Browsing by Subject "exercise"
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Item Accelerometer and GPS Analysis of Trail Use and Associations With Physical Activity(Human Kinetics, 2018-07) Tamura, Kosuke; Wilson, Jeffrey S.; Puett, Robin C.; Klenosky, David B.; Harper, William A.; Troped, Philip J.; Geography, School of Liberal ArtsBackground: Concurrent use of accelerometers and global positioning system (GPS) data can be used to quantify physical activity (PA) occurring on trails. This study examined associations of trail use with PA and sedentary behavior (SB) and quantified on trail PA using a combination of accelerometer and GPS data. Methods: Adults (N = 142) wore accelerometer and GPS units for 1–4 days. Trail use was defined as a minimum of 2 consecutive minutes occurring on a trail, based on GPS data. We examined associations between trail use and PA and SB. On trail minutes of light-intensity, moderate-intensity, and vigorous-intensity PA, and SB were quantified in 2 ways, using accelerometer counts only and with a combination of GPS speed and accelerometer data. Results: Trail use was positively associated with total PA, moderate-intensity PA, and light-intensity PA (P < .05). On trail vigorous-intensity PA minutes were 346% higher when classified with the combination versus accelerometer only. Light-intensity PA, moderate-intensity PA, and SB minutes were 15%, 91%, and 85% lower with the combination, respectively. Conclusions: Adult trail users accumulated more PA on trail use days than on nontrail use days, indicating the importance of these facilities for supporting regular PA. The combination of GPS and accelerometer data for quantifying on trail activity may be more accurate than accelerometer data alone and is useful for classifying intensity of activities such as bicycling.Item Achilles tendon material properties are greater in the jump leg of jumping athletes(ISMNI, 2016-06) Bayliss, Amy J.; Weatherholt, Alyssa M.; Crandall, Trent T.; Farmer, Danielle L.; McConnell, Jethro C.; Crossley, K. M.; Warden, Stuart J.; Department of Physical Therapy, School of Health and Rehabilitation SciencesPurpose: The Achilles tendon (AT) must adapt to meet changes in demands. This study explored AT adaptation by comparing properties within the jump and non-jump legs of jumping athletes. Non-jumping control athletes were included to control limb dominance effects. Methods: AT properties were assessed in the preferred (jump) and non-preferred (lead) jumping legs of male collegiate-level long and/or high jump (jumpers; n=10) and cross-country (controls; n=10) athletes. Cross-sectional area (CSA), elongation, and force during isometric contractions were used to estimate the morphological, mechanical and material properties of the ATs bilaterally. Results: Jumpers exposed their ATs to more force and stress than controls (all p≤0.03). AT force and stress were also greater in the jump leg of both jumpers and controls than in the lead leg (all p<0.05). Jumpers had 17.8% greater AT stiffness and 24.4% greater Young’s modulus in their jump leg compared to lead leg (all p<0.05). There were no jump versus lead leg differences in AT stiffness or Young’s modulus within controls (all p>0.05). Conclusion: ATs chronically exposed to elevated mechanical loading were found to exhibit greater mechanical (stiffness) and material (Young’s modulus) properties.Item ARTE index revisited: linking biomarkers of cardiometabolic health with free-living physical activity in postmenopausal women(American Physiological Society, 2022-04-01) Carter, Stephen J.; Baranauskas, Marissa N.; Singh,, Harshvardhan; Martins, Catia; Hunter, Gary R.; Exercise & Kinesiology, School of Health and Human SciencesActivity-related energy expenditure (AEE) correlates with physical activity volume; however, between-person differences in body size and walking economy (net V̇o2) can influence AEE. The ratio of total energy expenditure (TEE) and resting energy expenditure (REE) estimates physical activity level (PAL) relative to body mass, yet does not account for variance in walking economy. The activity-related time equivalent (ARTEwalk) circumvents such constraints by adjusting for individual-specific walking economy. Herein, we compared AEE, PAL, and ARTEwalk index in a cohort (n = 81) of postmenopausal women while examining possible associations with biomarkers of cardiometabolic health. Secondary analyses were performed on postmenopausal women dichotomized above/below age group 50th percentile for body fat percent. TEE was reduced by 10% for the thermogenesis of digestion wherein AEE was calculated by subtracting REE from adjusted TEE. PAL was calculated as the ratio of TEE/REE. AEE was divided by the mean net energy expenditure of nongraded walking to calculate the ARTEwalk index. Between-group differences were not detected for AEE or PAL. However, the ARTEwalk index revealed that participants with less adiposity were more physically active (258 ± 149 vs. 198 ± 115 min·day−1; P = 0.046; g = 0.46). AEE and PAL did not correlate with cardiorespiratory fitness or biomarkers of cardiometabolic health. Cardiorespiratory fitness (r = 0.32), arterial elasticity (r = 0.24), total cholesterol/HDL-c ratio (r = −0.22), and body fat% (r = −0.24) were correlated with ARTEwalk. The ARTEwalk index may offer utility in detecting possible differences in physical activity volume among postmenopausal women and appears better associated with cardiometabolic biomarkers compared with AEE or PAL.Item Bone Microarchitecture and Strength Adaptation to Physical Activity: A Within-Subject Controlled, HRpQCT Study(Wolters Kluwer, 2021) Warden, Stuart J.; Wright, Christian S.; Fuchs, Robyn K.; Physical Therapy, School of Health and Rehabilitation SciencesPurpose Physical activity benefits bone mass and cortical bone size. The current study assessed the impact of chronic (≥10 years) physical activity on trabecular microarchitectural properties and micro-finite element (μFE) analyses of estimated bone strength. Methods Female collegiate-level tennis players (n=15; age=20.3±0.9 yrs) were used as a within-subject controlled model of chronic unilateral upper-extremity physical activity. Racquet-to-nonracquet arm differences at the distal radius and radial diaphysis were assessed using high-resolution peripheral computed tomography (HRpQCT). The distal tibia and tibial diaphysis in both legs were also assessed, and cross-country runners (n=15; age=20.8±1.2 yrs) included as controls. Results The distal radius of the racquet arm had 11.8% (95% confidence interval [CI], 7.9 to 15.7%) greater trabecular bone volume/tissue volume, with trabeculae that were greater in number, thickness, connectivity, and proximity to each other than in the nonracquet arm (all p<0.01). Combined with enhanced cortical bone properties, the microarchitectural advantages at the distal radius contributed a 18.7% (95% CI, 13.0 to 24.4%) racquet-to-nonracquet arm difference in predicted load before failure. At the radial diaphysis, predicted load to failure was 9.6% (95% CI, 6.7 to 12.6%) greater in the racquet vs. nonracquet arm. There were fewer and smaller side-to-side differences at the distal tibia; however, the tibial diaphysis in the leg opposite the racquet arm was larger with a thicker cortex and had 4.4% (95% CI, 1.7 to 7.1%) greater strength than the contralateral leg. Conclusion Chronically elevated physical activity enhances trabecular microarchitecture and μFE estimated strength, furthering observations from short-term longitudinal studies. The data also demonstrate tennis players exhibit crossed symmetry wherein the leg opposite the racquet arm possesses enhanced tibial properties compared to in the contralateral leg.Item Bone Quality and Quantity are Mediated by Mechanical Stimuli(Springer, 2016-09) Berman, Alycia G.; Wallace, Joseph M.; Department of Biomedical Engineering, School of EngineeringPrevention of fracture through improved bone mechanical strength is of great importance given the large number of bone disease-related fractures each year, the decreased quality of life associated with fractures, and the large anticipated increase in fracture incidence over the upcoming years due to the aging population. Exercise and other forms of mechanical stimulation have been shown to increase bone mass, suggesting improved strength. However, while bone mass is a good indicator of strength, other components (such as bone quality) also contribute to bone mechanical integrity. While increased bone mass has been explored considerably using both exercise and targeted loading models, the role of mechanical stimulation in altering bone quality has been explored to a lesser degree. Understanding how to improve both the quantity and quality of bone is critical to increasing fracture resistance. Herein, we discuss quantity and quality-based improvements that have been observed using both exercise and targeted loading models of bone adaptation.Item Cancer survivors' uptake and adherence in diet and exercise intervention trials: an integrative data analysis(Wiley, 2015-01-01) Adams, Rebecca N.; Mosher, Catherine E.; Blair, Cindy K.; Snyder, Denise C.; Sloane, Richard; Demark-Wahnefried, Wendy; Department of Psychology, School of ScienceBACKGROUND: The health benefits of diet and exercise interventions for cancer survivors are well documented. However, little is known regarding demographic and medical predictors of survivors' willingness to participate in diet and exercise intervention trials, study enrollment, intervention adherence, and study completion. To assist in interpreting the generalizability of trial findings and to improve the design of future trials, this study examined predictors of these process measures. METHODS: An integrative data analysis was performed on data from 3 of the largest home-based diet and exercise intervention trials for cancer survivors (n = 23,841). Demographic and medical factors (ie, sex, race, age, time since diagnosis, and cancer type) were examined as predictors of willingness to participate, study enrollment, intervention adherence, and study completion in the pooled sample. A 99% confidence interval was used to determine statistical significance. RESULTS: Across trials, 11.1% of contacted survivors were willing to participate, and 5.7% were eligible and enrolled. Among enrollees, 53.4% demonstrated ≥75% adherence to the intervention, and 91.1% completed the study. Race (Caucasian vs others), age, time since diagnosis, and cancer type predicted survivors' willingness to participate (P < .01). All examined predictors were associated with the likelihood of study enrollment (P < .01). No significant predictors of intervention adherence or study completion were found among study enrollees (P ≥ .01). CONCLUSIONS: Cancer survivors' demographic and medical characteristics predicted their interest and participation in diet and exercise intervention trials. These findings have implications for the generalizability of results and can help to guide procedures used in future trials to enhance patient representation.Item Cardiovascular Adaptation in Athletes(Elsevier, 2016-01) Kovacs, Richard; Baggish, Aaron L.; Department of Medicine, IU School of MedicineMillions of athletes train for and participate in competitive athletics each year. Many of these athletes will present to a cardiovascular specialist with signs or symptoms that might indicate heart disease and these athletes/patients will ask for advice on their ability to continue to train and compete safely. By virtue of their training, athletes׳ hearts may undergo significant structural and electrical change, presenting a special challenge for the cardiovascular specialist. It is important to understand normal adaptive changes in order to separate normal physiology from pathology.Item Change in self-efficacy partially mediates the effects of the FRESH START intervention on cancer survivors' dietary outcomes(Wiley, 2008) Mosher, Catherine E.; Fuemmeler, Bernard F.; Sloane, Richard; Kraus, William E.; Lobach, David F.; Snyder, Denise Clutter; Demark-Wahnefried, WendyObjective: This study examined change in self-efficacy as a mediator of the effects of a mailed print intervention on the dietary and exercise practices of newly diagnosed breast and prostate cancer survivors. Method: A total of 543 breast and prostate cancer patients were recruited from 39 states and two provinces within North America. Participants were randomly assigned to receive a 10-month program of tailored mailed print materials that aimed to increase fruit and vegetable consumption, reduce fat intake, and/or increase exercise or a 10-month program of publically available materials on diet and exercise. Telephone surveys conducted at baseline and 1 year assessed dietary practices, physical activity, and self-efficacy for engaging in these health behaviors. Results: Results indicated that changes in self-efficacy for fat restriction and eating more fruits and vegetables were significant mediators of the intervention's effects on dietary outcomes at 1-year follow-up. The intervention did not significantly affect self-efficacy for exercise; however, a significant, positive relationship was found between self-efficacy for exercise and exercise duration at follow-up. Conclusions: Findings are largely consistent with Social Cognitive Theory and support the use of strategies to increase self-efficacy in health promotion interventions for cancer survivors. Copyright © 2008 John Wiley & Sons, Ltd.Item Contributions of Stepping Intensity and Variability to Mobility in Individuals Poststroke(American Heart Association, 2019-08-22) Hornby, T. George; Henderson, Christopher E.; Plawecki, Abbey; Lucas, Emily; Lotter, Jennifer; Holthus, Molly; Brazg, Gabrielle; Fahey, Meghan; Woodward, Jane; Ardestani, Marzieh; Roth, Elliot J.; Physical Medicine and Rehabilitation, School of MedicineBackground and Purpose: The amount of task-specific stepping practice provided during rehabilitation post-stroke can influence locomotor recovery, and reflects one aspect of exercise “dose” that can affect the efficacy of specific interventions. Emerging data suggest that markedly increasing the intensity and variability of stepping practice may also be critical, although such strategies are discouraged during traditional rehabilitation. The goal of this study was to determine the individual and combined contributions of intensity and variability of stepping practice to improving walking speed and distance in individuals post-stroke. Methods: This Phase 2, randomized, blinded assessor clinical trial was performed between May 2015-November 2018. Individuals between 18-85 years old with hemiparesis post-stroke of >6 months duration were recruited. Of the 152 individuals screened, 97 were randomly assigned to 1 of 3 training groups, with 90 completing >10 sessions. Interventions consisted of either high intensity stepping (70-80% heart rate [HR] reserve) of variable, difficult stepping tasks (high-variable), high intensity stepping performing only forward walking (high-forward), and low intensity stepping in variable contexts at 30-40% HR reserve (low-variable). Participants received up to 30 sessions over 2 months, with testing at baseline, post-training and a 3-month follow-up. Primary outcomes included walking speeds and timed distance, with secondary measures of dynamic balance, transfers, spatiotemporal kinematics and metabolic measures. Results: All walking gains were significantly greater following either high-intensity group vs low-variable training (all p<0.001) with significant correlations with stepping amount and rate (r=0.48-60; p<0.01). Additional gains in spatiotemporal symmetry were observed with high-intensity training, and balance confidence increased only following high-variable training in individuals with severe impairments. Conclusion: High intensity stepping training resulted in greater improvements in walking ability and gait symmetry than low-intensity training in individuals with chronic stroke, with potential greater improvements in balance confidence.Item Current and Future Therapeutic Regimens for Non-alcoholic Fatty Liver Disease (NAFLD) and Non-alcoholic Steatohepatitis (NASH)(Wiley, 2018) Younossi, Zobair M.; Loomba, Rohit; Rinella, Mary E.; Bugianesi, Elisabetta; Marchesini, Giulio; Neuschwander-Tetri, Brent A.; Serfaty, Lawrence; Negro, Francesco; Caldwell, Stephen H.; Ratziu, Vlad; Corey, Kathleen E.; Friedman, Scott L.; Abdelmalek, Manal F.; Harrison, Stephen A.; Sanyal, Arun J.; Lavine, Joel E.; Mathurin, Philippe; Charlton, Michael R.; Chalasani, Naga P.; Anstee, Quentin M.; Kowdley, Kris V.; George, Jacob; Goodman, Zachary D.; Lindor, Keith; Medicine, School of MedicineNASH/NAFLD is rapidly becoming one of top causes of cirrhosis, hepatocellular carcinoma and indication for liver transplantation. Except for life style modification through diet and exercise, there are currently no other approved treatments for NASH/NAFLD. Although weight loss can be effective, it is hard to achieve and sustain. In contrast, bariatric surgery can improve metabolic conditions associated with NAFLD and has been shown to improve liver histology. In order to have approved regimens for treatment of NASH/NAFLD, a number of issues that must be addressed. First, all stakeholders must agree on the most appropriate clinical trial endpoints for NASH. Currently, resolution of NASH (without worsening fibrosis) or reduction of fibrosis stage (without worsening NASH) are the accepted endpoints by the regulatory authorities. It is important to recognize the prognostic implication of histologic features of NASH. In this context, although histologic NASH has been associated with advanced stage of fibrosis, it is not an independent predictor of long term mortality. In contrast, there is significant data to suggest that stage of fibrosis is the only robust and independent predictor of liver-related mortality. In addition to the primary endpoints, a number of important secondary endpoints, including non-invasive biomarkers, long term outcomes, and patient reported outcomes, must be considered. In 2017, a few phase 3 clinical trials for treatment of NASH are in progress. Additionally, a number of phase 2a and 2b clinical trials targeting different pathogenic pathways in NASH enriches the pipeline of emerging therapies. Conclusion: Over the next 5 years, some of these regimens are expected to provide potential new treatment options for patients with NASH/NAFLD.