a standardized assessment of mobility function testing by a trained exercise staff at each site to establish a baseline mobility status. The body mass index (BMI) was determined from a baseline assessment of height and weight. The mobility function assessment included the (a) time to complete a 10-m
Odessa Addison, Monica C. Serra, Leslie Katzel, Jamie Giffuni, Cathy C. Lee, Steven Castle, Willy M. Valencia, Teresa Kopp, Heather Cammarata, Michelle McDonald, Kris A. Oursler, Chani Jain, Janet Prvu Bettger, Megan Pearson, Kenneth M. Manning, Orna Intrator, Peter Veazie, Richard Sloane, Jiejin Li and Miriam C. Morey
Youn Soo Jung, Steven A. Hawkins and Robert A. Wiswell
The purpose of this study was to determine the contribution of body composition and muscle strength to racial differences in bone mineral density (BMD) in chronically active older adults. Participants were 49 men and 56 women grouped according to self-selected race (Black, Asian, or White). BMD, body composition, and knee strength were measured. Asian men had significantly lower body mass, strength, and BMD than White and Black men did (p < .05). Asian and White women had significantly lower body mass and BMD than Black women did (p < .05), with few strength differences between groups. When lean mass was controlled by ANCOVA. racial differences in BMD disappeared for all bone sites in both sexes. Controlling for body mass eliminated most racial differences in BMD. Controlling for strength did not alter racial differences in BMD for either sex. These results suggest that racial differences in BMD might in part result from differences in lean mass.
Sijie Tan, Cheng Chen, Mingyang Sui, Lunan Xue and Jianxiong Wang
To explore the effects of exercise training on body composition, cardiovascular function, and physical fitness in 5-year-old obese and lean children.
42 obese and 62 lean children were randomly allocated into exercise and control groups separately. Body composition, cardiovascular function, and physical fitness were measured at baseline and the end of the intervention. The exercise groups participated in 10 weeks of supervised moderate intensity exercise training (at 50% of heart rate reserve), 50 training sessions in total.
The physical activity program was successfully completed and no sport injury occurred. Exercise training decreased BMI, waist circumference, body fat%, and fat mass; and slowed down the growth speed of body mass of both trained obese and lean children. Exercise training significantly decreased systolic blood pressure of obese children and decreased their heart rate responses during exercise. Trained obese children improved the performances of long jump, 10-m × 4 shuttle run, and 3-m balance beam walk; while trained lean children improved more items of physical fitness.
10 weeks of moderate intensity exercise training is an effective and safe treatment for children aged 5 years, either obese or with normal body mass.
Dorota Sadowska, Rafał Stemplewski and Robert Szeklicki
The aim of this study was to assess the effect of physical exercise on postural stability in sighted participants and individuals who are visually impaired, adjusted for potential modulatory effects of physical activity level and body mass index (BMI). The study included 23 participants who were severely visually impaired and 23 sighted participants. Postural stability measurements were taken with open eyes (session I) and with closed eyes (session II). During each session, the mean velocity of the center of pressure (COP) displacements was determined using a force plate both before and after physical exercise. During testing with open eyes, the 2 groups did not differ significantly in terms of their postural response to physical exercise. When examined with closed eyes, the individuals who were visually impaired showed markedly greater postexercise increase in mean velocity of the COP displacement in the mediolateral direction. This intergroup difference was likely a consequence of significantly higher preexercise values of posturographic parameters observed in the sighted participants. More pronounced postexercise changes in the postural stability of sighted participants were associated with lower levels of physical activity and higher values of BMI. Further research is needed to explain the character of the abovementioned relationships in individuals who are visually impaired.
Konstantinos Tambalis, Demosthenes Panagiotakos, Giannis Arnaoutis and Labros Sidossis
We aimed to model endurance, explosive power, and muscle strength in relation to body mass index (BMI) and physical-fitness tests in Greek children aged 7–10 years old. In the present large epidemiological study, anthropometric measurements and physical-fitness tests (i.e., multistage shuttle run, vertical jump, standing long jump, small ball throw and 30-m sprint) from 141,169 children were analyzed. Age- and sex-specific normative values for physical fitness tests were expressed as tabulated percentiles using the LMS statistical method. The correlation coefficients between BMI and performances were negative and significant for both sexes (p < .01) in all physical-fitness tests. The only exception was a positive correlation between ball throw and BMI (p < .01). Only 2.9% and 4.0% of boys and girls respectively, passed the upper quartiles in all tests. The performance in speed may serve as a predictive factor explaining, at least in part, the performance in aerobic endurance and explosive power in children aged 7–10 years. The presented population-based data for physical-fitness tests revealed that only a small percentage of these children are in the upper quartiles in all tests. Furthermore, the data suggests that speed performance can be used to predict physical fitness.
Binh Nguyen, Adrian Bauman and Ding Ding
To examine the combined effects of body mass index (BMI), physical activity (PA) and sitting on incident type 2 diabetes mellitus (T2DM) among Australian adults.
A sample of 29,572 adults aged ≥45 years from New South Wales, Australia, completed baseline (2006–2008) and follow-up (2010) questionnaires. Incident T2DM was defined as self-reported, physician-diagnosed diabetes at follow-up. BMI was categorized as normal/overweight/obese. PA was tertiled into low/medium/ high. Sitting was dichotomized as higher/lower sitting (≥ 8 hours/day or < 8 hours/day). Odds ratios (OR) were estimated for developing T2DM using logistics regression for individual and combined risk factors, and data stratified by BMI categories.
During a mean 2.7 (SD: 0.9) years of follow-up, 611 (2.1%) participants developed T2DM. In fully adjusted models, BMI was the only independent risk factor for incident T2DM. In stratified analyses, the association between BMI and T2DM did not differ significantly across sitting or PA categories. Overweight/obese individuals with high PA and lower sitting had higher odds of incident T2DM than normal counterparts with low PA and higher sitting.
High PA/low sitting did not attenuate the risk of T2DM associated with overweight/obesity. Maintaining a healthy weight, by adopting healthy lifestyle behaviors, is critical for T2DM prevention.
Leon Mabire, Ramakrishnan Mani, Lizhou Liu, Hilda Mulligan and David Baxter
Brisk walking is the most popular activity for obesity management for adults. We aimed to identify whether participant age, sex and body mass index (BMI) influenced the effectiveness of brisk walking.
A search of 9 databases was conducted for randomized controlled trials (RCTs). Two investigators selected RCTs reporting on change in body weight, BMI, waist circumference, fat mass, fat-free mass, and body fat percentage following a brisk walking intervention in obese adults.
Of the 5072 studies screened, 22 met the eligibility criteria. The pooled mean differences were: weight loss, –2.13 kg; BMI, –0.96 kg/m2; waist circumference, –2.83 cm; fat mass, –2.59 kg; fat-free mass, 0.29 kg; and body fat percentage, –1.38%. Meta-regression of baseline BMI showed no effect on changes.
Brisk walking can create a clinically significant reduction in body weight, BMI, waist circumference, and fat mass for obese men and women aged under 50 years. Obese women aged over 50 years can achieve modest losses, but gains in fat-free mass reduce overall change in body weight. Further research is required for men aged over 50 years and on the influence of BMI for all ages and sexes.
Martin Buchheit, Yannick Cholley, Mark Nagel and Nicholas Poulos
To examine the effect of body mass (BM) on eccentric knee-flexor strength using the Nordbord and offer simple guidelines to control for the effect of BM on knee-flexor strength.
Data from 81 soccer players (U17, U19, U21, senior 4th French division, and professionals) and 41 Australian Football League (AFL) players were used for analysis. They all performed 1 set of 3 maximal repetitions of the bilateral Nordic hamstring exercise, with the greatest strength measure used for analysis. The main regression equation obtained from the overall sample was used to predict eccentric knee-flexor strength from a given BM (moderate TEE, 22%). Individual deviations from the BM-predicted score were used as a BM-free index of eccentric knee- flexor strength.
There was a large (r = .55, 90% confidence limits .42;.64) correlation between eccentric knee-flexor strength and BM. Heavier and older players (professionals, 4th French division, and AFL) outperformed their lighter and younger (U17–U21) counterparts, with the soccer professionals presenting the highest absolute strength. Professional soccer players were the only ones to show strength values likely slightly greater than those expected for their BM.
Eccentric knee-flexor strength, as assessed with the Nordbord, is largely BM-dependent. To control for this effect, practitioners may compare actual test performances with the expected strength for a given BM, using the following predictive equation: Eccentric strength (N) = 4 × BM (kg) + 26.1. Professional soccer players with specific knee-flexor-training history and enhanced neuromuscular performance may show higher than expected values.
Giovani dos Santos Cunha and Gabriela Tomedi Leites
uptake per unit of body mass (VO 2 peak, mL·kg −1 ·min −1 ) appropriately controlled for body size differences in youth. The authors argued the use of the standard ratio is not based on sound scientific or statistical rationale. There are several instances where the indiscriminate use of VO 2 peak (mL
Greg Cox, Iñigo Mujika, Douglas Tumilty and Louise Burke
This study investigated the effects of acute creatine (Cr) supplementation on the performance of elite female soccer players undertaking an exercise protocol simulating match play. On two occasions, 7 days apart, 12 players performed 5 X 11-min exercise testing blocks interspersed with 1 min of rest. Each block consisted of 11 all-out 20-m running sprints, 2 agility runs, and 1 precision ball-kicking drill, separated by recovery 20-m walks, jogs, and runs. After the initial testing session, subjects were assigned to either a CREATINE (5 g of Cr, 4 times per day for 6 days) or a PLACEBO group (same dosage of a glucose polymer) using a double-blind research design. Body mass (BM) increased (61.7 ± 8.9 to 62.5 ± 8.9 kg, p < .01) in the CREATINE group; however, no change was observed in the PLACEBO group (63.4 ± 2.9 kg to 63.7 ± 2.5 kg). No overall change in 20-m sprint times and agility run times were observed, although the CREATINE group achieved faster post-supplementation times in sprints 11, 13, 14, 16, 21, 23, 25, 32, and 39 (p < .05), and agility runs3,5,and8 (p < .05). The accuracy of shooting was unaffected in both groups. In conclusion, acute Cr supplementation improved performance of some repeated sprint and agility tasks simulating soccer match play, despite an increase in BM.