Browsing by Author "Halliday, Tanya M."

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    Are the Initiation and Maintenance of a Resistance Training Program Associated with Changes to Dietary Intake and Non-Resistance Training Physical Activity in Adults with Prediabetes?
    Halliday, Tanya M. (Virginia Tech, 2016-05-02)
    Prediabetes is associated with an elevated risk for developing type 2 diabetes (T2DM) and associated cardiovascular complications. Lifestyle factors such as physical activity (PA) and dietary intake are strongly implicated in the development of metabolic disease, yet few Americans meet PA and dietary recommendations. Middle-aged and older adults are at increased risk for developing prediabetes and T2DM due to age-related muscle loss, increased fat mass, and alterations in glucose handling. In addition, this segment of the population is least likely to meet PA guidelines, particularly the resistance training (RT) recommendation of completing a whole body routine 2x/week. Ideally, individuals would alter their lifestyle in order to meet PA guidelines and habitually consume a healthy diet, to decrease disease risk. However, behavior change is difficult and optimal strategies to promote and maintain changes have yet to be determined. Furthermore, behavior change interventions tend to be time-, cost-, and resource-intensive, limiting the ability for efficacious programs to be translated into community settings and broadly disseminated. Evidence suggests that health-related behaviors, particularly diet and exercise habits, tend to cluster together. Thus, intervening on one behavior (e.g. PA) may elicit a spillover effect, promoting alterations in other behaviors (e.g. diet), though findings to date are conflicting. The purpose of this dissertation was to determine if participation in a social cognitive theory-based RT program targeting the initiation and maintenance of RT exerts a spillover effect and is associated with alterations in dietary intake and/or non-RT PA in a population at risk for T2DM. Data from the 15-month Resist Diabetes study was analyzed to evaluate this possibility. Sedentary, overweight/obese (BMI 25-39.9 kg/m2 ), middle-aged and older (50 -69 years) adults with prediabetes (impaired fasting glucose and/or impaired glucose tolerance) completed a 3 month initiation phase where they RT 2x/week in a lab-gym with an ACSM-certified personal trainer. Participants then completed a 6-month faded contact maintenance phase, and a 6-month no-contact phase during which they were to continue RT on their own in a public facility. No advice or encouragement was given to participants to alter dietary intake or non-RT PA habits. At baseline, and months 3, 9, and 15, three non-consecutive 24-hour diet recalls were collected to evaluate dietary intake and quality, the Aerobics Institute Longitudinal Study Questionnaire was completed to evaluate non-RT PA, and body mass, body composition, and strength (3 repetition maximum on leg and chest press) were measured. At months 3, 9, and 15 social cognitive theory (SCT) constructs were assessed with a RT Health Beliefs Questionnaire. In the first study, dietary intake was assessed at baseline and after 3 months of RT. Using paired sample t-tests, reductions in intake of energy (1914 ± 40 kcal vs. 1834 ± 427 kcal, p = 0.010), carbohydrate (211.6 ± 4.9 g vs. 201.7 ± 5.2 g, p = 0.015), total sugar (87.4 ± 2.7 g vs. 81.5 ± 3.1 g, p = 0.030), glycemic load (113.4 ± 3.0 vs. 108.1 ±3.2, p= 0.031), fruits and vegetables (4.6±0.2 servings vs. 4.1±0.2 servings, p= 0.018), and sweets and desserts (1.1 ± 0.07 servings vs. 0.89 ± 0.07 servings, p = 0.023) were detected from baseline to month 3. No changes in other dietary intake variables were observed. These findings supported additional investigation in this area. The second study assessed changes in overall diet quality (Healthy Eating Index [HEI]-2010 scores) and non-RT PA over the initiation, maintenance, and no-contact phases using mixed effects models. Demographic, physiological, and psychosocial factors that may predict alterations to diet quality and non-RT PA were also explored. Energy and carbohydrate intake decreased with RT (β= -87.9, p=.015 and β= -16.3, p<.001, respectively). No change in overall dietary quality (HEI-2010 score: β= -0.13, p=.722) occurred, but alterations in HEI-2010 sub-scores were detected. Maintenance of RT was accompanied by an increase in MET-min/week of total non-RT PA (β=153.5, p=0.01), which was predicted by increased self-regulation for RT (β=78.1, p=0.03). RT may be a gateway behavior leading to improvements in other health-related behaviors among adults with prediabetes. These results support the use of singlecomponent vs. multi-component interventions. This may have broad translational potential for the development of time-, resource-, and cost-efficient lifestyle interventions which can improve multiple health-related behaviors and decrease disease risk.
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    Dietary Intake, Body Composition, and Menstrual Cycle Changes during Competition Preparation and Recovery in a Drug-Free Figure Competitor: A Case Study
    Halliday, Tanya M.; Loenneke, Jeremy P.; Davy, Brenda M. (MDPI, 2016-11-20)
    Physique competitions are events in which competitors are judged on muscular appearance and symmetry. The purpose of this retrospective case study was to describe changes in dietary intake, body mass/composition, and the menstrual cycle during the 20-week competition preparation (PREP) and 20-week post competition recovery (REC) periods of a drug-free amateur female figure competitor (age = 26–27, BMI = 19.5 kg/m2). Dietary intake (via weighed food records) and body mass were assessed daily and averaged weekly. Body composition was estimated via Dual-energy X-ray absorptiometry (DXA) and 7-site skinfold measurements. Energy intake, body mass and composition, and energy availability decreased during the 20-week PREP period (changes of ~298 kcals, 5.1 kg, 6.5% body fat, and 5.4 kcal/kg fat free mass, respectively) and returned to baseline values by end of the 20-week REC period. Menstrual cycle irregularity was reported within the first month of PREP and the last menstruation was reported at week 11 of PREP. Given the potentially adverse health outcomes associated with caloric restriction, future, prospective cohort studies on the physiological response to PREP and REC are warranted in drug-free, female physique competitors.
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    Feasibility, effectiveness, and perceptions of an Internet- and incentive-based behavioral weight loss intervention for overweight and obese college freshmen: A mixed methods approach
    Davy, Brenda M.; Potter, Kerry L.; Dennis, Elizabeth A.; Harden, Samantha M.; Hill, Jennie L.; Halliday, Tanya M.; Estabrooks, Paul A. (2013)
    Challenges inherent with the transition to col- lege are often accompanied by weight gain among college freshmen. Weight gain and dura- tion of obesity increase metabolic syndrome and cardiovascular disease risk in young adulthood, which supports the need for weight loss inter- ventions tailored to college students. The pur- pose of this investigation was to conduct a mixed methods pilot trial to determine the effi- cacy and acceptability of a semester long Inter- net- and incentive-based weight loss interven- tion for overweight/obese college freshmen. Par- ticipants (n = 27, aged >18 yrs, BMI >25) were randomly assigned to a 12-week social cognitive theory (SCT)-based intervention (Fit Freshmen [FF]) or a health information control group. The FF intervention also included modest financial incentives for weight loss. Primary outcomes included body weight/composition, dietary and physical activity (PA) behaviors, and psychoso- cial measures (i.e. self-efficacy, self-regulation) associated with diet, PA, and weight loss. Stu- dents in the FF intervention participated in focus groups to provide qualitative feedback on pro- gram structure and design. FF participants demonstrated significant reductions (all group differences p < 0.10) in body weight (−1.2 kg), fat mass (−0.6 kg), dietary energy (−673 kcal/d), fat (−37 g/d) and added sugar intake (−41 g/d), and increases in diet and PA-related self-regulatory skills at week 12 compared to control partici- pants (+1.0 kg, +1.1 kg, −334 kcal/d, −15 g/d, −13 g/d, respectively). No changes in PA were noted, but FF participants demonstrated increases in self-efficacy to overcome barriers to PA relative to control participants. Themes for content im- provement from focus groups included reducing email contact and increasing in-person interac- tions. Program characteristics that were posi- tively evaluated included incentives for weight loss and access to an onsite weigh station kiosk. Overall, this efficacious SCT Internet- and incen- tive-based weight loss intervention was well received and can be adapted for larger-scale use in the college population.
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    Resist diabetes: A randomized clinical trial for resistance training maintenance in adults with prediabetes
    Davy, Brenda M.; Winett, Richard A.; Savla, Jyoti S.; Marinik, Elaina L.; Baugh, Mary Elizabeth; Flack, Kyle D.; Halliday, Tanya M.; Kelleher, Sarah A.; Winett, Sheila G.; Williams, David M.; Boshra, Soheir (PLOS, 2017-02-23)
    Objective To determine whether a social cognitive theory (SCT)-based intervention improves resistance training (RT) maintenance and strength, and reduces prediabetes prevalence. Research design and methods Sedentary, overweight/obese (BMI: 25±39.9 kg/m2) adults aged 50±69 (N = 170) with prediabetes participated in the 15-month trial. Participants completed a supervised 3-month RT (2×/wk) phase and were randomly assigned (N = 159) to one of two 6-month maintenance conditions: SCT or standard care. Participants continued RT at a self-selected facility. The final 6-month period involved no contact. Assessments occurred at baseline and months 3, 9, and 15. The SCT faded-contact intervention consisted of nine tailored transition (i.e., supervised training to training alone) and nine follow-up sessions. Standard care involved six generic follow-up sessions. Primary outcomes were prevalence of normoglycemia and muscular strength. Results The retention rate was 76%. Four serious adverse events were reported. After 3 months of RT, 34% of participants were no longer prediabetic. This prevalence of normoglycemia was maintained through month 15 (30%), with no group difference. There was an 18% increase in the odds of being normoglycemic for each % increase in fat-free mass. Increases in muscular strength were evident at month 3 and maintained through month 15 (P<0.001), which represented improvements of 21% and 14% for chest and leg press, respectively. Results did not demonstrate a greater reduction in prediabetes prevalence in the SCT condition. Conclusions Resistance training is an effective, maintainable strategy for reducing prediabetes prevalence and increasing muscular strength. Future research which promotes RT initiation and maintenance in clinical and community settings is warranted.
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    A Single-Carbon Stable Isotope Ratio Model Prediction Equation Can Estimate Self-Reported Added Sugars Intake in an Adult Population Living in Southwest Virginia
    Hedrick, Valisa E.; Halliday, Tanya M.; Davy, Brenda M.; Zoellner, Jamie M.; Jahren, A. Hope (MDPI, 2021-10-28)
    The δ13C value of blood is a novel proposed biomarker of added sugars (AS) intake. AS prediction equations using either a single- (δ13C) or dual-isotope model (δ13C and δ15N) were previously developed in an adult population with high AS intake living in southwest Virginia (reference group). The purpose of this investigation was to test the δ13C single- and δ13C and δ15N dual-isotope prediction equations for AS intake in adults with a lower mean AS intake and different demographic characteristics (test group). The blood samples for the reference (n = 257 for single-isotope, n = 115 for dual-isotope) and test groups (n = 56) were analyzed for δ13C and δ15N values using natural abundance stable isotope mass spectrometry and were compared to reported dietary AS intake. When the δ13C single-isotope equation was applied to the test group, predicted AS intake was not significantly different from reported AS intake (mean difference ± standard error = −3.6 ± 5.5 g, Z = −0.55, p = 0.51). When testing the dual-isotope equation, predicted AS was different from reported AS intake (mean difference ± SEM = 13.0 ± 5.4 g, Z = −2.95, p = 0.003). δ13C value was able to predict AS intake using a blood sample within this population subset. The single-isotope prediction equation may be an alternative method to assess AS intake and is more objective, cost-feasible, and efficient than traditional dietary assessment methods. However, more research is needed to assess this biomarker with rigorous study designs such as controlled feeding.
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    Skeletal muscle autophagy and mitophagy in endurance-trained runners before and after a high-fat meal
    Tarpey, Michael D.; Davy, Kevin P.; McMillan, Ryan P.; Bowser, Suzanne M.; Halliday, Tanya M.; Boutagy, Nabil E.; Davy, Brenda M.; Frisard, Madlyn I.; Hulver, Matthew W. (Elsevier, 2017-10-24)
    Objective: We tested the hypothesis that skeletal muscle of endurance-trained male runners would exhibit elevated autophagy and mitophagy markers, which would be associated with greater metabolic flexibility following a high-fat meal (HFM). Methods: Muscle biopsies were collected to determine differences in autophagy and mitophagy protein markers and metabolic flexibility under fasting conditions and 4 h following a HFM between endurance-trained male runners (n =10) and sedentary, non-obese controls (n = 9). Results: Maximal oxygen consumption (ml・kg・min⁻¹) was approximately 50% higher (p < 0.05) in endurance-trained runners compared with sedentary controls (65.8 ±2.3 and 43.1 ±3.4, respectively). Autophagy markers were similar between groups. Mitophagy and mitochondrial dynamics protein markers were significantly higher in skeletal muscle of endurance-trained runners compared with sedentary controls in the fasted state, although unaffected by the HFM. Skeletal muscle metabolic flexibility was similar between groups when fasted (p > 0.05), but increased in response to the HFM in endurance-trained athletes only (p < 0.005). Key mitophagy markers, phospho-Pink1Thr257 and phospho- ParkinS⁶⁵(r = 0.64, p < 0.005), and phospo-ParkinSer⁶⁵ and phospho-Drp1Ser⁶¹⁶ (r = 0.70, p < 0.05) were correlated only within the endurance-trained group. Autophagy and mitophagy markers were not correlated with metabolic flexibility. Conclusion: In summary, mitophagy may be enhanced in endurance-trained runners based on elevated markers of mitophagy and mitochondrial dynamics. The HFM did not alter autophagy or mitophagy in either group. The absence of a relationship between mitophagy markers and metabolic flexibility suggests that mitophagy is not a key determinant of metabolic flexibility in a healthy population, but further investigation is warranted.