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Ann L. Gibson, Vivian H. Heyward and Christine M. Mermier

This study assessed the predictive accuracy of a new hand-held, segmental, bioimpedance (BI) analyzer in estimating the relative body fat (%BF) of a sample of 25 men and 23 women (18–55 years, 7.0 to 42.8%BFHW). The reference method was hydrostatic weighing (HW) at residual lung volume. The %BF estimates obtained from manufacturer’s (Omron) gender-specific equations were cross-validated. There were high validity coefficients (ry,y=.91 and .83, for men and women, respectively), moderate prediction errors (SEE = 3.46%, E = 3.64%BF for men; SEE = 4.04%, E = 3.87%BF for women), and no significant difference (p >.05) between the average %BFHW and %BFOmron for women (21.8% vs. 2I.6%BF, respectively). For men, there was a small but significant (p < .05) difference in %BFHW (18.7%) and %BFOmron (20.1 %). For both men and women, the line of identity did not differ significantly (p > .05) from the line of best fit. The Omron® BI equations accurately estimated the %BF of 72% of the men and 65% of the women in this sample within ±3.5%BF. Therefore, use of the Omron® BI analyzer is suitable for assessing the %BF of adults having demographic characteristics similar to those of this sample.

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Gregory Severino, Marcos Sanchez-Gonzalez, Michelle Walters-Edwards, Michael Nordvall, Oksana Chernykh, Jason Adames and Alexei Wong

that traditional exercise, such as aerobic and resistance training, improves HRV and body composition in several populations. However, due to perceived or actual barriers associated with traditional exercise (e.g., musculoskeletal discomfort, lack of motivation, reduced physical activity) many obese

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Grant M. Tinsley and Brett S. Nickerson

When estimating body composition, a pervasive recommendation is to perform assessments after a period of rest and fasting. This recommendation seeks to minimize biological error induced by daily activities, such as food and fluid ingestion or exercise. Overnight fasts are implemented for a variety

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Pedro Curi Hallal, Felipe Fossati Reichert, Fernando Vinholes Siqueira, Samuel Carvalho Dumith, Juliano Peixoto Bastos, Marcelo Cozzensa da Silva, Marlos Rodrigues Domingues, Mario Renato Azevedo and Ulf Ekelund

Objectives:

The objective of this study was to evaluate physical activity (PA) levels in adults and their association with sex, age, and education level across categories of body mass index (BMI).

Methods:

We conducted a population-based, cross-sectional study including 3100 individuals age ≥20 years living in Pelotas, Brazil. PA was assessed using the leisure-time section of the long International Physical Activity Questionnaire. “No PA” was defined as zero minutes of activity/week; “insuffcient PA” was defined as <150 minutes of activity/week; “high PA” was defined as ≥500 minutes of activity/week. BMI was categorized into normal (<25 kg/m2), overweight (25–29.9 kg/m2), and obesity (≥30 kg/m2).

Results:

The prevalence of insufficient PA was 71.6% among normal BMI subjects, 71.3% among overweight individuals, and 73.7% among obese ones (P = .67). No PA and high PA were also not associated with BMI. The associations between sex, age, and education level and PA levels tended to be stronger among normal-weight individuals compared with overweight and obese individuals. Among the obese, most associations were not significant. Among normal-weight individuals, higher PA levels were observed in men, young adults, and those with higher education.

Conclusions:

Variables associated with leisure-time PA differed between normal-weight, overweight, and obese individuals. Studies on PA correlates might benefit from stratifying by BMI.

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David A. Rowe and Matthew T. Mahar

Background:

The purpose of the study was to evaluate race-specific FITNESSGRAM® body mass index (BMI) standards in comparison to the recommended standards, i.e., percent fat (%BF) ≥25 in boys and %BF ≥32 in girls.

Methods:

BMI and %BF were estimated in 1,968 Black and White children ages 6-14 years, using methods similar to those used to develop the current FITNESSGRAM standards. Multiple regression was employed to develop age-, sex-, and race-specific BMI standards. Percent agreement and modified kappa (κq) were used to evaluate agreement with the %BF standards, and sensitivity and specificity were used to evaluate classification accuracy.

Results:

Race significantly (p < .05) and meaningfully (β = 2.3% fat) added to the relationship between BMI and %BF. Agreement of the race-specific BMI standards with %BF standards was moderate to high (κq = .73–.88), and classification accuracy improved on the current FITNESSGRAM BMI standards.

Conclusions:

Race-specific BMI standards appear to be a more accurate representation of unhealthy %BF levels than the current FITNESSGRAM BMI standards.

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Donna W. Lockner, Vivian H. Heyward, Sharon E. Griffin, Martim B. Marques, Lisa M. Stolarczyk and Dale R. Wagner

The Segal fatness-specific bioelectrical impedance (BIA) equations are useful for predicting fat-free mass (FFM). Stolarczyk et al, proposed a modified method of averaging the two equations for individuals who are neither lean nor obese, thus eliminating the need to know % BF a priori. To cross-validate this modification, we compared FFM determined using the averaging method versus hydrostatic weighing for 76 adults. Per the averaging method, accuracy for males was excellent (r = .91, SEE = 2.7kg, E = 2.7kg), with 78% of individuals within ± 3.5% BF predicted by hydrostatic weighing. Accuracy for females was lower (r = .88, SEE = 3.0kg, E = 3.1 kg), with %BF of 51% within ±3.5% of the reference method. The relative ease and practicality of the averaging method and the results of this study indicate this method may be useful with a diverse group.

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Eric Joseph Rosario, Rudolph Gino Villani, Jeff Harris and Rudi Klein

Aging generally results in muscle and bone atrophy, with accelerated loss in the first few years after menopause contributing to decline in strength, balance, and mobility. This investigation compared the effects of 1 of year periodized high-intensity strength training on a group of less-than-5-years (LF) postmenopausal women (n = 10, mean age 51 years) with its effects on a more-than-10-years (MT) postmenopausal group (n = 11, mean age 60 years). Mean lean body mass, strength, and balance increased over the intervention period for both groups, with no significant intergroup differences. Mean total fat mass significantly decreased for both groups, with no significant difference between groups. Total and regional bone density and mineral content did not significantly change in either group. These results indicate that even during the accelerated muscle-loss period after menopause, women can gain muscle and strength with resistance training to a similar extent as older women.

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Neha Singhal and Anupa Siddhu

Background:

The relationship between leisure-time physical activity (LTPA) and cardiorespiratory fitness (CRF) is not clearly understood in Indian men. It is important to elucidate whether the duration or intensity of LTPA is responsible for increasing CRF. This will help in designing better physical activity intervention strategies for improving CRF in Indian men.

Methods:

Healthy nondiabetic urban Indian men with no history of coronary heart disease (CHD) were selected (n = 603; aged 22–64 years) and their energy intake and physical activity was determined using a questionnaire. Body fat (percent) was determined by leg-to-leg bioelectrical impedance analysis while CRF was measured on multistage, continuous treadmill test using Bruce protocol.

Results:

Intensity of physical activity (METs) emerged as the best independent predictor of CRF (β = 0.217; P < .001). Using univariate General Linear Model, it was found that CRF is more a function of LTPA intensity than LTPA duration, since LTPA duration was not related to CRF when controlled for LTPA intensity. However, LTPA intensity remained significantly associated with CRF even after adjustment for LTPA duration.

Conclusion:

LTPA of preferably higher intensity should be incorporated in the lifestyle to improve CRF and prevent CHD in Indian men.

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Taina Rantanen and Eino Heikkinen

The aim of this study was to examine alterations in maximal isometric strength of multiple muscle groups over 5 years and to compare strength changes between individuals who maintained a high level of physical activity and others who did not. As a part of the Evergreen Project, 20 men and 59 women participated in at least one strength test at the age of 80 and again 5 years later. Men displayed no decrease in lean body mass over the follow-up. and the only significant strength decrease was in elbow flexion strength. In women, both lean body mass and muscle strength decreased significantly (except trunk extension strength). Overall, those men and women who were considered to have maintained a high level of activity retained their strength at a higher level than the more sedentary participants. Older people should be encouraged to continue physically demanding activities to maintain muscle strength at an adequate level for independent living.

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Michael R. Esco, Brett S. Nickerson, Sara C. Bicard, Angela R. Russell and Phillip A. Bishop

The purpose of this investigation was to evaluate measurements of body-fat percentage (BF%) in 4 body-mass-index- (BMI) -based equations and dual-energy X-ray absorptiometry (DXA) in individuals with Down syndrome (DS). Ten male and 10 female adults with DS volunteered for this study. Four regression equations for estimating BF% based on BMI previously developed by Deurenberg et al. (DEBMI-BF%), Gallagher et al. (GABMI-BF%), Womersley & Durnin (WOBMI-BF%), and Jackson et al. (JABMI-BF%) were compared with DXA. There was no significant difference (p = .659) in mean BF% values between JABMI-BF% (BF% = 40.80% ± 6.3%) and DXA (39.90% ± 11.1%), while DEBMI-BF% (34.40% ± 9.0%), WOBMI-BF% (35.10% ± 9.4%), and GABMI-BF% (35.10% ± 9.4%) were significantly (p < .001) lower. The limits of agreement (1.96 SD of the constant error) varied from 9.80% to 16.20%. Therefore, BMI-based BF% equations should not be used in individuals with DS.