Physical activity and obesity editorial: is exercise pointless or was it a pointless exercise?

Serum myokine levels after linear and flexible non-linear periodized resistance training in overweight sedentary women

This study compared the capacity of linear-(LP) and non-linear periodized (NLP) resistance training to improve select myokines and metabolic parameters in overweight sedentary women. An additional purpose was to compare these variables between the overweight and lean women. Fitness- and age-matched overweight women between 28 and 43 years old were randomly allocated to LP (body fat [BF]% = 38.7 ± 2.6, n = 10), NLP (BF% = 39.3 ± 2.4, n = 9) and control (BF% = 39.8 ± 2.6, n = 9) groups. Lean women (BF% = 29.1 ± 2.3, n = 16) matched for age and fitness were also included for baseline comparison. Resistance training programmes (12 weeks, 3 d.wk^-1, 9 exercises, 60-90% of 1-repetition maximum [1RM]) were performed with different periodization schemes. Glucose, insulin, interleukin (IL)-7, IL-15, and insulin-like growth factor (IGF)-1 levels were measured at baseline and after training. Overweight subjects had significantly lower IL-15, IGF-1 and higher insulin, glucose, and insulin resistance (homeostasis model assessment, HOMA-IR) than lean subjects at baseline (all, P < .05). IL-15 and VO₂max increased significantly after NLP compared with CON, which was accompanied by a significant decrease in HOMA-IR (all, P < .03). Muscular endurance improved significantly in both models after training compared to CON (all, P < .01), but it increased more in NLP than in LP (P = .01). Both training protocols were equally effective at reducing BF% and increasing IGF-1, IL-7, muscle mass and bench press 1RM (P < .01). It appears that LP and NLP are both effective strategies for improving health markers in overweight women, but LP is not as effective as NLP to improve IL-15, HOMA-IR and aerobic capacity.Highlights Overweight women had a significantly lower IL-15 and IGF-1 compared to lean encounters, but no significant difference was noted for maximal strength, aerobic capacity, muscle mass, IL-7 and neutrophil/lymphocyte ratio.Twelve weeks of either linear or flexible non-linear periodized resistance training resulted in reduction in BF% and neutrophil/lymphocyte ratio, and increased IGF-1, IL-7, muscle mass and bench press 1RM, with no difference between the two training protocols.Linear protocol is not as effective as non-linear protocol to improve IL-15, HOMA-IR and aerobic capacity.

Clustering effects of health risk behavior on mental health and physical activity in Chinese adolescents

PURPOSE

Risk behaviors are significantly impacting physical and psychological health among adolescents, resulting in a tremendous public health issue. The aim of this study is to examine the association of clustered risk behaviors with mental health and physical activity, and identify to what extent the clustering of various risk behaviors is associated with psychological health and physical activity in Chinese adolescents.

METHODS

Students aged 16-18 years, male 16.2 ± 1.03, female 16.3 ± 1.56, were recruited from 30 high schools to complete an online questionnaire in fall semester 2017. A structured questionnaire, 2017 state and local youth risk behavior survey was revised, modified, and translated into Chinese. Five questions were designed to assess physical activity times of the last 7 days. Symptom checklist 90 (SCL-90) was used to investigate the mental health status of the participants. Statistical analyses were done employing chi-square tests, two step cluster analysis, logistic regression.

RESULT

Results illustrate that girls report a significantly higher mean of being bullied in school, electronically bullied, feeling sad or hopeless, and trying cigarette smoking. Two-step cluster analysis and regression analysis find that alcohol use, smoking and sedentary behavior have significant effect on adolescent health. Logic regression demonstrated that risk behaviors have significantly associated with mental health and physical activity in specific cluster.

CONCLUSION

This study finds that a specific behavior cluster has significant impact on mental health and physical activity among adolescents. Integrating risk behaviors cluster with factors can be employed to target high-risk adolescents who have poor physical and psychosocial health. The research suggest that more effective and feasible school intervention programs can be designed to promote adolescent health-related behavior in terms of those pathways.

Comparison of Nutritional Behaviors and Physical Activities between Overweight/Obese and Normal-Weight Adults

Background:

Overweight and obesity are major problems with increasing rates among adult populations. Nutritional behaviors and physical activity are the most important influencing factors. In this article, we conducted a survey on the nutritional behaviors and physical activities among normal-weight and overweight/obese adults.

Materials and Methods:

We conducted a survey on some of the nutritional behaviors and physical activities of 729 middle-aged adults. Data regarding desirable or undesirable use of fruits, fish, dairy products, oil, fast foods, and carbonated drinks and the intensity and duration of physical activities were collected from our data bank and analyzed using the SPSS software.

Results:

Our results indicated that overweight/obese people had an improper usage of fruits, oil, fast foods, and carbonated drinks and had lower physical activity. There was also a significant increase in intensity, duration per day, and weekly days of physical activity in healthy groups. Logistic regression analysis of nutritional behaviors, physical activities, and obesity also indicated that undesirable usage of oil, fast foods, and carbonated drinks and undesirable physical activity are associated with risks for overweight/obesity (odds ratio [OR] =10.70, OR = 7.45, OR = 7.48, and OR = 2.16, respectively) (P < 0.05).

Conclusion:

This article puts emphasis on the role of proper nutritional behaviors and higher physical activities in decreasing the risks of developing obesity, and we suggest that further interventions could be made based on the results of our study.

Physical Exercise-Induced Myokines and Muscle-Adipose Tissue Crosstalk: A Review of Current Knowledge and the Implications for Health and Metabolic Diseases

Physical exercise has beneficial effects on metabolic diseases, and a combined therapeutic regimen of regular exercise and pharmaceutical treatment is often recommended for their clinical management. However, the mechanisms by which exercise produces these beneficial effects are not fully understood. Myokines, a group of skeletal muscle (SkM) derived peptides may play an important part in this process. Myokines are produced, expressed and released by muscle fibers under contraction and exert both local and pleiotropic effects. Myokines such as IL-6, IL-10, and IL-1ra released during physical exercise mediate its health benefits. Just as exercise seems to promote the myokine response, physical inactivity seems to impair it, and could be a mechanism to explain the association between sedentary behavior and many chronic diseases. Myokines help configure the immune-metabolic factor interface and the health promoting effects of physical exercise through the release of humoral factors capable of interacting with other tissues, mainly adipose tissue (AT). AT itself secretes proinflammatory cytokines (adipokines) as a result of physical inactivity and it is well recognized that AT inflammation can lead to the development of metabolic diseases, such as type 2 diabetes mellitus (T2DM) and atherosclerosis. On the other hand, the browning phenotype of AT has been suggested to be one of the mechanisms through which physical exercise improves body composition in overweight/obese individuals. Although, many cytokines are involved in the crosstalk between SkM and AT, in respect of these effects, it is IL-6, IL-15, irisin, and myostatin which seem to have the decisive role in this “conversation” between AT and SkM. This review article proposes to bring together the latest “state of the art” knowledge regarding Myokines and muscle-adipose tissue crosstalk. Furthermore, it is intended to particularly focus on the immune-metabolic changes from AT directly mediated by myokines.

Physical activity and body mass shape quality of life trajectories in mid-age women

OBJECTIVE

To determine the combined longitudinal effect of body mass index (BMI) and physical activity (PA) on health-related quality of life (HrQoL), using the SF-6D (SF-36) utility measure.

METHODS

Five waves of self-reported data from the 1946-51 cohort (n=5,200; data collection, 2001-2013) of the Australian Longitudinal Study on Women's Health were used. Mixed effect models were employed to address the objective.

RESULTS

Women with high PA experienced higher HrQoL regardless of BMI group, however, for those healthy or overweight, there was a very small decline in HrQoL over time. Women reporting no PA levels experienced the lowest baseline mean SF-6D score within each BMI group, with decreasing trajectories over the follow-up period. The rate of decline was greatest in women with obesity. Within each BMI group, there was a large, increasing gap in HrQoL between those who reported no and low PA over time. Women with obesity and high PA experienced similar HrQoL trajectories to women with normal weight or overweight with low PA levels. Overweight women with moderate PA experienced similar HrQoL to those with low PA but normal weight.

CONCLUSIONS

PA may mitigate the adverse effect of overweight and obesity on HrQoL at mid-life, at higher activity levels. Implications for public health: PA benefits HrQoL regardless of body mass, with larger gains for those currently not physically active. Moderate to high PA may mitigate the effect of overweight and obesity.

Physical Fitness, Physical Activity, Sedentary Behavior, or Diet-What Are the Correlates of Obesity in Polish School Children?

There is substantial evidence of rising prevalence of overweight and obesity and its co-morbidities among children in western-high income developed countries. In the European Union, the prevalence of overweight and obesity is increasing fastest among Polish children. Yet, there is paucity of evidence on the relationship of behavioral factors with body weight status of children in Poland. This study examined the association of obesity with physical fitness, physical activity, sedentary behavior and diet among Polish children. A total of 641 children (10-15 years) recruited from the Lower Silesia region of Poland participated in this cross-sectional study. Participants' anthropometrics, physical fitness, physical activity, sedentary behavior and dietary intake were assessed. Outcome variables were weight categories (according to body mass index [BMI], waist-to-hip ratio [WHR], and percentage body fat [% BF]). The strongest negative correlation was found between VO₂max and %BF (r = -0.39, p <0.05). Significant negative correlation was also found between VO₂max and weight categories (r = -0.15). Results of the multinomial logit analysis showed that VO₂max increased in groups of overweight, normal weight and underweight children by 13%, 26% and 19%, respectively as compared to the group of obese children. VO₂max and weight and obesity indices were strongly correlated in both gender and age groups. Education and intervention programs to increase physical fitness (VO₂max) through aerobic training are recommended for Physical Education teachers, parents and children in order to reduce the rate of overweight and obesity among children in the Lower Silesia region of Poland.

Obesity and energy balance: What is the role of physical activity?

Despite billions of dollars spent over decades of research, debate remains over the causes and solutions of the obesity epidemic. The specific role of physical activity in the prevention or treatment of obesity seems a particularly contentious issue, with opposing views put forth in both academic and popular media. In an attempt to provide context and clarity to the specific question of the role of physical activity in determination of body weight, we have attempted to identify evidence or lack thereof in the scientific literature and provide a summary of our findings. Areas covered: Topics included in this narrative review are an overview of energy balance, the relationship between physical activity and energy expenditure, compensatory responses in non-exercise energy expenditure and energy intake, and the relationship between physical activity and obesity. Expert commentary: Based on a review of the existing literature, daily physical activity and structured exercise has beneficial effects on an individual's body weight. In most instances, exercise occurring in adequate amounts will increase total daily energy expenditure and create an acute energy deficit, without compensatory decreases in non-exercise physical activity or energy expenditure nor compensatory increases in energy intake. Several gaps in the literature exist, both in terms of the number of adequately powered clinical trials with rigorous assessments of both energy intake and expenditure, and with a variety of study populations (by age, sex, race, etc.) and with varying exercise volumes and intensities.

Associations among sedentary and active behaviours, body fat and appetite dysregulation: investigating the myth of physical inactivity and obesity

BACKGROUND

There is considerable disagreement about the association between free-living physical activity (PA) and sedentary behaviour and obesity. Moreover studies frequently do not include measures that could mediate between PA and adiposity. The present study used a validated instrument for continuous tracking of sedentary and active behaviours as part of habitual daily living, together with measures of energy expenditure, body composition and appetite dysregulation. This cross-sectional study tested the relationship between inactivity and obesity.

METHODS

71 participants (81.7% women) aged 37.4 years (±14) with a body mass index of 29.9 kg/m² (±5.2) were continuously monitored for 6-7 days to track free-living PA (light 1.5-3 metabolic equivalents (METs), moderate 3-6 METs and vigorous >6 METs) and sedentary behaviour (<1.5 METs) with the SenseWear Armband. Additional measures included body composition, waist circumference, cardiovascular fitness, total and resting energy expenditure, and various health markers. Appetite control was assessed by validated eating behaviour questionnaires.

RESULTS

Sedentary behaviour (11.06±1.72 h/day) was positively correlated with fat mass (r=0.50, p<0.001) and waist circumference (r=-0.65, p<0.001). Moderate-to-vigorous PA was negatively associated with fat mass (r=-0.72, p<0.001) and remained significantly correlated with adiposity after controlling for sedentary behaviour. Activity energy expenditure was positively associated with the level of PA and negatively associated with fat mass. Disinhibition and binge eating behaviours were positively associated with fat mass (r=0.58 and 0.47, respectively, p<0.001).

CONCLUSIONS

This study demonstrated clear associations among objective measures of PA (and sedentary behaviour), energy expenditure, adiposity and appetite control. The data indicate strong links between physical inactivity and obesity. This relationship is likely to be bidirectional.