Publications (49) View all
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Article: Advances in the science and application of body composition measurement.
Journal of Parenteral and Enteral Nutrition 01/2012; 36(1):96-107. · 3.29 Impact Factor -
Article: Accuracy of DXA in estimating body composition changes in elite athletes using a four compartment model as the reference method
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ABSTRACT: Abstract Background Dual-energy x-ray absorptiometry (DXA) provides an affordable and practical assessment of multiple whole body and regional body composition. However, little information is available on the assessment of changes in body composition in top-level athletes using DXA. The present study aimed to assess the accuracy of DXA in tracking body composition changes (relative fat mass [%FM], absolute fat mass [FM], and fat-free mass [FFM]) of elite male judo athletes from a period of weight stability to prior to a competition, compared to a four compartment model (4C model), as the criterion method. Methods A total of 27 elite male judo athletes (age, 22.2 ± 2.8 yrs) athletes were evaluated. Measures of body volume by air displacement plethysmography, bone mineral content assessed by DXA, and total-body water assessed by deuterium dilution were used in a 4C model. Statistical analyses included examination of the coefficient of determinant (r<sup>2</sup>), standard error of estimation (SEE), slope, intercept, and agreement between models. Results At a group level analysis, changes in %FM, FM, and FFM estimates by DXA were not significantly different from those by the 4C model. Though the regression between DXA and the 4C model did not differ from the line of identity DXA %FM, FM, and FFM changes only explained 29%, 36%, and 38% of the 4C reference values, respectively. Individual results showed that the 95% limits of agreement were -3.7 to 5.3 for %FM, -2.6 to 3.7 for FM, and -3.7 to 2.7 for FFM. The relation between the difference and the mean of the methods indicated a significant trend for %FM and FM changes with DXA overestimating at the lower ends and underestimating at the upper ends of FM changes. Conclusions Our data indicate that both at group and individual levels DXA did not present an expected accuracy in tracking changes in adiposity in elite male judo athletes.Nutrition & Metabolism. 01/2010; -
Article: Is bioelectrical impedance spectroscopy accurate in estimating changes in fat-free mass in judo athletes?
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ABSTRACT: Bioelectrical impedance spectroscopy (BIS) provides an affordable and practical assessment of fat-free mass (FFM). However, little information is available on the assessment of changes in fat-free mass in top-level athletes using BIS. The aim of this study was to examine the accuracy of BIS in tracking changes in fat-free mass of elite male judo athletes from a period of weight stability to just before competition, using the four-compartment model (4C model) as reference method. In total, 27 elite male judo athletes (age 22.2 ± 2.8 years) were evaluated. Measures of body volume assessed by air displacement plethysmography, bone mineral content by dual-energy X-ray absorptiometry, and total-body water assessed with deuterium dilution were used in a 4C model. Fat-free mass was also assessed by BIS (FFM(BIS)). Changes in FFM(BIS) were not significantly different from measured by the reference method (P = 0.000). Furthermore, the r² was 0.62 and the standard error of the estimate was 1.03 kg. The limits of agreement ranged from -3.36 to 2.59 kg with no bias observed. These findings demonstrate the viability of BIS as a valid tool for tracking fat-free mass in elite male judo athletes. However, based on the wide limits of agreement observed, BIS is less valid at an individual level for tracking fat-free mass in these athletes.Journal of Sports Sciences 06/2012; 30(12):1225-33. · 1.93 Impact Factor -
Article: Relationship between changes in total-body water and fluid distribution with maximal forearm strength in elite judo athletes.
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ABSTRACT: Among judo athletes, strong grip strength is crucial for performing offensive and defensive maneuvers that rely predominantly on forearm maximal strength (FMS). The study aims were to evaluate changes in total-body water (TBW) and its compartments (extracellular water [ECW] and intracellular water [ICW]) and their relationship with loss of FMS in elite judo athletes. At baseline (weight stability), 27 male elite athletes were evaluated (age: 23.2 ± 2.8 years) and again evaluated 1-3 days before competition. Athletes were free to gain or lose weight based upon their specific competition needs. Using dilution techniques (deuterium and bromide), TBW and ECW were estimated, and ICW was calculated (ICW = TBW - ECW). Fat, fat-free mass, and appendicular lean soft tissue (LST) were assessed by dual-energy x-ray absorptiometry. Handgrip was used to assess FMS. Using a reduction of 2% as a representative outcome for decreased FMS, 10 athletes were identified as having lost FMS, whereas 17 changed <2% or gained. Comparison of means and logistic regression analysis were performed. Results from baseline to before competition indicated that those who lost ≥2% of FMS significantly decreased TBW and ICW by -2.7 ± 3.0 and -4.4 ± 4.2%, respectively. The groups differed in ICW changes (-4.4 ± 4.2 vs. 1.9 ± 6.1%), respectively, for those who lost FMS by ≥2%. The ICW changes, but not in TBW or ECW, significantly predicted the risk of losing FMS (β = 0.206; p = 0.027), even adjusting for weight and arm LST changes. These findings indicated that reductions in ICW increased the risk of losing grip strength in elite judo athletes.The Journal of Strength and Conditioning Research 09/2011; 25(9):2488-95. · 1.83 Impact Factor -
Article: Impact of type 1 diabetes and body weight status on cardiovascular risk factors in adolescent children.
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ABSTRACT: Type 1 diabetes (T1D) is a risk factor for cardiovascular disease. However, it is unclear whether increased body weight amplifies that risk in T1D patients. This is a cross-sectional study examining the presence of cardiovascular risk factors in normal and overweight children, both with and without T1D. Sixty-six children (aged 16±2.2 years) were included in one of the following groups: (T1D and normal weight, T1D and overweight, healthy and normal weight, and healthy and overweight). A fasting blood sample was analyzed for lipid profile (triglyceride, cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol), apolipoprotein B (apoB), and apolipoprotein C-III (apoC-III) levels. Body composition was determined by dual energy x-ray absorptiometry and vascular elasticity by HDI/Pulsewave CR-2000 (Hypertension Diagnostics, Eagan, MN). Statistical analyses examined the effect of T1D and body weight status and their interactions on cardiovascular risk parameters. In this study, the authors were unable to demonstrate an additive effect of body weight status and T1D on cardiovascular risk profile. However, subgroup analysis of patients with T1D revealed higher apoC-III levels in overweight patients with T1D (P=.0453) compared with normal-weight diabetic children. Most notably, there was a direct relationship of small artery elasticity to body weight status. This seemingly paradoxical observation supports recent data and warrants further investigation.Journal of Clinical Hypertension 05/2011; 13(5):351-6. · 1.83 Impact Factor
