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The gold standard for bone measurement is DXA (dual energy X-ray absorptiometry). Typically, to observe changes in bone by DXA, a minimum of a 4-month intervention is required. Serum osteocalcin (OST) (a bone formation marker) and quantitative ultrasound (QUS) of the calcaneus can be used as indicators of bone change but the sensitivity and time course of these indices to short term interventions are unknown. The purpose of this study was twofold: to compare monthly changes in OST and QUS in response to jump training and to evaluate the relationship between DXA, OST and QUS. Young women with QUS t-scores less than 1.0 were randomized into a jump training (J) (n=16) or control (C) (n=16). J consisted of a progressive routine of 1 and 2-footed jumping performed 3 days per week for 4 months. Body composition, QUS and OST were measured at baseline, and monthly for 4 months. DXA and 24-hour dietary recalls were completed at baseline and 4 months. Low attrition rate (12.5%) and high compliance (98%) with the exercise intervention was recorded. No significant correlations between QUS and OST existed. No significant differences were observed between groups at baseline in body composition or bone variables. Monthly increases in OST were observed but there were no significant differences over time between groups in any bone variables. OST and QUS may be indicative of short term bone changes but these variables were not specifically sensitive to the jumping intervention in this population of women.
ContributorsHeumann, Kristin Joelle (Author) / Swan, Pamela D (Thesis advisor) / Alvar, Brent (Committee member) / Chisum, Jack (Committee member) / Lee, Chong (Committee member) / Vaughan, Linda (Committee member) / Arizona State University (Publisher)
Created2011
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 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
Description
An intervention study was conducted with elementary physical education teachers and their use of a newly developed series of fitness segments called Knowledge in Action (KIA). This study was designed to enable teachers to teach healthy behavior knowledge (HBK) in their classes without sacrificing physical activity levels. This study has two phases. First, the intervention was conducted to determine the effectiveness of the KIA fitness segment intervention. Second, teachers' perceptions of both teaching HBK and the KIA fitness segments were investigated. Ten teacher participants were randomly assigned to the intervention or control group. Intervention teachers participated in professional development, provided with all teaching materials, and YouTube videos that modeled the teaching of the KIA fitness segments. Teacher fidelity was measured through observations. Student physical activity patterns were measured in randomly selected teachers' classes (both intervention and control) to determine potential physical activity pattern differences between groups. Teachers were interviewed from one to three times across the project in order to determine perceptions of teaching HBK and the KIA fitness segments. Researchers used constant comparison method to uncover possible common themes. Student knowledge was assessed pre/post using PE Metrics Standard 3 cognitive test to determine HBK changes. Data analysis included General liner models (GLM) at the student level (gender) and Hierarchical linear models (HLM) at the school level (treatment, school). There was a moderate mean teacher fidelity score (77.9%) found among the intervention teachers. HLM results showed students in the intervention group had a 3.4(20%) greater improvement in HBK scores when compared with their control counterparts (p<0.001). Student activity levels were found to be similar in both groups with 871.33 and 822.22 steps in the intervention and control groups, respectively. Although all of the teachers thought it was important to teach HBK they were not spending time on it during classes at pretest. Three common themes were discovered: (a) Effective Teacher Training of the Segments, (b), Teachers Learned a Novel Strategy, and (c) Teachers Recommended Modifications. In summary, the KIA fitness segments received favorable views and gave teachers a way to teach HBK without reducing physical activity time.
ContributorsHodges, Michael (Author) / Kulinna, Pamela (Thesis advisor) / Van Der Mars, Hans (Committee member) / Lee, Chong (Committee member) / Arizona State University (Publisher)
Created2013
Description
Although maintaining an optimal level of muscle quality in older persons is necessary to prevent falls and disability, there has been limited research on muscle quality across age and gender groups. The associations of muscle quality, muscle strength, and muscle mass also remain less explored. Purpose: This study examined the muscle quality differences (arm and leg) between healthy young and elderly adults across gender groups. This study also examined the associations of muscle quality, muscle strength, and muscle mass in young and elderly adults, respectively. Methods: Seventy-one total subjects were recruited for this study within age groups 20-29 years old (20 females and 20 males) and 60-80 years old (18 females and 13 males). All participants completed anthropometric measures, dual-energy x-ray absorptiometry, pulse wave velocity, handgrip strength and leg strength tests, gait speed, and sit to stand test. Results: Young male adults had a greater leg muscle quality index (leg MQI) than did elderly male adults (21.8 Nm/kg vs. 16.3 Nm/kg, p = 0.001). Similarly, young female adults had a greater leg MQI than did old female adults (21.3 Nm/kg and 15.6 Nm/kg, p<0.001). For arm muscle quality index (arm MQI), there was a gender difference in young adults (p = 0.001), but not for the elderly adults. Among elderly adults, there was a positive association between leg MQI and isometric leg strength (r = 0.79, p<0.001). Notably, there was a negative association between leg MQI and leg lean mass (r = -0.70, p<0.001) and between arm MQI and arm lean mass (r = -0.58, p = 0.001). In young adults, there was also a positive association between arm MQI and handgrip strength (r = 0.53, p<0.001) and between leg MQI and isometric leg strength (r = 0.81, p<0.001). There was no association between muscle quality and muscle mass in young adults. Conclusion: Young adults had a greater leg muscle quality than did elderly adults in both men and women. Leg muscle quality is positively associated with leg muscle strength in both young and elderly adults but is inversely associated with leg muscle mass in the elderly adults.
ContributorsDierickx, Erin (Author) / Lee, Chong (Thesis advisor) / Swan, Pamela (Committee member) / Marsit, Joseph (Committee member) / Chisum, Jack (Committee member) / Arizona State University (Publisher)
Created2017