Dose-dependent associations of joint aerobic and muscle-strengthening exercise with obesity: A cross-sectional study of 280,605 adults

BACKGROUND

Emerging epidemiological evidence suggests that compared to engaging in 1 activity mode alone, a combination of moderate-to-vigorous physical activity (MVPA: brisk walking/jogging, cycling) and muscle-strengthening exercise (MSE: push-ups/sit-ups, using weight machines) has more favorable associations with optimal weight status. However, few studies have examined the dose-dependent and joint associations of MVPA and MSE with obesity.

METHODS

Based on cross-sectional analyses of the European Health Interview Survey Wave 2 (2013-2014), we examined prevalence ratios (PRs) of joint and stratified associations between MVPA (4 categories: (i) 0 min/week, (ii) 1-149 min/week, (iii) 150-299 min/week, and (iv) ≥300 min/week) and MSE (3 categories: (i) 0 day/week, (ii) 1 day/week, and (iii) ≥2 days/week) with body mass index-defined obesity (body mass index of ≥30.0 kg/m²) using Poisson regression with robust error variance. PRs were examined unadjusted and adjusted for sociodemographic and lifestyle characteristics (e.g., sex, age, education, income, and smoking status).

RESULTS

Data were available for 280,456 adults (≥18 years), of which 46,166 (15.5%) were obese. The interaction MVPA × MSE guideline adherence was statistically significant for obesity (p ≤ 0.05). The joint MVPA-MSE analysis showed that compared to the reference group (i.e., no MVPA and no MSE), the PRs followed a dose-dependent pattern, with the lowest observed among those reporting ≥150 MVPA min/week and ≥1 MSE days/week (PR: 0.43; 95% confidence interval: 0.41-0.46). When stratified across each MVPA strata, the PRs were mostly lower among those engaging in MSE 1 day/week, as compared to those doing MSE ≥2 days/week.

CONCLUSION

There was evidence for a dose-dependent association between joint MVPA-MSE with a reduced prevalence of obesity. Public health strategies for the prevention and management of obesity should recommend both MVPA and MSE.

Resistance Training and Mortality Risk: A Systematic Review and Meta-Analysis

INTRODUCTION

This study aimed to systematically review and meta-analyze the relationship between resistance training and all-cause, cardiovascular disease, and cancer mortality.

METHODS

Systematic review and meta-analysis following PRISMA guidelines (International Prospective Register of Systematic Reviews Registration Number CRD42019136654) was conducted. MEDLINE (OVID), Embase, Emcare, SPORTDiscus, The Cochrane Library, and SCOPUS were searched from inception to June 6, 2021. Included studies reported resistance training as the exposure and all-cause mortality, cardiovascular disease‒specific mortality, and/or cancer-specific mortality as outcome/s. Only studies conducted among nonclinical adult populations (aged ≥18 years) and written in English were included.

RESULTS

A total of 10 studies were included in the meta-analyses. Compared with undertaking no resistance training, undertaking any amount of resistance training reduced the risk of all-cause mortality by 15% (RR of 6 studies=0.85; 95% CI=0.77, 0.93), cardiovascular disease mortality by 19% (RR of 4 studies=0.81; 95% CI=0.66, 1.00), and cancer mortality by 14% (RR of 5 studies=0.86; 95% CI=0.78, 0.95). A dose-response meta-analysis of 4 studies suggested a nonlinear relationship between resistance training and the risk of all-cause mortality. A maximum risk reduction of 27% was observed at around 60 minutes per week of resistance training (RR=0.74; 95% CI=0.64, 0.86). Mortality risk reductions diminished at higher volumes.

DISCUSSION

This systematic review and meta-analysis provides the strongest evidence to date that resistance training is associated with reduced risk of all-cause, cardiovascular disease, and cancer-specific mortality. More research is needed to determine whether any potential mortality benefits gained from resistance training diminish at higher volumes.

Aerobic or Muscle-Strengthening Physical Activity: Which Is Better for Health?

ABSTRACT

The Physical Activity Guidelines recommend performing 150 min of moderate- to vigorous-intensity aerobic physical activity (MVPA) per week. These guidelines also recommend muscle-strengthening physical activity (MSPA) on ≥2 d·wk-1 for additional benefits including muscular fitness and bone health. The majority of the scientific evidence supporting the PA recommendations for health comes from studies of MVPA while the possible contributions of MSPA in these findings have been overlooked historically. Emerging evidence suggests that MSPA can independently protect against major cardiometabolic risk factors, chronic diseases, and mortality. Additional data from clinical trials indicate that many of the well-known health benefits of exercise, like improvements in cardiovascular disease risk factors, are more robust with combined MVPA and MSPA. This review will clarify the relative benefits of MSPA versus MVPA on health-related outcomes to determine the best type of PA for health.

Using Wearable Cameras to Categorize the Type and Context of Screen-Based Behaviors Among Adolescents: Observational Study

BACKGROUND

Automated wearable cameras present a new opportunity to accurately assess human behavior. However, this technology is seldom used in the study of adolescent's screen exposure, and the field is reliant on poor-quality self-report data.

OBJECTIVE

This study aimed to examine adolescents' screen exposure by categorizing the type and context of behaviors using automated wearable cameras.

METHODS

Adolescents (mean age 15.4 years, SD 1.6 years; n=10) wore a camera for 3 school evenings and 1 weekend day. The camera captured an image every 10 seconds. Fieldwork was completed between February and March 2020, and data were analyzed in August 2020. Images were date and time stamped, and coded for screen type, content, and context.

RESULTS

Data representing 71,396 images were analyzed. Overall, 74.0% (52,842/71,396) of images contained screens and 16.8% (11,976/71,396) of images contained multiple screens. Most screen exposures involved television sets (25,950/71,396, 36.3%), smartphones (20,851/71,396, 29.2%), and laptop computers (15,309/71,396, 21.4%). The context of screen use differed by device type, although most screen exposures occurred at home (62,455/64,856, 96.3%) and with solitary engagement (54,430/64,856, 83.9%). The immediate after-school period saw high laptop computer use (4785/15,950, 30.0%), while smartphone use (2059/5320, 38.7%) peaked during prebedtime hours. Weekend screen exposure was high, with smartphone use (1070/1927, 55.5%) peaking in the early morning period and fluctuating throughout the day.

CONCLUSIONS

There was evidence for high screen use during the after-school and weekend period, mostly through solitary engagement, and within the home environment. The findings may inform the basis of larger studies aimed at examining screen exposure in free-living conditions.

Is all activity equal? Associations between different domains of physical activity and depressive symptom severity among 261,121 European adults

BACKGROUND

Physical activity is often associated with better mental health. However, there is evidence that the domain of physical activity influences the strength and direction of this association. Therefore, this study aimed to examine the associations between different domains of physical activity and depression among a large sample of adults living in the European Union.

METHODS

Cross-sectional analyses were conducted on 261,121 adults, recruited in the European Health Interview Survey (wave 2). Validated items were used to assess physical activity domains (i.e., work-related, transport-related, leisure-time aerobic, and muscle-strengthening) and depression symptom severity (8-item personal health questionnaire). Generalized linear models with Poisson regressions provided adjusted prevalence ratios (APR) of depressive symptom severity categories across the physical activity domains.

RESULTS

Compared to doing no physical activity, any physical effort at work (APR: 0.82-0.86), moderate, high, and very high levels of transport-related (APR: 0.69-0.83) and aerobic leisure-time activity (APR: 0.78-0.87), and 3 days/week of muscle-strengthening (APR: 0.93) were associated with a lower prevalence of mild depressive symptom severity. Moreover, doing any level of physical activity in any domain was mostly associated with a lower prevalence of moderate (APR: 0.43-0.80), moderate-severe (APR: 0.34-0.82), and severe (APR: 0.26-0.56) depressive symptoms.

CONCLUSION

Favorable associations were seen between any domain (leisure-time, transport- and work-related) of physical activity and depressive symptom severity. The more severe the symptoms, the stronger the associations. Both modalities of leisure-time physical activity (aerobic and muscle-strengthening) demonstrated beneficial associations with depression, but slightly more so for aerobic physical activity.

The epidemiology of muscle-strengthening activity among adolescents from 28 European countries

AIMS

This study aimed to describe the prevalence and socio-demographic and lifestyle-related correlates of muscle-strengthening activity (MSA; strength/resistance training, sit-ups/push-ups, etc.) among a large sample of European adolescents.

METHODS

Data were drawn from the European Health Interview Survey Wave 2 (2013-2014), including 8818 adolescents (15-17 years) from 28 European countries. Self-reported MSA was assessed using a previously validated survey item. Population-weighted prevalence ratios were calculated for (a) 'none' (0 days/week), (b) 'insufficient MSA' (1-2 days/week) or (c) 'sufficient MSA' (⩾3 days/week). Generalised linear models using Poisson regression with robust error variance were used to calculate the prevalence ratios for adolescents reporting sufficient MSA by socio-demographic/lifestyle characteristics and by European region.

RESULTS

Overall, 19.4% (95% confidence interval (CI) 18.3-20.7) reported sufficient (⩾3 days/week) MSA and 57.9% (95% CI 56.4-59.6) reported none. Females, adolescents from Southern and Eastern European regions, those not meeting the aerobic guideline and adolescents classified as overweight were significantly associated with a lower likelihood of reporting sufficient MSA, independent of other characteristics.

CONCLUSIONS

The majority of European adolescents do not meet the MSA guidelines. Future large-scale MSA public-health interventions should target female and currently inactive adolescents, as well as those from Southern and Eastern European regions.

Is device-based total and domain-specific sedentary behaviour associated with psychological distress in Flemish workers?

BACKGROUND

There is increasing interest in the association between psychological distress and time spent in sedentary behaviour (e.g. sitting), a highly prevalent behaviour in modern society. The limited evidence is mixed and mainly based on studies using self-reported sedentary time. Few studies have investigated device-based total sedentary time in its association with distress. None, however, have examined device-based domain-specific sedentary time in relation to psychological distress. The aim of this study was to investigate whether device-based total and domain-specific sedentary behaviour were associated with psychological distress.

METHODS

Flemish employees (n = 401; 20-64 years; 42.6% male; 83.6% had a 'physically active occupation') of seven organizations in service and production sectors participated. Sedentary behaviour (exposure) was assessed by two Axivity AX3 accelerometers (one placed on the thigh and one placed between the shoulders) for two to four consecutive working days. Based on diary completion, domain-specific sedentary behaviour (leisure vs. work) was assessed. The 12-item General Health Questionnaire was used to assess psychological distress (outcome). Adjusted hierarchical multiple regression models were conducted to report on the associations between total and domain-specific sedentary behaviour and psychological distress.

RESULTS

About 35% of the sample had high levels of distress and average total sedentary time was 7.2 h/day. Device-based total sedentary behaviour [B = -0.009, 95% confidence interval (CI), -0.087 to 0.068], leisure-time (B = 0.001, 95% CI, -0.017 to 0.018) and work-related (B = 0.004, 95% CI, -0.006 to 0.015) sedentary behaviour were not significantly associated with psychological distress.

CONCLUSION

This cross-sectional study examining the association between device-based total and domain-specific sedentary behaviour and psychological distress among employees showed a lack of significant findings.

Resistance exercise, alone and in combination with aerobic exercise, and obesity in Dallas, Texas, US: A prospective cohort study

BACKGROUND

Obesity is a significant and growing public health problem in high-income countries. Little is known about the relationship between resistance exercise (RE), alone and in combination with aerobic exercise (AE), and the risk of developing obesity. The purpose of this prospective cohort study was to examine the associations between different amounts and frequencies of RE, independent of AE, and incident obesity.

METHODS AND FINDINGS

Participants were 11,938 healthy adults ages 18-89 years with a BMI < 30 kg/m2 at baseline who completed at least 2 clinical examinations during 1987-2005 as part of the Aerobics Center Longitudinal Study. Self-reported RE participation in minutes/week and days/week was collected from a standardized questionnaire. Incident obesity was defined as a BMI ≥ 30 kg/m2 at follow-up. Incident obesity was also defined by waist circumference (WC) > 102/88 cm for men/women and percent body fat (PBF) ≥ 25%/30% for men/women at follow-up in participants who were not obese by WC (n = 9,490) or PBF (n = 8,733) at baseline. During the average 6-year follow-up, 874 (7%), 726 (8%), and 1,683 (19%) developed obesity defined by BMI, WC, or PBF, respectively. Compared with no RE, 60-119 min/wk of RE was associated with 30%, 41%, and 31% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.70 [0.54-0.92], p = 0.008), WC (0.59 [0.44-0.81], p < 0.001), and PBF (0.69 [0.57-0.83], p < 0.001), respectively, after adjusting for confounders including age, sex, examination year, smoking status, heavy alcohol consumption, hypertension, hypercholesterolemia, diabetes, and AE. Compared with not meeting the RE guidelines of ≥2 d/wk, meeting the RE guidelines was associated with 18%, 30%, and 30% reduced risk of obesity defined by BMI (hazard ratio [95% CI], 0.82 [0.69-0.97], p = 0.02), WC (0.70 [0.57-0.85], p < 0.001), and PBF (0.70 [0.62-0.79], p < 0.001), respectively. Compared with meeting neither guideline, meeting both the AE and RE guidelines was associated with the smallest hazard ratios for obesity. Limitations of this study include limited generalizability as participants were predominantly white men from middle to upper socioeconomic strata, use of self-reported RE, and lack of detailed diet data for the majority of participants.

CONCLUSIONS

In this study, we observed that RE was associated with a significantly reduced risk of obesity even after considering AE. However, meeting both the RE and AE guidelines was associated with the lowest risk of obesity.

Physical Activity Tracking Among Sri Lankan Adults: Findings From a 7-Year Follow-up of the Ragama Health Study

Limited data are available on physical activity tracking among adults in low- and middle-income countries. Using a longitudinal design, we assessed trends and correlates of physical activity among Sri Lankan adults. Individuals selected through age-stratified random sampling, were screened initially in 2007 (n = 2986) and reevaluated in 2014 (n = 2148). On both occasions, structured interviews and clinical measurements were completed. Approximately 40% of the participants engaged in recommended levels of physical activity both at baseline and follow-up. One-fifth reported increased physical activity at follow-up, a similar proportion reported being persistently inactive or a reduction in physical activity. In the adjusted analysis, being persistently active was associated with male sex, a lower educational level and income, being free of any chronic disease conditions, better self-rated health, and sitting time <8 hours. Our findings support public health interventions to help maintain recommended physical activity levels over time, particularly for subgroups at high-risk of physical inactivity.

The epidemiology of muscle-strengthening and aerobic physical activity guideline adherence among 24,016 German adults

Despite the 2016 German "National Recommendations for Physical Activity and Physical Activity Promotion" stating that adults (≥18 years) should engage in: [a] ≥150 minutes of aerobic moderate-to-vigorous-intensity physical activity/week (MVPA); and [b] ≥2 days/week of muscle-strengthening exercise (MSE), there is limited research on the descriptive epidemiology on the adherence to these guidelines among German adults. This study describes the prevalence and correlates of physical activity guideline adherence among a nationally representative sample of German adults. Data were drawn from the 2014 German Health Update survey, collected via a combination of web-based and mail surveys. Self-reported physical activity levels were assessed using the previously validated European Health Interview Survey Physical Activity Questionnaire. Weighted prevalence levels of the sample meeting the aerobic MVPA (≥150 minutes/week), MSE (≥2 times/week), and combined MVPA-MSE guidelines were calculated. Poisson regressions were used to assess prevalence ratios for physical activity guideline adherence categories across sociodemographic and lifestyle-related variables. Out of 24,016 participants (response rate = 27.6%), aged ≥ 18 years, 45.3% (95% CI: 44.5%-46.0%), 29.4% (95% CI: 28.7%-30.1%), and 22.6% (95% CI: 21.9%-23.2%) met the aerobic MVPA, MSE, and combined guidelines, respectively. Population sub-groups less likely to meet the combined guidelines included those with poor self-rated health, being unemployed, low socioeconomic status, being a current smoker, and those being overweight or obese. Since ~ 80% of German adults do not meet the nationally recommended combined aerobic MVPA-MSE physical activity guidelines, there is a necessity for large-scale public health interventions promoting both aerobic MVPA and MSE.

Association of meeting both muscle strengthening and aerobic exercise guidelines with prevalent overweight and obesity classes - results from a nationally representative sample of German adults

OBJECTIVES

German national physical activity guidelines specify adults (≥18 years) should engage in at least: (i) 150 min of aerobic moderate-to-vigorous-intensity physical activity/week (MVPA); and (ii) muscle-strengthening exercise (MSE) 2 days/week. However, the relationship between MVPA and MSE and overweight/obesity has not been examined among German adults. Aim of this study was to examine whether meeting the guidelines for both MVPA and MSE is associated with a lower prevalence of overweight/obesity compared to meeting MVPA or MSE alone or none of them, among a nationally representative sample of German adults.

METHODS

The cross-sectional study drew data from the 2014 German Health Update (GEDA) (n=22,822; ≥18 years). Physical activity (MVPA-MSE), height/weight, socio-demographic, health and lifestyle factors were assessed by self-report via validated questionnaires. Generalized linear models with Poisson regression were used to assess prevalence ratios of Body Mass Index-derived (BMI) overweight/obesity across categories of physical activity guideline adherence (met neither; MSE only; MVPA only; met both).

RESULTS

Compared to other physical activity groups, meeting both the MVPA-MSE guidelines was associated with the lowest prevalence rate of overweight/obesity (Adjusted Prevalence Ratios [APR] range: 0.25-0.73). Associations between BMI and physical activity were strongest among Class II obesity (APR range: 0.25-0.45). The associations remained consistent after adjusting sociodemographic and lifestyle factors.

CONCLUSIONS

Meeting the combined MVPA-MSE guideline, as suggested in the German national physical activity recommendations, showed the lowest overweight/obesity prevalence. Promoting uptake and adherence of both MVPA and MSE at the population level could help to reduce the public health burden of obesity.

Screen-based behaviors in Australian adolescents: Longitudinal trends from a 4-year follow-up study

The longitudinal trends of screen time, a highly prevalent behavior in adolescents, are relatively unknown. This study examined longitudinal trends in screen time among a large sample of Australian primary school-aged children transitioning into secondary school-aged adolescence. Data were derived from the Longitudinal Study of Australian Children (LSAC). In 2010, 2179 children (49.7% boys; 10.3 ± 1.1 years) completed a time-use diary, recording their main activities during waking hours. This was repeated with the same sample in 2012 (12.4 ± 0.5 years) and 2014 (14.4 ± 0.5 years). Data were analyzed for time spent in TV viewing, computer use, electronic gaming, and social networking and online communication. Repeated-measures MANCOVA tests were performed to analyze trends in screen time. Trends were also analyzed by sex. Total screen time significantly increased (+85.9 min/day) over four years (η_p² = 0.010, P < .001), but differed by sex, with a larger increase in boys (boys: +41.6, girls: +22.7 min/day). Electronic gaming increased in boys (+43.2 min/day) and decreased in girls (-16.8 min/day). In contrast, girls reported larger increases in TV viewing (boys: +0.4, girls: +29.1 min/day), computer use (boys: +24.8, girls: +34.3 min/day) and time communicating online and social networking (boys: +4.3, girls: +15.2 min/day). To conclude, screen time among adolescents increases between the ages of 10 and 14 years, but differs by sex and screen time domain. Future screen time reduction interventions may choose to focus on recreational computer use and electronic gaming in boys and TV viewing and time spent communicating online and social networking for girls.

Muscle-strengthening exercise and sleep quality among a nationally representative sample of 23,635 German adults

Regular physical activity is a key modifiable non-pharmacological treatment to enhance sleep quality, a key predictor of optimal health and wellbeing. Most of the evidence on physical activity and sleep quality is based on studies assessing the effects of aerobic moderate-to-vigorous physical activity (e.g. brisk walking, cycling, jogging). Emerging clinical evidence suggests that muscle-strengthening exercise (e.g. push-ups, using weight machines) may also be beneficial for sleep quality. However, since no studies have examined the associations between muscle-strengthening exercise with sleep quality among a large sample of community-dwelling adults, it is currently unknown how these findings translate to the population level. This study describes the associations between the weekly frequency of muscle-strengthening exercise and sleep quality among a nationally representative sample of German adults. Data were drawn for the 2014 German Health Update Survey (n = 23,635; ≥18 years). Validated survey items assessed muscle-strengthening exercise (times/week) and sleep quality (assessed via 4 point-scale: 'very poor' to 'good'). Poisson regression with robust error variance was used to calculate prevalence ratios of (PR) across weekly muscle-strengthening exercise frequency (None [reference]; 1, 2, 3-4 and ≥ 5 times/week), adjusting for potential confounders (e.g. age, sex, socioeconomic status, self-rated health, smoking, alcohol, aerobic physical activity). Compared with those reporting none, any muscle-strengthening exercise was associated with a reduced prevalence of 'poor' (PR range: 0.77-0.83) and 'very poor' (PR range: 0.57-0.70) quality sleep. Future health behavior modification strategies to enhance sleep quality at the population-level should consider promoting muscle-strengthening exercise.

The epidemiology of muscle-strengthening exercise in Europe: A 28-country comparison including 280,605 adults

OBJECTIVE

Muscle-strengthening exercise (use of weight machines, free weights, push-ups, sit-ups), has multiple independent health benefits, and is a component of the Global physical activity guidelines. However, there is currently a lack of multi-country muscle-strengthening exercise prevalence studies. This study describes the prevalence and correlates of muscle-strengthening exercise across multiple European countries.

METHODS

Data were drawn from the European Health Interview Survey Wave 2 (2013-14), which included nationally representative samples (n = 3,774-24,016) from 28 European countries. Muscle-strengthening exercise was assessed using the European Health Interview Survey Physical Activity Questionnaire. Population-weighted proportions were calculated for (1) "insufficient" (0-1 days/week) or (2) "sufficient" muscle-strengthening exercise (≥2 days/week). Prevalence ratios were calculated using multivariate Poisson regression for those reporting sufficient muscle-strengthening by country and by sociodemographic/lifestyle characteristics (sex, age, education, income, self-rated health etc.).

RESULTS

Data were available for 280,605 European adults aged ≥18 years. Overall, 17.3% (95% CI = 17.1%-17.5%) reported sufficient muscle-strengthening exercise (≥2 days/week). Muscle-strengthening exercise was geographically patterned with the lowest prevalence reported in South-eastern European countries (Romania, Malta and Cyprus: range: 0.7%-7.4%), and the highest prevalence in the Nordic countries (Iceland, Sweden, and Denmark: range: 34.1%-51.6%). Older age, insufficient aerobic activity, poorer self-rated health, lower income/education, being female, and being overweight/obese were significantly associated with lower likelihood of reporting sufficient muscle-strengthening exercise, independently of other characteristics.

CONCLUSIONS

Most European adults do not report sufficient muscle-strengthening exercise, and prevalence estimates varied considerably across countries. Low participation in muscle-strengthening exercise is widespread across Europe, and warrants public health attention.

Exploring contemporary screen time in Australian adolescents: A qualitative study

ISSUE ADDRESSED

Screen time, a highly prevalent behaviour, can be detrimental to adolescent health. To better understand this health-related behaviour, this study explores the nature of adolescents' contemporary screen engagement, adding to the currently limited body of qualitative research in this area.

METHODS

Sixteen adolescents (9 girls and 7 boys) aged 13-17 years from a secondary school in Queensland, Australia participated in semi-structured one-on-one interviews. All interviews were transcribed verbatim, anonymised and thematically analysed using an inductive approach.

RESULTS

Smartphone use was ubiquitous, occurring mostly at home, after school, and typically used for social, entertainment and functional activities. Binge-watching and multi-screening emerged as common sedentary patterns of contemporary screen engagement, often performed solitary. Screen time appeared to be an important aspect of adolescents' social lives, while there were also some psychological, physical and behavioural concerns. Family and friends were thought to influence adolescents' screen time either directly (co-participation) or indirectly (modelling), while social smartphone notifications were said to prompt habitual, frequent and prolonged screen engagement.

CONCLUSION

This study provided several new insights into the nature, functions, patterns, and benefits and concerns of adolescents' contemporary screen engagement. On the whole, adolescents engaged in a wide variety of screen-viewing practices, including newer digital media, mostly as a function to connect with friends and family. SO WHAT?: It might be desirable for screen time reduction interventions and policies to take into account the underlying social and psychological factors, and habitual nature of contemporary screen engagement among adolescents.

Associations of muscle-strengthening and aerobic exercise with self-reported components of sleep health among a nationally representative sample of 47,564 US adults

OBJECTIVES

Evidence demonstrates that physical activity is favorably associated with indicators of sleep health. However, population-based studies rarely examine the relationship between different physical activity modalities (ie, aerobic exercise vs muscle-strengthening exercise) with components of sleep health.

METHODS

Cross-sectional analyses were conducted on the US 2017 Behavioral Risk Factor Surveillance System. Validated items assessed self-reported moderate-to-vigorous-intensity aerobic physical activity (MVPA), muscle-strengthening exercise (MSE), sleep duration, difficulties and disorders. Poisson regression assessed prevalence ratios (PR) of 5 components of detrimental sleep health (short sleep; long sleep; poor quality sleep; observed snoring; and observed breathing stoppage) separately for adults 18-64 years and ≥65 years, across 4 categories of physical activity guideline adherence (met neither [reference]; MSE only; MVPA only; met both).

RESULTS

The sample comprised 47,564 adults (mean age: 48.4 years; ±1.4; 51.6% female). Among those 18-64 years, with the exception of short sleep (4-6 hours), for all other detrimental sleep health components, the lowest PRs were observed among those meeting both MVPA-MSE guidelines. Among those aged ≥65 years, for all 5 detrimental sleep health components, compared to the other physical activity categories, the lowest PRs were observed among those meeting both MVPA-MSE guidelines. All associations remained after adjusting for potential confounders (sex, education, income, smoking, alcohol, depression, hypertension, diabetes).

CONCLUSION

A physical activity routine that includes both MVPA and MSE is likely to be beneficial for better sleep health. Longitudinal studies are needed to establish the temporal relationships between MVPA/MSE guideline adherence and sleep health.

Adherence to aerobic and muscle-strengthening exercise guidelines and associations with psychological distress: A cross-sectional study of 14,050 English adults

Physical activity (PA) is beneficial for the prevention and management of psychological distress. However, no studies have investigated which combination/s of PA prescribed in the current global guidelines (i.e. aerobic moderate-to-vigorous PA [MVPA] and muscle-strengthening exercise [MSE]) are most strongly linked to reduced psychological distress. This study aimed to examine how PA guidelines adherence is associated with psychological distress. Using cross-sectional data of adults (n = 14,050) who participated in the 2012-2016 Health Survey for England, four categories of self-reported PA guidelines adherence were created: meeting none, only MSE, only aerobic MVPA, meeting both (exposure variables). Psychological distress (outcome) was measured using the General Health Questionnaire-12. The likelihood of experiencing high levels of psychological distress (cut-point of ≥4) across guidelines adherence categories was examined using logistic regression models adjusted for sociodemographic and lifestyle factors. About 17% of adults experienced high levels of psychological distress; 37.5% did not adhere to any PA guidelines (category 1), 1.3% met only MSE (category 2), 35.5% met only aerobic MVPA (category 3), and 25.7% met both guidelines (category 4). Compared to category 1, the likelihood of experiencing high psychological distress was lowest in category 4 (OR = 0.65, 95% CI: 0.54-0.77) followed by category 3 (OR = 0.78, 95% CI: 0.67-0.90), while it did not differ in category 2 (OR = 1.24, 95% CI: 0.75-2.05). This is the first study to identify the association between PA guidelines adherence and psychological distress in a large population sample. Findings suggest that meeting both aerobic MVPA and MSE guidelines might be most beneficial for mental health.

Muscle-strengthening Exercise Epidemiology: a New Frontier in Chronic Disease Prevention

This current opinion provides an overview of the emerging discipline of muscle-strengthening exercise epidemiology. First, we define muscle-strengthening exercise, and discuss its recent addition into the global physical activity guidelines, which were historically mainly focused on aerobic physical activity (walking, running, cycling etc.). Second, we provide an overview of the current clinical and epidemiological evidence on the associations between muscle-strengthening exercise and health, showing a reduced mortality risk, and beneficial cardiometabolic, musculoskeletal, functional and mental health-related outcomes. Third, we describe the latest epidemiological research on the assessment, prevalence, trends and correlates of muscle-strengthening exercise. An overview of recent population estimates suggests that the proportion of adults meeting the current muscle-strengthening exercise guideline (10-30%; ≥ 2 sessions/week) is far lower than adults reporting meeting the aerobic exercise guideline (~ 50%; ≥ 150 min/week). Fourth, we discuss the complexity of muscle-strengthening exercise promotion, highlighting the need for concurrent, coordinated, and multiple-level strategies to increase population-level uptake/adherence of this exercise modality. Last, we explore key research gaps and strategies that will advance the field of muscle-strengthening exercise epidemiology. Our objective is to provide a case for increased emphasis on the role of muscle-strengthening exercise for chronic disease prevention, and most importantly, stimulate more research in this currently understudied area of physical activity epidemiology.

Joint and dose-dependent associations between aerobic and muscle-strengthening activity with depression: A cross-sectional study of 1.48 million adults between 2011 and 2017

BACKGROUND

Research has shown that regular physical activity is key for the prevention and/or treatment of depression. However, epidemiological studies describing the associations between different physical activity modes (i.e., aerobic vs. muscle-strengthening exercise) with depression are limited.

METHODS

Cross-sectional analyses were conducted on pooled data from four U.S. health surveillance surveys (2011-2017). Validated survey items assessed self-reported moderate-to-vigorous-intensity physical activity (MVPA) and muscle-strengthening activity (MSA). Twenty groups were created, ranging from (a) "inactive" (0 MVPA min/week & MSA 0 times/week) to (xx) "most active" (≥300 MVPA min/week & MSA ≥4 times/week). Poisson regression with a robust error variance was used to assess prevalence ratios (PRs) of self-reported clinically diagnosed depression (outcome variable) across physical activity groups (exposure variables).

RESULTS

The sample contained 1,477,981 adults (≥18 years), of which 286,325 (18.0%) had depression. Compared to the reference group (i.e., no MVPA and no MSA), almost all physical activity combinations were associated with lower depression prevalence. Lowest prevalence of depression was shown for those combining sufficient MVPA-MSA (MVPA ≧300 min/week and MSA ≥2 times/week; adjusted prevalence ratio range: 0.54-0.63). All associations remained after stratification and/or adjustment for sociodemographic (age, sex, income, education), lifestyle characteristics (body mass index, self-rated health, smoking, alcohol), comorbidities (e.g., arthritis, diabetes, hypertension), and year of survey.

CONCLUSIONS

A physical activity routine that includes both aerobic and MSA is likely to be optimal for the prevention of depression. Public health approaches targeting depression should endorse joint aerobic and MSA as key lifestyle modification strategy.

Muscle Strengthening, Aerobic Exercise, and Obesity: A Pooled Analysis of 1.7 Million US Adults

OBJECTIVE

Both aerobic physical activity and muscle-strengthening exercise are recommended for obesity prevention. However, at the population level, the independent and/or combined associations of these physical activity modalities with obesity are unknown. The aim of this study was to examine the associations between aerobic physical activity and muscle-strengthening exercise with obesity among a representative sample of adults.

METHODS

Data were pooled from four US public health surveillance surveys from 2011 to 2017. Cross-sectional associations between adherence to the aerobic physical activity (≥ 150 min/wk) and muscle-strengthening exercise (≥ 2 times/wk) guidelines with different classes of BMI-defined obesity were examined using Poisson regression. Prevalence ratios are reported as both unadjusted and adjusted for sociodemographic and lifestyle characteristics.

RESULTS

Data were available for 1,677,108 adults (≥ 18 years old). Compared with meeting neither guideline (reference category), meeting both guidelines was associated with the lowest adjusted prevalence ratios (APRs) for the following: Class I obesity and above (BMI ≥ 30.0 kg/m² ), APR = 0.54 (95% CI: 0.53-0.54); Class II obesity and above (BMI ≥ 35.0 kg/m² ), APR = 0.32 (95% CI: 0.31-0.33); and Class III obesity and above (BMI ≥ 40.0 kg/m² ), APR = 0.21 (95% CI: 0.20-0.21).

CONCLUSIONS

Among nearly 1.7 million US adults, meeting both aerobic and muscle-strengthening exercise guidelines was associated with a lower obesity prevalence, and associations were more pronounced for higher obesity classes.

The epidemiology of aerobic physical activity and muscle-strengthening activity guideline adherence among 383,928 U.S. adults

BACKGROUND

The World Health Organization's 'Global Recommendations on Physical Activity for Health' state that adults should engage in regular moderate-to-vigorous intensity aerobic physical activity (MVPA; e.g. walking, running, cycling) and muscle-strengthening activity (MSA; e.g. strength/resistance training). However, assessment of both MVPA and MSA is rare in physical activity surveillance. The aim of this study is to describe the prevalence, correlates and chronic health conditions associated with meeting the combined MVPA-MSA guidelines among a population representative sample of U.S. adults.

METHODS

In this cross-sectional study, data were drawn from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone interviews, MVPA and MSA were assessed using validated questionnaires. We calculated the proportions meeting both the global MVPA and MSA physical activity guidelines (MVPA ≥150 min/week and MSA ≥2 sessions/week). Poisson regressions with a robust error variance were used to assess: (i) prevalence ratios (PR) for meeting both guidelines across sociodemographic factors (e.g. age, sex, education, income, race/ethnicity); and (ii) PRs of 12 common chronic health conditions (e.g. diabetes, coronary heart disease, hypertension, depression) across different categories of physical activity guideline adherence (met neither [reference]; MSA only; MVPA only; met both).

RESULTS

Among 383,928 adults (aged 18-80 years), 23.5% (95% CI: 20.1, 20.6%) met the combined MVPA-MSA guidelines. Those with poorer self-rated health, older adults, women, lower education/income and current smokers were less likely to meet the combined guidelines. After adjustment for covariates (e.g. age, self-rated health, income, smoking) compared with meeting neither guidelines, MSA only and MVPA only, meeting the combined MVPA-MSA guidelines was associated with the lowest PRs for all health conditions (APR range: 0.44-0.76), and the clustering of ≥6 chronic health conditions (APR = 0.33; 95% CI: 0.31-0.35).

CONCLUSIONS

Eight out of ten U.S. adults do not meet the global physical activity guidelines. This study supports the need for comprehensive health promotion strategies to increase the uptake and adherence of MVPA-MSA among U.S. adults. Large-scale interventions should target specific population sub-groups including older adults, women, those with poorer health and lower education/income.

Associations between aerobic and muscle-strengthening exercise with depressive symptom severity among 17,839 U.S. adults

For the prevention and management of chronic diseases, global physical activity guidelines state that an adult should engage in regular moderate-to-vigorous aerobic physical activity (MVPA; e.g. walking, cycling, running) and muscle-strengthening exercise (MSE; e.g. strength/resistance training). However, the associations between combined MVPA-MSE with chronic health conditions are rarely examined in large population studies. In particular, little is known associations between combined MVPA-MSE with depressive disorders, one of the leading causes of disability worldwide. The aim of this study is to describe the associations between MVPA and MSE with depressive symptom severity among a large sample of U.S. adults. Data were drawn from the U.S. 2015 Behavioral Risk Factor Surveillance System. During phone interviews, MVPA, MSE and depressive symptom severity were assessed by validated questionnaires. Poisson regression with a robust error or variance were used to assess prevalence ratios (PR) of depressive symptom severity (mild, moderate, moderately severe/severe) across categories of physical activity guideline adherence (met neither [reference]; MSE only; MVPA only; met both), adjusting for a set of potential cofounders. Data were available on 17,839 adults (18-85 years). When compared with those meeting neither guideline, for mild, moderate and moderately severe/severe depressive symptoms, the PRs were lowest among meeting both guidelines (range: 0.26-0.54), followed by MVPA only (range: 0.36-0.62) and MSE only (range: 0.49-0.84). Among a large sample of U.S. adults, compared to other guideline adherence categories, meeting both MVPA-MSE guidelines was associated with a lowest likelihood of reporting depressive symptoms.

Run, lift, or both? Associations between concurrent aerobic-muscle strengthening exercise with adverse cardiometabolic biomarkers among Korean adults

BACKGROUND

Clinical exercise interventions show that combining moderate to vigorous intensity physical activity (MVPA) and muscle strengthening exercise (MSE) has more favourable cardiometabolic health benefits than engaging in only one mode of physical activity. However, few studies have examined these associations among community-based samples and none among Asian adults.

METHODS

This cross-sectional analysis included 9120 participants aged 20-80 years from the 2014-2015 Korea National Health and Nutritional Examination Survey. Fasting blood samples were analysed for adverse cardiometabolic biomarkers (e.g. high glucose/glycohaemoglobin/triglycerides) and MVPA and MSE were assessed using validated questionnaires. Poisson regression models examined the association between the individual and total number of adverse biomarkers across categories of MVPA-MSE guideline adherence (met neither (reference); met MSE only; met MVPA only; met both) and prevalence ratios are reported adjusted for covariates (e.g. age, education, smoking, waist circumference and sitting time).

RESULTS

The mean ± SD age was 46.2 ± 16.3 years and 50.3% of the participants were women. Compared with meeting neither guideline, meeting both guidelines had the lowest prevalence ratios for four out of eight individual adverse cardiometabolic biomarkers. In a sex-stratified analysis of men, only meeting both guidelines had a lower prevalence ratio for ≥4 adverse biomarkers (prevalence ratio 0.67; 95% confidence interval 0.53-0.85). For women, the prevalence ratio for ≥4 adverse biomarkers was lowest among those meeting both guidelines (prevalence ratio 0.46; 95% confidence interval 0.31-0.66), followed by MSE only (prevalence ratio 0.65; 95% confidence interval 0.42-0.96) and MVPA only (prevalence ratio 0.78; 95% confidence interval 0.65-0.92).

CONCLUSIONS

Among a large sample of Korean adults, concurrent MVPA-MSE was independently associated with favourable cardiometabolic outcomes. This study supports public health action to promote adherence to MVPA-MSE guidelines to enhance cardiovascular health among Korean adults.

Muscle-Strengthening Exercise Among 397,423 U.S. Adults: Prevalence, Correlates, and Associations With Health Conditions

INTRODUCTION

Although muscle-strengthening exercise has multiple independent health benefits, little is known about muscle-strengthening exercise participation and associations with adverse health conditions among U.S. adults.

METHODS

In 2017, data were analyzed from the U.S. 2015 Behavioral Risk Factor Surveillance System. During telephone surveys, respondents reported how many times during the past week they engaged in muscle-strengthening exercise. Weighted weekly muscle-strengthening exercise frequencies were calculated for the total sample and across sociodemographic and lifestyle characteristics. A multivariable logistic regression assessed the odds of having self-reported adverse health conditions (e.g., diabetes, coronary heart disease) according to weekly muscle-strengthening exercise frequency.

RESULTS

Data were available on 397,423 adults (aged 18-80 years). Overall, 30.2% (95% CI=29.9, 30.5) met the muscle-strengthening exercise recommendations (two or more times/week) and 57.8% (95% CI=57.5, 58.2) reported no muscle-strengthening exercise. Older age, insufficient aerobic activity, lower income, lower education, poorer self-rated health, being female, and being overweight/obese were significantly associated with lower odds of meeting the muscle-strengthening exercise recommendations independently of other characteristics. After adjusting for confounders (e.g., age, sex, income, smoking, aerobic activity), when compared with those who did none, muscle-strengthening exercise was associated with lower odds for several adverse health conditions, including prevalent diabetes, cancer (non-skin), poor self-rated health, and obesity.

CONCLUSIONS

Three in five U.S. adults do not engage in any muscle-strengthening exercise, despite an association for muscle-strengthening exercise with better health conditions. Future muscle-strengthening exercise promotion strategies should target older adults, females, those with low education/income, and those with a poor health status.

Equity of a government subsidised exercise referral scheme: A population study

BACKGROUND

Health inequities could increase if utilisation of physical activity interventions is lower among socioeconomically disadvantaged groups. We examined associations between area level socioeconomic disadvantage and utilisation of Australian government-subsidised, general practitioner (GP)-referred, accredited exercise physiologist (AEPs) services.

METHODS

We conducted a cross-sectional analysis of Australian Medical Benefits Scheme (MBS) data (N = 228,771 AEP services) for the 2015-2016 financial year and aggregated publicly available data from several sources. Spearman's correlations examined associations between utilisation of AEP services and area-level socioeconomic disadvantage, indicated by Index of Relative Socioeconomic Disadvantage (IRSD) decile scores. Lower IRSD scores indicate greater levels of socioeconomic disadvantage.

RESULTS

Significant correlations between IRSD score and study variables were as follows: Out-of-pocket expenses/service (rs = 0.52); number of patients/AEP provider (rs = -0.42); number of patients/1000 population (rs = -0.24); AEP services/1000 population (rs = -0.18); average services/patient (rs = 0.24); and AEP provider/1000 population (rs = 0.14).

CONCLUSION

Patients living in areas of greater disadvantage utilised government-subsidised, GP-referred AEP services at a higher rate and paid lower out-of-pocket fees than those living in more affluent areas. Thus, AEP services are equitably distributed, from a utilisation perspective, and acceptable to patients living in areas of disadvantage. However, the higher caseloads and lower fees that characterise AEP services in areas of greater disadvantage may result in shorter consultation times. Further research on exercise referral schemes is warranted, particularly whether socioeconomic disadvantage is associated with adherence to exercise sessions and health outcomes.

Feasibility for the Use of a Standardized Fitness Testing Protocol Among Australian Fitness Industry Professionals

PURPOSE

There is currently no standardized testing protocol for assessing clients' fitness/health within the Australian fitness industry. This study examined the perceptions of the feasibility of using a standardized testing protocol among Australian fitness industry professionals.

METHOD

In 2014, 1,206 registered fitness industry professionals (aged 17-69 years) completed an online survey. Perceived feasibility for using a standardized testing protocol was assessed based on responses to 6 items. Respondents were classified as having a high level of perceived feasibility if they reported all 6 items to be "definitely feasible." A multivariate logistic regression analysis, adjusting for demographic and fitness industry-related factors (e.g., qualification/years of experience), assessed the likelihood of having a high level of perceived feasibility.

RESULTS

Overall, 25.5% (95% CI [23.1%, 28.0%]) of the sample perceived the use of a standardized testing protocol as highly feasible. Items ranked most often as "definitely feasible" were "undertaking training to use the protocol" (55%) and "conducting follow-up testing every 6 to 12 weeks" (52%). After adjustment for the effect of confounding factors, casually employed professionals (OR = 0.63; 95% CI [0.45, 0.90]) and group instructors (OR = 0.58; 95% CI [0.41, 0.82]) were less likely to perceive standardized testing protocols as highly feasible.

CONCLUSIONS

Among a large sample of Australian fitness industry professionals, slightly more than a quarter perceived using a standardized testing protocol to be highly feasible. Group instructors and casual employees perceived lower feasibility. Further research should determine the barriers to implementing a standardized testing protocol across the fitness industry.

Physical activity and sedentary behaviour research in Thailand: a systematic scoping review

BACKGROUND

The number of deaths per year attributed to non-communicable diseases is increasing in low- and middle-income countries, including Thailand. To facilitate the development of evidence-based public health programs and policies in Thailand, research on physical activity (PA) and sedentary behaviour (SB) is needed. The aims of this scoping review were to: (i) map all available evidence on PA and SB in Thailand; (ii) identify research gaps; and (iii) suggest directions for future research.

METHODS

A systematic literature search was conducted through 10 bibliographic databases. Additional articles were identified through secondary searches of reference lists, websites of relevant Thai health organisations, Google, and Google Scholar. Studies written in Thai or English were screened independently by two authors and included if they presented quantitative or qualitative data relevant to public health research on PA and/or SB.

RESULTS

Out of 25,007 screened articles, a total of 564 studies were included in the review. Most studies included PA only (80%), 6.7% included SB only, and 13.3% included both PA and SB. The most common research focus was correlates (58.9%), followed by outcomes of PA/SB (22.2%), prevalence of PA/SB (12.4%), and instrument validation (3.2%). Most PA/SB research was cross-sectional (69.3%), while interventions (19.7%) and longitudinal studies (2.8%) were less represented. Most studies (94%) used self-reports of PA/SB, and few (2.5%) used device-based measures. Both sexes were examined in most studies (82.5%). Adults were the main target population group (51.1%), followed by older adults (26.9%), adolescents (15.7%), and children (6.3%). Clinical populations were investigated in the context of PA/SB in a relatively large number of studies (15.3%), most frequently those with cardiovascular disease, diabetes, and hypertension (22%, 21%, and 21% respectively).

CONCLUSIONS

The number of Thai papers on PA published per year has been increasing, indicating a growing interest in this research area. More studies using population-representative samples are needed, particularly among children and adolescents, and investigating SB as a health risk factor. To provide stronger evidence on determinants and outcomes of PA/SB, longitudinal studies using standardised measures of PA and SB are required.

Australian fitness professionals' level of interest in engaging with high health-risk population subgroups: findings from a national survey

OBJECTIVES

Fitness industry professionals (personal trainers, group instructors) may have a role in health promotion, particularly when working with subgroups with known health risks (e.g. older adults, obese). The aim of this study is to examine fitness professionals' level of interest in engaging with high-risk populations.

STUDY DESIGN

Cross-sectional evaluation of a national survey.

METHODS

In 2014, 9100 Australian registered exercise professionals were invited to complete an online survey. Respondents reported their level of interest in engaging with nine health-risk population subgroups. A multivariable logistic regression analysis assessed the odds of being classified as having a 'low level' of interest in training high health-risk subgroups, adjusting for demographic and fitness industry-related factors.

RESULTS

Of 1185 respondents (aged 17-72 years), 31.1% reported having a 'high level' of interest in training high health-risk subgroups. The highest level of interest was among 'obese clients' and 'adults (18-64 years) with chronic health conditions'. In the adjusted analysis, males (odds ratio [OR], 1.55, 95% confidence interval [CI]: 1.06-2.25) and those in urban settings (OR, 2.26, 95% CI: 1.54-3.37) were more likely to have a 'low level' of interest.

CONCLUSIONS

Fitness professionals have a modest level of interest in training high health-risk subgroups. In addition to the development of strategies to increase interest, research should examine whether fitness professionals are able to safely prescribe exercise to high health-risk subgroups.

Participant characteristics of users of holistic movement practices in Australia

OBJECTIVES

The aim of this study was to compare the characteristics of users of holistic movement practices in Australia to people who were physically active but not using holistic movement practices. A second aim was to compare characteristics of users of specific holistic movement practices (yoga/Pilates and t'ai chi/qigong).

DESIGN

We performed a secondary data analysis on pooled data of a nationally-representative physical activity survey conducted yearly 2001-2010 (n = 195,926).

SETTING

Australia-wide Exercise, Recreation, and Sport Survey (ERASS).

MAIN OUTCOME MEASURES

A range of socio-demographic and participation characteristics were documented and compared between users and non-users of holistic movement practices and between yoga/Pilates and t'ai chi/qigong users, employing descriptive statistics, chi square, and multiple logistic regression analyses.

RESULTS

Users of holistic movement practices (n = 6826) were significantly more likely than non-users to be female, older, have fewer children at home, and have higher levels of education, socio-economic background, and physical activity involvement (p < 0.001). Yoga/Pilates (n = 5733) and t'ai chi/qigong (n = 947) users were also found to differ on a number of characteristics, including age, sex, socioeconomic background, and marital status.

CONCLUSION

As a group, Australian users of holistic movement practices differ on a range of characteristics from those Australians active in other types of physical activities. However, differences between yoga/Pilates and t'ai chi/qigong users suggest these practices attract somewhat different sub-populations. To what extent these differences are due to characteristics inherent to the practices themselves or to differences in delivery-related parameters needs to be examined in future research.

Effectiveness of interventions for reducing non-occupational sedentary behaviour in adults and older adults: a systematic review and meta-analysis

Background

No systematic reviews of the effectiveness of interventions for reducing non-occupational sedentary behaviour are available. Therefore, the aim of this systematic review was to assess the effectiveness of interventions for reducing non-occupational sedentary behaviour in adults and older adults.

Methods

An electronic search of nine databases was performed. Randomised controlled trials (RCT) and cluster RCTs among adults testing the effectiveness of interventions aimed to reduce non-occupational sedentary behaviour were considered for inclusion. Two review authors independently screened studies for eligibility, completed data extraction and assessed the risk of bias.

Results

Nineteen studies that evaluated multicomponent lifestyle interventions, counselling or education, television (TV) control devices and workplace interventions were included. Evidence from the meta-analyses suggested that interventions can reduce leisure sitting time in adults in the medium term (−30 min/day; 95% CI −58 to –2), and TV viewing in the short term (−61 min/day; 95% CI −79 to –43) and medium term (−11 min/day; 95% CI −20 to –2). No significant pooled effects were found for transport sitting time, leisure-time computer use and longer term outcomes. No evidence was available on the effectiveness of interventions for reducing non-occupational sedentary time in older adults.

Conclusions

The findings of this systematic review suggest the interventions may be effective in reducing non-occupational sedentary behaviour in the short to medium term in adults. However, no significant effect was found on longer term outcomes. The quality of evidence was, however, low to very low. No evidence was available on the effectiveness of non-occupational interventions on reducing sedentary time in older adults. Further high-quality research with larger samples is warranted.

Associations between multiple indicators of socio-economic status and muscle-strengthening activity participation in a nationally representative population sample of Australian adults

BACKGROUND

Muscle-strengthening activity (MSA) (e.g. weight training), confers unique health benefits. While socioeconomic status (SES) correlates with leisure time physical activity, little is known about its relation with MSA.

METHODS

Cross-sectional study of a representative sample of 8993 Australian adults (>18years) who participated in the National Nutrition and Physical Activity Survey 2011-12. Information was collected on SES (income, education, socio-economic disadvantage and remoteness) and MSA participation.

RESULTS

17.9% (CI: 16.8-19.0) met the national guidelines for MSA (≥2 sessions/week). Men and younger adults (<35years) met MSA guidelines more than females (19.7%; CI: 18.3-21.1% vs 16.1%; CI: 14.6-17.6%; p<0.001) and older adults respectively (25.0%; CI: 22.4-27.7% vs 10.4%; CI: 8.9-11.8%; p<0.001). All SES indicators were associated with meeting the guidelines in unadjusted analyses. When adjusting for total physical activity and mutually adjusting for each socioeconomic indicator only remoteness (OR for city vs rural=1.65; CI: 1.17-2.32; p<0.001) was associated with MSA participation (education OR=1.09 for high vs low; CI: 0.80-1.47, p=0.748; income OR=1.31 for Q5 vs Q1, CI: 0.93-1.85, p=0.328; social disadvantage OR=1.04 for v.high vs v.low, CI: 0.76-1.43, p=0.855). These associations were further attenuated when adjusting for BMI, smoking status and self-rated health.

CONCLUSION

Remoteness, and to a lesser degree, education, income and social disadvantage, were independently associated with MSA participation. Public health interventions should improve access to strength training facilities, and/or increase home-based muscle-strengthening activity in remote areas.

Assessment and monitoring practices of Australian fitness professionals

OBJECTIVES

Assessment and monitoring of client health and fitness is a key part of fitness professionals' practices. However, little is known about prevalence of this practice. This study describes the assessment/monitoring practices of a large sample of Australian fitness professionals.

DESIGN

Cross-sectional.

METHODS

In 2014, 1206 fitness professionals completed an online survey. Respondents reported their frequency (4 point-scale: [1] 'never' to [4] 'always') of assessment/monitoring of eight health and fitness constructs (e.g. body composition, aerobic fitness). This was classified as: (i) 'high' ('always' assessing/monitoring ≥5 constructs); (ii) 'medium' (1-4 constructs); (iii) 'low' (0 constructs). Classifications are reported by demographic and fitness industry characteristics. The odds of being classified as a 'high assessor/monitor' according to social ecological correlates were examined using a multiple-factor logistic regression model.

RESULTS

Mean age of respondents was 39.3 (±11.6) years and 71.6% were female. A total of 15.8% (95% CI: 13.7%-17.9%) were classified as a 'high' assessor/monitor. Constructs with the largest proportion of being 'always' assessed were body composition (47.7%; 95% CI: 45.0%-50.1%) and aerobic fitness (42.5%; 95% CI: 39.6%-45.3%). Those with the lowest proportion of being 'always' assessed were balance (24.0%; 95% CI: 24.7%-26.5%) and mental health (20.2%; 95% CI: 18.1%-29.6%). A perceived lack of client interest and fitness professionals not considering assessing their responsibility were associated with lower odds of being classified as a 'high assessor/monitor'.

CONCLUSIONS

Most fitness professionals do not routinely assess/monitor client fitness and health. Key factors limiting client health assessment and monitoring include a perceived lack of client interest and professionals not considering this their role.

Participation trends in holistic movement practices: a 10-year comparison of yoga/Pilates and t'ai chi/qigong use among a national sample of 195,926 Australians

BACKGROUND

In recent decades, the evidence supporting the physical and mental health benefits of holistic movement practices such as yoga and t'ai chi have become increasingly established. Consequently, investigating the participation prevalence and patterns of these practices is a relevant pursuit in the public health field. Few studies have provided population-level assessment of participation rates, however, and even fewer have focused on patterns over time. The purpose of this study was to examine participation prevalence and trends in yoga/Pilates and t'ai chi/qigong over a ten-year period in a nationally representative sample of Australians aged 15 years and over, with particular attention to sex and age. A secondary purpose was to juxtapose these findings with participation trends in traditional fitness activities over the same period.

METHODS

Data comprised modes and types of physical activity, age, and sex variables collected through the Exercise, Recreation and Sport Survey (ERASS), a series of independent cross-sectional Australia-wide surveys conducted yearly between 2001 and 2010. For each year, weighted population estimates were calculated for those participating in yoga/Pilates, t'ai chi/qigong, and fitness activities (e.g. aerobics, calisthenics). Linear regression and multiple logistic regression analyses were used to examine trends in prevalence rates over time and differences among sex and age (15-34; 35-54; 55+ years) groups, respectively.

RESULTS

Average prevalence rates between 2001 and 2010 were 3.0% (95% CI 2.9-3.1) for yoga/Pilates, 0.6% (95% CI 0.5-0.6) for t'ai chi/qigong, and 19.2% (95% CI 18.9-19.4) for fitness activities. Across the decade, overall participation rates remained relatively stable for yoga/Pilates and t'ai chi/qigong, while increasing linearly for fitness activities. For both genders and in all three age groups, participation in fitness activities increased, whereas only in the 55+ age group was there a significant increase in yoga/Pilates participation; participation in t'ai chi/qigong declined significantly in the two younger age groups.

CONCLUSIONS

Participation rates in yoga/Pilates and t'ai chi/qigong in Australia were low and relatively stable. As fitness activities increased in popularity across the decade, holistic movement practices did not. These findings point to the need to investigate activity-specific barriers and facilitators to participation, including intrapersonal, interpersonal, organisational, and environmental factors.

Sources of practice knowledge among Australian fitness trainers

Few studies have examined the sources of practice knowledge fitness trainers use to inform their training methods and update knowledge. This study aims to describe sources of practice knowledge among Australian fitness trainers. In July 2014, 9100 Australian fitness trainers were invited to complete an online survey. Respondents reported the frequency of use of eight sources of practice knowledge (e.g. fitness magazines, academic texts). In a separate survey, exercise science experts (n = 27) ranked each source as either (1) 'high-quality' or (2) 'low-quality'. Proportions of users of 'high-quality' sources were calculated across demographic (age, sex) and fitness industry-related characteristics (qualification, setting, role). A multivariate logistic regression analysis assessed the odds of being classified as a user of high-quality sources, adjusting for demographic and fitness industry-related factors. Out of 1185 fitness trainers (response rate = 13.0%), aged 17-72 years, 47.6% (95% CI, 44.7-50.4%) were classified as frequent users of high-quality sources of practice knowledge. In the adjusted analysis, compared to trainers aged 17-26 years, those aged ≥61 years (OR, 2.15; 95% CI, 1.05-4.38) and 40-50 years (OR, 1.54; 95% CI, 1.02-2.31) were more likely to be classified as a user of high-quality sources. When compared to trainers working in large centres, those working in outdoor settings (OR, 1.81; 95% CI, 1.23-2.65) and medium centres (OR, 1.59; 95% CI, 1.12-2.29) were more likely to be classified as users of high-quality sources. Our findings suggest that efforts should be made to improve the quality of knowledge acquisition among Australian fitness trainers.

Self-reported health-enhancing physical activity recommendation adherence among 64,380 finnish adults

The Finnish recommendations for health-enhancing physical activity (PA) for adults (≥18 years) recommend: (i) ≥150 minutes of moderate-to-vigorous-intensity physical activity (MVPA) and (ii) activities that develop muscle strength and balance ≥2 days/week. However, adherence to these recommendations among the Finnish adults is currently unknown. This study reports on the self-reported adherence to the PA recommendations and associations with sociodemographic factors among Finnish adults. Data were used from the Finnish "Regional Health and Well-being Study." In 2013-2014, postal questionnaires were sent to 132,560 persons, with 69,032 responding (response rate =52.1%). The weighted proportions adhering to the: (i) MVPA recommendation, (ii) sufficient muscle-strengthening activity (≥2 days/week), (iii) sufficient balance training (≥2 days/week), and (iv) Finnish health-enhancing PA recommendations (Finnish recommendations) were calculated. Associations with sociodemographic variables (eg, age, education level, self-rated health) were assessed using multiple logistic regression analyses. Of 69,032 respondents, 92.6% (n=64,380, response rate =48.6%, 18-98 years) reported on their physical activity levels. A total of 31.2% (95% CI: 30.8%-31.6%) met the aerobic MVPA recommendation, 17.2% (95% CI: 16.9%-17.6%) reported sufficient muscle-strengthening activity, 6.7% (95% CI: 6.4%-6.9%) reported sufficient balance training, and 10.8% (95% CI: 10.5%-11.1%) met the Finnish recommendations. In the adjusted analysis, those with poorer self-rated health, older age, lower education levels, and those classified overweight or obese were independently associated with lower odds of meeting the Finnish recommendations. The vast majority of Finnish adults do not meet the full PA recommendations. Public health action is needed to increase PA in Finland.

Too much sitting and all-cause mortality: is there a causal link?

Background

Sedentary behaviours (time spent sitting, with low energy expenditure) are associated with deleterious health outcomes, including all-cause mortality. Whether this association can be considered causal has yet to be established.

Using systematic reviews and primary studies from those reviews, we drew upon Bradford Hill’s criteria to consider the likelihood that sedentary behaviour in epidemiological studies is likely to be causally related to all-cause (premature) mortality.

Methods

Searches for systematic reviews on sedentary behaviours and all-cause mortality yielded 386 records which, when judged against eligibility criteria, left eight reviews (addressing 17 primary studies) for analysis. Exposure measures included self-reported total sitting time, TV viewing time, and screen time. Studies included comparisons of a low-sedentary reference group with several higher sedentary categories, or compared the highest versus lowest sedentary behaviour groups. We employed four Bradford Hill criteria: strength of association, consistency, temporality, and dose–response. Evidence supporting causality at the level of each systematic review and primary study was judged using a traffic light system depicting green for causal evidence, amber for mixed or inconclusive evidence, and red for no evidence for causality (either evidence of no effect or no evidence reported).

Results

The eight systematic reviews showed evidence for consistency (7 green) and temporality (6 green), and some evidence for strength of association (4 green). There was no evidence for a dose–response relationship (5 red). Five reviews were rated green overall. Twelve (67 %) of the primary studies were rated green, with evidence for strength and temporality.

Conclusions

There is reasonable evidence for a likely causal relationship between sedentary behaviour and all-cause mortality based on the epidemiological criteria of strength of association, consistency of effect, and temporality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3307-3) contains supplementary material, which is available to authorized users.

Variations in area-level disadvantage of Australian registered fitness trainers usual training locations

Background

Leisure-time physical activity and strength training participation levels are low and socioeconomically distributed. Fitness trainers (e.g. gym/group instructors) may have a role in increasing these participation levels. However, it is not known whether the training location and characteristics of Australian fitness trainers vary between areas that differ in socioeconomic status.

Methods

In 2014, a sample of 1,189 Australian trainers completed an online survey with questions about personal and fitness industry-related characteristics (e.g. qualifications, setting, and experience) and postcode of their usual training location. The Australian Bureau of Statistics ‘Index of Relative Socioeconomic Disadvantage’ (IRSD) was matched to training location and used to assess where fitness professionals trained and whether their experience, qualification level and delivery methods differed by area-level disadvantage. Linear regression analysis was used to examine the relationship between IRSD score and selected characteristics adjusting for covariates (e.g. sex, age).

Results

Overall, 47 % of respondents worked in areas within the three least-disadvantaged deciles. In contrast, only 14.8 % worked in the three most-disadvantaged deciles. In adjusted regression models, fitness industry qualification was positively associated with a higher IRSD score (i.e. working in the least-disadvantaged areas) (Cert III: ref; Cert IV β:13.44 [95 % CI 3.86-23.02]; Diploma β:15.77 [95 % CI: 2.17-29.37]; Undergraduate β:23.14 [95 % CI: 9.41-36.86]).

Conclusions

Fewer Australian fitness trainers work in areas with high levels of socioeconomic disadvantaged areas than in areas with low levels of disadvantage. A higher level of fitness industry qualifications was associated with working in areas with lower levels of disadvantage. Future research should explore the effectiveness of providing incentives that encourage more fitness trainers and those with higher qualifications to work in more socioeconomically disadvantaged areas.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3250-3) contains supplementary material, which is available to authorized users.

The descriptive epidemiology of total physical activity, muscle-strengthening exercises and sedentary behaviour among Australian adults--results from the National Nutrition and Physical Activity Survey

BACKGROUND

The current Australia's Physical Activity and Sedentary Behaviour Guidelines recommend that adults engage in regular moderate-to-vigorous-intensity physical activity (MVPA) and strength training (ST), and minimise time spent in sedentary behaviours (SB). However, evidence about the specific individual and concurrent distribution of these behaviours in Australia is scarce. Therefore, the aim of this study was to determine the prevalence and sociodemographic correlates of MVPA, ST and SB in a national-representative sample of Australian adults.

METHODS

Data were collected using face-to-face interviews, as part of the National Nutrition and Physical Activity Survey 2011-12. The population-weighted proportions meeting the MVPA (≥ 150 min/week), ST (≥ 2 sessions/week) and combined MVPA-ST guidelines, and proportions classified as having 'low levels of SB' (< 480 min/day) were calculated, and their associations with selected sociodemographic and health-related variables were assessed using multiple logistic regression analyses. This was also done for those at potentially 'high-risk', defined as insufficient MVPA-ST and 'high-sedentary' behaviour.

RESULTS

Out of 9345 participants (response rate = 77.0 %), aged 18-85 years, 52.6 % (95 % CI: 51.2 %-54.0 %), 18.6 % (95 % CI: 17.5 %-19.7 %) and 15.0 % (95 % CI: 13.9 %-16.1 %) met the MVPA, ST and combined MVPA-ST guidelines, respectively. Female gender, older age, low/medium education, poorer self-rated health, being classified as underweight or obese, and being a current smoker were independently associated with lower odds of meeting the MVPA, ST and combined MVPA-ST guidelines. A total of 78.9 % (95 % CI: 77.9 %-80.0 %) were classified as having low levels of SB. Females, older adults and those with lower education were more likely to report lower levels of SB, whilst those with poor self-rated health and obese individuals were less likely to report lower levels of SB (i.e. SB = ≥ 480 min/day). A total of 8.9 % (95 % CI: 8.1 %-9.6 %) were categorised as individuals at potentially 'high-risk'. Those with poorer self-rated health, obese individuals, those aged 25-44, and current smokers were more likely to be in the 'high risk' group.

CONCLUSIONS

The large majority of Australian adults do not meet the full physical activity guidelines and/or report excessive SB. Our results call for public health interventions to reduce physical inactivity and SB in Australia, particularly among the subgroups at the highest risk of these unhealthy behaviours.

Unaccustomed eccentric contractions impair plasma K+ regulation in the absence of changes in muscle Na+,K+-ATPase content

The Na⁺,K⁺-ATPase (NKA) plays a fundamental role in the regulation of skeletal muscle membrane Na⁺ and K⁺ gradients, excitability and fatigue during repeated intense contractions. Many studies have investigated the effects of acute concentric exercise on K⁺ regulation and skeletal muscle NKA, but almost nothing is known about the effects of repeated eccentric contractions. We therefore investigated the effects of unaccustomed maximal eccentric knee extensor contractions on K⁺ regulation during exercise, peak knee extensor muscle torque, and vastus lateralis muscle NKA content and 3-O-MFPase activity. Torque measurements, muscle biopsies, and venous blood samples were taken before, during and up to 7 days following the contractions in six healthy adults. Eccentric contractions reduced peak isometric muscle torque immediately post-exercise by 26±11% and serum creatine kinase concentration peaked 24 h post-exercise at 339±90 IU/L. During eccentric contractions, plasma [K⁺] rose during Set 1 and remained elevated at ∼4.9 mM during sets 4–10; this was despite a decline in work output by Set 4, which fell by 18.9% at set 10. The rise in plasma [K⁺].work⁻¹ ratio was elevated over Set 2 from Set 4– Set 10. Eccentric contractions had no effect on muscle NKA content or maximal in-vitro 3-O-MFPase activity immediately post- or up to 7 d post-exercise. The sustained elevation in plasma [K⁺] despite a decrease in work performed by the knee extensor muscles suggests an impairment in K⁺ regulation during maximal eccentric contractions, possibly due to increased plasma membrane permeability or to excitation-contraction uncoupling.

The prevalence and correlates of sitting in European adults - a comparison of 32 Eurobarometer-participating countries

Background

Prolonged sitting is an emerging health risk. However, multi-country comparative sitting data are sparse. This paper reports the prevalence and correlates of sitting time in 32 European countries.

Methods

Data from the Eurobarometer 64.3 study were used, which included nationally representative samples (n = 304-1,102) from 32 European countries. Face-to-face interviews were conducted during November and December 2005. Usual weekday sitting time was assessed using the International Physical Activity Questionnaire (short-version). Sitting time was compared by country, age, gender, years of education, general health status, usual activity and physical activity. Multivariable-adjusted analyses assessed the odds of belonging to the highest sitting quartile.

Results

Data were available for 27,637 adults aged 15–98 years. Overall, mean reported weekday sitting time was 309 min/day (SD 184 min/day). There was a broad geographical pattern and some of the lowest amounts of daily sitting were reported in southern (Malta and Portugal means 194–236 min/day) and eastern (Romania and Hungary means 191–276 min/day) European countries; and some of the highest amounts of daily sitting were reported in northern European countries (Germany, Benelux and Scandinavian countries; means 407–335 min/day). Multivariable-adjusted analyses showed adults with low physical activity levels (OR = 5.10, CI₉₅ = 4.60-5.66), those with high sitting in their main daily activity (OR = 2.99, CI₉₅ = 2.74-3.25), those with a bad/very bad general health state (OR = 1.87, CI₉₅ = 1.63-2.15) and higher education levels (OR = 1.48, CI₉₅ = 1.38-1.59) were more likely to be in the highest quartile of daily sitting time. Adults within Greece (OR = 2.91, CI₉₅ = 2.51-3.36) and Netherlands (OR = 2.56, CI₉₅ = 2.22-2.94) were most likely to be in the highest quartile. High-sit/low-active participants comprised 10.1% of the sample. Adults self-reporting bad/very bad general health state (OR = 4.74, CI₉₅ = 3.97-5.65), those within high sitting in their main daily activities (OR = 2.87, CI₉₅ = 2.52-3.26) and adults aged ≥65 years (OR = 1.53, CI₉₅ = 1.19-1.96) and were more likely to be in the high-sit/low-active group.

Conclusions

Weekday sitting time and its demographic correlates varied considerably across European countries, with adults in north-western European countries sitting the most. Sitting is prevalent across Europe and merits attention by preventive interventions.

Associations between social ecological factors and self-reported short physical activity breaks during work hours among desk-based employees

OBJECTIVE

To examine the associations between potential social ecological correlates and self-reported short physical activity breaks during work hours (defined as any interruption in sitting time during a typical work hour) among a sample of employees who commonly sit for working tasks.

METHODS

801 employed adults aged 18-70 years from metropolitan Melbourne, Australia were surveyed in 2009 about their short physical activity breaks from sitting during work hours and potential social ecological correlates of this behaviour.

RESULTS

Men reported significantly more short physical activity breaks per work hour than did women (2.5 vs. 2.3 breaks/h, p=0.02). A multivariable linear regression analysis adjusting for clustering and meeting the public health physical activity recommendations showed that the factors associated with frequency of short physical activity breaks per work hour were perceptions of lack of time for short physical activity breaks for men (-0.31 breaks/h, 95% confidence intervals [CI] -0.52, -0.09) and lack of information about taking short physical activity breaks for women (-0.20 breaks/h, CI -0.47, -0.05).

CONCLUSION

These findings suggest that providing male employees with support for short physical activity breaks during work hours, and female employees with information on benefits of this behaviour may be useful for reducing workplace sedentary time.