Physical Activity Frequency, Independent of Volume, Is Directly Associated With C-Reactive Protein: NHANES 2003 – 2006

Purpose: Physical activity (PA) has shown consistent positive effects on cardiovascular risk, yet the individual contributions of frequency, intensity and duration remain unclear. The purpose of this investigation was to explore the associations between objectively-measured PA frequency and cardiometabolic risk factors, independent of total PA volume. Methods: Data were analyzed for 5,549 adults with at least four valid days of accelerometry from the 2003 – 2006 US National Health and Nutrition Examination Survey (NHANES). Meeting PA guidelines was defined as 150+ minutes of moderate- to vigorous-intensity PA per week, accumulated in 10+ minute bouts. Frequency was defined as the number of days containing at least one bout, and categorized as 1-3, 4-5, or 6-7 days per week (d∙wk-1). Risk factors were described for frequency categories after direct age adjustment and stratification by total weekly duration. Multivariate linear regression was used to analyze the independent associations between risk factors and PA frequency. Results: Among those meeting PA guidelines, people in the lower total volume stratum and with higher frequency (4-5 or 6-7 d∙wk-1) showed significantly higher C-reactive protein (CRP) compared to those in the lowest frequency category (1-3 d∙wk-1) (0.12 and 0.14 mmol/L vs. 0.08 mmol/L, respectively, p \u3c 0.05). Similar results were seen in the higher duration stratum, though differences in CRP between frequency categories did not reach significance. Small differences in hemoglobin-A1c and HDL-c were seen between frequency categories at both levels of duration (p\u3c0.05). After adjustment for multiple confounders, a significantly higher CRP was seen in those accruing recommended PA on 4- 5 versus 1- 3 d∙wk-1 (+40.3%, p = 0.024) and 6- 7 versus 1-3 d∙wk-1 (+39.0%, p = 0.018). Conclusions: Controlling for total volume, moderate- to vigorous-intensity PA done on more days per week appears to be associated with higher CRP. This may be due to accumulation of CRP between bouts of PA when insufficient time is available for full clearance. This may decrease the prognostic value of CRP among frequently active subjects, and may offer an explanation for divergent findings between experimental and observational studies on the PA – CRP relationship

Times in physical activity and sedentary behavior associated with awareness and knowledge of the 2008 Physical Activity Guidelines for Americans

Objective: In this study, we examined the associations between awareness and knowledge of the 2008 Physical Activity Guidelines for Americans and device-based measures of physical activity (PA). Methods: Overall, 222 college students participated in the current study. Based on their awareness and knowledge of the 2008 Guidelines, the participants were categorized into 3 groups: don't know, awareness only, and knowledge. We used 2 questions for identifying awareness and knowledge of government PA guidelines. Accelerometers were employed to evaluate times spent in moderate-to-vigorous intensity physical activity (MVPA). Comparison among the 3 groups was conducted for total time spent in MVPA using one-way Welch ANOVA. Results: There was a statistically significant difference in the average time of MVPA by the knowledge of the 2008 Guidelines (p = .035). The knowledge group had a greater average time of MVPA com-pared to the other 2 groups; we found no statistically significant difference in MVPA between the awareness only and don't know groups. Conclusion: Knowledge of the 2008 Guidelines was positively associated with PA levels among college students. More effective dissemination of PA guidelines would appear to be warranted in promoting PA.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

Patterns of physical activity and sedentary behavior outside of a college physical activity course

Objectives: We investigated the patterns of physical activity (PA) and sedentary behavior (SB) outside of a college weight training course. Methods: We recruited university undergraduate students (N = 225) enrolled in a weight training course. The variables included bouted moderate-to-vigorous intensity physical activity (PA), total sedentary time, and compliance with PA guidelines. Results: More than half of the participants did not meet the recommended aerobic PA guidelines outside of the weight training class. Gender discrepancy exists in the patterns of PA and SB. No differences in the variables were found between PA and non-PA students. Conclusions: Despite a participation in physical activity course, additional physical activity outside of the class is necessary to achieve physical activity guidelines.Peer reviewedCommunity Health Sciences, Counseling and Counseling Psycholog

When Meeting Physical Activity Guidelines is not Enough: the Interplay of Sedentary and Active Behaviors

ABSTRACT The combined effects of physical activity (PA) and sitting time on health have been inadequately studied. Sitting time has not been thoroughly measured in existing studies. The high prevalence of sitting in modern society may well present a situation where merely meeting guidelines is insufficient to realize health benefits. Identifying a dose of PA that negates the harmful effects of prolonged sitting should be a priority as research into the health effects of sitting progresses. Utilizing a group of high socio-economic status, highly active subjects of varying PA volume may allow identification of such a threshold, which may, in turn, shed light on more effective PA recommendations for highly sedentary individuals. Additional investigations into different sitting contexts, enhanced measurement techniques, and expanded surveillance may also be warranted

When Meeting Physical Activity Guidelines is not Enough: the Interplay of Sedentary and Active Behaviors

ABSTRACT The combined effects of physical activity (PA) and sitting time on health have been inadequately studied. Sitting time has not been thoroughly measured in existing studies. The high prevalence of sitting in modern society may well present a situation where merely meeting guidelines is insufficient to realize health benefits. Identifying a dose of PA that negates the harmful effects of prolonged sitting should be a priority as research into the health effects of sitting progresses. Utilizing a group of high socio-economic status, highly active subjects of varying PA volume may allow identification of such a threshold, which may, in turn, shed light on more effective PA recommendations for highly sedentary individuals. Additional investigations into different sitting contexts, enhanced measurement techniques, and expanded surveillance may also be warranted

Association Between Concussion History and Factors Relating to Cognitive, Behavioral, and Emotional Health Among American High School Athletes: A Cross-sectional Analysis

Background: The cognitive, behavioral, and emotional deficits that may be associated with sports-related concussions among adolescents are unclear. Purpose: To examine the association between reported concussion history and factors relating to cognitive, behavioral, and emotional health among a population-based sample of US high school-aged adolescents. Study design: Cross-sectional study; Level of evidence, 3. Methods: Participants included a representative sample of US high school student-athletes who reported a concussion history (in the past 12 months) and relevant behaviors/outcomes within 3 domains: cognitive (academics, difficulty concentrating), behavioral (drinking and driving, carrying a weapon, physically fighting, tobacco use, marijuana use, binge drinking), and emotional (symptoms of depression, suicidal thoughts/actions). The adjusted relative odds of experiencing 0 and at least 1, 2, 3, or ≥4 concussions were modeled while mutually adjusting for the behaviors of interest in addition to age, race/ethnicity, and sleep problems. Data were reported in sex stratum. Results: A total of 13,268 participants were included in the unweighted data set. Overall, 14.5% (95% CI, 12.9%-16.2%) of female and 18.1% (95% CI, 16.4%-19.8%) of male student-athletes had at least 1 concussion in the past 12 months. As compared with those who reported not engaging in any of the behaviors deleterious to health or having had any of the negative health outcomes (composite score of 0), female athletes with composite scores of 1 to 4, 5 to 7, and 8 to 11 were 1.94 (95% CI, 1.55-2.43), 3.13 (95% CI, 2.30-4.33), and 6.05 (95% CI, 3.75-9.75) times more likely to have a recent history of concussions after accounting for relevant factors. As compared with those having a composite score of 0, male athletes with composite scores of 1 to 4, 5 to 7, and 8 to 11 were 2.03 (95% CI, 1.58-2.59), 3.80 (95% CI, 2.71-5.34), and 8.23 (95% CI, 4.91-13.77) times more likely to have a recent history of concussions after accounting for relevant factors. Conclusion: Self-reported concussions among US high school athletes is related to several deleterious health behaviors and outcomes. These associations should be confirmed in longitudinal analyses

Associations Between School Transport and Obesity by Gender, Grade, Physical Activity, Race/Ethnicity, and Economic Disadvantage

Declining rates of active transportation to school have coincided with the childhood obesity epidemic. The contribution of school transport modes to obesity among children may vary by sociodemographic characteristics. PURPOSE: To examine the prevalence of school transport modes and obesity by gender, grade, physical activity, race/ethnicity, and economic disadvantage in a representative sample of Texas school children. METHODS: Cross-sectional data on reported sociodemographic characteristics, school transport mode, and physical activity behavior were collected from the Texas School Physical Activity and Nutrition (SPAN) Survey, 2015-2016. Measured height and weight were used to calculate BMI and classify 4th, 8th, and 11th grade students by obesity status. The sampling frame had 14,976 students from 359 schools to provide weighted state-level estimates by grade. Associations were conducted between school transport modes and obesity. Interaction terms were included to test if school transport mode-obesity associations differed by gender, grade, physical activity, race/ethnicity, or economic disadvantage. RESULTS: Active and passive school transport modes were not significantly associated with obesity (p\u3e0.05). Gender, grade, physical activity, race/ethnicity, and economic disadvantage were significantly associated with obesity (p\u3c0.05). Bike to school by race/ethnicity and walk to school by grade were significantly associated with obesity (p\u3c0.05), after controlling for all other sociodemographic characteristics. Hispanic/African American students who biked to school were significantly more likely to have obesity compared to White/Other students who did not bike to school (OR=5.48, p\u3c0.05, 95% CI: 1.25, 24.00). Students in 8th grade who walked to school were significantly less likely to have obesity than 4th/11th grade students who did not walk to school (OR=0.42, p\u3c0.05, 95% CI: 0.19, 0.91). CONCLUSION: These findings suggest that associations between active school transport modes and obesity differ by sociodemographic characteristics, including race/ethnicity and grade. Population-based approaches to childhood obesity prevention may benefit from understanding disparities in opportunities for school transport modes

The Safety of Maximal Exercise Testing

Previous reports on the safety of exercise testing have been based on surveys from different testing facilities with a variety of testing protocols and patient types. From 1971 through 1987, 71,914 maximal exercise tests conducted in a population with a low prevalence of known coronary heart disease under uniform conditions at a single medical facility resulted in six major cardiac complications including one death. No complications have occurred in the past 10 years in 45,000 maximal tests. The overall cardiac complication rate in men and women is 0.8 complications per 10,000 tests with 95% confidence intervals of 0.3-1.9 complications per 10,000 tests. Maximal exercise testing appears safer than some previously published reports have suggested and seems to be getting safer with time