Tamara D Hew-Butler

Tamara D Hew-Butler
Wayne State University | WSU · Division of Kinesiology

40.03
 · 
DPM, PhD, FACSM

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158
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Introduction
Skills and Expertise

Publications

Publications (158)
Article
Full-text available
Exercise-associated hyponatremia (EAH) is defined by a serum or plasma sodium concentration below the normal reference range of 135 mmol·L-1 that occurs during or up to 24 h after prolonged physical activity. It is reported to occur in individual physical activities or during organized endurance events conducted in environments in which medical car...
Article
Full-text available
Background It remains unclear if ad libitum water drinking, as a hydration strategy, prevents exercise-associated hyponatremia (EAH) during prolonged exercise. The aim of this study was to determine the incidence of EAH within the broader context of fluid regulation among soldiers performing a 40-km route-march ingesting water ad libitum. Methods...
Article
Full-text available
The detrimental effects of dehydration, to both mental and physical health, are well-described. The potential adverse consequences of overhydration, however, are less understood. The difficulty for most humans to routinely ingest ≥2 liters (L)—or “eight glasses”—of water per day highlights the likely presence of an inhibitory neural circuit which l...
Article
Clinically significant derangements in plasma electrolytes rarely occur outside of excessive exercise and/or extreme dietary habits. Overzealous hydration facilitates exercise-associated disorders of sodium concentration ([Na⁺]) as robust overhydration may induce hyponatremia, whereas severe fluid restriction may cause hypernatremia. Excessive exer...
Article
Apply It! Gain a better understanding of exertional rhabdomyolysis (ER). Understand how ER can affect your clients/athletes, how to identify the signs and symptoms, and most importantly, learn how you can work to prevent it from developing.
Article
Previous studies demonstrated a positive relationship between blood sodium concentration and bone mineral density (BMD) in ultramarathon runners following a 100-mile race (1) and a negative relationship in walkers (treadmill walking for 45-minutes) following an oral sodium load (2). However, accurate assessment of sweat sodium concentration ([Na⁺])...
Article
Background: In 2014, 6 collegiate swimmers were hospitalized for symptomatic exertional rhabdomyolysis. Objective: To serially monitor and assess relationships between skeletal muscle membrane disruption, upper body soreness (UBS) and lower body soreness (LBS), and stress during the first 6 weeks (timepoints) of preseason training in collegiate...
Chapter
Exercise-associated hyponatremia (EAH) refers to below-normal serum sodium concentrations [Na⁺] that develop during exercise. The pathogenesis of EAH is best described as a spectrum ranging between profound polydipsia to modest sweat sodium losses with hypovolemia and relative dilution. Non-osmotic arginine vasopressin (AVP) remains the unifying pa...
Article
Full-text available
Although traditional high-intensity interval training (HIIT) has been effective in improving body composition and physical fitness, it is unclear how multimodal HIIT affects these variables. This study compared the differences between these two training programs on body composition and physical fitness in apparently healthy, nonobese young adult fe...
Article
Full-text available
Exercise-associated hyponatraemia (EAH) always involves a component of overhydration relative to available exchangeable sodium stores. In the majority of cases, this is purely due to excessive consumption of fluids during exercise. In a lesser number of cases, it is apparent that excessive sodium loss through sweat may play a role by decreasing the...
Article
Full-text available
Clinical medicine defines dehydration using blood markers that confirm hypertonicity (serum sodium concentration ([Na⁺])>145 mmol/L) and intracellular dehydration. Sports medicine equates dehydration with a concentrated urine as defined by any urine osmolality (UOsm) ≥700 mOsmol/kgH2O or urine specific gravity (USG) ≥1.020. Objective To compare bl...
Article
Full-text available
Objectives: To determine whether oral administration of 3% hypertonic saline (HTS) is as efficacious as intravenous (IV) 3% saline in reversing symptoms of mild-to-moderate symptomatic exercise-associated hyponatremia (EAH) in athletes during and after a long-distance triathlon. Design: Noninferiority, open-label, parallel-group, randomized cont...
Article
Full-text available
Background: Functional and structural asymmetries attributed to limb dominance are equivocal in soccer players. Previous authors hypothesize the existence of between-limb asymmetry secondary to the repetitive unilateral nature of kicking. However, symmetry is often present, particularly in measures of muscle strength. Purpose: The purpose of the...
Article
Full-text available
Severe exercise-associated hyponatremia (EAH) is largely dilutional, whereas contributions of sodium loss remain equivocal. We present a case of EAH with encephalopathy involving an experienced male cyclist with no recollection of the event. We thereby conducted a retrospective analysis of biochemical trajectories during hospital recovery. The norm...
Article
Full-text available
Exercise-associated hyponatremia (EAH) was initially described in the 1980s in endurance athletes, and work done since then has conclusively identified that overdrinking beyond thirst and non-osmotic arginine vasopressin release are the most common etiologic factors. In recent years, EAH has been described in a broader variety of athletic events an...
Article
Full-text available
Objectives: Creatine kinase (CK) is a sensitive enzyme marker for muscle damage in athletes. Elevated CK levels have been reported in many endurance physical activities. The consequence and possible long-term sequela of the CK elevation in athletes is unknown. There is a paucity of literature stating actual numerical values of CK associated with c...
Article
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Every number tells a story. As such, clinical laboratory science empowers modern medicine with a vast yet growing repertoire of analytes, which subsequently guide the diagnosis, treatment and prognosis of most – if not all - medical conditions. The body’s integrated response to dynamic perturbations in homeostasis creates an elusive trail of bioche...
Article
Full-text available
Hypernatremia is biochemically defined by a blood sodium concentration ([Na+]) above the normal reference range for the laboratory performing the test (typically >145 mmol/L). The clinical relevance of an above normal blood [Na+] is largely determined by the severity of the clinical signs and symptoms associated with cellular shrinkage (crenation)....
Article
Full-text available
In both hyponatremia and hypernatremia, the sodium value (numerator) appears the most deranged. However, it is the changes in water content (denominator) that is most responsible for the pathophysiology, morbidity and mortality associated with dysnatremia. Therefore, fluid homeostasis involves both short-term and long-term water regulation at the m...
Article
Full-text available
Hyponatremia is biochemically defined by a blood sodium concentration ([Na+]) below the normal reference range for the laboratory performing the test (typically <135 mmol/L). The clinical relevance of a below normal blood [Na+] is largely determined by the severity of the clinical signs and symptoms associated with cellular swelling. Severe hyponat...
Article
Full-text available
Background: Current literature evaluating body mass (BM) changes across a variety of running race distances is limited. The primary objective of this study was to profile the range of BM changes across race distances. The secondary objective was to evaluate the prevalence of exercise-associated hyponatremia (EAH) in runners admitted to the on-site...
Article
Full-text available
Background: Current literature evaluating body mass (BM) changes across a variety of running race distances is limited. The primary objective of this study was to profile the range of BM changes across race distances. The secondary objective was to evaluate the prevalence of exercise-associated hyponatremia (EAH) in runners admitted to the on-site...
Article
A 37-year-old woman presented to the emergency department with severe headache, which quickly progressed to altered mental status and seizure activity in hospital. Her initial serum sodium concentration ([Na+]) was 126 mmol/L. In the 24 hours before admission, she exercised vigorously for 120 minutes (interval training plus yoga) and also consumed...
Article
Objective: To identify midseason risk factors for symptomatic exertional rhabdomyolysis (sER) in swimmers after a novel upper body workout. Design: Retrospective (1) survey and (2) analyses of observational laboratory data conducted over a 16-week training period, 2 months before sER. Setting: Midwest University. Participants: Thirty-four co...
Article
Purpose: It is not known if exercise-associated hyponatremia (EAH) is a cause or consequence of exertional rhabdomyolysis (ER).We hypothesized that osmotic stress (EAH) coupled with mechanical stress (running) potentiated muscle cell breakdown (ER). This concept would be supported if a nadir in serum sodium concentration ([Na(+)]) temporally prece...
Article
This study explored possible contributing factors to gastrointestinal distress, including endotoxemia, hyperthermia, dehydration and nutrition, during a 161-km ultramarathon. Thirty runners participated in the study and 20 finished the race. At three checkpoints and the finish, runners were interviewed to assess the incidence and severity of 12 gas...
Article
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Kenney et al. reported that 54.5% of 4134 children were inadequately hydrated, as defined by a single urine osmolality (Uosm) of 800 or greater milliosmoles per kilogram of water.(1) This "dehydration" threshold was inferred from experimental data first described in 1965,(2) with subsequent studies on US, Jewish, German, and Swedish children demons...
Article
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Irisin is a hormone which mimics the favorable metabolic effects associated with regular exercise, by converting subcutaneous white fat into brownish fat, in rodents. Thirty-three human subjects (16 runners, 17 nonrunners) were measured for: resting energy expenditure (REE), body composition, VO2 Peak test, [irisin]p, and plasma metabolic profile....
Article
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Abstract Athletes are often advised to drink in order to "fully replace bodyweight losses" in order to prevent exertional heatstroke (EHS) during exercise in the heat. There is little evidence that "dehydration" in the range experienced by athletes adversely affects thermoregulation or is the exclusive cause of EHS. In contrast it is established th...
Article
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The purpose of the study was to assess changes in multidimensional physical self-concept (PSC) over time of novice obese female runners participating in a 10-week running intervention. Multidimensional Physical Self-Concept was assessed at pre-and postintervention times and 3 months postintervention. A repeated measures MANOVA was significant, F (2...
Article
(1) To examine the incidence of exercise-associated hyponatremia (EAH) during and after an ultramarathon and (2) to evaluate hypothesized nonosmotic stimuli [interleukin-6 (IL-6), hypoglycemia, ambient temperature] with arginine vasopressin (AVP) concentrations in hyponatremic versus normonatremic runners.
Article
The low cost, ease of application and portability of bioelectrical impedance analysis (BIA) and spectroscopy (BIS) devices make them attractive tools for measuring acute changes in body composition before and after exercise, despite potential limitations from active compartmental fluid shifts. The primary study aim was to evaluate use of dual energ...
Article
Full-text available
A regulatory effect of arginine vasopressin (AVP) on sweat water conservation has been hypothesized but not definitively evaluated. AVP-mediated insertion of sweat and salivary gland aquaporin-5 (AQP5) water channels through activation of the vasopressin type 2 receptor (V2R) remains an attractive, yet unexplored, mechanism that could result in a m...
Article
: There is a growing trend for runners to use compression stockings (CS) to improve performance. The purpose of this study was to determine the effect of CS on physiological variables associated with running performance. Participants were ten NCAA Division III cross-country runners. The study utilized a randomized, crossover design with two conditi...
Article
To determine more conclusively whether intravenous (IV) administration of 3% saline is more efficacious than oral administration in reversing below normal blood sodium concentrations in runners with biochemical hyponatremia. Randomized controlled trial. 26 hyponatremic race finishers participating in the 161-km Western States Endurance Run were ran...
Article
Purpose: To determine if beliefs about physiology and rehydration affect ultramarathon runners' hydration behaviors or if these beliefs increase the risk for exercise-associated hyponatremia (EAH). Methods: Participants of the 2011 161-km Western States Endurance Run completed a prerace questionnaire, prerace and postrace body-mass measurements, an...
Article
Salt replacement is often recommended to prevent exercise-associated hyponatremia (EAH) despite a lack of evidence to support such practice. EAH is known to be a complex process resulting from the interplay of hydration, arginine vasopressin (AVP), and sodium balance. While evidence suggests overhydration is the dominant pathophysiologic factor in...
Article
Full-text available
Symptomatic exercise-associated hyponatremia (EAH), which is relatively common among marathon runners, is an uncommon event among ultra-endurance athletes. A 44-year-old man presented to the emergency department with increased thirst after successfully completing a 100-mile mountain bike race in Leadville, Colorado. Initial laboratory tests reveale...
Article
Both hyponatremia and osteopenia separately have been well documented in endurance athletes. Although bone has been shown to act as a "sodium reservoir" to buffer severe plasma sodium derangements in animals, recent data have suggested a similar function in humans. We aimed to explore if acute changes in bone mineral content were associated with ch...
Article
Exercise-associated hyponatremia (EAH) typically occurs during or up to 24 hours after prolonged physical activity, and is defined by a serum or plasma sodium concentration below the normal reference range of 135 mEq/L. It is also reported to occur in individual physical activities or during organized endurance events conducted in austere environme...
Article
Context: Gastrointestinal (GI) distress is common during ultrarunning. Purpose: To determine if race diet is related to GI distress in a 161-km ultramarathon. Methods: Fifteen (10 male, 5 female) consenting runners in the Javelina Jundred (6.5 loops on a desert trail) participated. Body mass was measured immediately prerace and after each loop...
Article
This study sought to identify runner characteristics or symptoms that could distinguish those finishers developing exercise-associated hyponatremia (EAH) from those not developing EAH in a 161-km ultramarathon. Of 310 finishers, 207 (67%) underwent postrace blood studies. Twelve (6%) finishers had EAH (blood sodium range 131-134 mmol/L). Experience...
Chapter
Exercise-associated hyponatremia (EAH) is the development of a low serum sodium in association with endurance exercise of any type. The pathogenesis includes excessive water intake, inappropriate vasopressin release, impairment in urinary dilution, as well as other mechanisms. Prompt recognition of the signs and symptoms of EAH can be life saving....
Article
Purpose: To determine if beliefs about physiology and rehydration affect ultramarathon runners' hydration behaviors or if these beliefs increase the risk for exercise-associated hyponatremia (EAH). Methods: Participants of the 2011 161-km Western States Endurance Run completed a prerace questionnaire, prerace and postrace body-mass measurements,...
Article
Full-text available
Objectives: To evaluate the efficacy of Ringer's lactate, isotonic saline and hypertonic saline on the clinical and biochemical recovery of athletes with exercise-associated hyponatraemic encephalopathy caused by fluid overload. Methods: We retrospectively reviewed serial blood sodium concentrations (Na+) and qualitative signs of recovery and ti...
Article
Purpose: This work combines and reanalyzes 5 yr of exercise-associated hyponatremia (EAH) research at 161-km ultramarathons in northern California with primary purposes to define the relationship between postrace blood sodium concentration ([Na]) and change in body weight; to examine the interactions among EAH incidence, ambient temperature, and h...
Article
Abstract This study examined whether urine dipstick testing might be useful to predict the development of acute kidney injury after an ultramarathon. Participants in the 2011 161-km Western States Endurance Run underwent post-race blood and urine dipstick analyses. Of the 310 race finishers, post-race urine dipstick testing was completed on 152 (49...