Search

Purpose: To identify factors that influence Black women’s body size perceptions Design: Interviews (cognitive mapping exercise) with 25 women; focus group with 7 additional women Setting: Mississippi Delta Participants: Thirty-two black women Measures: Influences on body size perceptions, body mass index, and body satisfaction Analysis: Interviewee maps were combined and condensed, using matrix addition and qualitative aggregation, to create a social map. The social map was presented to a focus group. A paired sample t test and descriptive statistics were run to assess weight perception accuracy and body satisfaction. Results: The initial social map contained 27 variables. Male preferences (87.5%) and appearance (64%) were believed by most participants to influence perceptions of body size. The focus group identified lack of encouragement, stress, and substance use as factors worth adding to the map. A statistically significant proportion of interviewees possessed an inaccurate weight perception, t(24) = 2.741, P < .05. Furthermore, 76% were dissatisfied with their current weight status and 80% desired a healthy body size. Conclusion: These findings provide practitioners with leverage points, beyond diet and physical activity, that may improve the efficacy of weight reduction interventions among black women. Considering the paucity of research regarding influences on body size perceptions, this study also provides researchers with participant-defined variables worthy of further examination.

Context: Studies developed the frail elderly handgrip strength (HGS) diagnostic criteria using multiple types of handgrip dynamometers. If different handgrip dynamometers report different values, then this would have the potential to misclassify people into the wrong diagnostic category. Objective: To examine the characteristics of HGS measured by 2 standard handgrip dynamometers and to investigate the influence of hand size on HGS. Setting: University research laboratory. Participants: A total of 87 young and middle-aged adults between the ages of 20 and 60 years participated in this study. Main Outcome Measures: Standard methods of HGS measurements were used for hydraulic and Smedley spring-type dynamometers, although the participants were instructed to maintain an upright standing position in both tests. Results: Test–retest reliability of hydraulic and Smedley dynamometers provided comparable results to that observed with previous studies. However, the difference in HGS between the 2 dynamometers (Hydraulic–Smedley difference) was positively associated (r = .670, P 45 kg) produced greater strength values with the hydraulic compared with the Smedley. The hand and palm lengths were weakly correlated (r = .349 and r = .358, respectively, both Ps Conclusions: Test–retest reliability of hydraulic and Smedley dynamometers provides comparable results to previous studies. However, the difference in HGS between the 2 dynamometers was positively associated with the mean of the 2 dynamometers. This Hydraulic–Smedley difference would not affect persons who have relatively low HGS (at least

Functional limitations persist in obese patients after total knee arthroplasty (TKA). This study assessed the effect of an exercise program (EP) and fitness trackers (FT) in obese patients with TKA. Sixty patients 1 year after orthopedic surgery were recruited and received a 16-week tailored EP; half were randomized to receive an FT. FT had no measurable effect compared with EP alone. EP improved knee range of motion, strength, and quality-of-life scores. This study provides preliminary evidence that a 16-week EP in obese individuals 1 year post TKA is feasible and effective in improving function and quality of life.

Objectives To develop regression-based equations for estimating dual-energy x-ray absorptiometry (DXA) derived appendicular fat-free adipose tissue (FFAT) using a single ultrasound image in the forearm, and to investigate the validity of those equations to calculate FFAT-free appendicular lean mass (aLM-minus-FFATappendicular) in 311 Japanese adults aged 60 to 79 years. Methods Subjects were randomly separated into two groups: 215 in the model-development group (91 men and 124 women) and 96 in the cross-validation group (42 men and 54 women). Appendicular fat mass and aLM were measured by the DXA, and subcutaneous adipose tissue (AT-forearm) and muscle (MT-ulna) thicknesses were measured by ultrasound. Appendicular FFAT was calculated based on the results of a previous study (appendicular FFAT = appendicular fat mass/0.85 x 0.15). The aLM was estimated from MT-ulna using a previously published equation (aLM = 4.89 x MT-ulna x body height – 9.15). Stepwise linear regression analysis was used to determine predictive models for DXA-derived appendicular FFAT from AT-forearm, sex, age, and anthropometrical variables. The best ultrasound prediction equation for estimation of appendicular FFAT was developed and then cross-validated in a subsample of older adults. Results There was no significant difference between the DXA-derived and ultrasound-predicted aLM-minus-FFATappendicular. A strong correlation was observed between the DXA-derived and ultrasound-predicted aLM-minus-FFATappendicular (r = 0.935, P

Obese patients are more likely to have osteoarthritis and total knee arthroplasty (TKA). This investigation sought to evaluate physical function, activity level, and quality of life (QOL). Obese participants near 1-year postsurgical follow-up appointment were recruited. Evaluation included QOL and activity questionnaire, medical histories, anthropometrics, strength, and aerobic capacity. Sixty participants completed assessments. Obese TKA patients have physical performance limitations and low physical activity levels 1 year after surgery and completion of postoperative rehabilitation.

The aim of this review was to highlight research that has focused on examining expressions of peak oxygen uptake (VO2peak) in children and youth, with special reference to allometric scaling. VO2peak is considered the highest VO2 during an increasing workload treadmill or bicycle ergometer test until volitional termination. We have reviewed scholarly works identified from PubMed, One Search, EBSCOhost and Google Scholar that examined VO2peak in absolute units (L·min(-1)), relative units [body mass, fat-free mass (FFM)], and allometric expressions [mass, height, lean body mass (LBM) or LBM of the legs raised to a power function] through July 2015. Often, the objective of measuring VO2peak is to evaluate cardiorespiratory function and fitness level. Since body size (body mass and height) frequently vary greatly in children and youth, expressing VO2peak in dimensionless units is often inappropriate for comparative or explanatory purposes. Consequently, expressing VO2peak in allometric units has gained increased research attention over the past 2 decades. In our review, scaling mass was the most frequent variable employed, with coefficients ranging from approximately 0.30 to over 1.0. The wide variance is probably due to several factors, including mass, height, LBM, sex, age, physical training, and small sample size. In summary, we recommend that since skeletal muscle is paramount for human locomotion, an allometric expression of VO2peak relative to LBM is the best expression of VO2peak in children and youth.

To test the validity of published equations, 79 Caucasian adults (40 men and 39 women) aged 50–78 y had muscle thickness (MT) measured by ultrasound at nine sites of the body. Fat-free mass (FFM), lean soft tissue mass (LM) and total muscle mass (TMM) were estimated from MT using equations previously published in the literature. Appendicular LM (aLM) was estimated using dual-energy X-ray absorptiometry (DXA) and this method served as the reference criterion. There were strong correlations (range r = 0.85–0.94) between DXA-derived aLM and estimated FFM, leg LM or TMM. Total error between DXA-derived aLM and TMM (∼2 kg) was lower compared with the three other selected equations (6–10 kg). A Bland-Altman plot revealed that there was no systematic bias between aLM and TMM; however, the other three equations included systematic error. Our results suggest that an ultrasound equation for TMM is appropriate and useful for evaluating skeletal muscle mass in the body.

Prior work has reported that the declines observed in body mass index (BMI) and circumference measurements in their cross-sectional data were twice as large when calculated from distance energy expenditure estimations compared to energy expenditure estimations based on time and intensity. The primary purpose of this study was to compare walking/running for distance to walking/running for time as part of an exercise intervention. This study followed a between-subjects, repeated measures design. Fifteen overweight, but otherwise healthy participants completed the study. The time-based group walked/ran for self-reported time while the distance-based group walked/ran for self-reported distance. A mixed-factor repeated-measures ANOVA was used to compare all dependent variables both within-subjects and between-subjects. Weekly adherence rates to the exercise program did not exhibit a significant difference (p > 0.05). Significant interactions were shown for mean body mass loss between groups as well as mean blood glucose level (p < 0.05). Distance-based group exhibited a decline in body mass and blood glucose while the time-based group exhibited an increase in both variables. To the best of the authors’ knowledge, the present study is the first to directly compare a distance-based vs. a time-based exercise program for walking and running for improvement of risk factors of cardiovascular disease. The results of this study would suggest that a distance-based exercise prescription of walking or running should provide a clinician or researcher with a closer estimation of overall accumulated exercise and resultant weight loss.

It is unknown whether age-related site-specific muscle loss is associated with areal bone mineral density (aBMD) in older adults. To examine the relationships between aBMD and whole-body muscle thickness distribution, 97 healthy adults (46 women and 51 men) aged 50-78 years volunteered. Total and appendicular lean soft tissue mass, aBMD of the lumbar spine (LS-aBMD) and femoral neck (FN-aBMD) were determined using dual-energy X-ray absorptiometry. Muscle thickness (MT) was measured by ultrasound at nine sites of the body (forearm, upper arm, trunk, upper leg, and lower leg). Relationships of each co-variate with aBMD were tested partialling out the effect of age. aBMD was not correlated with either MT of the trunk or anterior lower leg in either sex. In men, significant and relatively strong correlations were observed between anterior and posterior upper arms, posterior lower leg, and anterior upper leg MT and LS-aBMD or FN-aBMD. In women, significant correlations were observed between anterior and posterior upper legs, posterior lower leg, and anterior upper arm MT and FN-aBMD. LS-aBMD was only correlated with forearm and posterior upper leg MT in women. In conclusion, the site-specific association of MT and aBMD differs between sexes and may be associated with the participants' daily physical activity profile.

To develop regression-based equations for estimating dual-energy x-ray absorptiometry (DXA) derived appendicular fat-free adipose tissue (FFAT) using a single ultrasound image in the forearm, and to investigate the validity of those equations to calculate FFAT-free appendicular lean mass (aLM-minus-FFATSubjects were randomly separated into two groups: 215 in the model-development group (91 men and 124 women) and 96 in the cross-validation group (42 men and 54 women). Appendicular fat mass and aLM were measured by the DXA, and subcutaneous adipose tissue (AT-forearm) and muscle (MT-ulna) thicknesses were measured by ultrasound. Appendicular FFAT was calculated based on the results of a previous study (appendicular FFAT = appendicular fat mass/0.85 x 0.15). The aLM was estimated from MT-ulna using a previously published equation (aLM = 4.89 x MT-ulna x body height - 9.15). Stepwise linear regression analysis was used to determine predictive models for DXA-derived appendicular FFAT from AT-forearm, sex, age, and anthropometrical variables. The best ultrasound prediction equation for estimation of appendicular FFAT was developed and then cross-validated in a subsample of older adults.There was no significant difference between the DXA-derived and ultrasound-predicted aLM-minus-FFATOur results indicated that a single ultrasound forearm measurement can be used to accurately estimate DXA-derived aLM-minus-FFAT

Purpose: Use of alternative footwear options such as flip-flop style sandals and minimalist athletic shoes are becoming increasingly popular footwear choices. The purpose of the investigation was to analyze the energy expenditure and oxygen consumption requirements of walking at preferred pace while wearing flip-flops, slip-on style shoes, and minimalist athletic shoes. Methods: Eighteen healthy male adults participated in this study. In addition to an initial familiarization session, participants were tested in three different footwear conditions [thong-style flip-flops (FF), Croc® slip on shoes (CROC), and Vibram Fivefingers® minimalist shoes (MIN)]. Then after a brief warm-up, participants walked a one-mile distance at their preferred pace. Immediately following completion of the one-mile walk, participants stood quietly on the treadmill for an additional period to assess excess post-exercise oxygen consumption (EPOC). Results: A repeated-measures ANOVA that the following variables did not show evidence of a significant differently value between conditions: preferred pace (p = 0.392), average oxygen consumption (p = 0.804), energy expenditure per mile (p = 0.306), or EPOC (p = 0.088). There was shown to be a significantly higher RER during exercise in CROC compared to MIN (p = 0.031) with no significant differences observed when comparing CROC to FF (p = 0.106) or FF to MIN (p = 0.827). Conclusion: Based on the results of the current study, it appears that the alternative footwear selected for evaluation do not lead to a substantial alteration of walking pace or overall EE. However, the significant difference in RER suggesting a slightly elevated exercise intensity while wearing the CROC could perhaps be related to the softer sole, influencing overall mechanical efficiency. The study was funded by a grant awarded by the Graduate Student Council at the author’s University.

Unless a subject’s muscle is relatively small, a single image from a standard ultrasound can only measure muscle thickness (MT). Thus, it is important to know whether MT is related to morphological and functional characteristics of individual muscles of the extremity and trunk. In this review, we summarize previously published articles in the upper extremity and trunk demonstrating the relationships between ultrasound-measured MT and muscle morphology (cross-sectional area, CSA and muscle volume, MV) and muscular or respiratory function. The linear relationship between MT and muscle CSA or MV has been observed in biceps brachii, triceps brachii, pectoralis major, psoas major, and supraspinatus muscles. Previous studies suggest that MT in the upper arm and trunk may reflect muscle CSA and MV for the individual muscles. Unfortunately, few studies exist regarding the functional relationship with ultrasound MT in the upper extremity and trunk. Future research is needed to investigate these findings further.

An equation published by Loftin, Waddell, Robinson, and Owens (2010) was cross-validated using ten normal-weight walkers, ten overweight walkers, and ten distance runners. Energy expenditure was measured at preferred walking (normal-weight walker and overweight walkers) or running pace (distance runners) for 5 min and corrected to a mile. Energy expenditure per mile was predicted using the Loftin et al. (2010) equation yielding a mean predicted value of 99.7 ± 13.8 kcal · mile−1. This was significantly different (p < .05) than the mean actual value from the cross-validation group (107.8 ± 15.5 kcal · mile−1), although the difference was within the published standard error of estimate. A Chow test revealed no significant differences between regression coefficients of the original equation and the cross-validation group equation. It appears the Loftin et al. (2010) regression equation is useful for exercise prescription of energy expenditure for walking or running a mile in normal-weight and overweight adults.

Aim To test the hypothesis that static balance is associated with site-specific loss of muscle mass in older adults. Methods A total of 57 active women aged 52–83 years had their muscle thickness (MTH) measured by ultrasound at four sites on the anterior and posterior aspects of their upper- and lower-leg. MTH ratios were calculated to assess the site-specific muscle loss. One-leg standing balance with eyes open and maximum isometric knee extension/flexion strength were measured. Daytime physical activity was also measured. The participants were separated into three groups based on achieved timed one-leg balance test: less than 60 s (n = 19, G1), 60–120 s (n = 12, G2) and over 120 s (n = 26, G3). Results Age was inversely correlated to the upper-leg (A50 : P70) MTH ratios (r = −0.389, P

Dual-energy X-ray absorptiometry (DXA) is an attractive method for evaluating sarcopenia, age-related loss of skeletal muscle mass and function, using appendicular lean tissue (aLT) mass for criteria of diagnosis, although minimal radiation is exposed. Skeletal muscle (SM) mass can be estimated by using ultrasound-measured muscle thickness (MTH). However, the association between these two methods is unclear. To examine the relationship between DXA-derived aLT mass and total body SM mass estimated by ultrasound, thirty-six healthy adults (18 men and 18 women) aged 19 - 65 years participated in this study. Ultrasound-measured muscle thickness was used to estimate the total SM mass. DXA was used to estimate whole body and regional body composition, and aLT mass was considered equivalent to the sum of lean tissue in both the right and left arms and legs. Total SM mass (26.3 ± 4.4 kg for men and 15.7 ± 2.6 kg for women) estimated by ultrasound was similar to DXA-estimated aLT mass (24.5 ± 3.8 kg for men and 15.7 ± 2.7 kg for women). There was a strong correlation between DXA-measured aLT mass and total SM mass estimated by ultrasound in men (r = 0.927, n = 18) and women (r = 0.931, n = 18) as well as overall sample (r = 0.975, n = 36). The ratio of total SM mass to aLT mass was 1.07 for men and 1.00 for women. These results suggest that DXA-derived aLT mass can be accurately predicted from ultrasound estimated total SM mass, although the predicted value may underestimate in men (approximately 7% at the group level).

The incidence of breast cancer is increasing worldwide, and this seems to be related to an increase in lifestyle risk factors, including physical inactivity and overweight/obesity. We have reported previously that exercise induced a circulating angiostatic phenotype characterized by increased soluble fms-like tyrosine kinase-1 (sFlt-1) and endostatin and decreased unbound vascular endothelial growth factor (VEGF) in men. However, there are no data on women. The present study determines the following: (a) whether moderate exercise increased sFlt-1 and endostatin and decreased unbound VEGF in the circulation of adult female volunteers and (b) whether overweight/obese women have a higher plasma level of unbound VEGF than lean women. A total of 72 African American and White adult women volunteers ranging in age from 18 to 44 years were enrolled in the exercise study. All the participants walked on a treadmill for 30 min at a moderate intensity (55-59% heart rate reserve), and oxygen consumption (VO(2)) was quantified utilizing a metabolic cart. We obtained blood samples before and immediately after exercise from 63 participants. ELISA assays showed that the plasma levels of sFlt-1 were 67.8±3.7 pg/ml immediately after exercise (30 min), significantly higher than the basal levels, 54.5±3.3 pg/ml, before exercise (P

It is unknown whether severe sarcopenia produces unfavorable effects on cardiovascular risk factors. To examine the influence of severe and moderate sarcopenia on selected cardiovascular risk factors, 687 men were screened; those exhibiting clinically relevant diseases and higher body fat percentage (25% fat) were excluded. A total of 410 men aged 40-76 years (mean age 56.0 years) were used for data analyses.Sarcopenia was defined as a skeletal muscle mass (SM) index (muscle mass/height squared) of 1-2 standard deviations (SD) below (moderate) or2 SDs below (severe) the mean for young adult men. Ultrasound-measured subcutaneous fat and muscle thicknesses were used to estimate the SM, percent body fat, and fat-free mass. Serum total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) levels were determined using fasting blood samples. Systolic blood pressure and diastolic blood pressure were also measured.HDL-C was similar among the groups, but TC was lower in severe and moderate sarcopenia groups compared to the normal group. As a result, the TC:HDL-C ratio was lower in the moderate and severe sarcopenia groups than in the normal group. After adjusting for age, body mass index (BMI), waist circumference, and percent body fat, HDL-C was lower in both sarcopenia groups compared to the normal group, but other parameters were similar among the groups. A low prevalence of high HDL-C and high prevalence of moderate HDL-C were observed in the severe and the moderate sarcopenia groups.Our results suggest that moderate and severe sarcopenia may influence the HDL-C level, although the values are still maintained in the clinically normal range.

The purpose of this study was to investigate the time course of hypertrophic adaptations in both the upper arm and trunk muscles following high-intensity bench press training. Seven previously untrained young men (aged 25±3 years) performed free-weight bench press training 3 days (Monday, Wednesday and Friday) per week for 24 weeks. Training intensity and volume were set at 75% of one repetition maximum (1-RM) and 30 repetitions (3 sets of 10 repetitions, with 2–3 min of rest between sets), respectively. Muscle thickness (MTH) was measured using B-mode ultrasound at three sites: the biceps and triceps brachii and the pectoralis major. Measurements were taken a week prior to the start of training, before the training session on every Monday and 3 days after the final training session. Pairwise comparisons from baseline revealed that pectoralis major MTH significantly increased after week-1 (p=0.002), triceps MTH increased after week-5 (p=0.001) and 1-RM strength increased after week-3 (p=0.001) while no changes were observed in the biceps MTH from baseline. Significant muscle hypertrophy was observed earlier in the chest compared to that of the triceps. Our results indicate that the time course of the muscle hypertrophic response differs between the upper arm and chest.

The purpose of this study was to examine changes in physical activity and fitness variables in members of 8 volunteer families after 3 months of home use of the Wii Fit™ interactive video game. Pre and postintervention measurements were obtained from 21 subjects relative to physical activity (5 days of accelerometry), aerobic fitness (graded treadmill test), muscular fitness (push-ups), flexibility (sit-and-reach test), balance (composite equilibrium score), and body composition (body mass index and % body fat). Use characteristics of the Wii Fit™ device were also determined. A series of 2 (age group) × 2 (time) repeated measures analyses of variance were conducted to assess changes over time and between adults and children. Three months of home Wii Fit™ use revealed no significant age group × time interactions or main effects of group or time for daily physical activity, muscular fitness, flexibility, balance, or body composition. An age group × time interaction (p = 0.04) was observed in peak VO2 (ml·kg(-1)·min(-1)) with children displaying a significant (p = 0.03) increase after 3 months of Wii Fit™ use, whereas adults showed no significant (p = 0.50) change. Daily Wii Fit™ use per household declined by 82% (p < 0.01) from 21.5 ± 9.0 min·d(-1) during the first 6 weeks to 3.9 ± 4.0 min·d(-1) during the second 6 weeks. Most measures of health-related fitness in this exploratory study remained unchanged after 3 months of home use of the popular Wii Fit™ whole-body movement interactive video game. Modest daily Wii Fit™ use may have provided insufficient stimulus for fitness changes.

body, constitutes approximately 40% of fat-free body mass in young adults1 but decreases with advancing age, especially after the fifth decade of life.2 These age-related changes lead to a decline of strength and power, a decrease in physical performance, and disability.3 Because the population of elderly people is growing in most countries, including Japan, the agerelated loss of skeletal muscle mass is likely to have a severe economic impact on the healthcare system. Age-related loss of skeletal muscle mass (Sarcopenia) has been studied extensively by evaluating muscle volume, muscle cross-sectional area (CSA), and anatomical muscle thickness (MTH).4 Recently, Abe and colleagues demonstrated that age is associated with site-specific loss of skeletal muscle mass in Japanese men and women5,6 and in German men7. Interestingly, in the anterior and posterior regions of the thigh, age-related muscle loss was observed in the quadriceps but not in the hamstrings and adductors.8 The etiology of sitespecific sarcopenia is multifactorial and complex. Several factors have been implicated such as declining anabolic hormone concentrations, nutritional deficiencies, chronic inflammation, and insulin resistance.5,7 Decreased physical activity levels that occur with aging also contribute to sarcopenia. It is well established that hormonal receptors for mRNA and transcriptional activity are increased8 and that there is reduced insulin resistance9 in exercising muscles following an acute bout of exercise for sedentary individuals. There are therefore many important interrelationships between physical activity levels and other etiologic factors associated with health and aging that may contribute in varying degrees to the age-related loss of skeletal muscle mass in older populations. More recently, we examined the effect of habitual physical activity on age-related loss of skeletal muscle and found that there is site-specific loss in both active (more than once a week) and inactive old women.10 In that study, the subjects were classified into active and inactive groups based on their self-reported habitual physical activity. The effect of exercise intensity and duration of daily physical activities on site-specific loss of thigh muscle is unknown. However, muscle mass and strength losses associated with increasing age

The purpose of this study was to compare peak cardiorespiratory parameters during treadmill and cycle ergometry in severely overweight youth. Twenty-one participants from the Committed to Kids Pediatric Weight Management program at the Louisiana State University Health Sciences Center volunteered. Participants completed peak treadmill and cycle ergometer tests on separate days. In order to examine reliability, six subjects completed a second treadmill test and seven subjects a second cycle test. Physical characteristics included the following: Age (yrs) 12.5 ± 2.8; Body weight (BW) (kg) 78.5 ± 27.0, Height (m) 1.56 ± 0.13; and % fat 42.8 ± 7.5. No statistical significant differences (p ≤ 0.05) were found between treadmill and cycle peak tests. Treadmill VO2 peak (l·min(-1)) averaged 1.57 ± 0.40 and cycle 1.46 ± 0.30 and VO2 peak relative to BW 21.5 ± 4.1 and 20.3 ± 5.5 for treadmill and cycle ergometry, respectively. Therefore treadmill values were 7.0% and 5.6% higher than cycle values. In normal weight or children and adolescents at risk for overweight, treadmill values typically average from 7 to 12% higher than cycle values. Reliability of VO2 peak as indicated by intraclass correlation coefficients ranged from 0.70 to 0.96 for a single or repeated tests. Intra individual variability averaged 0.5% for VO2 peak (l·min(-1)) during treadmill ergometry and 5.7% for cycle ergometry. Also, standard errors of measurement were low (40 to 90 ml min or 1.0 to 1.7 ml.kg(-1). min(-1)) for the peak treadmill or cycle tests. In summary, our data suggest that both treadmill and cycle ergometry provide reliable methods for determining VO2 peak in overweight youth. Key PointsTreadmill peak VO2 higher than cycle ergometry in severely overweight youth.VO2peak test-retest or single trial reliability high in both treadmill and cycle VO2 peak.Standard errors of measure low for both treadmill and cycle VO2peak.

The purpose of this study was to compare heart rate peak in obese (n=43) and normal weight (n=45) female youth. Heart rate (HR) peak was significantly lower (p2 (L min-) peak similar between groups (1.77±20.53, 1.97±0.60). Bivariate correlations for heart rate peak with body weight, percent fat, and body mass index yielded the following: -0.53, -0.54, and -0.57. These findings agree with the adult data indicating low HR peak in obese individuals. Further research is needed to explore physiologic factors that may lead to reduced HR peak in obese female youth.

The aim of the study was to objectively determine whether the Nutrition and Physical Activity Self-Assessment for Child Care (NAP SACC) program improved physical activity levels during the school day.The study compared the physical activity levels of subjects from 26 daycare centers, randomized into treatment (N=13) and control (N=13) groups. The subjects were 3 to 5 year olds (N=209, 104 males and 105 females; age [years]=3.85±0.8 [mean±standard deviation]), and accelerometry was used to determine the subjects' physical activity levels. Accelerometers were attached to each subject for 2 days before and immediately after a 6-month intervention. Height, mass, and waist were also measured.Regression analyses indicated that the treatment group demonstrated significant increases in moderate and vigorous physical activity, as compared to the control group (F(1, 207)=6.3, p0.05, Cohen's d=0.30; F(1, 207)=4.7, p0.05, Cohen's d=0.25, respectively). The treatment group also showed significant increases in total physical activity (F(1, 218)=12.4; p0.05) from pre- to post-test with significant increases in moderate and vigorous intensity physical activity (F(1, 218)=18.6, p0.05; F(1, 218)=23.3, p0.05, respectively). Regression analyses revealed significant increases in height for both groups from pre- to post-tests, but no differences were noted between groups.Implementation of the NAP SACC program in treatment daycare facilities resulted in significant increases in objectively measured physical activity levels, compared to the control group, demonstrating physical activity improvement in the treatment daycare centers.

AB Purpose: Childhood cancer survivors (CCS) experience late effects that interfere with physical function. Limitations in physical function can affect CCS abilities to actively participate in daily activities. The purpose of this investigation was to evaluate the concordance between self-reported physical performance and clinically evaluated physical performance among adult CCS. Methods: CCS 18 yr or older and 10 yr or older from diagnosis who are participants in the St. Jude Lifetime cohort study responded to the physical function section of the Medical Outcome Survey Short Form (SF-36). Measured physical performance was evaluated using the Physical Performance Test and the 6-Minute Walk Test. Results: Individuals (N = 1778, 50.8% female) with a median time since diagnosis of 24.9 yr (range = 10.9-48.2) and a median age of 32.4 yr (range = 19.1-48.2) completed testing. Limitations in physical performance were self-reported by 14.1% of participants. The accuracy of self-report physical performance was 0.87 when the SF-36 was compared with the 6-Minute Walk Test or the Physical Performance Test. Reporting inaccuracies most often involved reporting a physical performance limitation. Poor accuracy was associated with previous diagnosis of a bone or CNS tumor, lymphoma, older age, and large body size. Conclusions: These results suggest that self-report, using the physical performance subscale of the SF-36, correctly identifies CCS who do not have physical performance limitations. In contrast, this same measure is less able to identify individuals who have performance limitations.

Exercise mode and intensity/duration are important factors for influencing muscle morphology and function as well as bone. However, it is unknown whether masters cyclists who undergo regular moderate- to high-intensity exercise maintain lower-body skeletal muscle mass (SM) and function and bone health when compared with young adults. The purpose of this study was to compare SM, areal bone mineral density (aBMD), and gait performance between masters cyclists and young adults. Fourteen male masters cyclists (aged 53-71 years) and 13 moderately active young men (aged 20-30 years, exercising less than twice a week) volunteered. The masters cyclists were all training actively (four to five times per week, ∼200 miles per week) for on average the last 17 years (range 7-38 years). Thigh SM was estimated from an ultrasound-derived prediction equation using muscle thickness (MTH). Appendicular lean mass (aLM) and aBMD were also estimated using dual-energy X-ray absorptiometry. There were no significant differences (p0.05) in thigh SM, anterior and posterior thigh MTH ratio, or aLM between masters cyclists and young men. Maximum straight and zigzag walking times were also similar between groups. Lumbar spine (L1-L4) aBMD was not different between groups, but femoral neck aBMD was lower (p0.05) in the cyclists than in the young men. Our results suggest that appendicular as well as site-specific thigh muscle loss with aging were not observed in masters cyclists. This maintenance of muscle mass in masters cyclists may preserve walking performance to similar levels as moderately active young adults. However, long-term cycling does not preserve femoral neck aBMD.

Hydrodensitometry (HD), skinfold thickness measurements (SK), and dual-energy X-ray absorptiometry (DXA) were compared for estimating percent body fat (%BF) in youth competitive swimmers. Agreement was assessed using Bland-Altman plots and linear regression of the differences between methods compared to method means. Limits of agreement between the three techniques were large. Hydrodensitometry and SK demonstrated no difference in precision. Variance was observed between DXA and the other two techniques, with DXA demonstrating a wider distribution of measurement scores than HD or SK. These methods do not appear to be interchangeable when measuring percent body fat in youth swimmers.

OBJECTIVE The conventional ratio method (milliliters O(2) per mass) typically is used to express VO(2) peak. The goal of the current study was to compare VO(2) peak of obese girls with normal-weight girls by ratio and allometric scaling methods. RESEARCH METHODS AND PROCEDURES We compared VO(2) peak by ratio and allometric methods in 46 obese and 47 normal-weight girls. Indirect calorimetry was used to measure VO(2) peak during either treadmill running or walking. Regression analysis was used to determine coefficients for mass and stature for each group with ANOVA used to compare data between groups. RESULTS The obese girls were taller and had higher values of body fatness (p < or = 0.05). Absolute VO(2) peak (liters per minute) was similar between groups; however VO(2) peak relative to mass was 50% lower (p < or = 0.05) in the obese girls. When VO(2) peak (milliliters per minute per kilogram) and mass were correlated, r = -0.48 was found in the obese group. Allometric scaling of logarithmic transformed stature and mass reduced this to r = -0.002, thus eliminating the bias associated with the ratio method. Adjusting VO(2) peak allometrically scaled for mass, stature, and the combination of mass and stature reduced the difference between groups from 50% (ratio method) to 10% to 11% (p < or = 0.05) with higher values found in the normal-weight girls. DISCUSSION These results demonstrate the bias associated with the ratio method when comparing VO(2) peak in obese girls with VO(2) peak in normal-weight girls. Allometric scaling eliminated the bias and thus may reflect a truer comparative response.

Background: Safe and effective exercise programs are needed to prevent and treat chronic diseases in childhood. In particular, preadolescent obese children should participate in activities that are specific to their special needs. Resistance or strength training has been prescribed for adult obese persons. Research is limited concerning the use of resistance training in programs that treat obese preadolescents. Methods: Nineteen treatment subjects (7-12 years of age) were enrolled in a 1 O-week weight management program which included diet, behavior modification, and aerobic and flexibi lity exercises. Forty-eight control subjects (7-12 years of age) participated in the diet, behavior modification program, and a thrice-a-week walking program. The efficacy of the overall weight management program was examined by anthropometry at 10 weeks and 1 year. Results: Fifteen treatment subjects completed the 10-week program (retention rate, 78.9%). Thereafter compliance decreased by approximately 33% for the long-term study. Seventeen control subjects completed the program (retention rate, 35%). Weight, percent of ideal body weight, and body mass index were reduced significantly at 10 weeks (P and did not increase significantly at 1-year follow-up in both treatment and control groups. Height increased significantly at 1 year in both treatment and control subjects. In the treatment subjects, percent fat decreased significantly (p P > 0.05). Conclusions: A resistance-training program may be included safely in a multidisciplinary weight management program for obese preadolescent male and female children. The addition of specific exercise regimes such as resistance training may improve program retention especially in severely obese youth.

Peak cardiorespiratory responses, physical activity patterns, and the association of VO2peak and physical activity were examined in 16 elementary (ES) and 16 high school (HS) females. Peak responses were assessed during treadmill running, and physical activity patterns were examined over two 12-hour weekdays. Results indicated similar relative VO2peak responses between groups (ES: M = 46.8 ml · kg−1 · min−1;HS:M = 46.6 ml · kg−1 · min−1). No statistical differences (p ≤ .05) were noted when moderate to vigorous physical activity (MVPA) and vigorous physical activity (VPA) were compared. Also, a three-way (Group × HR level × Sustained minutes) ANOVA revealed no statistical differences. A median correlation (r = .27) was found from 8 independent correlations of habitual physical activity and VO2peak. ES and HS appeared similar in regard to VO2peak, accumulative and sustained MVPA and VPA. Low levels of sustained MVPA and VPA (≥ 10 min) were evident in both groups.

To test the hypothesis that static balance is associated with site-specific loss of muscle mass in older adults.A total of 57 active women aged 52-83 years had their muscle thickness (MTH) measured by ultrasound at four sites on the anterior and posterior aspects of their upper- and lower-leg. MTH ratios were calculated to assess the site-specific muscle loss. One-leg standing balance with eyes open and maximum isometric knee extension/flexion strength were measured. Daytime physical activity was also measured. The participants were separated into three groups based on achieved timed one-leg balance test: less than 60 s (n = 19, G1), 60-120 s (n = 12, G2) and over 120 s (n = 26, G3).Age was inversely correlated to the upper-leg (A50 : P70) MTH ratios (r = -0.389, P 0.001), but not lower-leg ratio (r = 0.047), thus site-specific muscle loss was observed in the upper-leg. Total muscle mass was similar among the groups. A50 : P70 MTH ratio and absolute and relative knee flexion strength were lower in G1 than in G3. Step counts and durations of moderate and vigorous exercise were lower in G1 and G2 than in G3. There were significant correlations between one-leg balance and A50 : P70 MTH ratio (r = 0.271, P 0.05) and physical activity level (r = 0.357-0.481, P 0.01). After adjusting for step count, one-leg balance was only correlated significantly with duration of vigorous exercise (r = 0.319, P 0.05).Higher physical activity could have more impact on balance regulation, as the influence of site-specific muscle loss was weak in active women.

The purpose of this study was to compare the prevalence of severe sarcopenia detected by total skeletal muscle mass (SM) index and of site-specific thigh sarcopenia for differing age groups in men and women. Japanese nonobese men and women aged 20 to 85 (n = 1,994, 55 % women) had muscle thickness (MTH) measured by ultrasound at six sites on the anterior and posterior aspects of the body. SM was estimated from ultrasound-derived prediction equations. Site-specific thigh sarcopenia was calculated using ultrasound-measured MTH at the anterior and posterior aspects of the thigh (MTH ratio, anterior 50 %/posterior 50 % thigh MTH (A50/P50 MTH)). Sarcopenia was defined as a SM index (SM divided by height2) of >2 standard deviations (SD) below the mean for young adults. Site-specific thigh sarcopenia was defined as a ratio of A50/P50 MTH of >2 SD below the mean for young adults. Age was inversely correlated to SM index and A50/P50 MTH in men (r = −0.480 and r = −0.522) and women (r = −0.243 and r = −0.516). The prevalence rate of sarcopenia was less than 3 % for women under the age of 60, 7 % for ages 60–69, and 24 % for ages 70–80. In men, the prevalence rate of sarcopenia was less than 7 % under the age of 50, 18 % for ages 50–59, 33 % for ages 60–69, and 47 % for ages 70–85. Compared to the sarcopenia estimated by SM index, there was a higher prevalence of site-specific thigh sarcopenia observed in both sexes. These results suggest that site-specific thigh sarcopenia appears before it is able to be detected at the whole body level.

It is unknown if the site-specific muscle loss of ageing muscle is associated with accelerometer-determined daily step count and/or intensity of physical activity. The purpose of this study was to examine the relationships between accelerometer- determined physical activity and lower body muscle size in women.Forty-eight women aged 52 to 76 years had their muscle thickness (MTH) measured by B-mode ultrasound at seven sites on the anterior and posterior aspects of their upper- and lower-leg. Daytime physical activity was measured using an accelerometer on 30 consecutive days and the total duration of each level of exercise intensity (light-PA, moderate-PA and vigorous-PA), average step count, and physical activity-related energy expenditure were calculated.Age was inversely correlated with anterior 30% upper-leg MTH (r=-0.296, p0.05), but not with other measured MTH sites. Light-PA was not significantly (p0.05) correlated with measured lower body MTH. However, moderate-PA was correlated (p0.05) with lower-leg MTH, while vigorous-PA was correlated (p0.05) with lower-leg and anterior 30% upper- leg MTH. Following adjustment for confounding factors, the anterior and posterior lower-leg MTH was positively correlated (p0.05) with duration of moderate- PA and vigorous-PA, as well as average step count.Thus daily moderate and vigorous physical activity was associated with higher muscle mass in the lower leg, but not in the upper-leg muscle, suggesting that the site-specific upper-leg muscle loss may not be prevented or attenuated by daily physical activity.

Sarcopenia is observed as a site-specific loss of skeletal muscle mass, however, it is unknown whether the site-specific sarcopenia is associated with development of physical disability. The purpose of this study was to examine the relationship between age-related thigh muscle loss and gait performance. Fifty-three women aged 52-83 years had their thigh muscle thickness (MTH) measured by ultrasound at five sites on the anterior (30%, 50%, and 70% of thigh length) and posterior (50% and 70% of thigh length) aspects of their thigh. Maximum and normal walking speeds, zig-zag walking time, and maximal voluntary isometric knee extension and flexion strength were measured. Age was inversely correlated to the anterior and posterior MTH ratio (e.g., anterior 50%:posterior 70% MTH ratio [r=-0.426, p=0.002]), thus the site-specific muscle loss of the thigh was observed in the present sample. There were no significant correlations between the anterior/posterior MTH ratio and maximum and normal walking speeds. However, the ratios of anterior 50%:posterior 70% MTH (r=-0.430) and anterior 30%:posterior 70% MTH (r=-0.444) were correlated (p=0.001) to zig-zag walking test. After adjusting for age, height and weight, the anterior 30%:posterior 70% MTH (r=-0.292, p=0.040) was inversely correlated to zig-zag walking performance. Isometric knee extension strength was also inversely correlated to zig-zag walking. Our results suggest that an age-related loss of adductor/quadriceps muscles may be associated with a decrease in a relatively difficult task performance such as zig-zag walking.

The multidisciplinary, four-phase approach, which includes PSMF, BEM, and MPE is successful in treating mild, moderate, and severe degrees of childhood and adolescent obesity. The MPE program is appropriate for use with PSMF and BEM due to its progressive nature, variety of options, and moderate intensity level. In addition, the MPE program is of sufficient intensity, duration, and frequency to promote a significant increase in estimated aerobic capacity (VO2max) and to promote the maintenance of lean body mass and resting energy expenditure. The short-term intervention of PSMF, BEM, and MPE also results in an improvement in body composition, lipid profiles, and IGF-1 and T3 levels. The 1200-calorie balanced diet, MPE, and BEM also provide a successful method of weight maintenance in children and adolescents, as indicated by further improvement in body composition at the 26-week measure. Additional studies are needed to assess the contribution of exercise to the maintenance of lean body mass and resting energy expenditure in obese children and adolescents. In addition, it will be important to assess long-term weight maintenance in obese adolescents who effectively lose weight in this multidisciplinary program.

We compared the energy expenditure to walk or run a mile in adult normal weight walkers (NWW), overweight walkers (OW), and marathon runners (MR). The sample consisted of 19 NWW, 11 OW, and 20 MR adults. Energy expenditure was measured at preferred walking speed (NWW and OW) and running speed of a recently completed marathon. Body composition was assessed via dual-energy x-ray absorptiometry. Analysis of variance was used to compare groups with the Scheffe's procedure used for post hoc analysis. Multiple regression analysis was used to predict energy expenditure. Results that indicated OW exhibited significantly higher (p0.05) mass and fat weight than NWW or MR. Similar values were found between NWW and MR. Absolute energy expenditure to walk or run a mile was similar between groups (NWW 93.9 ± 15.0, OW 98.4 ± 29.9, MR 99.3 ± 10.8 kcal); however, significant differences were noted when energy expenditure was expressed relative to mass (MRNWWOW). When energy expenditure was expressed per kilogram of fat-free mass, similar values were found across groups. Multiple regression analysis yielded mass and gender as significant predictors of energy expenditure (R = 0.795, SEE = 10.9 kcal). We suggest that walking is an excellent physical activity for energy expenditure in overweight individuals that are capable of walking without predisposed conditions such as osteoarthritis or cardiovascular risk factors. Moreover, from a practical perspective, our regression equation (kcal = mass (kg) × 0.789 - gender (men = 1, women = 2) × 7.634 + 51.109) allows for the prediction of energy expenditure for a given distance (mile) rather than predicting energy expenditure for a given time (minutes).

Five men and five women from a university cross‐country team were tested during the first 2 weeks and at the conclusion of a 7‐week cross‐country season. Maximal and submaximal cardiorespiratory responses, body composition, and performance variables were compared for seasonal and gender differences by analysis of variance and analysis of covariance. Male runners had significantly less (p ≤0.05) body fat, more fat‐free body (FFB) mass, a larger cardiorespiratory capacity, and ran more economically and faster than female runners. The difference in cardiorespiratory capacity and performance may have been due to a larger FFB (muscularity) and the increased training volume practiced by the male runners. Several gender but no seasonal differences were observed during a running economy test (214 m·min−1). A difference in oxygen uptake (VO2; ml·min−1‐kg BW−1) during the running economy test between male and female runners was unexpected and may have been due to fatigue in the female runners since their late seaso...

Purpose:The aim of this investigation was to compare gender differences in physiologic and perceptual responses during a 1-h run at recent marathon pace and running economy at three speeds in recreational marathon runners.Methods:In a counterbalanced design, 10 men and 10 women completed a 1-h treadmill run and a running economy test. Treadmill speed for the 1-h run ranged from 141 to 241 m·min−1 and 134, 168, and 188 m·min−1 for running economy. Physiologic parameters (oxygen uptake, carbon dioxide production, pulmonary ventilation, and heart rate) and perceived exertion were measured. Repeated-measures ANOVA was used to compare any gender differences (P < .05) during the 1-h run and a two-way ANOVA was used to compare running economy. With this sample, estimated marathon energy expenditure, body composition, and maximal physiologic function was reported.1Results:With the exception of an allometric expression of VO2 (mL·min−1·kg BW−0.75), similar gender physiologic and perceptual responses were found during the 1-h run. Although not significant, the females exercised at a higher percent VO2max (8% to 9%) during the run. Similar gender differences were also noted during the running economy tests.Conclusions:Although the male runners completed a recent marathon significantly faster than the females, similar gender physiologic and perceptual responses were generally found during the 1-h treadmill run and the running economy tests.