Psychological and physiological effects of an acute bout of yoga before a simulated academic exam in university students

Objective: Test anxiety is common among nursing students. Yoga is one form of physical activity which may be beneficial for pretest anxiety. Participants: Thirteen undergraduate students (85% nursing majors, 15% awaiting program entry, 20 ± 4.9 years of age) completed the crossover design study. Methods: Participants completed a yoga or control intervention (independent quiet study) on opposing testing days. At three time points, participants provided ratings of anxiety (visual analog scales), saliva samples for cortisol and alpha amylase, and seated heart rate variability (HRV, time and frequency domains) was recorded. Results: Yoga prior to a simulated exam had a positive impact on subjective measures of stress but did not positively impact cortisol or HRV compared to the control condition. Conclusions: There may be benefits to participating in 30 min of moderate intensity yoga for reduced perception of stress before a scholarly examination. Further research regarding the impacts of acute yoga on physiological measures of HRV and/or cortisol are warranted.

Participant Bias in Community-Based Physical Activity Research: A Consistent Limitation?

Physical activity is a beneficial, yet complex, health behavior. To ensure more people experience the benefits of physical activity, we develop and test interventions to promote physical activity and its associated benefits. Nevertheless, we continue to see certain groups of people who choose not to, or are unable to, take part in research, resulting in "recruitment bias." In fact, we (and others) are seemingly missing large segments of people and are doing little to promote physical activity research to equity-deserving populations. So, how can we better address recruitment bias in the physical activity research we conduct? Based on our experience, we have identified 5 broad, interrelated, and applicable strategies to enhance recruitment and engagement within physical activity interventions: (1) gain trust, (2) increase community support and participation, (3) consider alternative approaches and designs, (4) rethink recruitment strategies, and (5) incentivize participants. While we recognize there is still a long way to go, and there are broader community and societal issues underlying recruitment to research, we hope this commentary prompts researchers to consider what they can do to try to address the ever-present limitation of "recruitment bias" and support greater participation among equity-deserving groups.

Moms on the move: A qualitative exploration of a postpartum group exercise program on physical activity behaviour at three distinct time points

PURPOSE

Physical activity (PA) after the birth of a child is associated with improved physical and mental health benefits. The aim of the study was to explore new mothers' experiences of PA before and after participation in a group-based PA program for new mothers. The study has three research questions: how new mothers felt; 1) about PA after the birth of their child 2) about engaging in a group-based PA program and 3) after the program ended about ongoing PA engagement.

METHODS

We conducted an 8-week bi-weekly PA program for postpartum women. To understand the experience of postpartum women engaging in a group-based PA program we conducted one-on-one semi-structured interviews before, after, and at 6-month follow-up.

RESULTS

Of the n = 21 participants in the Moms on the Move study; n = 17 completed pre interviews.s. One primary theme emerged from pre-program interviews where mothers shared how they were lost as to where to start PA. Post-program interviews produced two primary themes; engaging in PA helped mothers, and mothers learned to rethink PA.

CONCLUSIONS

Postpartum women who participated in this group-based PA program had positive benefits to their mental and physical health and were able to alter their PA behaviour.

Active by nature: exploring cancer survivors' exercise barriers, facilitators, preferences, and psychosocial benefits of engaging in outdoor physical activity

Introduction

Large numbers of cancer survivors struggle with mental health after cancer diagnosis. Cancer survivors are encouraged to engage in physical activity in order to improve physical and mental health. Additional benefits to physical activity engagement in natural environments have been reported but this has not been explored in cancer survivors.

Methods

Study participants had to be over the age of 19, a Canadian resident, and have had a cancer diagnosis. Recruitment to complete an online survey occurred through social media and snowball sampling. The data collected included physical activity participation, preferences and location, barriers and facilitators of engagement in outdoor physical activity, nature-related questions, and measures of psychosocial health. The sample was split by the number of outdoor physical activity minutes (> 150 min per week). Correlations were computed to examine the role of outdoor physical activity minutes on measured psychosocial health outcomes.

Results

One hundred and fourteen (N = 114) cancer survivors completed the online questionnaire. More than half of the respondents indicated that an outdoor environment was central to their physical activity of choice with walking identified as the most common outdoor physical activity. Group support was the main expected facilitator of success in an outdoor walking program. Outdoor active participants were significantly more motivated and confident to be physically active and reported significantly more benefit and enjoyment in being physically active than outdoor inactive participants. Minutes of outdoor physical activity was significantly correlated with subjective happiness, nature relatedness, and higher quality of life. No significant correlations were found between minutes of outdoor physical activity and generalized anxiety.

Conclusion

While future research is needed to further explore the role of nature in cancer survivor psychosocial health, we believe that our data suggests preference and benefit for outdoor physical activity in cancer survivors.

Does body size impact muscle recruitment during law enforcement physical control simulator use?

This study examined muscle activation during the 'push-pull' component of law enforcement physical abilities testing and assessed activation differences based on sex, height, and body mass index. Fifty participants (40 male) completed the 'push-pull' task while surface electromyograms were recorded from ten upper and lower extremity muscles, and six trunk muscles. Muscle activation was amplitude-normalized to maximum voluntary isometric contraction and compared between sexes and tertiles of height and body mass index (BMI). Women had significantly higher activation of anterior deltoid and pectoralis major on the pull, and posterior deltoid and triceps on the push. Significant differences largely remained after controlling for body size in regression analyses. The lowest tertile of height had significantly higher triceps activity on the push. The highest tertile of BMI had significantly higher rectus abdominus and external obliques activity on the pull, and external obliques activation on the push. Practitioner summary: Muscle activation during the 'push-pull' component of law enforcement standardised testing was examined, including differences based on sex, height, and BMI. Minimal differences existed between sexes (females had higher deltoid, pectoralis major, triceps activity), height (shorter people had higher triceps activity) and BMI tertiles (larger people had more abdominal activity). Abbreviations: ANOVA: analysis of variance; BMI: body mass index; COPAT: correctional officer's physical abilities test; EMG: electromyogram; IMU: inertial measurement unit; MVIC: maximum voluntary isometric contraction; PARE: physical abilities requirement evaluation; PCS: physical control simulator; POPAT: police officer's physical abilities test; RMS: root mean square.

Effectiveness of Exercise on Visceral Adipose Tissue in Older South Asian Women

INTRODUCTION

Individuals of South Asian (SA) origin have a greater risk for type 2 diabetes and cardiovascular disease than other ethnic populations. This increased risk is in part explained by the unique obesity phenotype of elevated visceral adipose tissue (VAT) among this population. Aerobic exercise in Europeans is effective at reducing VAT, but this has not been studied in SA, who have some of the lowest levels of physical activity in the world. Therefore, the purpose of this study was to determine whether exercise can reduce VAT given the unique obesity phenotype and associated disease risk in the SA population.

METHODS

A total of 75 physically inactive, postmenopausal SA women were randomized to either culturally based (Bhangra dance), standard (gym-based), or control (nonexercise) program for 12-wk. The primary outcome was change in VAT.

RESULTS

The average attendance in the culturally based and standard program was 78% ± 33% and 67% ± 25%, respectively. After an intention-to-treat analysis, VAT was not significantly reduced in culturally based (-60 cm, 95% confidence interval [CI] = -172 to 54, P = 0.300) or standard (-98 cm, 95% CI = -216 to 21, P = 0.106) exercise compared with control after adjustment for baseline physical activity and age. In those participants who attended more than two-thirds of the exercise classes, VAT was significantly reduced compared with control (-109 cm, 95% CI = -204 to -13, P = 0.026).

CONCLUSION

In intention-to-treat analysis VAT was not significantly reduced after 12 wk of either standard or culturally based exercise. However, attendance in both standard and culturally based exercise was high, and VAT was significantly reduced among SA women who adhered to these programs.

The predictive relationship between baseline insulin and glucose with subclinical carotid atherosclerosis after 5 years in a multi-ethnic cohort

BACKGROUND AND AIMS

We aimed at exploring the relationship between baseline insulin and glucose and the progression of carotid atherosclerosis in a multi-ethnic cohort.

METHODS

Males and females (n = 797) of European, Chinese, South Asian and Aboriginal origin were assessed as part of the Multicultural Community Health Assessment Trial (MCHAT) study for socio-demographics, smoking status, fasting insulin and glucose at baseline. IMT, plaque area and total area were assessed after 5 years.

RESULTS

A total of 545 participants returned after 5 years for a follow-up assessment. Average age of the study participants was 47.5 (SD 8.9) years. At baseline, the median and interquartile range for insulin was 62.0 (49.5) pmol/L, and glucose was 5.2 (0.60) mmol/L. Baseline glucose and insulin predicted the 5-year progression of atherosclerosis in our models, after adjusting for covariates. We found significant insulin-ethnicity interactions in the IMT model (p = 0.044) with the slope of the relationship showing that for every percentage change in insulin the Europeans experienced 7.3% more increase in IMT at 5 years than the Aboriginals. In the plaque area and total area models, there were significant glucose-ethnicity interactions (p = 0.009 and p=0.016 respectively), with the slope showing a 101% and 121% increase for plaque area and total area, respectively, in Europeans, at 5 years per percent change in glucose at baseline. Logistic regression found a significant glucose-ethnicity interaction with the presence of plaques (OR = 0.31, p = 0.03) such that compared to the Europeans, the South Asians had a lower odds of developing plaque presence. Similarly, we found glucose-ethnicity interactions in the logistic regression when comparing the Chinese to the Europeans (OR = 0.2, p=0.005), with the Chinese being less likely to develop plaque presence.

CONCLUSIONS

Ethnicity modifies the predictive relationship between insulin and glucose with sub-clinical indicators of carotid atherosclerosis but not consistently so.

Association between exercise-induced change in body composition and change in cardiometabolic risk factors in postmenopausal South Asian women

The South Asian population suffers from a high prevalence of type 2 diabetes and cardiovascular disease (CVD). A unique obesity phenotype of elevated visceral adipose tissue (VAT) is associated with CVD risk among South Asians. Exercise-induced reduction in VAT and body fat is an effective mechanism to improve cardiometabolic risk factors but this has not been shown in South Asians. Whether exercise-induced changes in measurements such as waist circumference (WC) are independently related to changes in cardiometabolic risk factors in South Asians is unknown. Multi-slice computed tomography scanning was used to assess VAT, cardiometabolic risk factors through a fasting blood sample, and body fat using dual-energy X-ray absorptiometry. Forty- nine postmenopausal South Asian women who participated in two 12-week aerobic exercise programs were included. Bivariate correlations were used to assess associations between change in cardiometabolic risk factors and change in body composition. Regression analyses were conducted with change in glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) as dependent variables and change in body composition as independent variables of interest. There were significant associations between changes in fasting insulin, glucose, and HOMA-IR with change in VAT. The association between change in VAT and these cardiometabolic risk factors was independent of change in other body composition variables of interest. South Asian women should be encouraged to engage in aerobic activity to reduce their risk of type 2 diabetes and CVD, and physicians should be aware of improvements in glucose regulation with exercise training not observed through reductions in WC.

The association between cardiorespiratory fitness and abdominal adiposity in postmenopausal, physically inactive South Asian women

In South Asians, a unique obesity phenotype of high abdominal fat is associated with increased cardiovascular risk. Low cardiorespiratory fitness (CRF) is associated with abdominal fat and an increased risk of cardiovascular disease. The purpose of this paper is to determine whether CRF as assessed by VO2 peak, in post-menopausal South Asian women, was associated with body fat distribution and abdominal fat. Physically inactive post-menopausal South Asian women (n = 55) from the Greater Vancouver area were recruited and assessed from January to August 2014. At baseline, VO2 peak was measured with the Bruce Protocol, abdominal fat with CT imaging, and body composition with dual energy X-ray absorptiometry. ANOVA was used to assess differences in subcutaneous abdominal adipose tissue (SAAT), visceral adipose tissue (VAT) and total abdominal adipose tissue (TAAT) between tertiles of CRF. Bivariate correlation and multiple linear regression analyses explored the association between VO2 peak with SAAT, VAT, TAAT and body composition. Models were further adjusted for body fat and body mass index (BMI). Compared to women in the lowest tertile of VO2 peak (13.8-21.8 mL/kg/min), women in the highest tertile (25.0-27.7 mL/kg/min) had significantly lower waist circumference, BMI, total body fat, body fat percentage, lean mass, SAAT, VAT and TAAT (p < 0.05). We found VO2 peak to be negatively associated with SAAT, VAT and TAAT, independent of age and body fatness but not independent of BMI. Further research is necessary to assess whether exercise and therefore improvements in CRF would alter SAAT, VAT and TAAT in post-menopausal South Asian women.

The association between physical activity and liver fat after five years of follow-up in a primary prevention multi-ethnic cohort

OBJECTIVE

Excess liver fat (LF) is associated with dyslipidemia, insulin resistance and cardiovascular disease. Evidence suggests that there is an independent relationship between physical activity (PA) and LF although little is known of the role of PA intensity in reducing LF. The purpose was to evaluate whether meeting PA guidelines, the amount of PA and the intensity of PA at baseline were associated with LF after five-years.

METHODS

Men and women (n=478) living in Vancouver, Canada of Aboriginal, Chinese, European or South Asian background completed baseline measurements in 2004-2005. Liver fat was assessed using CT scans at 5-year follow-up, and PA using a PA questionnaire at baseline as well as demographics and anthropometry.

RESULTS

In separate unadjusted models, meeting moderate-vigorous PA (MVPA) guidelines (p=0.009), vigorous PA (p=0.002) and MVPA (p=0.017) but not moderate PA (p=0.068) was predictive of LF at five years (p=0.009). In multiple linear regression models, when adjusted for covariates, meeting MVPA guidelines and MVPA with LF at five years was no longer significant (p>0.05) while vigorous PA remained significant (p=0.021).

CONCLUSION

Meeting PA guidelines through MVPA may not be adequate to prevent the accumulation of LF and PA guidelines may require revision. Vigorous PA should be encouraged to prevent LF accumulation.

The association between "hypertriglyceridemic waist" and sub-clinical atherosclerosis in a multiethnic population: a cross-sectional study

Background

"Hypertriglyceridemic waist" (HTGW) phenotype, an inexpensive early screening tool for detection of individuals at risk for type 2 diabetes and cardiovascular disease was found to be associated with subclinical atherosclerosis in various patient populations such as those with diabetes mellitus, chronic kidney disease, and those infected with human immunodeficiency virus. However, less is known regarding an association between HTGW and subclinical atherosclerosis in the apparently healthy, multiethnic population. Therefore, the aim of the study was to explore the association between HTGW and sub-clinical atherosclerosis in an apparently healthy, multiethnic population; and to investigate whether the effect of HTGW on sub-clinical atherosclerosis persists over and above the traditional atherosclerosis risk factors.

Methods

We studied 809 individuals of Aboriginal, Chinese, European and South Asian origin who were assessed for indices of sub-clinical atherosclerosis (intima-media thickness (IMT), total area and presence of carotid plaques), socio-demographic and lifestyle characteristics, anthropometrics, lipids, glucose, blood pressure, and family history of cardiovascular disease.

Results

We found that, compared to individuals without HTGW and after adjusting for age, ethnicity, smoking, and physical activity; men and women with HTGW had a significantly higher: IMT (men: B (95%CI = 0.084 (0.037, 1.133), p < 0.001; women: B (95%CI) = 0.041 (0.006, 0.077), p = 0.020); and total area (men: B (95%CI = 0.202 (0.058, 0.366), p = 0.005; women: B (95%CI) = 0.115 (0.006, 0.235), p = 0.037). The association between HTGW waist and presence of plaques was significant for men (OR (95%CI) = 1.904 (1.040, 3.486), p = 0.037 vs. men without HTGW), but not for women (p = 0.284). Once analyses were adjusted for additional, traditional risk factors for atherosclerosis, the effect of HTGW on sub-clinical atherosclerosis was no longer significant.

Conclusions

In conclusion, HTGW may serve as an early marker of subclinical atherosclerosis in men and women, irrespective of ethnicity. However, once individuals are assessed for all traditional risk factors for atherosclerosis, the additional assessment for HTGW is not warranted.

The association between acculturation and dietary patterns of South Asian immigrants

Dietary acculturation, specifically the adoption of western dietary habits, may result in adverse health effects such as obesity and type 2 diabetes. Therefore, it is necessary to explore the role of acculturation in dietary patterns as well as awareness and knowledge of healthy nutrition among South Asian immigrants. This is an especially important population to target as South Asians have higher prevalence rates of type 2 diabetes and cardiovascular disease, which may be magnified with immigration. The current investigation is a sub-study of the Multi-Cultural Community Health Assessment Trial (M-CHAT). There were 207 participants of South Asian origin included in the initial study, 129 were born outside of Canada and had immigrated after the age of 18. The length of residence in Canada was used as a marker for acculturation. A questionnaire addressing perceived changes in dietary patterns, food preparation, and nutrition knowledge and awareness since immigration was used to assess dietary practices. The association between length of residence and variables related to perceived changes in dietary patterns was explored with Spearman correlation and significant associations were subsequently analyzed with ordinal logistic regression analysis adjusted for age, sex, education and body mass index. South Asian immigrants in Canada reported a variety of positive dietary practices, including an increased consumption of fruits and vegetables and an improvement in food preparation (including an increase in grilling and a decrease in deep frying when cooking). However, there was a reported increase in the consumption of convenience foods, sugar-sweetened beverages, red meat and in dining out. South Asian immigrants in Canada reported a variety of positive dietary practices including an improvement in food preparation. Future health promotion strategies should encourage cultural sensitivity in efforts to reduce the consumption of sugar-sweetened beverage, convenience foods and to encourage eating at home rather than dining out.

Characterization of aerobically fit individuals with cardiovascular disease

With an ageing population there is an increased prevalence of individuals living with cardiovascular disease (CVD). Characteristics of older aerobically fit individuals with previously diagnosed CVD have not been studied. Therefore, our knowledge is limited as to how, or if, aerobically fit individuals with CVD attempt to adapt their physical activity and the intensity of their training programmes. The objective of this paper is to characterise the physical activity habits and behaviours of older aerobically fit individuals with CVD. We identified 28 aerobically fit patients with CVD from those who completed a minimum of 15 and 12 min of the Bruce treadmill protocol for men and women, respectively. Consenting participants responded to questionnaires regarding physical activity levels, competitive event participation and self-monitoring since diagnosis of heart disease. Average age and treadmill time of participants were 56 and 49 years and 15.6 and 13.0 min for males and females, respectively. Data were obtained regarding recent medical history (medical diagnoses, surgeries/procedures). Despite the majority of individuals participating in the same or more activity since their diagnosis, 25% indicated that their condition limited their activity and 39% reported having symptoms during activity. Nearly all participants (93%) indicated that they monitored their heart rate during exercise. However, only 14% of participants stated that their physician advised them on how to exercise safely. It is necessary for physicians and cardiac rehabilitation programmes to be involved in safe and effective exercise programming to allow individuals to return to sport after CVD.

The effect of body fat distribution on ethnic differences in cardiometabolic risk factors of Chinese and Europeans

This study aimed to examine the differences in body fat distribution and cardiometabolic risk between individuals of Chinese and European origin and the role of body fat distribution on ethnic differences in cardiometabolic risk. A total of 418 participants from the Multicultural Community Health Assessment Trial were assessed for visceral adipose tissue (VAT), subcutaneous abdominal adipose tissue (SAT), anthropometric variables, blood pressure, and lipid, insulin, and glucose levels. Multiple regression analyses were split by sex and adjusted for appropriate covariates in model 1a and further adjusted for VAT in model 1b or SAT in model 1c. A secondary model replaced body mass index (BMI) with waist circumference (WC). Chinese males had higher levels of triglycerides, insulin, homeostasis model assessment, and SAT than European males, as well as higher total cholesterol (TC), glucose, and VAT in the model adjusted for WC. Chinese females had higher glucose levels than European females after adjustment for either BMI or WC. When VAT was added to the models, differences in cardiometabolic risk factors remained significant but were attenuated between Chinese and European males and females; SAT did not attenuate the ethnic difference in cardiometabolic risk. These findings suggest that the higher VAT levels seen in the Chinese population do not fully account for the ethnic disparities in these risk factors. Given the observed interethnic difference in body composition, current BMI and WC cutoffs might be misleading when it comes to identifying Chinese individuals at risk for type 2 diabetes or cardiovascular disease.

A review of obesity and body fat distribution and its relationship to cardio-metabolic risk in men and women of Chinese origin

Obesity is increasing in people of Chinese background whether in China or in other countries. The purpose of this review is to discuss the associations of obesity in men and women of Chinese background with cardio-metabolic risk with specific attention to body fat distribution. Evidence suggests that current BMI and WC targets may actually underestimate the cardio-metabolic risk in Chinese compared to European populations from which they were derived. Through a number of investigations, we and others have identified that Chinese men and women tend to have higher cardio-metabolic risk factors at a given body size than people of European background (from which guidelines are generally derived). Our additional investigations have indicated that Chinese men and women have greater amounts of VAT, but similar amounts of DSAT at a given body fat than Europeans and it may be the higher VAT in Chinese people that is, in part, responsible for the greater cardio-metabolic risk in the Chinese. Further investigation of this topic should prove fruitful in shedding light onto the determinants of body fat accumulation and distribution that may help to inform obesity prevention and treatment strategies.

A Cross-Sectional Analysis of the Association between Physical Activity and Visceral Adipose Tissue Accumulation in a Multiethnic Cohort

Higher levels of VAT at the same body size and lower levels of physical activity (PA) have been reported in persons of Chinese and South Asian origin compared to European origin. The purpose of this study was to test the hypothesis that higher levels of VAT in persons of Chinese and South Asian origin versus European origin are associated with lower levels of PA. Chinese, European, and South Asian participants were assessed for sociodemographics, obesity-related measures, anthropometrics, and PA. Bivariate correlations, analysis of covariance, and regression models were used to explore ethnic differences in PA and the role of PA in explaining obesity-related measures. We observed ethnic differences in both body fat distribution and PA. Chinese and South Asians had higher amounts of VAT at a given BMI but lower amounts of moderate PA, vigorous PA, and moderate-to-vigorous PA (MVPA). Furthermore, we found ethnic-specific differences in the associations between body fat distribution and PA with only Europeans showing a consistent negative relationship between body fat distribution and PA. When ethnic differences in PA were taken into account, there were no longer any differences in VAT between the Chinese and European groups, while VAT remained higher in South Asians than Europeans.