Rebecca A. Schlaff

Accuracy of body mass index in volunteer firefighters

BACKGROUND Obesity is prevalent among career firefighters and may contribute to heart attacks, a leading cause of on-duty fatalities. The US National Fire Protection Association estimates that 800 000 of 1.1 million firefighters are volunteers. Body mass index (BMI) is commonly used to assess obesity, but little is known about its accuracy in volunteer firefighters, in whom muscle mass may be higher, given firefightings physical demands, reducing its accuracy in identifying obesity. AIMS To evaluate the accuracy of BMI in identifying obese volunteer firefighters. METHODS Height, weight and body composition were measured in 73 male volunteer firefighters (mean age 40±12). The proportions with BMI ≥ 25kg/m(2), ≥30kg/ m(2) and percent fat ≤ 20th percentile were determined. Using the age-specific 20th percentile for percent fat (Cooper Clinic) as the criterion for being over-fat, the accuracy of BMI was assessed using sensitivity and specificity calculations. RESULTS The means ± standard deviation of BMI and percent fat were 32±6 and 25±5, respectively. The proportions with a BMI ≥ 25 and ≥30 were 90% and 60%, respectively. Fifty-one percent had a percent fat ≤ 20th percentile. The measure BMI ≥ 25 had a perfect sensitivity (1.0) and low specificity (0.19) and BMI ≥ 30 had a high sensitivity (0.89) and moderate specificity (0.69). CONCLUSIONS Although BMI ≥ 30 accurately predicted being over-fat, it misclassified large and lean firefighters. Although BMI should be used cautiously, it can identify over-fat firefighters at risk of cardiovascular disease, and its measurement is cost-effective and simple.

Body Mass Index is Associated With Appropriateness of Weight Gain but not Leisure-Time Physical Activity During Pregnancy

BACKGROUND Little is known about how leisure-time physical activity (LTPA) influences gestational weight gain (GWG) among body mass index (BMI) categories. The purpose of this study was to examine the relationship between pregnancy LTPA and the proportion of normal, overweight, and obese women who meet GWG recommendations. METHODS Participants included 449 subcohort women from the Pregnancy Outcomes and Community Health (POUCH) study. LTPA was collapsed into 3 categories [(None, < 7.5 kcal/kg/wk (low), ≥ 7.5 kcal/kg/wk (recommended)]. GWG was categorized according to IOM recommendations (low, recommended, or excess). Chi-square and logistic regression analyses were used to evaluate relationships among LTPA, BMI, and GWG. RESULTS Overweight women were more likely to have high GWG vs. normal weight women (OR = 2.3, 95% CI 1.3-4.0). Obese women were more likely to experience low GWG (OR = 7.3, 95% CI 3.6-15.1; vs. normal and overweight women) or excess GWG (OR = 3.5, 95% CI 1.9-6.5; vs. normal weight women). LTPA did not vary by prepregnancy BMI category (P = .55) and was not related to GWG in any prepregnancy BMI category (P = .78). CONCLUSIONS Regardless of prepregnancy BMI, LTPA did not affect a womans GWG according to IOM recommendations. Results may be due to LTPA not differing among BMI categories.

Perceptions of body weight and nutritional practices among male and female National Collegiate Athletic Association Division II athletes

ABSTRACT Objective: This study investigated body weight and nutritional behavior perceptions among Division II collegiate athletes. Participants: The sample was composed of 155 collegiate athletes who responded to a survey. Methods: Data were self-reported by athletes via questionnaire. Independent-sample t tests were used to identify significant gender differences related to body weight perceptions, nutritional practices, and ideal weight difference (IWD). An alpha level of .05 was used to determine statistical significance. Results: Mean ± SD female and male IWD was −6.8 ± 8.8 and 1.3 ± 12.3 lbs, respectively (p < .001). Significant differences in level of agreement regarding perceived body weight effects on performance and dietary practices existed between genders. Conclusions: Significant gender differences may exist regarding body weight perceptions and nutritional practices among collegiate athletes. Deliverance of gender-specific educational information about proper nutritional practices is warranted. To properly tailor interventions to specific sports, research with larger sample sizes is needed.

Examining the energy cost and intensity level of prenatal yoga

Context: A popular form of pregnancy physical activity (PA) is prenatal yoga. However, little is known about the intensity and energy cost of this practice. Aims: To examine the energy cost and intensity level of prenatal yoga. Methods: Pregnant women in a prenatal yoga class (n = 19) wore a Sense Wear Armband during eleven 60 min classes each, and self-reported demographic variables, height and weight, prepregnancy weight, and PA behaviors and beliefs. Sense Wear Armband data included kilocalories, metabolic equivalent (MET) values, and time spent in various intensities. Descriptive statistics and frequencies were utilized to describe energy expenditure and intensity. Results: Energy expenditure averaged 109 ± 8 kcals, and the average MET value was 1.5 ± 0.02. On average, 93% and 7% of classes were sedentary and moderate intensity PA, respectively. Conclusions: Time spent in a prenatal yoga class was considered to be primarily a sedentary activity. Future research should utilize larger samples, practice type, and skill level to increase generalizability.

Effects of a Group-Based Behavioral Intervention on Dietary Behaviors in Older Adults.

Objective: The aim of this study is to examine the effects of a 12-week, behavioral nutrition intervention on dietary behaviors. Method: Inactive older adults (N = 50) were randomized to a 12-week, behavioral nutrition or physical activity intervention, delivered in a group-based format. Questionnaires assessed fruit and vegetable (FV) consumption, and fat- and fiber-related behaviors at baseline and postintervention. Height and weight were measured. Repeated-measures ANOVAs examined changes in dietary behaviors over time between groups, controlling for age, gender, and education. Results: Participants averaged 64.1 ± 8.4 years of age and had a body mass index (BMI) of 33.3 ± 7.5 kg/m2. Group × Time interactions were significant for FV consumption (p = .003), and fat- (p = .02) and fiber-related (p = .008) behaviors at 12 weeks. At 12 weeks, dietary behaviors improved significantly in the nutrition but not in the physical activity group. Effect sizes were medium to large. Discussion: A 12-week, behavioral nutrition intervention improved dietary behaviors. Behavioral interventions may be a low-cost way to improve dietary behaviors among older adults, potentially affecting population health significantly.

Physical Activity Device Reliability and Validity during Pregnancy and Postpartum

Current physical activity (PA) recommendations for women experiencing a normal pregnancy reflect recent research showing numerous health benefits for mother and offspring. However, few studies have evaluated PA devices’ reliability and validity during pregnancy, because anatomical and physiological changes throughout gestation could affect an instrument’s accuracy. PurposeThis study aimed to determine the reliability and validity of PA devices worn on the hip, ankle, and triceps during pregnancy and postpartum. MethodsThirty-three women performed six activities of daily living and one treadmill walk at approximately 21 and 32 wk of pregnancy, and 12 wk postpartum. There were two visits at each time period, 1 wk apart. Energy expenditure (oxygen consumption) was measured by using indirect calorimetry (IC; criterion measure), whereas PA was quantified by using accelerometers and pedometers placed at the right hip and ankle and left triceps. Interclass reliability and monitor validity compared with IC in relative (mL·kg−1·min−1) terms were calculated using Pearson correlation. Both multitrial and single-trial intraclass reliabilities (ICC) were estimated using ANOVA to assess monitor reliability at each time period. SEM values were calculated in relative terms for each time period. ResultsThe reliability of the devices was moderate/strong because 66% of the Pearson correlations were between 0.6 and 1.0. Multitrial ICC values were largely in the moderate/strong range because 38% of the ICC values were between 0.6 and 0.79 and 50% were between 0.8 and 1.0. The SEM values for each device between visits ranged from 7% to 23% of the mean values. Comparison between IC and devices showed that 40% and 46% of the validity coefficients were between 0.4 and 0.59 and between 0.6 and 0.79, respectively. ConclusionsPA devices show moderate/strong reliability and moderate validity for measuring PA during pregnancy and postpartum.

Patterns of Sedentary Behavior in Older Adults

OBJECTIVES We measured the volume and patterns of sedentary behavior (including breaks from sedentary behavior) in a sample of older adults via accelerometry. METHODS Inactive, older adults (≥50 years of age) were eligible to participate. A cut point of <100 counts/minute was used to estimate: (1) total volume; (2) > 10-, > 30-, and > 60-minute bouts; and (3) patterns of sedentary behavior according to time of day and day of the week were computed. Total breaks in sedentary time also were calculated. RESULTS Participants (N = 67) were sedentary 62% of the day, engaging in 73.3 total bouts of daily sedentary behavior, and each bout lasted, on average, 7.8 minutes. All participants engaged in >1 daily bout of sedentary behavior > 10 and > 30 minutes. Sedentary time was slightly greater during the evening and on weekdays. Participants averaged 72.9 daily breaks from sedentary behavior, with each break lasting approximately 4.4 minutes. CONCLUSIONS Our findings add valuable insights into the patterns of sedentary behaviors among older adults. Concentrated research efforts should be made to gain a clearer understanding of patterns and enablers to sedentary behaviors, which will allow for development of targeted interventions for this high-risk population.

The Influence of Risk Perceptions and Efficacy Beliefs on Leisure-Time Physical Activity During Pregnancy

BACKGROUND Pregnancy risk perceptions and physical activity efficacy beliefs may facilitate or impede pregnancy leisure-time physical activity (LTPA). We examined the separate and joint influence of these variables on LTPA behavior among pregnant women. METHODS Pregnant women (n = 302) completed a survey containing questions on LTPA efficacy beliefs and behavior, as well as pregnancy risk perceptions with respect to the health of the unborn baby. As stipulated by the Risk Perception Attitude (RPA) Framework, 4 attitudinal groups were created: Responsive (High Risk+High Efficacy), Proactive (Low+High), Avoidant (High+Low), and Indifferent (Low+Low). Moderate LTPA and vigorous LTPA were dichotomized for study analyses. RESULTS A total of 82 women (27.2%) met the moderate physical activity guideline and 90 women (30.1%) performed any vigorous LTPA. Responsive and proactive pregnant women (those with high efficacy) were most likely to meet the moderate guideline and participate in vigorous LTPA. Hierarchical logistic regression did not reveal an interactive effect of pregnancy risk perceptions and LTPA efficacy beliefs for meeting the moderate guideline (OR = 0.94, 95% CI = 0.66-1.36) or any vigorous LTPA participation (OR = 1.41, 95% CI = 0.86-2.29). CONCLUSIONS LTPA efficacy beliefs appear important in facilitating greater levels of pregnancy LTPA. Significant interactive effects between pregnancy risk perceptions and LTPA efficacy beliefs were not found.

Barriers to Resistance Training among College-aged Women

ABSTRACT Objective: To examine resistance training (RT) barriers among college-aged women. Participants: Female college students (n = 223) from a Midwestern university. Methods: Data were collected in September 2014. Participants completed a survey assessing demographics, current and past RT habits, and barriers to resistance training. Descriptive statistics were used to examine barrier agreement. Differences between current and past RT participation, residency, and class standing were analyzed. Results: A majority of participants were Caucasian (78.9%) and, on average, 19.7 ± 1.5 years of age; 52% participated in RT and 46.6% met RT recommendations. Women who did not report current RT participation reported significantly higher mean agreement with all barriers, compared to those who do RT. Highest agreement was observed within socially based barriers. Conclusion: A majority of college-aged women are not meeting RT recommendations. Providing educational programs and avenues for finding same-sex RT partners may be most beneficial for overcoming common RT barriers.

Effects of a Self-Directed Nutrition Intervention Among Adults With Chronic Health Conditions:

Chronic diseases are common among adults. A healthy diet may be beneficial for managing the consequences of such conditions. The purpose of this study was to evaluate the effects of a self-directed nutrition program on dietary behaviors among adults with chronic health conditions. As part of a larger trial examining the effects of a self-directed exercise program, participants with arthritis were randomized to a 12-week self-directed exercise or nutrition intervention. Self-reported fruit and vegetable consumption, fat- and fiber-related behaviors were assessed at baseline, 12 weeks, and 9 months. Repeated measures analyses of covariance examined Group × Time changes in dietary behaviors. Effect sizes were computed. Participants (n = 321) were, on average, 56.5 ± 10.5 years old, had a mean body mass index of 32.9 ± 8.3 kg/m2, and had 2.0 ± 1.0 chronic health conditions; 88% were female, 65% White, 88% had at least some college education, and 62% married. There were significant Group × Time interactions favoring the nutrition group at 12 weeks for all dietary behaviors (p < .05) but not at 9 months. Between-group effect sizes were small at 12 weeks and decreased at 9 months. Within-group effect sizes were larger for the nutrition group (small to medium) than the exercise group (none to small) at both time points. A self-directed nutrition intervention can result in meaningful improvements in dietary behaviors among adults with chronic health conditions in the short term.