Individualized hydration plans improve performance outcomes for collegiate athletes engaging in in-season training.

BACKGROUND: Athletes commonly consume insufficient fluid and electrolytes just prior to, or during training and competition. Unlike non-athletes or athletes who do not engage in frequent rigorous and prolonged training sessions, "hard trainers" may require additional sodium and better benefit from a hydration plan tailored to their individual physiology. The purpose of this randomized cross-over study was to determine whether a hydration plan based off of an athlete's sweat rate and sodium loss improves anaerobic and neurocognitive performance during a moderate to hard training session as well as heart rate recovery from this session. METHODS: Collegiate athletes who were injury free and could exercise at ≥ 75% of their maximum heart rate for a minimum of 45 min were recruited for this randomized, cross-over study. After completing a questionnaire assessing hydration habits, participants were randomized either to a prescription hydration plan (PHP), which considered sweat rate and sodium loss or instructed to follow their normal ad libitum hydration habits (NHP) during training. Attention and awareness, as well as lower body anaerobic power (standing long jump) were assessed immediately before and after a moderate to hard training session of ≥ 45 min. Heart rate recovery was also measured. After a washout period of 7 days, the PHP group repeated the training bout with their normal hydration routine, while the NHP group were provided with a PHP plan and were assessed as previously described. RESULTS: Fifteen athletes from three different sports, aged 20 ± 0.85 years, participated in this study. Most participants reported feeling somewhat or very dehydrated after a typical training session. Compared to their NHP, participants following a PHP jumped 4.53 ± 3.80 in. farther, tracked moving objects 0.36 ± 0.60 m/second faster, and exhibited a faster heart rate recovery following a moderate to hard training session of 45-120 min in duration. CONCLUSION: A tailored hydration plan, based on an athlete's fluid and sodium loss has the potential to improve anaerobic power, attention and awareness, and heart rate recovery time.

Evaluating behavioral responses of nesting lesser snow geese to unmanned aircraft surveys.

Unmanned aircraft systems (UAS) are relatively new technologies gaining popularity among wildlife biologists. As with any new tool in wildlife science, operating protocols must be developed through rigorous protocol testing. Few studies have been conducted that quantify the impacts UAS may have on unhabituated individuals in the wild using standard aerial survey protocols. We evaluated impacts of unmanned surveys by measuring UAS-induced behavioral responses during the nesting phase of lesser snow geese (Anser caerulescens caerulescens) in Wapusk National Park, Manitoba, Canada. We conducted surveys with a fixed-wing Trimble UX5 and monitored behavioral changes via discreet surveillance cameras at 25 nests. Days with UAS surveys resulted in decreased resting and increased nest maintenance, low scanning, high scanning, head-cocking and off-nest behaviors when compared to days without UAS surveys. In the group of birds flown over, head-cocking for overhead vigilance was rarely seen prior to launch or after landing (mean estimates 0.03% and 0.02%, respectively) but increased to 0.56% of the time when the aircraft was flying overhead suggesting that birds were able to detect the aircraft during flight. Neither UAS survey altitude nor launch distance alone in this study was strong predictors of nesting behaviors, although our flight altitudes (≥75 m above ground level) were much higher than previously published behavioral studies. Synthesis and applications: The diversity of UAS models makes generalizations on behavioral impacts difficult, and we caution that researchers should design UAS studies with knowledge that some minimal disturbance is likely to occur. We recommend flight designs take potential behavioral impacts into account by increasing survey altitude where data quality requirements permit. Such flight designs should consider a priori knowledge of focal species' behavioral characteristics. Research is needed to determine whether any such disturbance is a result of visual or auditory stimuli.

Efficacy of an Exercise and Nutritional Supplement Program on Physical Performance and Nutritional Status in Older Adults With Mobility Limitations Residing at Senior Living Facilities.

This cluster-randomized trial was designed to determine the efficacy of a 6-month exercise-nutritional supplement program (ENP) on physical function and nutritional status for older adults and the feasibility of implementing this program in a senior living setting. Twenty senior-living facilities were randomized to either a 3 day per week group-based ENP led by a trained facility staff member or a health education program (SAP). Participants (N = 121) completed a short physical performance battery, 400-m walk, handgrip strength test, and mini-nutrition assessment. 25-hydroxyvitamin D [25(OH)D], insulin-like growth-factor 1 (IGF-1), and activity level were also measured. The ENP did not significantly improve physical function or nutritional status compared with the SAP. Compared with baseline, participants in the ENP engaged in 39 min less physical activity per week at 6 months. Several facility characteristics hindered implementation of the ENP. This study highlights the complexity of implementing an evidence-based program in a field setting.

Recruitment of Mobility Limited Older Adults Into a Facility-Led Exercise-Nutrition Study: The Effect of Social Involvement.

PURPOSE OF THE STUDY: Older adults are among the most challenging population groups to enroll into health-related research. This article describes two methods used by investigators to recruit mobility limited older adults residing at assisted living or senior housing (SH) facilities into a facility-led exercise-nutrition research study. DESIGN AND METHODS: Sedentary older adults were recruited from 42 different assisted living facilities (ALFs) or SH communities. Two different recruitment approaches were used: At 22 sites, investigators conducted heavily advertised informational sessions to recruit participants (Info only). At 20 locations, these sessions were preceded by attendance of a study team member at various activities offered by the facility over the preceding 2 weeks (activity attendance). Population reach, enrollment, personnel cost, and time required to recruit at least five participants at each facility was measured. Reasons for declining participation and withdrawal rate were also measured. RESULTS: Sixty percent more residents elected to be screened for eligibility when study personnel attended an activity offered by the facility. Activity attendance resulted in significantly less time, costs, and participant withdrawals compared with facilities with no activity attendance. IMPLICATIONS: Study team member attendance at activities offered by senior living facilities reduces cost and duration of recruitment and improves study retention. Interventions targeting this demographic are likely to benefit from deliberately building trust and familiarity among the resident population at senior living communities as part of the recruitment process.

Dietary modulators of statin efficacy in cardiovascular disease and cognition.

Cardiovascular disease remains the leading cause of morbidity and mortality in the United States and other developed countries, and is fast growing in developing countries, particularly as life expectancy in all parts of the world increases. Current recommendations for the prevention of cardiovascular disease issued jointly from the American Academy of Cardiology and American Heart Association emphasize that lifestyle modification should be incorporated into any treatment plan, including those on statin drugs. However, there is a dearth of data on the interaction between diet and statins with respect to additive, complementary or antagonistic effects. This review collates the available data on the interaction of statins and dietary patterns, cognition, genetics and individual nutrients, including vitamin D, niacin, omega-3 fatty acids, fiber, phytochemicals (polyphenols and stanols) and alcohol. Of note, although the available data is summarized, the scope is limited, conflicting and disparate. In some cases it is likely there is unrecognized synergism. Virtually no data are available describing the interactions of statins with dietary components or dietary pattern in subgroups of the population, particularly those who may benefit most were positive effects identified. Hence, it is virtually impossible to draw any firm conclusions at this time. Nevertheless, this area is important because were the effects of statins and diet additive or synergistic harnessing the effect could potentially lead to the use of a lower intensity statin or dose.

Flavonoid basics: chemistry, sources, mechanisms of action, and safety.

In our efforts to understand how various dietary factors can influence the risk and progression of chronic disease, much recent research has focused on phytochemicals. Phytochemicals are defined as nonessential nutrients found in plant-based food, many of which have been established as bioactive and thus may affect human health. The largest group of phytochemicals is the polyphenols, comprised principally of the flavonoids, which are characterized chemically by two benzene rings joined by a linear carbon chain. Evidence from observational studies indicates that regular consumption of foods containing flavonoids may reduce the risk several chronic conditions, including neurodegenerative diseases, atherosclerosis, and certain forms of cancer. These results have generated considerable interest in flavonoids, although much basic information about their nutrient characteristics in humans remains limited, e.g., their bioavailability and metabolism, interactions with other dietary factors, mechanisms of action, and intakes associated with specific health outcomes. Although flavonoids are commonly defined as dietary antioxidants and their putative health benefits commonly attributed to this mechanism, it now appears their principal actions are mediated in vivo via other biochemical and molecular pathways.

The effect of 17ß-estradiol on cholesterol content in human macrophages is influenced by the lipoprotein milieu.

Estrogen and testosterone are thought to modulate coronary heart disease (CHD) risk. To examine how these hormones affect human macrophage cholesterol transport, a key factor in atherogenesis, we obtained monocytes from healthy male and postmenopausal female donors (age 50­70 years). Cells were allowed to differentiate in autologous serum. Human monocyte-derived macrophages (HMDMs) were exposed to estrogen, testosterone, or vehicle, during differentiation.Cells were cholesterol enriched with oxidized low-density lipoprotein (oxLDL) in the presence of treatment. Cell cholesterol mass, efflux, and the expression of proteins involved in HMDM cholesterol transport were examined.Estrogen significantly reduced cholesteryl ester (CE) content in both female and male HMDMs while having no measurable effect on cholesterol efflux. Testosterone did not affect cholesterol content or efflux. Both hormones significantly but modestly affected the gene expression of several proteins involved in HMDM transport, yet these effects did not translate into significant changes in protein expression. In THP-1 macrophages, the effect of estrogen on CE content was more potent in unloaded macrophages and was estrogen receptor dependent. A trend for a reduction in nonoxLDL uptake by estrogen was observed and was also found to be dependent upon estrogen receptor activation. Our data indicate that estrogen, but not testosterone, reduces CE accumulation in HMDMs obtained from a CHD age relevant population, independent of changes in the expression of proteins important to macrophage cholesterol transport. In THP-1 cells, this effect is reduced in the presence of oxLDL, indicating that a pro-atherogenic lipoprotein milieu is an important variable in sex hormone modulation of CHD.

Sex hormone modulation of proinflammatory cytokine and C-reactive protein expression in macrophages from older men and postmenopausal women.

Inflammation plays a central role in the development and progression of coronary heart disease (CHD). The sex hormones estrogen and testosterone have been shown to modify the inflammatory response by influencing cytokine expression in human macrophages obtained from younger individuals. The effect of these hormones on the expression of proinflammatory markers in macrophages obtained from a CHD age-relevant population has not been studied. Human monocyte-derived macrophages (HMDMs) were obtained from healthy normolipidemic men and postmenopausal women (age 50-70 years), and cultured in autologous serum along with both physiological and supraphysiological concentrations of estrogen or testosterone. HMDMs were stimulated with oxidized low-density lipoproteins, and the expression of the cytokines tumor necrosis factor alpha (TNF-alpha or TNF), interleukin (IL)6, and IL-1 beta (IL1B) and of the acute-phase protein C-reactive protein (CRP) was measured. Both physiological and supraphysiological concentrations of testosterone reduced the expression and secretion of TNF-alpha and reduced the expression of IL-1 beta, but did not affect the expression of IL6 or CRP. Estrogen did not modify the expression of TNF-alpha, IL6, and IL-1 beta. Estrogen caused a variable response in CRP expression that was positively associated with the plasma small dense LDL-cholesterol concentration of the donors. There were no gender differences in any of the observed effects. Our results indicate that testosterone may exert anti-inflammatory effects by reducing macrophage TNF-alpha expression, while the effects of estrogen on macrophage CRP expression may depend upon the extracellular lipid environment.

Skeletal muscle lipid deposition and insulin resistance: effect of dietary fatty acids and exercise.

Mounting evidence indicates that elevated intramyocellular triacylglycerol concentrations are associated with diminished insulin sensitivity in skeletal muscle. This lipid accumulation is most likely due to enhanced fatty acid uptake into the muscle coupled with diminished mitochondrial lipid oxidation. The excess fatty acids are esterified and either stored or metabolized to various molecules that may participate or interfere with normal cellular signaling, particularly insulin-mediated signal transduction, thus altering cellular and, subsequently, whole-body glucose metabolism. Impaired insulin responsiveness, if not managed, can further progress to type 2 diabetes mellitus, an all too common condition. For most of the human population this is avoidable, given that causes of intramyocellular lipid deposition are predominantly lifestyle-mediated. Chronic overconsumption of calories coupled with deleterious intakes of saturated or trans-unsaturated fatty acids inconsistent with the recommendations outlined in the Dietary Guidelines for Americans have been shown to increase the risk of insulin resistance. Furthermore, lack of exercise, which can have a profound effect on skeletal muscle lipid turnover, is implicated in this lipid-induced insulin resistance. This review summarizes the current understanding of the effects of elevated intramyocellular lipids on insulin signaling and how these effects may be altered by varying dietary fat composition and exercise.