Browsing by Subject "Fitness"
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Item Beyond obesity : historical, social change approaches to improve the fitness of Americans(2014-08) Harrell, Baker Christian; Todd, JanAmerica's growing concern about fatness during the twentieth century developed in parallel with a society that made it increasingly harder to live a healthy lifestyle. Since the 1970s, sweeping political, economic, cultural, and familial changes have occurred in the United States. Many researchers argue that these changes have created an "obesogenic" environment that has contributed to the increased prevalence of overweight and obesity in America by favoring inactivity and the over consumption of highly-processed, calorie-dense foods and beverages. As a result, the field of public health has increasingly begun to recognize obesity as a "societal disease." In 2001, The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity categorized the number of overweight and obese Americans as reaching "nationwide epidemic proportions." Since that time, America has waged an all-out "war on obesity." Instead of a broader emphasis on health promotion, some public health researchers have suggested that this heightened focus on obesity is 1) guided by America's historically-rooted social disdain for fatness and 2) insufficient to improve the healthy lifestyles of Americans. In searching for a solution to the so-called "obesity epidemic," a growing number of researchers have begun to look to models of social change. After an introductory chapter describing the scope of the problem, this dissertation provides an historical analysis of two, relevant social change models. The first historical case study is an examination of the Centers for Disease Control and Prevention's VERB social marketing campaign. The second study explores the model of social movements through the history of the aerobics "boom" of 1970s America. Based on these histories, this dissertation concludes by proposing a blended approach that harnesses the strengths of both models to organize and advance America's healthy living movement.Item Cerebrovascular reactivity and the fMRI-BOLD response in cardiorespiratory fitness(2015-08) Gonzales, Mitzi Michelle; Haley, Andreana P.; Tanaka, Hirofumi; Mumford, Jeanette A; Schnyer, David M; Maddox, W. ToddAccumulating evidence indicates that poorer vascular health accelerates cognitive decline and increases the likelihood of dementia in old age. Aerobic fitness, as a protective factor against vascular dysfunction, may thus serve to attenuate age-related cognitive pathology. The overarching aim of the current investigations was to determine the impact of cardiorespiratory fitness on cognition and its underlying neural substrates. Sedentary and endurance-trained middle-aged adults underwent general health assessment, neuropsychological testing, and functional magnetic resonance imaging (fMRI) during a working memory task and a hypercapnic (breath-hold) challenge. As compared with sedentary age-matched controls, the endurance-trained adults displayed a trend towards better executive function performance and faster reaction time on the working memory task, indicating enhanced speed of information processing. The neural substrates underlying fitness-related cognitive enhancement were explored by examining the blood oxygen level dependent (BOLD) response to a 2-Back working memory task. Additionally, breath-hold calibration of the working memory task was performed in order reduce vascular variance and provide a closer approximation of the neural contributions to the BOLD signal. After breath-hold calibration, the endurance-trained adults displayed greater working memory-related activation in the right middle frontal gyrus, indicating that fitness likely benefits the neural processes underlying cognition over and above global fitness-related changes in cerebrovascular reactivity. Finally, endothelial function was examined as a potential mechanism underlying fitness-related differences in cerebrovascular reactivity. Peripheral endothelial function failed to predict the BOLD signal to hypercapnia, suggesting that the response may be governed by nonendothelial-dependent vasoregulators. In summary, higher cardiorespiratory fitness at midlife may increase executive function abilities by enabling greater recruitment of neural resources during challenging cognitive tasks. Longitudinal studies will be instrumental in determining if these fitness-related changes are capable of modulating the trajectory of cognitive decline across the lifespan.Item Color vision variation, feeding behavior, and reproductive output in a group of wild Ateles belzebuth(2023-08) Rettke, Samantha Paige; Di Fiore, Anthony, Ph. D.Color vision among primates is remarkably diverse. Catarrhines and howler monkeys have independently acquired routine trichromacy through duplication of the middle-to-long wavelength-sensitive (M/LWS) opsin gene on the X chromosome. Most platyrrhines and some strepsirrhines, however, possess polymorphic color vision due to allelic variation at a single M/LWS locus; heterozygous females are trichromats, while males and homozygous females are dichromats. Four mechanisms – heterozygote (trichromat) advantage, frequency-dependent selection, mutual benefit of association, and niche divergence – have been proposed to explain the maintenance of the opsin polymorphism, yet the selective advantages of individual phenotypes remain unclear. I reviewed the diversity in platyrrhine color vision as well as the studies that have evaluated each hypothesis. Next, I tested two of these hypotheses in one social group of white-bellied spider monkeys (Ateles belzebuth) that has been monitored at Tiputini Biodiversity Station since 2005. Spider monkeys – a genus of large-bodied frugivorous platyrrhines – have two possible opsin alleles determined by a SNP in exon 5 of the M/LWS locus; in reconstituted pigments they have absorption spectra with peaks at 538 and 553 nm, respectively. Using fecal-extracted DNA, I sequenced exon 5 for 44 group members, identifying 14 male dichromats (seven P538, seven P553), 10 female dichromats (two P538, eight P553), and 20 female trichromats (P538/P553). Then, to investigate the possibility of heterozygote advantage, I compared the interbirth intervals and number of offspring produced for dichromat versus trichromat females. There were no differences in these measures of reproductive output, suggesting that the conditional advantages of trichromacy may not translate to higher fitness. To assess niche divergence, I examined the proportion of total feeding time spent by dichromat versus trichromat adult and subadult males and females on each of three major food types – fruits, new leaves, and flowers – plus all three substrates combined. Additionally, I tested for niche divergence within dichromats by comparing the foraging behavior of P538 versus P553 individuals. Analyses revealed no difference in foraging activity budgets between groups in either case. Future work may consider other aspects of fitness and finer-scale niche differentiation to better understand how multiple visual phenotypes have been maintained in this population.Item Determination of the genetic basis of seed oil composition and melting point—adaptive quantitative traits—and their fitness effects in Arabidopsis thaliana(2013-12) Pelc, Sandra Elaine; Linder, C. RandalEvidence indicates seed oil melting point is likely an adaptive quantitative trait in many flowering plant species. An adaptive hypothesis suggests selection has changed the melting point of seed oils to covary with germination temperatures because of a trade-off between total energy stores and the rate of energy acquisition during germination under competition. The predicted differences in relative fitness under different temperatures have not yet been tested and little is known about the genetic basis of differences in oil composition. I used Arabidopsis thaliana to: (1) assess the fitness consequences of high and low melting point seeds germinating at different temperatures, (2) assess what genes underlie natural variation in seed oil composition, and (3) consider how these genes may be used to create oils with particular characteristics. To assess the effects of seed oil melting point on timing of seedling emergence and fitness, I competed high and low melting point lines of A. thaliana under cold and warm temperatures. Emergence timing between these lines was not significantly different at either temperature, which comported with warm temperature predictions but not cold temperature predictions. Under all conditions, plants competing against high melting point lines had lower fitness relative to those against low melting point lines, which matched expectations for undifferentiated emergence times. To assess the genetic basis of naturally occurring variation in seed oil melting point, the seed oil compositions of 391 accessions of A. thaliana were used in a genome-wide association study. Twelve genes were tightly linked with SNPs significantly associated with seed oil melting point variation. Seven encoded lipid synthesis enzymes or regulatory products. The remaining 5 encoded products with no clear relation to seed oil melting point. Results suggest selection can alter quantitative trait variation in response to local conditions through a small set of genes. 268 seed-expressed, candidate genes were linked to 103 SNPs associated with A. thaliana seed oil fatty acids. Eight genes were involved in lipid metabolism, and thirty-four encoded regulatory products. I discuss how knowledge of these genes can be used to breed and engineer desirable oil compositions for industry and nutrition.Item Effects of cardiovascular risks and acute exercise on cognitive and brain functioning in young adults(2016-08) Calvert, Hannah Grace; Castelli, Darla M., 1967-; Bartholomew, John; Haley, Andreana; Maslowsky, JulieCardiovascular disease (CVD) is characterized by damage to the vasculature, leading to impaired blood circulation. This damage is related to structural deficits in the brain as well as decreased cognitive performance. Risks for CVD are more common among young adults now than in previous generations of this cohort. While associations between CVD states and cognition are well studied, little is known about how risk factors for CVD may influence cognitive functioning in young populations. Physical activity engagement is one potential method for decreasing CVD risks and improving cognitive performance. The purpose of this dissertation was to examine the effects of CVD risks and acute exercise on cognitive and neural outcomes in young adults. A sample of 100 young adults aged 18-30 was recruited for this study. Participants underwent a blood draw, an aerobic fitness assessment, and a cognitive battery. A subset was randomly assigned to exercise (n=40) and control (n = 31) groups to examine the effects of a bout of exhaustive exercise on cognitive function. On separate a day, participants (n=17) engaged in a moderate intensity acute exercise with cognitive and functional neuroimaging assessments at baseline and post-exercise. In the first study, cross-sectional analyses revealed that young adults who possessed three or more risks for CVD had significantly inferior performance on cognitive tests requiring incongruent processing compared to their peers with no identified CVD risks. Participants who engaged in a bout of acute exhaustive exercise had increased cognitive performance post exercise compared to resting controls, in the second study. In study three, an acute bout of moderate intensity exercise had no effects on neural activation in the overall sample of participants. However, blood pressure moderated the effects of acute exercise on neural activation such that pre-hypertensive individuals experienced a differential increase in task-related brain activation after exercise in several brain regions. Young adults who possess several CVD risk factors may already be experiencing subtle decrements to their executive functioning, specifically during incongruent tasks. Short bouts of exercise produce cognitive benefits in this population and also increase brain activation during executive functioning tasks in those who have several CVD risks. Findings from these three studies have public health implications as regular engagement in moderate to very vigorous physical activity has cognitive benefits related to the prevention of age-related cognitive impairments.Item Embracing inclusivity in fitness facilities and health clubs(2018-06-25) Grana, Courtney Rachelle; Jensen, Jody L.; Buchanan, PamelaThe Embracing Inclusivity Workshop will take the reader through a thorough and complete guide on how to design fitness facilities as accessible and inviting spaces for those with disabilities, as well as how to train fitness instructors on developing fitness programs, with awareness for specific modifications and assistive devices. All individuals have a need and a desire to stay healthy and fit, and people will generally choose to go to public fitness facilities, including health clubs and other privately owned membership gyms to exercise. Therefore, these facilities must be equipped with effective access routes, equipment, and programs for people with impairments or disabilities. Several materials have been created addressing access issues, little has been done, however, to ensure that the fitness trainers, health and wellness coaches, and fitness facilities are equipped with the knowledge and practice to train people those with impairments or disabilities. The unique needs and risks of those with disabilities, paired with the unaccommodating characteristics of most fitness environments, make it extremely challenging for people with special needs to stay physically fit and healthy. This workshop will address, first, the program outline and goals with specific attention to the obesity rate, health condition, and physical activity participation percentages in those with a disability as well as the importance of inclusive and accessible fitness centers. Next the Embracing Inclusivity Workshop will address the current guidelines for training people with disabilities, with specific attention to: auditory disabilities, visual disabilities, physical disabilities, autism spectrum, intellectual disabilities, mental health, and chronic disease/ illness. Finally, the workshop will conclude with the barriers fitness facilities should address regarding architecture, attitude, communication, and programming. In this section, the reader will learn detail requirements of their facility in order to make their site accessible including exercise equipment, marketing materials, assistive devices, removing disability stigma, and smart and effective programming.