Matching Items (9)
Filtering by

Clear all filters

152062-Thumbnail Image.png
Description
Eccentric muscle action (ECC) occurs when the force exerted by a working muscle is less than that of an outside resistance. This is characterized by muscle lengthening, despite actin-myosin crossbridge formation. Research has indicated that muscles acting eccentrically are capable of producing more force when compared to muscles acting concentrically.

Eccentric muscle action (ECC) occurs when the force exerted by a working muscle is less than that of an outside resistance. This is characterized by muscle lengthening, despite actin-myosin crossbridge formation. Research has indicated that muscles acting eccentrically are capable of producing more force when compared to muscles acting concentrically. Further, research has shown ECC muscle actions may have different fatigue patterns that CON actions. The purpose of this study was to determine if a) ECC bench press yields greater strength than concentric (CON) as measured by one-repetition maximum (1RM), b) there is a difference between the number of repetitions that can be completed concentrically and eccentrically under the same relative intensities of 1RM (90%, 80%, 70%, 60%), c) a prediction model may be able to predict ECC 1RM from CON 1RM or CON repetitions to fatigue. For this study, 30 healthy males (age = 24.63 + 5.6 years) were tested for 1RM in CON and ECC bench press, as well as the number of repetitions they were able to complete at various intensities of mode-specific 1RM. A mechanical hoist was affixed to a gantry crane and placed over a standard weightlifting bench. The hoist was connected to 45lb plates that were loaded on a standard barbell, which allowed for mechanical raising and lowering of the barbell. For CON repetitions, the weight was mechanically lowered to the chest and the participant pressed it up. For ECC repetitions, the weight was mechanically raised and the participant lowered it. Paired t-tests showed that ECC 1RM was significantly (p < 0.05) greater than CON 1RM (ECC =255.17 + 68.37lbs, CON = 205.83 + 58.43lbs). There was a significant difference (p < 0.05) between the number of repetitions completed at 90% 1RM (CON = 4.57 + 2.21 repetitions, ECC = 7.67 + 3.24 repetitions). There were no differences in repetitions completed at any other intensity 1RM. CON 1RM and the number of repetitions completed with two different absolute loads (130-150lbs and 155-175lbs) concentrically and eccentrically were valid predictors of ECC 1RM. These data indicate that ECC actions yield increased force capabilities than CON actions, there is no difference in the rate of the fatigue, and ECC 1RM may be predicted from various CON tests.
ContributorsKelly, Stephen B., Jr (Author) / Hooker, Steven (Thesis advisor) / Brown, Lee (Committee member) / Buman, Matthew (Committee member) / Gaesser, Glenn (Committee member) / Swan, Pamela (Committee member) / Arizona State University (Publisher)
Created2013
151598-Thumbnail Image.png
Description
Cardiovascular disease (CVD) is the number one cause of death in the United States and type 2 diabetes (T2D) and obesity lead to cardiovascular disease. Obese adults are more susceptible to CVD compared to their non-obese counterparts. Exercise training leads to large reductions in the risk of CVD and T2D.

Cardiovascular disease (CVD) is the number one cause of death in the United States and type 2 diabetes (T2D) and obesity lead to cardiovascular disease. Obese adults are more susceptible to CVD compared to their non-obese counterparts. Exercise training leads to large reductions in the risk of CVD and T2D. Recent evidence suggests high-intensity interval training (HIT) may yield similar or superior benefits in a shorter amount of time compared to traditional continuous exercise training. The purpose of this study was to compare the effects of HIT to continuous (CONT) exercise training for the improvement of endothelial function, glucose control, and visceral adipose tissue. Seventeen obese men (N=9) and women (N=8) were randomized to eight weeks of either HIT (N=9, age=34 years, BMI=37.6 kg/m2) or CONT (N=8, age=34 years, BMI=34.6 kg/m2) exercise 3 days/week for 8 weeks. Endothelial function was assessed via flow-mediated dilation (FMD), glucose control was assessed via continuous glucose monitoring (CGM), and visceral adipose tissue and body composition was measured with an iDXA. Incremental exercise testing was performed at baseline, 4 weeks, and 8 weeks. There were no changes in weight, fat mass, or visceral adipose tissue measured by the iDXA, but there was a significant reduction in body fat that did not differ by group (46±6.3 to 45.4±6.6%, P=0.025). HIT led to a significantly greater improvement in FMD compared to CONT exercise (HIT: 5.1 to 9.0%; CONT: 5.0 to 2.6%, P=0.006). Average 24-hour glucose was not improved over the whole group and there were no group x time interactions for CGM data (HIT: 103.9 to 98.2 mg/dl; CONT: 99.9 to 100.2 mg/dl, P>0.05). When statistical analysis included only the subjects who started with an average glucose at baseline > 100 mg/dl, there was a significant improvement in glucose control overall, but no group x time interaction (107.8 to 94.2 mg/dl, P=0.027). Eight weeks of HIT led to superior improvements in endothelial function and similar improvements in glucose control in obese subjects at risk for T2D and CVD. HIT was shown to have comparable or superior health benefits in this obese sample with a 36% lower total exercise time commitment.
ContributorsSawyer, Brandon J (Author) / Gaesser, Glenn A (Thesis advisor) / Shaibi, Gabriel (Committee member) / Lee, Chong (Committee member) / Swan, Pamela (Committee member) / Buman, Matthew (Committee member) / Arizona State University (Publisher)
Created2013
151604-Thumbnail Image.png
Description
Purpose: The purpose of this study was to examine the acute effects of two novel intermittent exercise prescriptions on glucose regulation and ambulatory blood pressure. Methods: Ten subjects (5 men and 5 women, ages 31.5 ± 5.42 yr, height 170.38 ± 9.69 cm and weight 88.59 ± 18.91 kg) participated

Purpose: The purpose of this study was to examine the acute effects of two novel intermittent exercise prescriptions on glucose regulation and ambulatory blood pressure. Methods: Ten subjects (5 men and 5 women, ages 31.5 ± 5.42 yr, height 170.38 ± 9.69 cm and weight 88.59 ± 18.91 kg) participated in this four-treatment crossover trial. All subjects participated in four trials, each taking place over three days. On the evening of the first day, subjects were fitted with a continuous glucose monitor (CGM). On the second day, subjects were fitted with an ambulatory blood pressure monitor (ABP) and underwent one of the following four conditions in a randomized order: 1) 30-min: 30 minutes of continuous exercise at 60 - 70% VO2peak; 2) Mod 2-min: twenty-one 2-min bouts of walking at 3 mph performed once every 20 minutes; 3) HI 2-min: eight 2-min bouts of walking at maximal incline performed once every hour; 4) Control: a no exercise control condition. On the morning of the third day, the CGM and ABP devices were removed. All meals were standardized during the study visits. Linear mixed models were used to compare mean differences in glucose and blood pressure regulation between the four trials. Results: Glucose concentrations were significantly lower following the 30-min (91.1 ± 14.9 mg/dl), Mod 2-min (93.7 ± 19.8 mg/dl) and HI 2-min (96.1 ± 16.4 mg/dl) trials as compared to the Control (101.1 ± 20 mg/dl) (P < 0.001 for all three comparisons). The 30-min trial was superior to the Mod 2-min, which was superior to the HI 2-min trial in lowering blood glucose levels (P < 0.001 and P = 0.003 respectively). Only the 30-min trial was effective in lowering systolic ABP (124 ± 12 mmHg) as compared to the Control trial (127 ± 14 mmHg; P < 0.001) for up to 11 hours post exercise. Conclusion: Performing frequent short (i.e., 2 minutes) bouts of moderate or high intensity exercise may be a viable alternative to traditional continuous exercise in improving glucose regulation. However, 2-min bouts of exercise are not effective in reducing ambulatory blood pressure in healthy adults.
ContributorsBhammar, Dharini Mukeshkumar (Author) / Gaesser, Glenn A (Thesis advisor) / Shaibi, Gabriel (Committee member) / Buman, Matthew (Committee member) / Swan, Pamela (Committee member) / Lee, Chong (Committee member) / Arizona State University (Publisher)
Created2013
151090-Thumbnail Image.png
Description
Introduction: Several faith-based or faith-placed programs have focused on the physical dimension of wellness in efforts to improve health by increasing physical activity and improving diet behaviors. However, these programs were not designed to intervene on the mental dimension of wellness which is critical for stress reduction and health behavior

Introduction: Several faith-based or faith-placed programs have focused on the physical dimension of wellness in efforts to improve health by increasing physical activity and improving diet behaviors. However, these programs were not designed to intervene on the mental dimension of wellness which is critical for stress reduction and health behavior change. Purpose: To evaluate the feasibility of a spirituality-based stress reduction and health behavior change intervention using the Spiritual Framework of Coping (SFC) model. Methods: This study was a quasi-experimental one group pretest posttest design. The study was a total of eight weeks conducted at a non-denominational Christian church. Participants were recruited from the church through announcements and flyers. The Optimal Health program met once a week for 1.5 hours with weekly phone calls during an additional four week follow-up period. Feasibility was assessed by the acceptability, demand, implementation, practicality, integration, and limited efficacy of the program. Analysis: Frequencies for demographics were assessed. Statistical analyses of feasibility objectives were assessed by frequencies and distribution of responses to feasibility evaluations. Limited efficacy of pretest and posttest measures were conducted using paired t-test (p <.05). Results: The Optimal Health Program was positively accepted by participants. The demand for the program was shown with average attendance of 78.7%. The program was successfully implemented as shown by meeting session objectives and 88% homework completion. The program was both practical for the intended participants and was successfully integrated within the existing environment. Limited efficacy changes within the program were mostly non-significant. Conclusion: This study tested the feasibility of implementing the Optimal Health program that specifically targeted the structural components of the Spiritual Framework of Coping Model identified to create meaning making and enhance well-being. This program may ultimately be used to help individuals improve and balance the spiritual, mental, and physical dimensions of wellness. However, length of study and limited efficacy measures will need to be reevaluated for program success.
ContributorsWalker, Jenelle R (Author) / Swan, Pamela (Thesis advisor) / Ainsworth, Barbara (Committee member) / Chisum, Jack (Committee member) / Fleury, Julie (Committee member) / Hooker, Steven (Committee member) / Arizona State University (Publisher)
Created2012
136618-Thumbnail Image.png
Description
This study examines the effect of exercise therapy on a stationary bike on cognitive function, specifically inhibition and set-switching, in adolescents with Down syndrome. 44 participants were randomly divided between the voluntary cycling therapy group (VCT) (i.e., self-selected cadence), assisted cycling therapy group (ACT) (i.e., 30% faster than self-selected cadence

This study examines the effect of exercise therapy on a stationary bike on cognitive function, specifically inhibition and set-switching, in adolescents with Down syndrome. 44 participants were randomly divided between the voluntary cycling therapy group (VCT) (i.e., self-selected cadence), assisted cycling therapy group (ACT) (i.e., 30% faster than self-selected cadence accomplished by a motor), and a control group (NC) in which the participants did not undergo any exercise therapy. Both cycling groups rode a stationary bicycle, for 30 minutes, three times a week, for eight-weeks. At the beginning (i.e., pretest) and end (i.e., posttest) of the eight-week session the participants completed tasks to evaluate their cognitive function. They completed three trials of the card sort test (i.e., set-switching) and three trials of the knock-tap test (i.e, inhibition) before and after eight-weeks of cycling therapy. The scores of these tests were analyzed using one-way ANOVA between groups and paired samples t-tests. The results showed that after eight-weeks of cycling therapy the participants in the VCT group performed worse in the knock-tap test, but improved in two trials of the card sort test. The results also showed that the participants in the ACT group performed worse after eight-weeks of exercise therapy in one trial of the card sort test. No significant changes were seen for the control group. Due to the fact that on average the participants in the VCT group cycled with a higher heart rate, our results suggest exercise that significantly elevates heart rate can improve cognitive function, specifically set-switching, in adolescents with Down syndrome.
ContributorsBenson, Alicia Meigh (Author) / Ringenbach, Shannon (Thesis director) / Amazeen, Eric (Committee member) / Maraj, Brian (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
149587-Thumbnail Image.png
Description
It is broadly accepted that physical activity provides substantial health benefits. Despite strong evidence, approximately 60% to 95% of US adults are insufficiently active to obtain these health benefits. This dissertation explored five projects that examined the measurement properties and methodology for a variety of physical activity assessment methods. Project

It is broadly accepted that physical activity provides substantial health benefits. Despite strong evidence, approximately 60% to 95% of US adults are insufficiently active to obtain these health benefits. This dissertation explored five projects that examined the measurement properties and methodology for a variety of physical activity assessment methods. Project one identified validity evidence for the new MyWellness Key accelerometer in sixteen adults. The MyWellness Key demonstrated acceptable validity evidence when compared to a criterion accelerometer during graded treadmill walking and in free-living settings. This supports the use of the MyWellness Key accelerometer to measure physical activity. Project two evaluated validity (study 1) and test-retest reliability evidence (study 2) of the Global Physical Activity Questionnaire (GPAQ) in a two part study. The GPAQ was compared to direct and indirect criterion measures including object and subjective physical activity instruments. These data provided preliminary validity and reliability evidence for the GPAQ that support its use to assess physical activity. Project three investigated the optimal h.d-1 of accelerometer wear time needed to assess daily physical activity. Using a semi-simulation approach, data from 124 participants were used to compare 10-13 h.d-1 to the criterion 14 h.d-1. This study suggested that a minimum accelerometer wear time of 13 h.d-1 is needed to provide a valid measure of daily physical activity. Project four evaluated validity and reliability evidence of a novel method (Movement and Activity in Physical Space [MAPS] score) that combines accelerometer and GPS data to assess person-environment interactions. Seventy-five healthy adults wore an accelerometer and GPS receiver for three days to provide MAPS scores. This study provided evidence for use of a MAPS score for future research and clinical use. Project five used accelerometer data from 1,000 participants from the 2005-2006 National Health and Nutrition Examination Study. A semi-simulation approach was used to assess the effect of accelerometer wear time (10-14 h.d-1) on physical activity data. These data showed wearing for 12 h.d-1 or less may underestimate time spent in various intensities of physical activity.
ContributorsHerrmann, Stephen (Author) / Ainsworth, Barbara (Thesis advisor) / Gaesser, Glenn (Committee member) / Der Ananian, Cheryl (Committee member) / Kang, Minsoo (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2011
149593-Thumbnail Image.png
Description

Health care providers (HCPs) are an important source of physical activity (PA) information. Two studies were conducted to qualitatively and quantitatively examine nurse practitioners'(NPs) and physician assistants' current PA counseling practices, knowledge and confidence to provide PA counseling and providers' perceptions about their current PA counseling practices. The specific aims

Health care providers (HCPs) are an important source of physical activity (PA) information. Two studies were conducted to qualitatively and quantitatively examine nurse practitioners'(NPs) and physician assistants' current PA counseling practices, knowledge and confidence to provide PA counseling and providers' perceptions about their current PA counseling practices. The specific aims for these two studies included quantitatively and qualitatively identifying the prevalence of PA counseling, perceived counseling knowledge and confidence, and educational training related to counseling. In study 1, survey respondents were currently practicing NPs and physician assistants. Participants completed a modified version of the Promotion of Physical Activity by Nurse Practitioners Questionnaire either online or in person during a population specific conference. The majority of both NP and physician assistant respondents reported routinely counseling patients about PA. There were no differences in perceived knowledge or confidence to provide PA counseling between the two populations. Approximately half of all respondents reported receiving training to provide PA counseling as part of their educational preparation for becoming a health practitioner. Nearly three-quarters of respondents reported interest in receiving additional PA counseling training. In study 2, five focus groups (FGs), stratified by practice type, were conducted with NPs and physician assistants. Both NPs and physician assistants reported discussing PA with their patients, particularly those with chronic illness. Participants reported that discussing lifestyle modifications with patients was the most common type of PA counseling provided. Increased confidence to counsel was associated with having PA knowledge and providing simple counseling, such as lifestyle modifications. Barriers to counseling included having more important things to discuss, lack of time during appointments, the current healthcare system, lack of reimbursement and perceived patient financial barriers. PA recommendation knowledge was highly variable, with few participants reporting specific guidelines. FG participants, while not familiar with the American College of Sports Medicines' "Exercise is Medicine" initiative indicated interest in its use and learning more about it. The findings of these two studies indicate that while NPs and physician assistants are knowledgeable, confident and currently providing some amount of PA counseling to patients, additional training in PA counseling is needed and desired.

ContributorsGrimstvedt, Megan (Author) / Der Ananian, Cheryl (Thesis advisor) / Ainsworth, Barbara (Committee member) / Keller, Colleen (Committee member) / Sebren, Ann (Committee member) / Woolf, Kathleen (Committee member) / Arizona State University (Publisher)
Created2011
157417-Thumbnail Image.png
Description
Physical inactivity is a continuing public health crisis because of its negative effects on health (e.g. hypertension, cardiovascular disease, type II diabetes). To combat the rising prevalence of these non-communicable diseases, physical activity (PA) promotion is a public health priority. However, current programs seem to be ineffective in the long-term

Physical inactivity is a continuing public health crisis because of its negative effects on health (e.g. hypertension, cardiovascular disease, type II diabetes). To combat the rising prevalence of these non-communicable diseases, physical activity (PA) promotion is a public health priority. However, current programs seem to be ineffective in the long-term promotion of PA. Resultingly new, effective interventions are needed. Recent studies have established a link between mindfulness and PA engagement. Based on the current literature, the present study sought to investigate the associations between trait mindfulness, behavioral regulation towards exercise, exercise intention, stress, and self-reported PA. This study also examined whether trait mindfulness was independently associated with meeting weekly, leisure-time, moderate-to-vigorous PA [MVPA] recommendations in university undergraduate students after controlling for demographic characteristics, past PA experience, exercise intention, stress, and motivation.

The study used a cross-sectional design and participants consisted of 180 undergraduate university students (aged 18 to 24 years). Participants completed a one-time survey that assessed demographic characteristics, trait mindfulness, behavioral regulation toward exercise, exercise intention, perceived stress and PA. Bivariate associations between the variables were assessed with Pearson or Spearman correlations. A logistic regression analysis was conducted to determine which variables were independently associated with meeting weekly, leisure-time MVPA guidelines. Results of this study found weak positive associations between the mindfulness domain of acceptance and leisure time MVPA ( = .168, p < .05), no associations between mindfulness and transportation PA, and negative associations between mindfulness (MAAS,  = –.238, p < .01; acceptance,  = –.175, p < .05) and sitting time. Results of logistic regression found that only relative autonomy (OR = 1.085, 95% CI [1.008, 1.168], p = .030) and intention (OR = 2.193, 95% CI [1.533, 3.138], p < .0001) were independently associated with meeting weekly, leisure- time MVPA recommendations. The results of this study show that while there is only a weak direct relationship between trait mindfulness and PA, mindfulness may be related with other factors associated with PA. More research is needed in order to better understand the potential mechanisms behind the results found in this, and past, studies.
ContributorsNapolitano, Vinson (Author) / Der Ananian, Cheryl (Thesis advisor) / Sebren, Ann (Committee member) / Ainsworth, Barbara (Committee member) / Arizona State University (Publisher)
Created2019
190774-Thumbnail Image.png
Description
This dissertation research project developed as an urgent response to physical inactivity, which has resulted in increased rates of obesity, diabetes, and metabolic disease worldwide. Incorporating enough daily physical activity (PA) is challenging for most people. This research aims to modulate the brain's reward systems to increase motivation for PA

This dissertation research project developed as an urgent response to physical inactivity, which has resulted in increased rates of obesity, diabetes, and metabolic disease worldwide. Incorporating enough daily physical activity (PA) is challenging for most people. This research aims to modulate the brain's reward systems to increase motivation for PA and, thus, slow the rapid increase in sedentary lifestyles. Transcranial direct current stimulation (tDCS) involves brain neuromodulation by facilitating or inhibiting spontaneous neural activity. tDCS applied to the dorsolateral prefrontal cortex (DLPFC) increases dopamine release in the striatum, an area of the brain involved in the reward–motivation pathways. I propose that a repeated intervention, consisting of tDCS applied to the DLPFC followed by a short walking exercise stimulus, enhances motivation for PA and daily PA levels in healthy adults. Results showed that using tDCS followed by short-duration walking exercise may enhance daily PA levels in low-physically active participants but may not have similar effects on those with higher levels of daily PA. Moreover, there was a significant effect on increasing intrinsic motivation for PA in males, but there were no sex-related differences in PA. These effects were not observed during a 2-week follow-up period of the study after the intervention was discontinued. Further research is needed to confirm and continue exploring the effects of tDCS on motivation for PA in larger cohorts of sedentary populations. This novel research will lead to a cascade of new evidence-based technological applications that increase PA by employing approaches rooted in biology.
ContributorsRuiz Tejada, Anaissa (Author) / Katsanos, Christos (Thesis advisor) / Neisewander, Janet (Committee member) / Sadleir, Rosalind (Committee member) / Buman, Matthew (Committee member) / Arizona State University (Publisher)
Created2023