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The effects of a long-term combat deployment on a soldier's physical fitness are not well understood. In active duty soldiers, combat deployment reduced physical fitness compared to pre-deployment status, but no similar research has been performed on Army National Guard soldiers. This study is the first to identify physical fitness changes in Arizona National Guard (AZNG) soldiers following deployment to a combat zone and to assess the relationships between physical fitness and non-combat injuries and illness (NCII). Sixty soldiers from the Arizona National Guard (AZNG) completed a battery of physical fitness tests prior to deployment and within 1-7 days of returning from a 12-month deployment to Iraq. Pre and post-deployment measures assessed body composition (Bod Pod), muscular strength (1RM bench press, back-squat), muscular endurance (push-up, sit-up), power (Wingate cycle test), cardiorespiratory fitness (treadmill run to VO2 peak), and flexibility (sit-and-reach, trunk extension, shoulder elevation). Post deployment, medical records were reviewed by a blinded researcher and inventoried for NCII that occurred during deployment. Data were analyzed for changes between pre and post-deployment physical fitness. Relationships between fitness and utilization of medical resources for NCII were then determined. Significant declines were noted in mean cardiorespiratory fitness (-10.8%) and trunk flexibility (-6.7%). Significant improvements were seen in mean level of fat mass (-11.1%), relative strength (bench press, 10.2%, back-squat 14.2%) and muscular endurance (push-up 16.4%, sit-up 11.0%). Significant (p < 0.05) negative correlations were detected between percentage change in fat mass and gastrointestinal visits (r = -0.37); sit-and-reach and lower extremity visits (r= -0.33); shoulder elevation and upper extremity visits (r= -0.36); and cardiorespiratory fitness and back visits (r= -0.31); as well as behavioral health visits (r= -0.28). Cardiorespiratory fitness changes were grouped into tertiles. Those who lost the greatest fitness had significantly greater number of NCII visits (8.0 v 3.1 v 2.6, p = .03). These data indicate a relationship between the decline in cardiorespiratory fitness and an overall increase in utilization of medical resources. The results may provide incentive to military leaders to ensure that soldiers maintain their cardiorespiratory fitness throughout the extent of their deployment.
ContributorsWarr, Bradley (Author) / Swan, Pamela (Thesis advisor) / Lee, Chong (Committee member) / Campbell, Kathryn (Committee member) / Erickson, Steven (Committee member) / Alvar, Brent (Committee member) / Arizona State University (Publisher)
Created2011
Description
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
Background: The purpose of this study was to assess the efficacy of a lifestyle intervention on cardiorespiratory fitness in Latino youth with obesity and prediabetes. <br/>Methods: Participants (n=50) in this study were taken from a larger randomized controlled trial (n=180, BMI ≥ 95th percentile). Youth participated in a 6-month lifestyle intervention that included physical activity (60 minutes, 3x/week) and nutrition and wellness classes (60 minutes, 1x/week) delivered to families at the Lincoln Family YMCA in Downtown Phoenix. The primary outcome was cardiorespiratory fitness measured at baseline and post-intervention.<br/>Results: The mean BMI for the sample was 33.17 ± 4.54 kg/m2, which put the participants in the 98.4th percentile. At baseline, the mean VO2max was 2737.02 ± 488.89 mL/min. The mean relative VO2max was 30.65 ± 3.87 mL/kg/min. VO2max values significantly increased from baseline to post-intervention (2737.022 ± 483.977 mL/min vs 2932.654 ± 96.062 mL/min, p<0.001). <br/>Conclusion: Culturally-grounded, family-focused lifestyle interventions are a promising approach for improving cardiorespiratory fitness in high-risk youth at risk for diabetes.
ContributorsEstrada, Lourdes Alexa (Author) / Shaibi, Gabriel (Thesis director) / Peña, Armando (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Larger people generally have more muscle mass and are stronger than smaller people. Muscular strength usually decreases with age, possibly as a function of increases in body fat percentage. However, the effect of age, body fat, and lean mass on peak muscular strength or muscular fatigue is not clear. This was an observational study to determine: a) the relationship of fat mass (FM) and fat free mass (FFM) to peak knee extensor strength and fatigue in young (Y) and middle-aged (MA) women, and b) to determine differences in peak torque between Y and MA women. Participants included 132 women from two age cohorts (Y: 18-33 yrs, n = 70 and MA: 45-65 yrs, n = 62). Data from the MA cohort were collected as part of a previous study and combined with data from the Y group. Both cohorts completed physical activity questionnaires and were measured for body fat using bioelectrical impedance analysis. Both cohorts used identical procedures and machinery to assess isokinetic knee extensor peak torque (PT) at 60°/sec and to determine fatigue index (FI). FI was calculated as the percent decline of PT during 50 maximal repetitions at 240°/sec. Data were assessed for normality, and appropriate Pearson or Spearman correlations were used to compare PT and FI with body composition variables. A one-way ANOVA was used to examine differences in PT and body composition indices between age groups. In Y, FFM and FM were strongly correlated with peak torque. The correlation of FM to PT disappeared when controlling for FFM. There were no significant correlations between FFM or FM and PT in MA. PT was negatively correlated with FI in the combined groups. PT normalized for body mass and FFM were similar between age groups, but decreased with increasing size. In conclusion, PT was positively related to FFM in the combined age groups. Higher FM was not detrimental to absolute PT in Y or MA, but was detrimental to relative PT in both groups. These data suggest that perhaps FM may attenuate the normal relationship between PT and body mass.
ContributorsDeWeese, Robin (Author) / Swan, Pamela (Thesis advisor) / Pabedinskas, Joana (Committee member) / Lee, Chong (Committee member) / Arizona State University (Publisher)
Created2011
Description
Obesity in Hispanic youth has reached alarmingly high levels, increasing the risk of type 2 diabetes, hyperlipidemia, hypertension, and cardiovascular disease. In Mexican American children ages 6-11 years, 41.7% are overweight and obese, 24.7% are obese and 19.6% have a Body Mass Index (BMI) greater than the 97th percentile. While personal, behavioral, and environmental factors contribute to these high rates, emerging literature suggests acculturation, self-efficacy and social support are key influences. The one-group, pre- and post-test, quasi-experimental design used a community-based participatory research (CBPR) method to test the feasibility, acceptability, and preliminary efficacy of the 8-week intervention. Social Cognitive Theory (SCT) was used to guide the design. Measurements included an analysis of recruitment, retention, participant satisfaction, observation of intervention sessions, paired t-tests, effect sizes, and bivariate correlations between study variables (acculturation, nutrition and physical activity [PA] knowledge, attitude and behaviors, perceived confidence and social support) and outcome variables (BMI z-score, waist circumference and BP percentile) Findings showed the SSLN program was feasible and acceptable. Participants (n = 16) reported that the curriculum was fun and they learned about nutrition and PA. The retention rate was 94%. The preliminary effects on adolescent nutrition and PA behaviors showed mixed results with small-to-medium effect sizes for nutrition knowledge and attitude, PA and sedentary behavior. Correlation analysis among acculturation and study variables was not significant. Positive associations were found between perceived confidence in eating and nutrition attitude (r = .61, p < .05) and nutrition behavior (r = .62, p < .05), perceived confidence in exercise and nutrition behavior (r = .66, p < .05), social support from family for exercise and PA behavior (r = .67, p < .01) and social support from friends for exercise and PA behavior (r = .56, p < .05). These findings suggest a culturally specific healthy eating and activity program for adolescents was feasible and acceptable and warrants further investigation, since it may fill a gap in existing obesity programs designed for Hispanic youth. The positive correlations suggest further testing of the theoretical model.
ContributorsStevens, Carol (Author) / Gance-Cleveland, Bonnie (Thesis advisor) / Komnenich, Pauline (Committee member) / Shaibi, Gabriel (Committee member) / Arcoleo, Kimberly (Committee member) / Arizona State University (Publisher)
Created2011
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. 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
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
Background: Evidence about the purported hypoglycemic and hypolipidemic effects of nopales (prickly pear cactus pads) is limited. Objective: To evaluate the efficacy of nopales for improving cardiometabolic risk factors and oxidative stress, compared to control, in adults with hypercholesterolemia. Design: In a randomized crossover trial, participants were assigned to a 2-wk intervention with 2 cups/day of nopales or cucumbers (control), with a 2 to 3-wk washout period. The study included 16 adults (5 male; 46±14 y; BMI = 31.4±5.7 kg/m2) with moderate hypercholesterolemia (low density lipoprotein cholesterol [LDL-c] = 137±21 mg/dL), but otherwise healthy. Main outcomes measured included: dietary intake (energy, macronutrients and micronutrients), cardiometabolic risk markers (total cholesterol, LDL-c, high density lipoprotein cholesterol [HDL-c], triglycerides, cholesterol distribution in LDL and HDL subfractions, glucose, insulin, homeostasis model assessment, and C-reactive protein), and oxidative stress markers (vitamin C, total antioxidant capacity, oxidized LDL, and LDL susceptibility to oxidation). Effects of treatment, time, or interactions were assessed using repeated measures ANOVA. Results: There was no significant treatment-by-time effect for any dietary composition data, lipid profile, cardiometabolic outcomes, or oxidative stress markers. A significant time effect was observed for energy, which was decreased in both treatments (cucumber, -8.3%; nopales, -10.1%; pTime=0.026) mostly due to lower mono and polyunsaturated fatty acids intake (pTime=0.023 and pTime=0.003, respectively). Both treatments significantly increased triglyceride concentrations (cucumber, 14.8%; nopales, 15.2%; pTime=0.020). Despite the lack of significant treatment-by-time effects, great individual response variability was observed for all outcomes. After the cucumber and nopales phases, a decrease in LDL-c was observed in 44% and 63% of the participants respectively. On average LDL-c was decreased by 2.0 mg/dL (-1.4%) after the cucumber phase and 3.9 mg/dL (-2.9%) after the nopales phase (pTime=0.176). Pro-atherogenic changes in HDL subfractions were observed in both interventions over time, by decreasing the proportion of HDL-c in large HDL (cucumber, -5.1%; nopales, -5.9%; pTime=0.021) and increasing the proportion in small HDL (cucumber, 4.1%; nopales, 7.9%; pTime=0.002). Conclusions: These data do not support the purported benefits of nopales at doses of 2 cups/day for 2-wk on markers of lipoprotein profile, cardiometabolic risk, and oxidative stress in hypercholesterolemic adults.
ContributorsPereira Pignotti, Giselle Adriana (Author) / Vega-Lopez, Sonia (Thesis advisor) / Gaesser, Glenn (Committee member) / Keller, Colleen (Committee member) / Shaibi, Gabriel (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2013
Description
The body is capable of regulating hunger in several ways. Some of these hunger regulation methods are innate, such as genetics, and some, such as the responses to stress and to the smell of food, are innate but can be affected by body conditions such as BMI and physical activity. Further, some hunger regulation methods stem from learned behaviors originating from cultural pressures or parenting styles. These latter regulation methods for hunger can be grouped into the categories: emotion, environment, and physical. The factors that regulate hunger can also influence the incidence of disordered eating, such as eating in the absence of hunger (EAH). Eating in the absence of hunger can occur in one of two scenarios, continuous EAH or beginning EAH. College students are at a particularly high risk for EAH and weight gain due to stress, social pressures, and the constant availability of energy dense and nutrient poor food options. The purpose of this study is to validate a modified EAH-C survey in college students and to discover which of the three latent factors (emotion, environment, physical) best predicts continual and beginning EAH. To do so, a modified EAH-C survey, with additional demographic components, was administered to students at a major southwest university. This survey contained two questions, one each for continuing and beginning EAH, regarding 14 factors related to emotional, physical, or environmental reasons that may trigger EAH. The results from this study revealed that the continual and beginning EAH surveys displayed good internal consistency reliability. We found that for beginning and continuing EAH, although emotion is the strongest predictor of EAH, all three latent factors are significant predictors of EAH. In addition, we found that environmental factors had the greatest influence on an individual's likelihood to continue to eat in the absence of hunger. Due to statistical abnormalities and differing numbers of factors in each category, we were unable to determine which of the three factors exerted the greatest influence on an individual's likelihood to begin eating in the absence of hunger. These results can be utilized to develop educational tools aimed at reducing EAH in college students, and ultimately reducing the likelihood for unhealthy weight gain and health complications related to obesity.
ContributorsGoett, Taylor (Author) / Johnston, Carol (Thesis advisor) / Lee, Chong (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2013