In this quantitative research paper, we explored the correlation between the six dimensions of motivation as part of the Self-Determination Theory spectrum and physical activity. In addition, our aim was to also see if Transcranial Direct Current Stimulation (tDCS) paired with exercise as an intervention would affect motivation to exercise over time.
In this quantitative research paper, we explored the correlation between the six dimensions of motivation as part of the Self-Determination Theory spectrum and physical activity. In addition, our aim was to also see if Transcranial Direct Current Stimulation (tDCS) paired with exercise as an intervention would affect motivation to exercise over time.
In light of recent school-policy movements that encourage recess be moved before lunch, the present study seeks to examine the relationship between food consumption and immediate, subsequent physical activity (PA) and, more specifically, if a risk would be posed to the amount of children's PA if food is not consumed directly before activity. A cross-section study was performed measuring (a) lunch composition (in terms of food groups defined by the USDA's food plate), (b) lunch consumption, and (c) moderate-to-vigorous physical activity (MVPA) during the following recess period, in consenting third through sixth grade students. The relationship between food consumption and percentage of recess time spent in MVPA was determined to be weak. However, the study identified low average provision and consumption rates across all food groups and evaluated this through the lease of current school lunch policy/formatting.
The prevalence of obesity continues to increase in the United States, along with its risk for other associated cardiovascular and metabolic diseases. Several therapeutic methods are aimed at targeting and reducing obesity, now defined as a state of chronic, low-grade inflammation (in addition to BMI > 30 kg/m2). In an attempt to expand on these therapeutic methods, research on the concept of browning in white adipose tissue (WAT) and brown adipose tissue (BAT) is being conducted. Brown adipose tissue (BAT), and a newly discovered type of adipocyte, beige adipocytes, are heavily involved in thermogenesis with the use of uncoupling protein-1 (UCP-1). This paper focuses on the analysis of common browning genes, ATP-related genes, and metabolic genes in varying biological groups in mice (Chow/High-Fat Diet and Inguinal FAT and Perigonadal Fat) and in humans (Lean/Obese and Subcutaneous WAT (SC) and Omental WAT (OM)) using methods such as RT-PCR and immunohistochemistry. The data obtained shows an increase in browning in the leaner group, specifically in the subcutaneous fat. Further, browning is significantly reduced in the obese groups of subjects and mice tested, in addition to omental/perigonadal versus subcutaneous/inguinal fat depots. Interestingly, two key ATP genes, UCP-1 and COX4I1 are vastly elevated in the OM WAT, indicating that browning may not be as important in the OM, but rather may have a potential role in SC. This is contrary to prior research findings that attempt to exclude mice surrogates in future experimentation of the browning phenomenon. Further experimentation is needed to expand on the findings of this paper.
A total of 26 human subjects were used in this study. Each subject was classified as either lean or obese, according to their BMI measurement. First, the subjects underwent an oral glucose tolerance test. Blood samples were taken to measure glucose levels in the blood. After the test subject characteristics for each subject was obtained. These included age, BMI, body fat percentage, fat free mass (FFM), height, total mass, waist circumference, hip circumference, and waist to hip ratio. After the subject characteristics and blood glucose were measured the blood samples taken previously were then centrifuged, and the blood plasma was extracted. The blood plasma was then used to undergo an Insulin ELISA test. After extensive analysis, the Matsuda Index of each subject was obtained. Subjects with a Matsuda value of 6.0 or under were considered insulin resistant while subjects with a Matsuda value higher than 6.0 were considered insulin sensitive. Subjects were also required to submit a dietary record over the course of three days. The food intake was then put into a food processing software which gave a daily average of the macro and micro nutrients for each subject. Both the subject and dietary values were put into a multiple regression with a significance factor of p < 0.5 to see which factors contributed most to the Matsuda value.
It was found that BMI, height, total mass, insulin and fat free mass, all of which were subject characteristics, were considered to be significant. Some of these factors an individual has no control over, such as height and insulin. However other factors such as BMI, total mass and fat free mass can be affected by both a healthy diet and frequent exercise. This study validated that diet and physical activity can greatly influence an individual’s susceptibility to insulin resistance and ultimately T2DM.
According to the CDC, obesity has increased from 30.5% to 42.4% over the past 18 years. Western diets (WDs) consist of large portions in high fats, high carbohydrates, excess sugar and high-glycemic foods that can cause metabolic complications and mitochondrial dysfunction. Diet-induced obesity can lead to changes in muscle metabolism and muscle fiber phenotypes, which in turn lead to metabolic complications. Muscle fiber phenotype is determined protein isoform-content of myosin heavy chain (MHC). Regular exercise alters mitochondrial content and fat oxidation and shifts MHC proportions under healthy circumstances. However, diet and exercise-driven fiber type shifts in diet-induced obesity are less understood. We designed our experiment to better understand the impact of diet and/ or exercise on fiber type content of gastrocnemius muscle in diet-induced obese mice. Exercise and genistein may be used as a treatment strategy to restore the MHC proportions in obese subjects to that of the lean subjects. We hypothesized that genistein and exercise would have the greatest MHC I change in muscle fiber phenotype of mouse gastrocnemius muscles. Further, we also hypothesized that a standard diet would reverse the expected increase in fast fiber phenotype (MHC IIb). Lastly, we also hypothesized that exercise would also reduce the abundance of MHC IIb. Gastrocnemius muscles were collected from mice, homogenized, run through gel electrophoresis and stained to give muscle fiber proportions. Paired sample t-tests were conducted for differences between the MHC isoforms compared to the lean (LN) and high-fat diet (HFD) control groups. The results showed that genistein and exercise significantly increased the abundance of MHC I muscle fibers (19%, p<0.05). Additionally, diet and exercise restored the muscle fiber phenotype to that of lean control. As expected, HFD obese mice exhibited elevated fast twitch fibers compared to only 3% slow twitch fibers. These findings show the potential for exercise and supplementation of genistein as a strategy to combat diet induced obesity. Future research should aim to understand the mechanisms that genistein acts on to make these changes, and aim to replicate these data in humans with obesity.
