Thesis (M.S.)--University of Florida, 2004. / Title from title page of source document. Document formatted into pages; contains 81 pages. Includes vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 52-56).

Thesis (M.S.)--Brigham Young University. Dept. of Exercise Sciences, 2005. / Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 56-59).

Thesis (Ph.D.) -- Virginia Commonwealth University, 2006. / Title from title-page of electronic thesis. Prepared for: School of Nursing. Bibliography: p. 123-136.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 149-160).

AN ABSTRACT OF THE THESIS OF DAGONG RAN, for the MASTER OF ARTS degree in PSYCHOLOGY, presented on JULY 5, 2016, at Southern Illinois University Carbondale. TITLE: HEART RATE VARIABILITY IN CHILDREN: TONIC CHARACTERISTICS AND REACTIVITY MAJOR PROFESSOR: Dr. Sarah Kertz This study investigated tonic heart rate variability (HRV) and heart rate variability reactivity in response to stress in children with anxiety and worry symptoms. Twenty-nine children age 8 to 12 from a rural Midwestern region completed the study and were included in the data analyses. Participants completed an artificial auditioning task in which they were asked to sing in front of a video camera. Electrocardiogram were recorded prior, during, and after the task. Frequency and time domain analyses of HRV were conducted. Neither parent-report or child self-report anxiety/worry symptom levels were associated with baseline frequency domain and time domain HRV. All participants showed similar HRV reactivity in response to the stress task. Specifically, high frequency HRV was higher during baseline than during stress task, and low frequency HRV was higher during baseline than both during stress task and recovery. These findings contradicted with previous literature results. More studies are needed to examine the association between anxiety and HRV in children.

This thesis includes one qualitative literature review, three empirical studies and one meta-analysis examining the measurement of physical activity in children. Previous research has highlighted the difficulties inherent in measuring children's habitual activity. This has lead to confusion regarding the relationships between physical activity and health in children. Recently a new type of activity monitor has been developed. Uniaxial (WAM, Computer Science Applications, Shalimar, Florida, USA) and triaxial (Tritrac, Professional Products, a division of Reining International, Madison, WI, USA) accelerometers that record temporal, frequency and intensity information of movement are now commercially available. The aims of this thesis were to evaluate the validity of these and other measures of physical activity in children, to examine the relationship between physical activity and body fat in children and to investigate the effect the mode of activity measurement has on this relationship. The main findings were: a) The Tritrac provided a significantly better estimate of scaled oxygen consumption during typical children's activities than the WAM, heart rate or pedometry; b) Physical activity, measured by the Tritrac or the pedometer, was inversely correlated with body fat and positively correlated with aerobic fitness; c) Heart rate measures of physical activity did not correlate significantly with body fat or aerobic fitness; d) Meta-analytic procedures showed a small to moderate relationship between activity levels and body fat in children; e) The strength of this relationship was heavily dependent on the method used to assess activity levels. Observation methods produced an effect size significantly higher than questionnaire or heart rate methods, though not significantly different to motion counter methods. In conclusion it appears that heart rate methods are inappropriate for the assessment of habitual activity in children. The use of motion counters or observation methods for assessing activity are recommended. Motion counter methods are particularly appropriate for medium to large sample sizes.

This thesis examined the conscious processing hypothesis as a potential explanation for the way in which anxiety affects motor performance. The thesis is written as a series of research papers (studies). The five papers are preceded by a general introduction and followed by a general discussion. The first study replicated and extended previous research in the area of conscious processing. Participants acquired the skill of golf putting explicitly and implicitly across 400 trials. During a high anxiety transfer test, the performance of participants who learned explicitly was less robust than that of participants who learned implicitly, supporting the conscious processing hypothesis. Study 2 tested the conscious processing hypothesis using a performance rather than learning paradigm to control for possible desensitisation effects identified as a possible alternative explanation for the results of study 1. Results supported the conscious processing hypothesis, but an alternative attentional explanation was identified. Study 3 examined the conscious processing hypothesis while controlling for both desensitisation and attentional effects. Kinematic measures were also adopted to examine the golf putting task in vivo. Performance results partially supported the conscious processing hypothesis. Study 4 replicated and extended the design adopted in study 3. Study 4 also examined processing efficiency theory as a plausible alternative to the conscious processing hypothesis. Kinematic and cardiovascular measures were incorporated into the design. Performance scores suggested a processing efficiency interpretation. However, conscious processing effects could not be totally discounted. The fifth study examined the suggestion that the use of process goals by skilled but anxious performers might actively encourage lapses into conscious processing. Increases in state anxiety did not produce performance decrements. A lack of training in the use of goals was identified as an explanation for the absence of performance impairment. Implications for future research and applied practice are derived from the five studies.

abstract: ABSTRACT Objective: The purpose of this randomized parallel two-arm trial was to examine the effect that an intervention of combining daily almond consumption (2.5 ounces) with a walking program would have on heart rate recovery and resting heart rate when compared to the control group that consumed a placebo (cookie butter) in men and postmenopausal women, aged 20-69, in Phoenix, Arizona. Design: 12 men and women from Phoenix, Arizona completed an 8-week walking study (step goal: 10,000 steps per day). Subjects were healthy yet sedentary, non-smokers, free from gluten or nut allergies, who had controlled blood pressure. At week 5, participants were randomized into one of two groups: ALM (2.5 oz of almonds daily for last 3 weeks of trial) or CON (4 tbsp of cookie butter daily for last 3 weeks of trial). Body weight, BMI, and percent body fat were measured using a stadiometer and Tanita at the screening visit. Resting heart rate, heart rate recovery, and anthropometric measurements were taken at weeks 0, 5, and 8. Results: 8 weeks of walking 10,000 steps per day, with or without 3 weeks of almond consumption did not significantly improve heart rate recovery (p=0.818) or resting heart rate (0.968). Conclusions: Almond consumption in combination with a walking intervention does not significantly improve heart rate recovery or resting heart rate. / Dissertation/Thesis / Masters Thesis Nutrition 2016