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

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

Prevalência de atividade física em adolescentes e fatores associados

OBJECTIVE: To estimate the prevalence and identify correlates of physical activity among adolescents. METHODS: Cross-sectional study nested within a cohort of 4,325 subjects from the city of Pelotas, Southern Brazil, aged 14-15 years in 2008. Physical activity was analyzed using three different approaches: (1) prevalence of any leisure-time physical activity; (2) prevalence of any active commuting to school; and (3) prevalence of engaging in at least 300 minutes per week of both (1) and (2) combined. Independent variables included sociodemographic, behavioral, social, and biological characteristics, and number of different leisure-time physical activites practiced. Statistical analyses were carried out using Poisson regression. RESULTS: The proportion of adolescents involved in any type of leisure-time physical activity was 75.6%, while 73.4% displayed some form of active commuting to school. Prevalence of total physical activity score (>; 300 min/week) was 48.2%, being greater among boys (62.6%) than among girls (34.5%). Furthermore, prevalence increased along with the number of physical activity modalities practiced (pOBJETIVO: Estimar la prevalencia de actividad física entre adolescentes y identificar los factores asociados. MÉTODOS: Estudio transversal anidado en una cohorte con 4.325 individuos de 14-15 años en Pelota, Sur de Brasil, en 2008. La actividad física fue analizada por medio de tres diferentes abordajes: 1) prevalencia de alguna actividad física de ocio; 2) prevalencia de algún traslado activo para la escuela; 3) prevalencia de compromiso de por lo menos 300 minutos por semana en la combinación de ambos (1 y 2). Variables independientes incluyeron características demográficas, socioeconómicas, comportamentales, sociales y biológicas y número de actividades físicas practicadas en el tiempo de ocio. Los análisis estadísticos fueron hechos por la regresión de Poisson. RESULTADOS: La proporción de adolescentes envueltos en alguna actividad física de ocio fue 75,6% mientras que 73,4% presentaron alguna forma de traslado activo para la escuela. La prevalencia de actividad física total (escore ³ 300 min/sem) fue 48,2% siendo mayor para los niños (62,6%) que para las niñas (34,5%). Además, la prevalencia aumentó de acuerdo con el número de actividades físicas practicadas (pOBJETIVO: Estimar a prevalência de atividade física entre adolescentes e identificar fatores associados. MÉTODOS: Estudo transversal aninhado em uma coorte com 4.325 indivíduos de 14-15 anos em Pelotas, RS, em 2008. A atividade física foi analisada por meio de três diferentes abordagens: 1) prevalência de alguma atividade física de lazer; 2) prevalência de algum deslocamento ativo para a escola; 3) prevalência de engajamento em pelo menos 300 minutos por semana da combinação de ambos (1 e 2). Variáveis independentes incluíram características demográficas, socioeconômicas, comportamentais, sociais e biológicas e número de atividades físicas praticadas no tempo de lazer. As análises estatísticas foram feitas pela regressão de Poisson. RESULTADOS: A proporção de adolescentes envolvidos em alguma atividade física de lazer foi 75,6%, enquanto 73,4% apresentou alguma forma de deslocamento ativo para a escola. A prevalência de atividade física total (escore >; 300 min/sem) foi 48,2%, sendo maior para os meninos (62,6%) do que para as meninas (34,5%). Além disso, a prevalência aumentou de acordo com o número de atividades físicas praticadas (p < 0,001). Os fatores associados à maior prática de atividade física (lazer + deslocamento) nos níveis recomendados foram: cor de pele não-branca, ter repetido de ano na escola e jogar videogame. As variáveis menor nível socioeconômico, maior tempo de uso de computador e atividade física dos pais estiveram associadas ao desfecho apenas entre as meninas. CONCLUSÕES: Menos da metade dos adolescentes atingiu as recomendações para a prática de atividade física, e essa proporção tende a diminuir entre os sujeitos de maior nível socioeconômico. Os fatores associados diferiram entre lazer e deslocamento. Engajamento em uma ampla variedade de atividades físicas deve ser encorajado desde a infância