Browsing by Subject "exercise"

Now showing 1 - 9 of 9
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    Acute contraction-induced strength loss, muscle inexcitability and recovery after exercise in males with Duchenne muscular dystrophy
    (2020-11) Trost, Joyceann
    This dissertation had three objectives with the overall goal to explore contraction-induced strength loss and recovery in males with Duchenne muscular dystrophy (DMD) specifically to: 1) evaluate a novel protocol, combining voluntary and evoked contractions to measure strength and excitability of wrist extensor muscles, for safety, feasibility, reliability and discriminant validity for males with DMD and aged-matched controls, 2) explore strength loss and muscle fiber inexcitability contribution to strength loss after submaximal isometric contractions in males with DMD, and. 3) determine the recovery of strength and muscle excitability immediately following contraction-induced force loss in males with DMD. Through the literature review, I discovered a need for a reliable and valid measurement protocol of muscle contractile function that could be used for DMD across all disease levels. Several measures for walking and upper extremity function are currently used to measure outcomes during clinical trials. However, none of the current measurements for DMD incorporate a way to quantitatively measure both voluntary and evoked strength along with muscle excitability over disease progression or in response to an intervention. The key to the assessment and protocol design needed to be feasibility and safety for boys and men with DMD at different stages of the disease process. I was able to design and evaluate a novel protocol, combining voluntary and evoked contractions to measure strength and excitability of wrist extensor muscles for safety, feasibility, reliability and discriminant validity between males with DMD and controls (Chapter 3). Wrist extensor muscle strength and excitability were assessed in males with DMD (N=10; mean 15.4 [SD 5.9] years) (Brooke 1-6) and age-matched healthy male controls (N=15; mean 15.5 [SD 5.0] years). Torque and EMG measurements were analyzed under maximum voluntary and stimulated conditions at two visits. I discovered that our protocol of multiple maximal voluntary contractions (MVC) and evoked twitch contractions was feasible and safe, with 96% of the participants able to complete the assessment protocol maintaining >93% strength both for DMD and controls (P≥0.074). Reliability was excellent for voluntary and evoked measurements. Torque, EMG and timing of twitch onset measurements discriminated between DMD and controls (P<0.001). This first part of the study demonstrated a useful protocol for measuring skeletal muscle function in clinical trials in males with DMD across various ages and disease levels. The second part of the study addressed in the context of a neuromuscular disease the concern of injury to dystrophic deficient skeletal muscle during and after repeated contractions (exercise) that result in acute strength loss. I knew that a feature of dystrophin-deficient skeletal muscle in the mdx mouse model was a hypersensitivity to strength loss from eccentric exercise due to fibers becoming unexcitable. I wanted to explore how this feature translated to humans lacking dystrophin. We hypothesized that there would be no difference in strength loss during exercise and that males with Duchenne muscular dystrophy (DMD) would have more significant impairment in muscle excitability corresponding with a loss of strength than age-matched controls (Chapter 4). Males with DMD and a group of age-matched controls performed a sub-maximal voluntary isometric wrist extensor exercise protocol until 55% of maximal voluntary contraction (MVC) could no longer be sustained. Voluntary and evoked force and EMG were accessed before, during, and after exercise. There was a significant interaction (time*group) (p<0.001) for MVC torque during exercise, suggesting that the two groups were different in how they reached muscle fatigue. No difference was measured between groups in MVC torque decrement at the time of exercise cessation (by design). Evoked twitch torque decrement was 34% for DMD and 36% for control with no group*time interaction observed (p=0.834). Muscle excitability contributed to the evoked torque variance in DMD (76%) and control (59%). The groups were not different in RMS EMG decrement (P=0.986) or M-wave decrement (P=0.911) during exercise, which does not support our hypothesis that the DMD groups had a more considerable decline in muscle excitability with fatigue during exercise. Lastly, the recovery of both strength and muscle excitability was explored and compared between groups. The DMD group recovered MVC baseline strength by 10 minutes post-exercise (P=0.530) and evoked torque by 5 minutes (P=0.266). In contrast, controls were still different from MVC and evoked torque baseline at 15 minutes after exercise (P<0.002). Strength loss from submaximal intermittent isometric exercise does not result in more significant impairment of muscle excitability is transient, and recovers faster in males with DMD than controls, suggesting a different mechanism of peripheral fatigue between the groups. The work contained in my dissertation begins to address the fear of exercise that has been a common concern for individuals with DMD and will contribute to knowledge of evidence-based exercise prescription in the future.
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    Aerobic exercise in pregnancy
    (2010-09-15) Huynh, Tam
    This pamphlet discusses aerobic exercise during pregnancy. Non-contact aerobic exercises that are done 2-3 times a week improve the mother physical fitness. There is not enough data to determine if there are adverse/beneficial effects on fetal outcome.
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    Assessment of a pharmacist-led comprehensive medication management and wellness program
    (University of Minnesota, College of Pharmacy, 2015) Janovick, Daniel L.; Green, Tara R.; Bright, David R.
    Background: Pharmacists are currently providing comprehensive medication management in the outpatient setting. However, there is little documented evidence demonstrating pharmacists are generating further improved health outcomes utilizing non-pharmacologic support, such as fitness and nutrition counseling. The objective of this study is to determine if a pharmacist-led wellness program with medication management and lifestyle modifications through fitness and nutrition coaching can lead to improved biometric markers. Methods: The wellness program targeted corporate employees and was offered in a corporate headquarters' setting with an on-site workout facility. The program was expected to recruit approximately 15 patients into the wellness program consisting of two treatment arms. The standard group featured nutrition-based classes, medication therapy management and fitness education. The intervention group performed the standard group’s activities plus direct, supervised fitness training once weekly. Measured biometric markers were assessed at baseline, 3.5 months, and 7 months and included body mass index (BMI), waist circumference (WC), fasting blood glucose (FBG), systolic and diastolic blood pressure (SBP and DBP), and full lipid panel (TC, TG, HDL, and LDL). Results: Seventeen patients were enrolled in the study. The standard group (n = 11) and intervention group (n = 6) had relatively similar biometric markers at baseline. Seven total patients completed the study (4 from standard group, 3 from intervention group). The majority of biometric markers improved in both groups, and BP and LDL control was maintained for all who completed the study. Conclusion: These data suggest that a licensed pharmacist with certified personal trainer credentials may be capable of maintaining biometric markers at healthy levels and improving where necessary in an employee wellness program through one-on-one medication, fitness and nutrition support. Additional, large-scale research is needed to verify the clinical outcomes and feasibility in a larger group setting.
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    Effects of Virtual Reality Exercise on Promoting Physical Activity and Health among College Students: A 4-week Randomized Controlled Trial
    (2021-07) Liu, Wenxi
    Background: Despite the known benefits of physical activity, the prevalence of physical inactivity and sedentary behavior are significant issues in public health. Young adults, such as college students, are a population at risk for decreased physical activity participation due to the newfound responsibility of balancing school, work, and personal responsibilities. Previous findings indicated the lack of motivation was one of the important factors explaining the decreased physical activity participation. The emerging technology of immersive virtual reality combining with exercise provide a fun and motivating means for promoting physical activity and health-related outcomes. The cross-sectional studies have shown the promising influences of immersive virtual reality exercise on health-related outcomes, however, there is no experimental study to further conclude the findings. Therefore, the purpose of this randomized control trial was to examine the effectiveness of a 4-week VR-based exercise intervention on promoting PA and improving physiological and psychological outcomes among college students. Methods: A total of 36 college students were recruited from the University of Minnesota Twin Cities. Participants were randomly assigned to two groups: (1) intervention group – participants were asked to exercise on an immersive virtual reality-based exercise bike for one hour per session, two times per week, for 4 weeks; (2) control group – participants were asked to maintain their usual activities for 4 weeks. Participants’ weight, height, percentage of body fatness, and cardiovascular fitness were assessed by the validated instruments at baseline and 4 weeks. The exercise motivation, mood states, and depressive symptoms were assessed via a battery of surveys at baseline and 4 weeks. Participants’ physical activity levels were assessed via International Physical Activity Questionnaire at baseline and post-intervention follow-up. A two-way repeated measures ANOVA was used to examine the differences between intervention and control group on physiological and psychological outcomes over time. The within-subjects factor was “time” and the between-subjects factor was “group”. Results: The Chi-Square test and the independent t-test indicated that there was no statistically significant difference regarding baseline demographic, physiological, and psychological outcomes between intervention and control group at baseline. Regarding exercise motivation, significant interactions were observed on identified regulation (F(1,34) = 6.55, p = 0.02) and intrinsic regulation (F(1,34) = 11.21, p = 0.02). Regarding mood states, significant interactions were observed on confusion (F(1,34) = 6.72, p = 0.01), fatigue (F(1,34) = 6.46, p = 0.02), tension (F(1,34) = 10.44, p = 0.003), and vigor (F(1,34) = 7.22, p = 0.01). In addition, a significant interaction was observed on the depression symptoms (F(1,34) = 5.53, p = 0.03). Regarding physiological outcomes, significant interactions were observed on percentage of body fatness (F(1,34) = 17.26, p <0.001) and cardiovascular fitness (F(1,34) = 30.05, p <0.001). Lastly, a significant interaction was observed on physical activity levels (F(1,34) = 17.35, p < 0.001). Conclusion: The findings of the current study indicated that a 4-week virtual reality-based exercise intervention is effective in promoting college students’ intrinsic motivation and identified regulation toward exercise, improving overall mood states, depressive symptoms, cardiovascular fitness, body composition, and enhancing greater physical activity. It is suggested that immersive virtual reality exercise could be a fun and motivating means for promoting young adults’ physical activity and health-related physiological and psychological outcomes.
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    Estimates Of Central Hemodynamics Using Gas Exchange In Patients With Cystic Fibrosis
    (2016-07) Kasak, Alexander
    Pulmonary artery capacitance (PVCAP) is the ability of the pulmonary artery to accept a volume of blood at a given pressure. Traditionally measured invasively with heart catheterization; PaCAP may be estimated non-invasively through the measurement of end-tidal CO2 (PETCO2) and stroke volume (SV), known as gas-exchange capacitance (GXCAP) where a higher capacitance means improved pulmonary vasodilation. The degree of pulmonary vascular dysfunction at rest and during exercise remains unclear in patients with cystic fibrosis (CF). PURPOSE: To determine the effects of exercise on GXCAP in patients with CF, when compared to healthy subjects. METHODS: 19 patients with CF (age=22±2yrs, BMI=23±1kg/m2, VO2=56±6%pred., FVC=83±5%pred., FEV1=72±6%pred., FEV1/FVC=0.72±0.02) and 17 healthy subjects (age=22±1yrs, BMI=23±1kg/m2, VO2=81±5%pred., FVC=93±3%pred., FEV1=89±2%pred., FEV1/FVC=0.81±0.02) were recruited for this study. Exercise testing was performed on a cycle ergometer. PETCO2 was assessed using a metabolic cart, SV was assessed using the acetylene rebreathe technique and GXCAP was calculated from the product of PETCO2 and SV. RESULTS: At rest, SV and GXCAP were higher in healthy subjects when compared to CF (SV=72±6 vs. 54±5ml, GXCAP=22±2 vs. 17±2, for healthy and CF, respectively. PETCO2 remained unchanged between healthy and CF subjects (PETCO2 30±1 and 30±1 respectively). Healthy subjects exercised at a higher absolute intensity, but intensity expressed as a percentage of max was similar between healthy and CF (watts=159±10 vs. 102±8, watts/max watts=96±3 vs. 95±5% for healthy and CF, respectively). At peak exercise, SV and GXCAP increased in both healthy and CF but remained higher in healthy subjects when compared to CF (SV=108±5 vs. 84±6ml, GXCAP=40±3 vs. 29±2, for healthy and CF, respectively, p<0.05). When matched for a workload designed to match for SV, there was no difference in percent of max watts (%MaxW=63±4 vs. 66±5W), Q (11±1 vs. 13±1L/min), or SV (89±4 vs. 90±4ml/beat). When matched, the previous difference in GXCAP in healthy and CF was abolished (GXCAP=32±2 vs. 32±2mL/BEAT ∙ min). CONCLUSION: Gas exchange capacitance is lower in patients with CF at rest and through peak exercise. However, when matched for SV and workload, GXCAP was statistically similar between healthy and CF. This lower GXCAP is likely due to lower SV at rest and with peak exercise in CF patients, when compared to healthy subjects. Therefore, these findings suggest that there is no evidence of pulmonary vasculature dysfunction in these CF patients. Future, more invasive studies are warranted to confirm the lack of difference in pulmonary vascular function in patients with CF.
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    Investigation of Sarcopenia in a Murine Model: Symptoms of Age-Related Neuromuscular Decline and Resistance Training Intervention
    (2015-05) Graber, Ted
    The world population demographic is rapidly aging. With advancing age comes the onset of age-related diseases and syndromes such as sarcopenia, the age-associated loss of muscle mass and strength. Sarcopenia leads to a multitude of adverse outcomes including a reduced quality of life, increased mortality, functional disability, and eventual loss of independence. Currently no cure for sarcopenia exists and its etiology is still largely undefined. Thus, there is a need for animal models for preclinical investigation of novel interventions. The overall purpose was to first investigate, characterize, and describe the neuromuscular healthspan of the C57BL/6 mouse, a common animal model of aging, and then to subsequently create a treatment model for sarcopenia by producing and validating a voluntary resistance training protocol for mice. The first research chapters (2 and 3) investigate and define the neuromuscular healthspan and the age-related decline of contractile parameters in the mouse. Chapter 2 outlines the neuromuscular healthspan scoring system, a composite score consisting of two functional measures combined with in vitro maximum isometric force of the extensor digitorum longus (EDL). This composite outcome measurement increased the power to detect change beyond the capacity of the individual component measures alone. Chapter 3 examines unique aspects of contractile velocity and power production in the soleus and EDL, revealing that age has a greater effect on concentric contraction performed at higher percentages of maximum force. Because the only consensus treatment for sarcopenia is resistance exercise, in Chapter 4 a mouse model of voluntary resistance training was designed and validated. The protocol was designed using human principles of weight training and was assessed with a comprehensive battery of outcome measurements. The outcomes were selected to test whether the mice had the same type of adaptations as would be observed in humans undergoing a similar training intervention. In Chapter 5, the resistance training protocol was applied to a cohort of aged mice to test if signs of anabolic resistance would be detected. Overall, the thesis tells the story of age-related neuromuscular dysfunction that can be partially rescued though exercise and creates a novel preclinical animal model of voluntary resistance training.
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    Perception and Practice of Inclusion of Exercise and Exercise-Related Nutrition in Eating Disorder Treatment
    (2022-05) Gelhaus, Ashley
    Objective: The purpose of this study was to gain information regarding the utilization of exercise and exercise-related nutrition in current eating disorder treatment as well as gain insight into perceived effectiveness of including it in current or future practice from the viewpoint of both providers of eating disorder treatment as well as those with active eating disorders. Additionally, we hoped to gain an overall understanding of how providers and patients define exercise and how it is practiced within their own lives.Methods: This study was a descriptive research study and mostly exploratory in nature. This study included two study groups: patients with eating disorders and providers treating people who have eating disorders. Data was collected using two separate anonymous surveys via online portals. Results: Patients reported the inclusion of exercise in eating disorder treatment, while providers had more variance on whether they support or include exercise in eating disorder treatment. There was no consensus on the inclusion of exercise in treatment. Patients reported that they did not feel confident in their ability to provide adequate nutrition for exercise as well as providers stated that they believe inclusion of exercise-related nutrition benefits treatment but that it is not adequately talked about in treatment. Conclusion: There was no overall consensus on inclusion of exercise in treatment nor for approach taken in treatment. In regard to exercise-related nutrition there was more consensus that it would in fact be beneficial for treatment, however, it is not adequately covered in eating disorder treatment currently.
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    The relative effectiveness of supervised exercise with and without spinal manipulation, and home exercise in terms of fear-avoidance beliefs in chronic neck pain patients.
    (2015-12) Vihstadt, Corrie
    Neck pain and related disability place considerable burden on individuals and societies around the globe. Chronic neck pain is considered to be multifactorial in both mechanism and experience, including biological, psychological, and social factors. Little is known regarding the relationship of fear-avoidance beliefs, a specific psychological factor, to chronic neck pain. The primary objective here is to address the relative effectiveness of supervised exercise with and without spinal manipulation, versus home exercise in terms of fear-avoidance beliefs in chronic neck pain patients over time. This was a randomized, mixed-methods, comparative effectiveness trial conducted at an outpatient university-affiliated research clinic in the Minneapolis/St. Paul metropolitan area. Adults aged 18-65 with chronic, mechanical, non-specific neck pain rated at least 3 on 0-10 scale were included. Qualifying participants were individually randomized to receive one of three 12-week interventions: a) supervised rehabilitative exercise (SRE), b) SRE and spinal manipulative therapy (SMT), or c) home exercise with advice (HEA). The randomization scheme had a 1:1:1 allocation ratio using randomly permuted block sizes; treatment assignment was concealed in sequentially numbered, opaque, sealed envelopes. The self-report Fear-Avoidance Beliefs Questionnaire (FABQ) modified for neck was administered at baseline (week 0) and 4, 12, 26, and 52 weeks post-randomization. The two subscores, work (W) and physical activity (PA), were converted to a 0-100 point scale to facilitate comparison. The outcomes were analyzed with a linear mixed-effects model for repeated measures over time with baseline values treated as outcome. A total of 270 subjects were randomized into the trial. Loss-to-follow up rates at week 12 ranged from 5.6% to 7.7% for FABQ-PA and 8.0% to 10.9% for FABQ-W; these increased through week 52 to 16.7% to 18.7% for FABQ-PA and 21.3% to 29.7% for FABQ-W. At baseline, participants reported neck pain of nine to ten years in duration that was moderate in severity; they reported mild disability. Scores for FABQ-PA were 45.8 to 48.5 and FABQ-W scores were 22.0 to 25.4 on a 0-100 scale. For FABQ-W at 12 weeks, there was a statistically significant between-group difference (baseline to week 12) in favor of the SRE + SMT group when compared to the SRE group (5.30 points; 95% CI, 0.99 to 9.62; p=0.016); this difference lost significance at weeks 26 and 52. For FABQ-PA at 12 weeks, there were no statistically significant group differences (baseline to week 12); differences remained small and not statistically significant through week 52. Except for marginal improvements in fear-avoidance beliefs about work in favor of SRE+SMT in the short term (12 weeks), no other statistically significant between-group differences were observed for work and physical activity fear avoidance beliefs. These results should be interpreted cautiously due to limitations of the Fear-Avoidance Beliefs Questionnaire and the Fear-Avoidance Model of Exaggerated Pain Perception. Future research can address shortcomings of the FAM model and the FABQ instrument.
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