29 research outputs found
Concentration-Dependent Effects of a Dietary Ketone Ester on Components of Energy Balance in Mice
Objectives: Exogenous ketones may provide therapeutic benefit in treatment of obesity. Administration of the ketone ester (KE) R,S-1,3-butanediol acetoacetate diester (BD-AcAc2) decreases body weight in mice, but effects on energy balance have not been extensively characterized. The purpose of this investigation was to explore concentration-dependent effects of BD-AcAc2 on energy intake and expenditure in mice.Methods: Forty-two male C57BL/6J mice were randomly assigned to one of seven isocaloric diets (n = 6 per group): (1) Control (CON, 0% KE by kcals); (2) KE5 (5% KE); (3) KE10 (10% KE); (4) KE15 (15% KE); (5) KE20 (20% KE); (6) KE25 (25% KE); and (7) KE30 (30% KE) for 3 weeks. Energy intake and body weight were measured daily. Fat mass (FM), lean body mass (LBM), and energy expenditure (EE) were measured at completion of the study. Differences among groups were compared to CON using ANOVA and ANCOVA.Results: Mean energy intake was similar between CON and each concentration of KE, except KE30 which was 12% lower than CON (P < 0.01). KE25 and KE30 had lower body weight and FM compared to CON, while only KE30 had lower LBM (P < 0.03). Adjusted resting and total EE were lower in KE30 compared to CON (P < 0.03), but similar for all other groups.Conclusions: A diet comprised of 30% energy from BD-AcAc2 results in lower energy intake, coincident with lower body weight and whole animal adiposity; while KE20 and KE25 have significantly lower body weight and adiposity effects independent of changes in energy intake or expenditure
Evaluation of the Effectiveness of ROTC Army Cadet Exercise Training for the Army Combat Fitness Test
International Journal of Exercise Science 17(4): 172-182, 2024. The Army Combat Fitness Test (ACFT) is used to evaluate the fitness level of potential Cadets for military readiness. The purpose of this study was to evaluate the effectiveness of the exercise training program implemented by an Army Reserve Officers’ Training Corps (ROTC) program to gauge the performance metrics of the ACFT. METHODS: Twenty-six student Cadets of the ROTC at the University of Alabama at Birmingham (UAB) program participated in the study. Over an 8-month period, the ROTC Cadets trained on campus three days per week. Training was performed in a circuit training format and each participant cycled through each of the four training stations (Strength, Conditioning, Core, and Endurance) for 15 minutes each session (for a total training time of 60 minutes). Each Cadet had body mass and body composition assessed as well as each component of the ACFT [maximum dead lift (MDL), standing power throw (SPT), hand release push-up (HRP), sprint-drag-carry (SDC), leg tuck/plank (LTK/PLK), and 2-mile run (2MR)]. Each variable was evaluated at three time points (pre-, mid-, and post-training program). RESULTS: There was a significant difference in the 2MR score between time points [F(2,50) = 4.530, p = .016, = 0.153] with a significant difference between time point at pre- and post-training (p = .02). No other variables displayed a significant change: body mass (p = .741), body fat percentage (p = .238), MDL (p = .061), SPT (p = .308), HRP (p = .126), SDC (p = 0.132), LTK/PLK (p = 0.583). CONCLUSION: The results of this study suggest that the short-term training program used improves 2MR, but not other components of the ACFT over the course of an academic year
The relationship between hourly energy balance and fat mass in female collegiate soccer players
Introduction: Soccer athletes have better performance if they maintain low fat mass (FM) relative to fat-free mass. Recent evidence suggests that maintenance of energy balance (EB) is associated with lower FM in athletes. Prior studies have used daily EB rather than hourly, but this approach does not consider duration of time athletes spend in EB versus surplus or deficit. Objective: Test the hypotheses that (1) time spent in EB is inversely associated with FM, and (2) athletes with mean hourly EB in the deficit range have lower FM than those in balance or surplus. Methods: Collegiate female soccer players (n=20) were enrolled in this cross-sectional study. A 3-day diet/activity record was obtained and analysed to estimate EB in hourly increments. Hourly EB was categorized as: Surplus, >400 kcal EB; Balance, between ±400 kcal EB; Deficit, <-400 kcal EB. Total hours spent in each category and mean EB (kcals) was calculated from the 3-day period. Bioelectrical Impedance Analysis was used to derive indices of FM (total FM in kg, % fat, fat mass index). Pearson correlations evaluated associations between FM measures and time spent in each EB category. One-way ANOVA with Tukey post-hoc testing was used to assess differences in FM among athletes stratified into surplus, balance, or deficit based on mean hourly EB. Results: Hourly energy deficit was associated with higher FM compared to energy surplus or balance. Conclusion: Female collegiate soccer players who sustain EB during the day, and limit time spent in energy deficit, had lower FM measures.CEB is supported by Grant Number (T32HL105349) from The National Heart, Lung, and Blood Institute. Additional support was provided by Award Number (P30DK056336) from The National Institute of Diabetes and Digestive and Kidney Diseases
Concentration-Dependent Effects of a Dietary Ketone Ester on Components of Energy Balance in Mice
Exogenous ketones may provide therapeutic benefit in treatment of obesity. Administration of the ketone ester (KE) R,S-1,3-butanediol acetoacetate diester (BD-AcAc) decreases body weight in mice, but effects on energy balance have not been extensively characterized. The purpose of this investigation was to explore concentration-dependent effects of BD-AcAc on energy intake and expenditure in mice. Forty-two male C57BL/6J mice were randomly assigned to one of seven isocaloric diets ( = 6 per group): (1) Control (CON, 0% KE by kcals); (2) KE5 (5% KE); (3) KE10 (10% KE); (4) KE15 (15% KE); (5) KE20 (20% KE); (6) KE25 (25% KE); and (7) KE30 (30% KE) for 3 weeks. Energy intake and body weight were measured daily. Fat mass (FM), lean body mass (LBM), and energy expenditure (EE) were measured at completion of the study. Differences among groups were compared to CON using ANOVA and ANCOVA. Mean energy intake was similar between CON and each concentration of KE, except KE30 which was 12% lower than CON ( \u3c 0.01). KE25 and KE30 had lower body weight and FM compared to CON, while only KE30 had lower LBM ( \u3c 0.03). Adjusted resting and total EE were lower in KE30 compared to CON ( \u3c 0.03), but similar for all other groups. A diet comprised of 30% energy from BD-AcAc results in lower energy intake, coincident with lower body weight and whole animal adiposity; while KE20 and KE25 have significantly lower body weight and adiposity effects independent of changes in energy intake or expenditure
Paraoxonase responses to exercise and niacin therapy in men with metabolic syndrome
Our purpose was to characterize changes in paraoxonase 1 (PON1) activity and concentration after single
aerobic exercise sessions conducted before and after 6 weeks of niacin therapy in men with metabolic
syndrome (MetS). Twelve men with MetS expended 500 kcal by walking at 65% of VO2max before and after a 6-week regimen of niacin. Niacin doses were titrated by 500 mg/week from 500 to 1500 mg/day and maintained at 1500 mg/day for the last 4 weeks. Fasting blood samples were collected before and 24
hours after each exercise session and analyzed for PON1 activity, PON1 concentration, myeloperoxidase
(MPO), apolipoprotein A1, oxidized low-density lipoprotein (oLDL), lipoprotein particle sizes and
concentrations. PON1 activity, PON1 concentration, MPO, and oLDL were unaltered following the
independent effects of exercise and niacin (P > 0.05 for all). High-density lipoprotein particle size
decreased by 3% (P = 0.040) and concentrations of small very low-density lipoprotein increased (P =
0.016) following exercise. PON1 activity increased 6.1% (P = 0.037) and PON1 concentrations increased
11.3% (P = 0.015) with the combination of exercise and niacin. Exercise and niacin works synergistically
to increase PON1 activity and concentration with little or no changes in lipoproteins or markers of lipid
oxidation.UCR::VicerrectorÃa de Investigación::Unidades de Investigación::Ciencias Sociales::Centro de Investigación en Ciencias del Movimiento Humano (CIMOHU)UCR::VicerrectorÃa de Docencia::Ciencias Sociales::Facultad de Educación::Escuela de Educación FÃsic
A Daphnane Diterpenoid Isolated from Wikstroemia polyantha Induces an Inflammatory Response and Modulates miRNA Activity
MicroRNAs (miRNAs) are endogenously expressed single-stranded ∼21–23 nucleotide RNAs that inhibit gene expression post-transcriptionally by binding imperfectly to elements usually within the 3′untranslated region (3′UTR) of mRNAs. Small interfering RNAs (siRNAs) mediate site-specific cleavage by binding with perfect complementarity to RNA. Here, a cell-based miRNA reporter system was developed to screen for compounds from marine and plant extracts that inhibit miRNA or siRNA activity. The daphnane diterpenoid genkwanine M (GENK) isolated from the plant Wikstroemia polyantha induces an early inflammatory response and can moderately inhibit miR-122 activity in the liver Huh-7 cell line. GENK does not alter miR-122 levels nor does it directly inhibit siRNA activity in an in vitro cleavage assay. Finally, we demonstrate that GENK can inhibit HCV infection in Huh-7 cells. In summary, the development of the cell-based miRNA sensor system should prove useful in identifying compounds that affect miRNA/siRNA activity
Exercise and Dietary-Mediated Reductions in Postprandial Lipemia
Postprandial hyperlipemia produces long-term derangements in lipid/lipoprotein metabolism, vascular endothelial dysfunction, hypercoagulability, and sympathetic hyperactivity which are strongly linked to atherogenesis. The purpose of this review is to (1) provide a qualitative analysis of the available literature examining the dysregulation of postprandial lipid metabolism in the presence of obesity, (2) inspect the role of adiposity distribution and sex on postprandial lipid metabolism, and (3) examine the role of energy deficit (exercise- and/or energy restriction-mediated), isoenergetic low-carbohydrate diets, and omega-3 (n-3) fatty acid supplementation on postprandial lipid metabolism. We conclude from the literature that central adiposity primarily accounts for sex-related differences in postprandial lipemia and that aerobic exercise attenuates this response in obese or lean men and women to a similar extent through potentially unique mechanisms. In contrast, energy restriction produces only mild reductions in postprandial lipemia suggesting that exercise may be superior to energy restriction alone as a strategy for lowering postprandial lipemia. However, isoenergetic very low-carbohydrate diets and n-3 fatty acid supplementation reduce postprandial lipemia indicating that macronutrient manipulations reduce postprandial lipemia in the absence of energy restriction. Therefore, interactions between exercise/energy restriction and alterations in macronutrient content remain top priorities for the field to identify optimal behavioral treatments to reduce postprandial lipemia
Factors influencing the accumulation of recommended physical activity among Latinos in the deep south of the United States
Less than 40% of the U.S. population achieves the recommended amount of leisure-time physical activity (LTPA) recommended by the
American College of Sports Medicine [ACSM (>150 minutes/week of moderate-intensity or equivalent vigorous-intensity LTPA)]. The number of
Hispanic/Latino men and women who report being physically inactive is disproportionately higher than non-Hispanic/Latinos. The purpose of this
investigation is to evaluate factors which influence the achievement of meeting ACSM recommendations for LTPA among adults with Hispanic/Latino
ethnicity and whites (non-Hispanic/Latino) in the southern United States. Self-reported data collected as part of the Behavioral Risk Factor Surveillance
System (BRFSS) was analyzed in male and female Hispanic/Latinos and non-Hispanic/Latino whites using the Andersen Model and Chi Square Analysis
to examine the association between variables. Hispanic/Latino men/women were significantly less likely to meet the ACSM recommendations (> 150
minutes/week) compared to non-Hispanic/Latinos. Lower amounts of income, education, and access to health care were all significant factors of
whether Hispanic/Latinos in the Deep South achieved the ACSM recommendations for LTPA. Although the percentage of overweight Hispanic/
Latinos was considerably higher than White (non-Hispanic/Latino), reported obesity was highest among Whites (non-Hispanic/Latino). LTPA
between the two groups differed significantly, suggesting that not achieving the physical activity recommendations is associated with being overweight,
but other factors may also contribute to being overweight and obesity.Menos del 40% de la población de los Estados Unidos cumple con la cantidad de actividad fÃsica de tiempo libre (AFTL) recomendada por
el Colegio Americano de Medicina Deportiva [ACSM (> 150 minutos/semana de AFTL de intensidad moderada o su equivalente de intensidad
vigorosa)]. La cantidad de hombres y mujeres hispanos o latinos que reportan ser fÃsicamente inactivos es desproporcionadamente mayor que quienes
no lo son. El propósito de esta investigación es evaluar los factores que pueden influir en alcanzar las recomendaciones del ACSM para AFTL en adultos
de origen étnico hispano o latino y en caucásicos (que no son hispanos o latinos) en la región Sur de los Estados Unidos. Se recolectaron datos de
cuestionarios autoadministrados que son parte del Sistema de Vigilancia de Factores de Riesgo del Comportamiento (Behavioral Risk Factor Surveillance
System, BRFSS), los cuales se analizaron en hombres y mujeres hispanos o latinos y en caucásicos que no lo eran, por medio del Modelo de Andersen
y pruebas de Chi cuadrado para examinar la asociación entre variables. Se encontró que los hombres y las mujeres latinos tenÃan una menor probabilidad
de cumplir con las recomendaciones del ACSM (> 150 minutos/semana) en comparación con quienes no eran hispanos o latinos. Menores ingresos
económicos, educación y acceso a los servicios de salud fueron factores significativos que condicionaban si los hispanos o latinos en el extremo Sur
lograban las recomendaciones del ACSM para AFTL. Aunque el porcentaje de hispanos o latinos con sobrepeso fue considerablemente mayor que los
caucásicos (no hispanos o latinos), la obesidad reportada fue mayor entre los caucásicos (no hispanos o latinos). La AFTL entre los dos grupos fue
estadÃsticamente diferente, lo cual sugiere que no alcanzar las recomendaciones de actividad fÃsica se asocia con tener sobrepeso; sin embargo, otros
factores también pueden contribuir en tener sobrepeso y obesidad
Generalized Temporal Acceleration Scheme for Kinetic Monte Carlo Simulations of Surface Catalytic Processes by Scaling the Rates of Fast Reactions
A novel
algorithm is presented that achieves temporal acceleration
during kinetic Monte Carlo (KMC) simulations of surface catalytic
processes. This algorithm allows for the direct simulation of reaction
networks containing kinetic processes occurring on vastly disparate
time scales which computationally overburden standard KMC methods.
Previously developed methods for temporal acceleration in KMC were
designed for specific systems and often require a priori information
from the user such as identifying the fast and slow processes. In
the approach presented herein, quasi-equilibrated processes are identified
automatically based on previous executions of the forward and reverse
reactions. Temporal acceleration is achieved by automatically scaling
the intrinsic rate constants of the quasi-equilibrated processes,
bringing their rates closer to the time scales of the slow kinetically
relevant nonequilibrated processes. All reactions are still simulated
directly, although with modified rate constants. Abrupt changes in
the underlying dynamics of the reaction network are identified during
the simulation, and the reaction rate constants are rescaled accordingly.
The algorithm was utilized here to model the Fischer–Tropsch
synthesis reaction over ruthenium nanoparticles. This reaction network
has multiple time-scale-disparate processes which would be intractable
to simulate without the aid of temporal acceleration. The accelerated
simulations are found to give reaction rates and selectivities indistinguishable
from those calculated by an equivalent mean-field kinetic model. The
computational savings of the algorithm can span many orders of magnitude
in realistic systems, and the computational cost is not limited by
the magnitude of the time scale disparity in the system processes.
Furthermore, the algorithm has been designed in a generic fashion
and can easily be applied to other surface catalytic processes of
interest
Ketogenic Diet for Cancer: Critical Assessment and Research Recommendations
Despite remarkable improvements in screening, diagnosis, and targeted therapies, cancer remains the second leading cause of death in the United States. It is increasingly clear that diet and lifestyle practices play a substantial role in cancer development and progression. As such, various dietary compositions have been proposed for reducing cancer risk and as potential adjuvant therapies. In this article, we critically assess the preclinical and human trials on the effects of the ketogenic diet (KD, i.e., high-fat, moderate-to-low protein, and very-low carbohydrate content) for cancer-related outcomes. The mechanisms underlying the hypothesized effects of KD, most notably the Warburg Effect, suggest that restricting carbohydrate content may impede cancer development and progression via several pathways (e.g., tumor metabolism, gene expression). Overall, although preclinical studies suggest that KD has antitumor effects, prolongs survival, and prevents cancer development, human clinical trials are equivocal. Because of the lack of high-quality clinical trials, the effects of KD on cancer and as an adjunctive therapy are essentially unknown. We propose a set of research recommendations for clinical studies examining the effects of KD on cancer development and progression