16 years) by DXA (Hologic QDR-4500; Hologic Inc., Bedford, MA, USA) and BIA (HF (BIA 101, RJL System, Detroit, IL, USA) and FF (Body Fat Monitor Scale BF-625, Tanita Corporation of America Inc., Arlington Heights, IL, USA; Téfal Bodymaster Vision, Téfal, Rumilly, France)). Bland-Altman tests showed that, compared with DXA, FF-Tanita and FF-Téfal underestimated (P<0.05) fat mass (FM) less than HF-BIA (-1.7 (SD 3.1), -0.7 (SD 5.8) and -2.3 (SD 2.2) kg respectively, P<0.001). However, the limits of agreement between DXA and FF-Tanita or FF-Téfal were much greater than those obtained with HF-BIA (-7.7 and +4.3, - 12.0 and +10.6 v. -2.1 and +6.7 kg respectively). The differences between FM assessed using the FF-Tanita or the FF-Téfal analyser and DXA increased with the waist:hip ratio, and were higher in boys than in girls. The major limiting factor of FF-BIA was the inter-individual variability in FM estimates. In conclusion, FF-BIA and DXA are not interchangeable methods. FF-BIA could be acceptable to assess body composition in large groups of overweight or obese adolescents, but cannot be recommended for body composition assessment in obese subjects because of the large errors in individual estimates.

Absorptiometry, Photon↗

PubMed2004

Associations between plasma ghrelin levels and body composition in end-stage renal disease: a longitudinal study.

BACKGROUND: Ghrelin is a newly detected orexigenic gastric hormone that stimulates food intake. Increased levels of ghrelin are often found in disease states associated with wasting. Wasting is a common phenomenon in end-stage renal disease (ESRD) patients in whom elevated ghrelin levels have been reported. However, no data are available on the relationship between body composition and plasma ghrelin levels in this patient group. METHODS: The study population consisted of 108 (71 males) ESRD patients aged 53+/-12 years. Body composition, nutritional status (subjective global assessment), estimated protein intake (nPNA), plasma ghrelin, plasma insulin and serum leptin were evaluated close to the start of dialysis treatment. Twelve healthy subjects (nine males, 44+/-6 years) served as the control group. A longitudinal evaluation of changes in plasma ghrelin and body composition was performed in 52 of the patients after 12 months of dialysis treatment. RESULTS: Markedly elevated plasma ghrelin levels (843+/-485 vs 443+/-302 pg/ml; P<0.01) were observed in ESRD patients compared with controls. Basal plasma ghrelin levels correlated significantly with plasma insulin (R = -0.32; P<0.05), body mass index (R = -0.24; P<0.05), log serum leptin levels (R = -0.23; P<0.05) and truncal fat mass (R = -0.25; P<0.05). The longitudinal analysis of body composition demonstrated that whereas fat mass increased (23.7+/-8.6 to 25.3+/-9.9 kg; P<0.05) and plasma ghrelin levels decreased (855+/-429 to 693+/-408 pg/ml; P<0.05) significantly in peritoneal dialysis patients, no significant changes in either body composition or plasma ghrelin levels were found in patients treated by haemodialysis. CONCLUSION: Markedly elevated plasma ghrelin levels are found in advanced renal failure and correlate with fat mass, plasma insulin and serum leptin levels. Changes in plasma ghrelin during 12 months of peritoneal dialysis treatment are associated with changes in body composition.

Adult↗

PubMed1990

High precision in-vivo neutron activation analysis: a new era for compartmental analysis in body composition.

We have focused on two topics in body composition research. The first is basic: we must quantitatively define the interrelationships of the body compartments to one another in health before studying these relationships in disease. The precisions now available can enable us to get to do this work, over the full range of age, race, and occupational diversity. The second direction is more modest and more technical, but nonetheless important. It is the calibration and validation of surrogate measurement methods suitable for field research conditions, doctors' offices, intensive care units, etcetera. Our methods have advanced in fundamental ways. We have an obligation to see them applied effectively.

Adipose Tissue↗

PubMed1999

Comparison of bioelectrical impedance analysis and dual energy X-ray absorptiometry for assessment of body composition in children.

BACKGROUND: There are a variety of methods for assessing body composition. Bioelectrical impedance analysis (BIA) is an easy and non-invasive technique, but has limitations in underweight and overweight subjects. Few reports have investigated the validity of BIA in children. In this report, the characteristics of BIA, especially in overweight and underweight children, are assessed and the results are compared with those of dual energy X-ray absorptiometry (DXA), as a reliable method for assessing body composition. METHODS: Determination of the fat-free mass (FFM), body fat content and percent body fat (%fat) was carried out using both BIA and DXA. The subjects (60 males and 44 females) were divided into five groups according to the percentage of ideal bodyweight (%IBW). Ten obese children, who were treated with exercise and a low-energy diet for 1 month, were also enrolled in this study. RESULTS: The %fat, FFM and body fat content showed a close correlation when measured by BIA and DXA with the correlation coefficients being 0.90, 0.95, and 0.95, respectively. In the underweight group, the %fat value determined by BIA tended to be greater than that determined by DXA, while in the overweight group, the BIA value was lower than the DXA value. The same trend was also seen in obese children before and after therapy with exercise and diet. CONCLUSION: Bioelectrical impedance analysis seems to be a reasonable method for daily clinical use, but attention should be paid to the interpretation of %fat values in underweight and overweight children.

Absorptiometry, Photon↗

PubMed2001

Foot-to-foot bioelectrical impedance analysis: a valuable tool for the measurement of body composition in children.

OBJECTIVE: To determine the accuracy of foot-to-foot bioelectrical impedance analysis (BIA) and anthropometric indices as measures of body composition in children. DESIGN: Comparison of foot-to-foot BIA and anthropometry to dual-energy X-ray absorptiometry (DEXA)-derived body composition in a multi-ethnic group of children. SUBJECTS: : Eighty-two European, NZ Maori and Pacific Island children aged 4.9-10.9 y. MEASUREMENTS: DEXA body composition, foot-to-foot bioelectrical impedance, height, weight, hip and waist measurements. RESULTS: Using a BIA prediction equation derived from our study population we found a high correlation between DEXA and BIA in the estimation of fat-free mass (FFM), fat mass (FM) and percentage body fat (PBF) (r=0.98, 0.98 and 0.94, respectively). BIA-FFM underestimated DEXA-FFM by a mean of 0.75 kg, BIA-FM overestimated DEXA-FM by a mean of 1.02 kg and BIA-PBF overestimated DEXA-PBF by a mean of 2.53%. The correlation between six anthropometric indices (body mass index (BMI), ponderal index, Chinn's weight-for-height index, BMI standard deviation score, weight-for-length index and Cole's weight-for-height index) and DEXA were also examined. The correlation of these indices with PBF was remarkably similar (r=0.85-0.87), more variable with FM (r=0.77-0.94) and poor with FFM (r=0.41-0.75). CONCLUSIONS: BIA correlated better than anthropometric indices in the estimation of FFM, FM and PBF. Foot-to-foot BIA is an accurate technique in the measurement of body composition.

Absorptiometry, Photon↗

PubMed1998

Interaction between body composition, leptin and growth hormone status.

Administration of growth hormone (GH) induces changes in body composition, namely, increases in both bone and lean mass and a decrease in fatty tissue. However, the contrary issue, i.e. the way in which body composition affects the secretion of GH, is highly controversial. Disease states such as obesity and chronic hypercortisolism are associated with increased adiposity and/or the central distribution of fat. Ageing, characterized by excess adiposity, is also associated with impaired secretion of GH. In these states, both spontaneous and stimulated secretion of GH is severely impeded. At the other extreme, malnutrition and fasting are both associated with increased secretion of GH when confronted with most, if not all, stimuli. As the common factor in all of these situations is the increased or decreased adiposity, or the changes in energy homeostasis, it has been postulated that adipose tissue exerts a relevant role in the control of GH secretion in man. The link between adipose tissue and GH seems to be exerted through at least two signals produced by adipocytes: free fatty acids (FFA) and the recently cloned protein, leptin. An increase in FFA blocks secretion of GH, while a decrease in FFA enhances secretion. Leptin, a hormone whose main role is to regulate the intake of food and energy expenditure, seems to regulate GH secretion by acting at the hypothalamic level. In summary, body composition affects GH secretion by way of the degree of adiposity, and free fatty acids and leptin would appear to be the messages through which adipocytes participate in the regulation of GH secretion. This framework clarifies the metabolic control of GH, a hormone with profound metabolic activities.

Adipose Tissue↗

PubMed2005

Body composition and vertebral fracture risk in female patients treated with glucocorticoid.

INTRODUCTION: Glucocorticoid (GC) causes bone loss and an increase in bone fragility. However, fracture risk was found to be only partly explained by bone mineral density in GC-treated patients (GC patients). Although GC causes a change in the distribution of fat in the body, the relationship between body composition and fracture risk in GC patients remains unknown. METHODS: The present study examined the relationship between the presence or absence of vertebral fractures and various indices, including body composition, in 92 premenopausal GC patients, 122 postmenopausal GC patients and 122 postmenopausal age-matched control subjects. Dual-energy X-ray absorptiometry was employed to analyze body composition. RESULTS: Percentage lean body mass (LBM), % fat and % trunk fat were not significantly different between postmenopausal GC patients and the control women. When groups with and without vertebral fractures were compared, % LBM and % fat were significantly higher and lower in groups with vertebral fractures, respectively, in postmenopausal GC patients, but not in the postmenopausal control women, although % trunk fat was not significantly different between groups with and without vertebral fractures. Femoral neck BMD was negatively correlated with % LBM and positively correlated with % fat. In premenopausal GC patients, % trunk fat was significantly higher in the fracture group, although % LBM and % fat were not significantly different between groups with and without vertebral fractures. CONCLUSION: The present study revealed that body composition is related to vertebral fracture risk in GC-treated patients. Lower % fat can be included in the determination of vertebral fractures in postmenopausal GC-treated patients. The influence of body composition on vertebral fracture risk may be different between the pre- and postmenopausal state in GC patients.

Absorptiometry, Photon↗

PubMed2000

Hormones and body composition in humans: clinical studies.

Leptin in relation to body fat and hormonal regulation of body fat distribution will be treated. Leptin circulating levels are strongly related to the percentage of body fat and in women leptin values are always twofold those observed in men. A role of androgens has been suggested to explain this gender difference. Insulin resistance may contribute to the wide variation in leptin levels. Leptin levels and insulin resistance are increased at the end of pregnancy and normalize after delivery. Furthermore, insulin resistance is associated with elevated plasma leptin levels independent of body fat mass and leptin levels are significantly related to insulin sensitivity independent of BMI. Energy restriction can strongly influence leptin levels, overcoming the effects of body composition changes. The shift from a state of triglycerides storage to a state of release could down-regulate leptin production. Triglyceride flux at the intra-abdominal level depends on the balance between insulin and corticosteroids, which have liposynthetic activity, and between sexual and growth hormones, which have lipolytic activity. Both hormonal and body composition change with ageing, primarily due to a decrease in lipolytic activity, with consequent prevalence of liposynthesis and visceral fat accumulation. Enlargement of intra-abdominal adipose cells is more gradual in men and more abrupt in women after menopause.

Adipose Tissue↗

PubMed1991

Changes in body composition and energy expenditure after six weeks' growth hormone treatment.

Changes in body composition and energy expenditure were assessed in 15 children after six weeks of human growth hormone (hGH) treatment. Body composition measurements were made by stable isotope labelled water (H2(18)O) dilution, bioelectrical impedance, and skinfold thickness techniques. Energy expenditure was assessed both by indirect ventilated hood calorimetry (resting energy expenditure) and the stable isotope doubly labelled water (2H2(18)O) technique (free living daily total energy expenditure). Mean increases in weight of 0.96 kg and fat free mass of 1.37 kg and a mean decrease in fat mass of 0.41 kg were observed. Significant increases both in resting energy expenditure and free living daily energy expenditure were detected. Absolute changes in fat mass and resting energy expenditure were correlated. The data suggest (i) that the increase in the fat free mass is the most significant early clinical measure of hGH response and (ii) that hGH increases the metabolic activity of the fat free mass. Monitoring such changes may be predictive of the efficacy of hGH in promoting growth.

Adolescent↗

PubMed2005

Effects of calcium pyruvate supplementation during training on body composition, exercise capacity, and metabolic responses to exercise.

OBJECTIVE: We evaluated the effects of calcium pyruvate supplementation during training on body composition and metabolic responses to exercise. METHODS: Twenty-three untrained females were matched and assigned to ingest in a double blind and randomized manner either 5 g of calcium pyruvate (PYR) or a placebo (PL) twice daily for 30 d while participating in a supervised exercise program. Prior to and following supplementation, subjects had body composition determined via hydrodensiometry; performed a maximal cardiopulmonary exercise test; and performed a 45-min walk test at 70% of pre-training VO2 max in which fasting pre- and post exercise blood samples determined. RESULTS: No significant differences were observed between groups in energy intake or training volume. Univariate repeated measures ANOVA revealed that subjects in the PYR group gained less weight (PL 1.2 +/- 0.3, PYR 0.3 +/- 0.3 kg, P = 0.04), lost more fat (PL 1.1 +/- 0.5; PYR -0.4 +/- 0.5 kg, P = 0.03), and tended to lose a greater percentage of body fat (PL 1.0 +/- 0.7; PYR -0.65 +/- 0.6%, P = 0.07), with no differences observed in fat-free mass (PL 0.1 +/- 0.5; PYR 0.7 +/- 0.3 kg, P = 0.29). However, these changes were not significant when body composition data were analyzed by MANOVA (P = 0.16). There was some evidence that PYR may negate some of the beneficial effects of exercise on HDL values. No significant differences were observed between groups in maximal exercise responses or metabolic responses to submaximal walking. CONCLUSIONS: Results indicate that PYR supplementation during training does not significantly affect body composition or exercise performance and may negatively affect some blood lipid levels.

Adult↗