Michael Corcoran | Merrimack College (original) (raw)

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Papers by Michael Corcoran

ACSMʼs Health & Fitness Journal

Journal of the International Society of Sports Nutrition

Background: Athletes commonly consume insufficient fluid and electrolytes just prior to, or durin... more 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.

The journal of nutrition, health & aging

Medicine & Science in Sports & Exercise, 2016

The Gerontologist, Jan 20, 2015

Older adults are among the most challenging population groups to enroll into health-related resea... more 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. 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. Sixty percent more ...

The American journal of clinical nutrition, 2007

Mounting evidence indicates that elevated intramyocellular triacylglycerol concentrations are ass... more 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 ...

Molecular Aspects of Medicine, 2014

Cardiovascular disease remains the leading cause of morbidity and mortality in the United 32 Stat... more Cardiovascular disease remains the leading cause of morbidity and mortality in the United 32 States and other developed countries, and is fast growing in developing countries, particu-33 larly as life expectancy in all parts of the world increases. Current recommendations for 34 the prevention of cardiovascular disease issued jointly from the American Academy of Car-35 diology and American Heart Association emphasize that lifestyle modification should be 36 incorporated into any treatment plan, including those on statin drugs. However, there is a 37 dearth of data on the interaction between diet and statins with respect to additive, comple-38 mentary or antagonistic effects. This review collates the available data on the interaction of 39 statins and dietary patterns, cognition, genetics and individual nutrients, including vitamin 40 D, niacin, omega-3 fatty acids, fiber, phytochemicals (polyphenols and stanols) and alcohol. 41 Of note, although the available data is summarized, the scope is limited, conflicting and dis-42 parate. In some cases it is likely there is unrecognized synergism. Virtually no data are avail-43 able describing the interactions of statins with dietary components or dietary pattern in 44 subgroups of the population, particularly those who may benefit most were positive effects 45 identified. Hence, it is virtually impossible to draw any firm conclusions at this time. Never-46 theless, this area is important because were the effects of statins and diet additive or syner-47 gistic harnessing the effect could potentially lead to the use of a lower intensity statin or dose. 48

Journal of Molecular Endocrinology, 2011

Estrogen and testosterone are thought to modulate coronary heart disease (CHD) risk. To examine h... more 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 50–70 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 HM...

Journal of Endocrinology, 2010

Inflammation plays a central role in the development and progression of coronary heart disease (C... more 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 macrophage cells 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 monocytederived macrophage cells (HMDM) 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. HMDM were stimulated with oxidized low density lipoproteins (oxLDL) and the expression of the cytokines TNFα, IL-6, and IL-1β, and of the acute-phase protein CRP was measured. Both physiological and supraphysiological concentrations of testosterone reduced the expression and secretion of TNF-α and reduced the expression of IL-1β, but did not affect IL-6 or CRP expression. Estrogen did not modify the expression of TNF-α, IL-6, and IL-1β. Estrogen caused a variable response in CRP expression that was positively associated with the donor's plasma small dense LDL cholesterol concentration. 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-α expression while the effects of estrogen on macrophage CRP expression may depend upon the extracellular lipid environment.