1,156 research outputs found
Effects of Nutrition Education on Dietary Intake Quality and Nutrition Knowledge in Professional Soccer Players – A Pilot Study
Background and Aims: Nutrition is an important factor for optimal performance of professional athletes. Several studies have demonstrated that elite athletes, especially soccer players, don’t eat enough or a high quality diet. Research shows that a diet with 65-70% of calories from carbohydrates, 20-35% calories from fat and approximately 12% of calories from protein out of an approximate 5,000 kcal diet will show improvements in performance of athletes training at high intensities. This pilot study aimed to test the impact of a targeted nutrition education program on dietary intake quality and nutrition knowledge in professional soccer players.
Methods: We initially evaluated 35 professional soccer players in San Antonio at the beginning and/or end of pre-season training. However, the number of intervention players (n=3) that 1) accurately completed the evaluation diet log and knowledge survey and 2) remained with the team throughout the preseason were very limited (n=3). The intervention players were on the team roster at the beginning of the pre-season. The non-intervention players (n=3) were added to the team well after the intervention itself and matched the experience level of the intervention players. Pre-intervention evaluation consisted of a dietary analysis and nutrition knowledge survey given the first week of preseason (intervention players only). Educational intervention was given during the second week of pre-season and was designed to address major dietary deficiencies identified in pre-intervention dietary analysis and performance nutrition knowledge survey. At week 9 of preseason, dietary analysis and nutrition knowledge surveys were administered to both the intervention and non-intervention groups.
Results: We found no significant differences between the intervention group and the non-intervention group.
Discussion: The power of this evaluation was highly limited due to unforeseen logistical issues associated with professional soccer teams. These included 1) poor player compliance with diet logs and survey, 2) very limited access to players during pre-season, 3) budgetary restrictions on training related hydration and recovery nutrition supplements, 4) high player turnover within the 9-week period, and 5) very low subject number. Anecdotally, several players and coaches expressed increased knowledge of appropriate performance nutrition and found themselves practicing what they learned during the education sessions and have invited the investigators back this season to provide nutrition education
Effects of Acute Cold Exposure on Plasma Biomarkers Associated with Cardiovascular Disease Risk
Background and Aims: The underlying cause of the majority of the cases of CVD is atherosclerosis, which is a condition initiated and progressed by chronic inflammation and hyperlipidemia. We are interested in evaluating the efficacy of cold-exposure to increase shivering- and non-shivering thermogenesis energy expenditure (RMR) as a non-pharmaceutical weight loss tool analogous to low intensity exercise. Naturally, we are concurrently evaluating the possible effects of cold exposure on risk factors associated with CVD risk. Inflammatory cytokines and lipid mediators are used as biomarkers for CVD risk. This proposed study aims to measure cardiovascular inflammatory and lipid biomarkers to expand our knowledge of cold exposure and CVD risk. The two biomarkers collected during this study were Interleukin-1 Beta (IL-β) and Chemokine Ligand 2 (CCL2). The hypothesis was that there would be no change in biomarker values before and after cold exposure.
Methods: Twenty subjects were recruited and subjected to a 30-min cold exposure test while a metabolic cart collected metabolic data via indirect calorimetry. Venous plasma collected at: pre cold exposure, immediately after cold exposure, and 2 hours post cold exposure was centrifuged for subsequent biomarkers analysis.
Results: RMR increases dramatically during acute cold exposure during shivering and remains increased 5 minutes after the cessation of shivering. Five minutes post-cold exposure, RMR rapidly decreases to pre-cold exposure RMR and is maintained for up to 120 minutes. There was no change in CCL2 values when comparing the three stages. IL-β values increased between blood draws immediately after cold exposure and 2 hours post cold exposure, however this increase was not statistically significant.
Conclusions: With these pilot results, we conclude that cold exposure has no effect on biomarkers for CVD risk. However, this study was limited by 1) accuracy of analysis techniques, 2) cold exposure protocol, 3) analysis of only two representative biomarkers. Further biomarker analysis is underway for a more comprehensive picture of the purported cold exposure effects
Antarctic Station Based Seasonal Pressure Reconstructions Since 1905, Part 1: Reconstruction Evaluation
Seasonal mean Antarctic pressures at 17 stations are reconstructed based on the method of principal component regression, employing midlatitude pressure data as predictors. Several reconstruction methods were performed in order to assess the stability and reliability of the reconstructions obtained, including performing the reconstructions over a shorter 30 year window and withholding the remaining data for an independent validation. Generally, there were small differences between the various approaches, but typically reconstructions conducted on data with the trends still present and over the full period of observations achieved the highest skill. Seasonally, reconstruction skill was high in austral summer across the entire Antarctic continent. Reconstructions that employed gridded pressure data over oceans as well as the observations (here termed “pseudoreconstructions”) also performed remarkably well in austral winter. Spatially, the reconstruction skill was highest near the Antarctic Peninsula in all seasons, and weakest in coastal East Antarctica and the Antarctic Interior during austral spring and autumn; the spatial variability of the skill in part reflects the distance to the nearest midlatitude predictor. Nonetheless, for nearly all seasons and locations the observed trends since 1957 were well captured by the reconstructions, as was the low-frequency decadal-scale variability. These results suggest Antarctic pressure observations can be extended throughout the twentieth century with high confidence, especially in summer, allowing for a more precise understanding of the role and magnitude of natural atmospheric circulation variability across Antarctica
Non-invasive Measures of Core Temperature versus Ingestible Thermistor during Exercise in the Heat
International Journal of Exercise Science 10(2): 225-233, 2017 The accuracy of core temperature (Tc) thermometry from temporal, tympanic, and oral thermometry devices has been variable during exercise in a hot, humid environment. The purpose of the present study was to cross-validate temporal, two tympanic devices, and oral devices compared to an ingestible thermistor during exercise in a hot, humid environment. Fourteen young, active adults (6 women) completed a graded exercise test until voluntary exhaustion in an environmental chamber (35.5 ± 0.6 °C, 53.9 ± 5.8 % RH). There was no statistical difference in mean temperature between tympanic device 1 and pill-based core temperature (PBTc) measurements across all time points and were positively correlated (0.357; P\u3c0.001). Temperatures of tympanic device 2 were statistically higher than PBTc (37.8 ± 0.7 ºC vs. 37.6 ± 1.0 ºC; respectfully) (P=0.008). At all time points, temperatures for the second tympanic device and PBTc were positively correlated (0.192; P=0.043). Temporal and PBTc values did not differ across time points and were positively correlated (0.262; P=0.005) across all time points. Mean oral temperature was significantly less than mean PBTc across all time points. (37.0 ± 0.4 ºC vs. 37.6 ± 1.0 ºC, respectively) (P\u3c0.001). Across all time points, oral and PBTc were positively correlated (0.262; P=0.010). Tympanic and temporal devices can reflect Tc while exercising in a hot, humid environment. However, care should be taken when selecting the tympanic or temporal measurement device and validation is advised prior to heat illness mitigation in the field
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A Tropospheric Assessment of the ERA-40, NCEP, and JRA-25 Global Reanalyses in the Polar Regions
The reliability of the global reanalyses in the polar regions is investigated. The overview stems from an April 2006 Scientific Committee on Antarctic Research (SCAR) workshop on the performance of global reanalyses in high latitudes held at the British Antarctic Survey. Overall, the skill is much higher in the Arctic than the Antarctic, where the reanalyses are only reliable in the summer months prior to the modern satellite era. In the Antarctic, large circulation differences between the reanalyses are found primarily before 1979, when vast quantities of satellite sounding data started to be assimilated. Specifically for ERA-40, this data discontinuity creates a marked jump in Antarctic snow accumulation, especially at high elevations. In the Arctic, the largest differences are related to the reanalyses depiction of clouds and their associated radiation impacts; ERA-40 captures the cloud variability much better than NCEP1 and JRA-25, but the ERA-40 and JRA-25 clouds are too optically thin for shortwave radiation. To further contrast the reanalyses skill, cyclone tracking results are presented. In the Southern Hemisphere, cyclonic activity is markedly different between the reanalyses, where there are few matched cyclones prior to 1979. In comparison, only some of the weaker cyclones are not matched in the Northern Hemisphere from 1958-2001, again indicating the superior skill in this hemisphere. Although this manuscript focuses on deficiencies in the reanalyses, it is important to note that they are a powerful tool for climate studies in both polar regions when used with a recognition of their limitations
Energy Expenditure following Acute Cold Exposure
TACSM Abstract -
Energy Expenditure following Acute Cold Exposure
Stelly S, Bravo D, Hines N, Koehler L, Levi M and Fogt D
Exercise Biochemistry & Metabolism Laboratory; Department of Kinesiology, Health & Nutrition; The University of Texas at San Antonio; San Antonio, TX
Category: Masters
Advisor / Mentor: Fogt, Donovan ([email protected])
ABSTRACT
Whole body energy expenditure (i.e., RMR) increases during acute cold exposure. Whether this increase in energy expenditure persists in the post-cold term in humans due to non-shivering thermogenesis has not yet been evaluated. Therefore we tested the hypothesis that RMR would be different directly following acute cold exposure. RMR (kcal•min-1) was assessed via indirect calorimetry on eight (8) males and seven (7) females at six time points: prior to cold exposure (T1), at the end of 30 minutes of cold exposure (T2), immediately post-cold-post-shivering (T3), at 35 minutes post-cold (T4), at 75 minutes post-cold (T5), and at 115 minutes post-cold (T6). This RMR data for the aforementioned time points was analyzed using paired, dependent t-tests and one way ANOVA; the significance level was placed at p \u3c 0.05. The RMR data for each time point was as follows: T1 (1.19±0.21), T2 (2.30±0.94), T3 (1.37±0.25), T4 (1.12±0.19), T5 (1.14±0.22), and T6 (1.14±0.22). The analysis of the RMR data showed a significant difference between the cold (T2) data and all other time points (T1, T3, T4, T5, and T6). Additionally there was a significant difference between the pre-cold (T1) and the immediately post-cold (T3) data. However there was no significant difference between the pre-cold (T1) data when compared with the remaining post-cold data (T4 – T6). These results suggest that the human body is capable of returning RMR to baseline levels relatively immediately following the cessation of acute cold exposure
Determination of Anaerobic Threshold by Heart Rate or Heart Rate Variability using Discontinuous Cycle Ergometry
International Journal of Exercise Science 7(1) : 45-53, 2014. The purpose was to determine if heart rate (HR) and heart rate variability (HRV) responses would reflect anaerobic threshold (AT) using a discontinuous, incremental, cycle test. AT was determined by ventilatory threshold (VT). Cyclists (30.6±5.9y; 7 males, 8 females) completed a discontinuous cycle test consisting of 7 stages (6 min each with 3 min of rest between). Three stages were performed at power outputs (W) below those corresponding to a previously established AT, one at W corresponding to AT, and 3 at W above those corresponding to AT. The W at the intersection of the trend lines was considered each metric’s “threshold”. The averaged stage data for Ve, HR, and time- and frequency-domain HRV metrics were plotted versus W. The W at the “threshold” for the metrics of interest were compared using correlation analysis and paired-sample t-test. In all, several heart rate-related parameters accurately reflected AT with significant correlations (p≤0.05) were observed between AT W and HR, mean RR interval (MRR), low and high frequency spectral energy (LF and HR, respectively), high frequency peak (fHF), and HFxfHF metrics’ threshold W (i.e., MRRTW, etc.). Differences in HR or HRV metric threshold W and AT for all subjects were less than 14 W. The steady state data from discontinuous protocols may allow for a true indication of steady-state physiologic stress responses and corresponding W at AT, compared to continuous protocols using 1-2 min exercise stages
Effects of Acute Cold Exposure on Plasma Biomarkers Associated with Cardiovascular Disease
Inflammatory cytokines and lipid mediators are used as biomarkers for CVD risk. Cold exposure has been suggested to improve some of these biomarkers. We measured cardiovascular inflammatory and lipid biomarkers to expand our knowledge of cold exposure and CVD risk. Interleukin-1 Beta (IL-1 B) and Chemokine Ligand 2 (CCL2) are inflammatory cytokines associated with various disease states. Free fatty acids (FFA) are released from fat cells in response to stress. We evaluated the effects of acute 30 min cold exposure on these blood biomarkers. We hypothesized that the inflammatory markers and plasma FFA levels would increase at 2-h post-cold exposure. Twenty subjects (9 females, 23.9±2.7sd y, 1.71±10.2sd m, 74.2±13.5sd kg, 19.4±7.4sd %BF, 64.5±15.3sd kg FFM) were subjected to a 30-min seated cold exposure while metabolic data was collected via indirect calorimetry. Shivering started immediately upon cold exposure and ceased within 10 seconds following cold exposure. Estimated resting energy expenditure (kcal/min) during the exposure period (1.73±0.7sd, 1.47±0.6sd, 1.36±1.0sd for min 5, 15, and 30, respectively) was two-fold higher than pre-cold. Venous plasma was collected at pre-cold period, immediately after cold exposure, and 2 h post-cold, centrifuged, and stored at -80 ºC for subsequent biomarker analysis. ELISAs were used to measure plasma inflammatory cytokines; interlukin-1 beta (IL-1 B) and chemokine ligand 2 (CCL2) biomarkers and plasma free fatty acid (FFA) during and following cold exposure. Pre-cold IL-1B (pg/ml), CCL2 (pg/ml), and FFA (mM) values were 19±3.6se, 2.4±0.7se, and 507±87se, respectively. Immediate post-cold values were 18±3.8se, 3.4±1.2se, and 412±42se, respectively. Finally, 2 h post-cold values were 20±3.6se, 2.6±0.7se, and 458±48se, respectively. There was a 3.4±0.7se (p\u3c0.05) increase in IL-1 B plasma levels immediately after cold exposure that lasted up to two hours. CCL2 plasma levels and FFA were not different from baseline during the post-cold period. We conclude that acute cold exposure may worsen CVD risk through a select inflammatory response. Additional analyses of our samples will expand the possible list of affected CVD risk biomarkers. Whether or not extended exposure to cold would exacerbate these marker levels or affect the other markers measured is not known
Expression of hepatocyte growth factor and its receptor c-met, correlates with severity of pathological injury in experimental alcoholic liver disease.
Expression of hepatocyte growth factor (HGF) and its receptor, c-met is up-regulated in various forms of liver injury. This study evaluated the relationship between HGF and c-met expression and pathological changes in experimental alcoholic liver disease. Rats (5 per group) were fed ethanol and a diet containing saturated fat corn oil or fish oil by intragastric infusion. Dextrose isocalorically replaced ethanol in controls. In a second set of experiments, Kupffer cells, endothelial cells and hepatocytes were isolated from rats in each group. Pathological evaluation and analysis of HGF and c-met expression were performed in liver and the different cell types. Increased expression of HGF and c-met expression was detected in the liver of rats showing necroinflammatory changes. The Kupffer and endothelial cells were primarily responsible for the increase in HGF, c-met expression was seen only in hepatocytes. Thus, up-regulation of HGF and c-met occurred in the presence of the necrosis and inflammation suggesting that HGF may be acting to protect against liver injury or accelerate the regenerative process
Changes in whole body bone mineral composition in a community-based pilot study designed for Mexican-American women at risk for type II diabetes
Changes in whole body bone mineral composition in a community-based pilot study designed for Mexican-American women at risk for type II diabetes
David C. Castillo, B.S., Maria G. Placeres, B.S., Arely Perez, M.S., Danielle M. Bravo, B.S., Donovan L. Fogt, Ph.D., Zenong Yin, Ph.D.
Mobile Health Laboratory, Department of Health and Kinesiology
The University of Texas at San Antonio
Classification of First Author (Master’s)
Background: Osteoporosis is a serious public health concern in the United States that is expected to increase over the next several years, especially in women. The US Surgeon General’s Report on Bone Health states that individuals can decrease the risk of developing osteoporosis with proper combinations of nutrition and physical activity. Diet and exercise are two important factors that have been shown to prevent or delay the onset of type II diabetes, another national top health concern. Intensive lifestyle interventions, such as The Diabetes Prevention Program have shown that type II diabetes can be delayed or prevented by losing moderate amounts of weight through dietary changes and increased physical activity. It is not clear if a lifestyle intervention can impact bone health.
Purpose: This pilot study examined the effects of lifestyle intervention (dietary and physical activity behavior modification) on bone mineral density (BMD) and bone mineral content (BMC). The intervention was a 14-week community-based pilot study, based on The Diabetes Prevention Program, designed to reduce risk for type II diabetes in high-risk Mexican American women.
The research questions were: Did the lifestyle intervention affect the outcome measures (BMC and BMD)? Were there differences in BMC and BMD between age groups (low-age ≤45 yrs. vs. high-age \u3e45 yrs.)? Were there differences in BMC and BMD between body weight groups (≤78 kg vs. \u3e78.1 kg)?
Methods: The study used a one-group pre- and post-test design. Twenty-five non-diabetic Mexican-American females (average age = 45, SD = 10.9; BMI 25-40) participated in a 14-week lifestyle intervention pilot study. Changes in BMD (g/cm2) and BMC (g) were measured at baseline and 14 weeks after baseline using whole body dual-energy x-ray absorptiometry (DXA).
Results: results of paired t-test showed a significant increase in whole body BMC (p\u3c .0001) and a marginally significant increase in whole body BMD (p\u3c .06). Results of Analysis of Covariance revealed no significant difference in BMC between age groups and a marginally significant increase of BMD (p\u3c .07) in younger participants compared to older participants, after controlling pretest measure. There was a significant increase in BMC (p\u3c .01) and a marginally significant increase in BMD (p\u3c .08) in the high-body weight group compared to the low weight group after controlling for pretest measure.
Conclusions: A lifestyle intervention that utilized a combination of physical activity and dietary modification showed great promise toward preventing the onset of osteoporosis, especially in heavier Mexican-American women
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