Active video game interventions typically provide children a single game that may become unappealing. A peripheral device (jOG) encourages step-powered gaming on multiple games. This trial evaluated the effect of jOG on children’s objectively measured PA, body fat and self-reported behaviors. 42 of 58 eligible children (8–10 y) randomly assigned to an intervention (jOG) or control (CON) completed the trial. Intervention children received two jOG devices for home use. Analyses of covariance compared the intervention effect at 6 and 12 weeks from baseline. No differences were found between groups for counts per minute (CPM; primary outcome) at 6 and 12 weeks (p > .05). Active video gaming increased (adjusted change 0.95 (95% CI 0.25, 1.65) h·d−1, p<.01) and sedentary video gaming decreased (-0.34 (-1.24, 0.56) h·d−1, p > .05) at 6 weeks relative to CON. No body fat changes were observed between groups. Targeted changes in video game use did not positively affect PA. Larger trials are needed to verify the impact of active video games on children’s PA and health.
Lee E.F. Graves, Nicola D. Ridgers, Greg Atkinson and Gareth Stratton
Peter Pagels, Anders Raustorp, Trevor Archer, Ulf Lidman and Marie Alricsson
Health organizations suggest that adults ought to engage in at least 30 minutes of moderate-intensity daily physical activity. This study investigated the effects of a 30-minute single daily bout of brisk walking upon risk factors for coronary heart disease with blood lipid profile in particular.
Thirty-three (25–45 y) adults, were randomly assigned into an exercise group (EG; n = 16, 9w) and a control group (CG; n = 17, 6w). The EG walked briskly 30 minutes daily during the 3-week test period. Compliance/adherence was maximal throughout the 3-week intervention due to stringent daily monitoring.
The EG showed a significant decrease in concentrations of low density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) during the intervention period. A significant inverse correlation between Δ energy expenditure/day and Δ LDL-C (r = –0.39, P < .05) and an improvement in weight and BMI in the EG was found. Average steps during 30 minutes brisk walking bout was 3669 steps/bout generating a mean energy expenditure of 191 kcal/ bout.
The most unique findings were that daily single bouts of moderate-intensity physical activity for 30 minutes, during 3 weeks, induced favorable effects upon body weight, BMI, and blood concentration of LDL-C and TC in healthy adults.
Eric T. Trexler, Katie R. Hirsch, Bill I. Campbell and Abbie E. Smith-Ryan
The purpose of the current study was to evaluate changes in body composition, metabolic rate, and hormones during postcompetition recovery. Data were collected from natural physique athletes (7 male/8 female) within one week before (T1) competition, within one week after (T2), and 4–6 weeks after (T3) competition. Measures included body composition (fat mass [FM] and lean mass [LM] from ultrasongraphy), resting metabolic rate (RMR; indirect calorimetry), and salivary leptin, testosterone, cortisol, ghrelin, and insulin. Total body water (TBW; bioelectrical impedance spectroscopy) was measured at T1 and T2 in a subsample (n = 8) of athletes. Significant (p < .05) changes were observed for weight (T1 = 65.4 ± 12.2 kg, T2 = 67.4 ± 12.6, T3 = 69.3 ± 13.4; T3 > T2 > T1), LM (T1 = 57.6 ± 13.9 kg, T2 = 59.4 ± 14.2, T3 = 59.3 ± 14.2; T2 and T3 > T1), and FM (T1 = 7.7 ± 4.4 kg, T2 = 8.0 ± 4.4, T3 = 10.0 ± 6.2; T3 > T1 and T2). TBW increased from T1 to T2 (Δ=1.9 ± 1.3 L, p < .01). RMR increased from baseline (1612 ± 266 kcal/day; 92.0% of predicted) to T2 (1881 ± 329, 105.3%; p < .01) and T3 (1778 ± 257, 99.6%; p < .001). Cortisol was higher (p < .05) at T2 (0.41 ± 0.31 μg/dL) than T1 (0.34 ± 0.31) and T3 (0.35 ± 0.27). Male testosterone at T3 (186.6 ± 41.3 pg/mL) was greater than T2 (148.0 ± 44.6, p = .04). RMR changes were associated (p ≤ .05) with change in body fat percent (ΔBF%; r = .59) and T3 protein intake (r= .60); male testosterone changes were inversely associated (p≤ .05) with ΔBF%, ΔFM, and Δweight (r=-0.81–-0.88). TBW increased within days of competition. Precompetition RMR suppression appeared to be variable and markedly reversed by overfeeding, and reverted toward normal levels following competition. RMR and male testosterone increased while FM was preferentially gained 4–6 weeks postcompetition.
Ann L. Gibson, Vivian H. Heyward, Christine M. Mermier, Jeffrey M. Janot and M. Virginia Wilmerding
The authors used 3-component (3C) Db-mineral-model (Lohman, 1986) reference measures to cross-validate Siri’s (1961) 2-component (2C) conversion formula and dual-energy X-ray absorptiometry (DXA) estimates of relative body fat (%BF) for physically active adults. Participants varied in age (18 to 59 y), body fatness, ethnicity (black, Hispanic, white), and physical activity level. The 3C Db-mineral model was used to obtain reference measures of %BF (%BF3C) for comparison with body-composition measures from DXA and hydrodensitometry. For men (n = 110) and women (n = 110), %BF3C (14.0% BF and 24.4% BF, respectively) was more accurately estimated by Siri’s 2C formula (%BFSiri; men, r = 0.97, SEE = 1.77% BF; women, r = 0.98, SEE = 1.56% BF) than by DXA (%BFDXA; men, r = 0.86, SEE = 3.54% BF; women, r = 0.88, SEE = 3.73% BF). The average %BFSiri (men, 15.8% BF; women, 24.7% BF) and %BFDXA (men, 16.2% BF; women, 26.0% BF) differed significantly (P < 0.001) from %BF3C. Siri’s 2C model estimated the average %BF3C in this sample more accurately than DXA did.
Ann L. Gibson, Jenevieve L. Roper and Christine M. Mermier
Air displacement plethysmography (ADP) is a popular method for estimating body density (Db). Most ADP tests are performed once, with test-retest investigations scarce. Therefore, we investigated test-retest reliability of ADP. Active men (n = 25) and women (n = 25) volunteered and followed standard pretest guidelines. Participants wore dry, form-fitting swimwear and manufacturer-supplied swim caps. In a single session, two ADP trials with measured thoracic gas volume (TGV) were performed without repositioning participants. Separate 2 (sex) × 2 (ADP trial) repeated-measures ANOVAs were performed to investigate within-between comparisons of Db, TGV, body volume (Vb), and relative fatness (%BF). Paired t tests were used to investigate significant differences as appropriate. The Bland and Altman technique was used to depict individual intertrial variations. For all analyses, α =.05. A significant main effect for sex was found; men were lower in %BF and higher in all other variables compared with women. Individual variability was notable (ADP1–ADP2). The range of individual intertrial differences were larger for women than men, respectively, for Db (-0.0096–0.0045 g/cc; -0.0019–0.0054 g/cc), TGV (-0.623–1.325 L; -0.584–0.378 L), Vb (-0.249–2.10 L; -0.234–0.397 L), and %BF (-2.1–4.4%; -0.2–0.9%). When assessing body composition of women via ADP or using Db from ADP in a multicomponent model, at least two trials with measured TGV should be performed and the average of the values recorded and reported.
Eric C. Haakonssen, David T. Martin, Louise M. Burke and David G. Jenkins
Body composition in a female road cyclist was measured using dual-energy X-ray absorptiometry (5 occasions) and anthropometry (10 occasions) at the start of the season (Dec to Mar), during a period of chronic fatigue associated with poor weight management (Jun to Aug), and in the following months of recovery and retraining (Aug to Nov). Dietary manipulation involved a modest reduction in energy availability to 30–40 kcal · kg fat-free mass−1 · d−1 and an increased intake of high-quality protein, particularly after training (20 g). Through the retraining period, total body mass decreased (−2.82 kg), lean mass increased (+0.88 kg), and fat mass decreased (−3.47 kg). Hemoglobin mass increased by 58.7 g (8.4%). Maximal aerobic- and anaerobic-power outputs were returned to within 2% of preseason values. The presented case shows that through a subtle energy restriction associated with increased protein intake and sufficient energy intake during training, fat mass can be reduced with simultaneous increases in lean mass, performance gains, and improved health.
Patricia A. Hageman, Susan Noble Walker, Carol H. Pullen, Linda S. Boeckner and Maureen K. Oberdorfer
This study investigated physical activity and fitness of midlife and older rural women. Random-digit dialing was used to recruit 225 women (57.9 ± 5.6 years old). Self-reported activity (moderate activity, flexibility, and strength) and fitness (body composition, flexibility, strength, and estimated VO2max) were assessed. The women demonstrated low daily energy expenditure (30.74 ± 10.63 kcal · kg−1 · day−1) and estimated VO2max (20.12 ± 7.81 ml · kg−1 · min−1), with 51.5% reporting fair or poor health. Few women reported meeting Healthy People 2010 targets for moderate activity (43.1%), flexibility (28.9%), or strength (14.2%). When classified by estimated VO2max into three categories, differences were observed for body-mass index, percent body fat, sit and reach, and timed chair stands, with the poorest performance by those with low cardiorespiratory fitness. Adherence to Healthy People 2010 targets for moderate activity and strengthening was associated with higher cardiorespiratory fitness. These rural women are targets for physical activity interventions because of their sedentary behaviors and low cardiorespiratory fitness.
Ana Anton-Solanas, Barry V. O’Neill, Tessa E. Morris and Joe Dunbar
To assess changes in body composition and monitor cognitive function, subjective well-being, and physiological stress, as measured by salivary hormones and markers of mucosal immunity, during an Antarctic expedition.
A 36-y-old man (188.2 cm height, 94.5 kg body mass) took part in a world-record attempt. A total-body dual-energy X-ray absorptiometry scan and measurement of 8 skinfolds and 5 girths were performed before and after the expedition. In addition, daily subjective data were recorded (sleep quality, total hours of sleep, energy levels, perceived exertion, mood, muscle soreness, and muscle/joint pain) along with distance covered and hours of physical activity per day. As a measure of cognitive function, the athlete completed a computerized battery of tasks (Axon Sports Cognitive Priming Application) every third morning. Saliva samples were collected before, during, and after the expedition to determine salivary cortisol (sCort), testosterone (sT), alpha amylase (sAA), and secretory immunoglobulin A (sIgA).
The athlete lost 5.3 kg body mass and sum of 8 skinfolds decreased from 73 mm to 59 mm from preexpedition to postexpedition. Psychomotor speed declined over the course of the expedition. sT increased and sCort decreased throughout, and sAA and sIgA peaked toward the end of the expedition.
This case study provides novel data about the physiological and cognitive impact of an Antarctic expedition. The findings may inform strategies for future expeditions, allowing individuals undertaking expeditions of this nature to better prepare for success.
Bruce W. Bailey, Pamela Borup, James D. LeCheminant, Larry A. Tucker and Jacob Bromley
The purpose of this study was to assess the relationship between intensity of physical activity (PA) and body composition in 343 young women.
Physical activity was objectively measured using accelerometers worn for 7 days in women 17 to 25 years. Body composition was assessed using the BOD POD.
Young women who spent less than 30 minutes a week performing vigorous PA had significantly higher body fat percentages than women who performed more than 30 minutes of vigorous PA per week (F = 4.54, P = .0113). Young women who spent less than 30 minutes per day in moderate to vigorous PA (MVPA) had significantly higher body fat percentages than those who obtained more than 30 minutes per day of MVPA (F = 7.47, P = .0066). Accumulating more than 90 minutes of MVPA per day was associated with the lowest percent body fat. For every 10 minutes spent in MVPA per day, the odds of having a body fat percentage above 32% decreased by 29% (P = .0002).
Vigorous PA and MVPA are associated with lower adiposity. Young women should be encouraged to accumulate at least 30 minutes of MVPA per day, however getting more than 90 minutes a day is predictive of even lower levels of adiposity.
Kelly Samara Silva, Daniel Giordani Vasques, Caroline de Oliveira Martins, Laura Ashley Williams and Adair S. Lopes
Research has demonstrated that adolescents who actively commute have higher levels of physical activity (PA), which have declined precipitously over the past 30 years. The purpose of this study was to describe the prevalence of active commuting to school; and to identify barriers associated with active commuting.
A cross-sectional study was conducted with 1672 students (46.8% boys and 53.2% girls) from 11 to 17 years of age in Caxias do Sul/RS, Brazil. The students were asked to answer questionnaires about active transport, PA, and sedentary behaviors. They also completed a cardiovascular fitness test and body composition measurements. The study used a multivariate Poisson regression analysis.
A total of 62.5% of students were observed to actively commute and the prevalence ratio (PR) of not actively commuting was associated with the type of school (Private: 2.41; 1.47, 3.95) and the time spent on commuting (>20 min: 1.93; 1.23, 3.03). The associated barriers to passive commuting were distance (3.02; 1.95, 4.71), crime/ danger (2.65; 1.82, 3.85), and traffic (1.75; 1.19, 2.58).
This study showed that environmental variables were strongly associated with active commuting. However, no alterations in body composition or other behavioral variables were observed after adjustment.