Publications by authors named "Elaine C Lee"

61 Publications

Hormonal stress responses of growth hormone and insulin-like growth factor-I in highly resistance trained women and men.

Growth Horm IGF Res 2021 Aug 6;59:101407. Epub 2021 Jun 6.

Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.

The purpose of this study was to examine the responses of growth hormone (GH) and insulin-like growth factor-I (IGFI) to intense heavy resistance exercise in highly trained men and women to determine what sex-dependent responses may exist. Subjects were highly resistance trained men (N = 8, Mean ± SD; age, yrs., 21 ± 1, height, cm, 175.3 ± 6.7, body mass, kg, 87.0 ± 18.5, % body fat, 15.2 ± 5.4, squat X body mass, 2.1 ± 0.4; and women (N = 7; Mean ± SD, age, yrs. 24 ± 5, height, cm 164.6 ± 6.7, body mass, kg 76.4 ± 8.8, % body fat, 26.9 ± 5.3, squat X body mass, 1.7 ± 0.6). An acute resistance exercise test protocol (ARET) consisted of 6 sets of 10 repetitions at 80% of the 1 RM with 2 min rest between sets was used as the stressor. Blood samples were obtained pre-exercise, after 3 sets, and then immediately after exercise (IP), 5, 15, 30, and 70 min post-exercise for determination of blood lactate (HLa), and plasma glucose, insulin, cortisol, and GH. Determination of plasma concentrations of IGFI, IGF binding proteins 1, 2, and 3 along with molecular weight isoform factions were determined at pre, IP and 70 min. GH significantly (P ≤ 0.05) increased at all time points with resting concentrations significantly higher in women. Significant increases were observed for HLa, glucose, insulin, and cortisol with exercise and into recovery with no sex-dependent observations. Women showed IGF-I values that were higher than men at all times points with both seeing exercise increases. IGFBP-1 and 2 showed increase with exercise with no sex-dependent differences. IGFBP-3 concentrations were higher in women at all-time points with no exercise induced changes. Both women and men saw an exercise induced increase with significantly higher values in GH in only the mid-range (30-60 kD) isoform.  Only women saw an exercise induced increase with significantly higher values for IGF fractions only in the mid-range (30-60 kD) isoform, which were significantly greater than the men at the IP and 70 min post-exercise time points. In conclusion, the salient findings of this investigation were that in highly resistance trained men and women, sexual dimorphisms exist but appear different from our prior work in untrained men and women and appear to support a sexual dimorphism related to compensatory aspects in women for anabolic mediating mechanisms in cellular interactions.
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http://dx.doi.org/10.1016/j.ghir.2021.101407DOI Listing
August 2021

Heat Acclimation Following Heat Acclimatization Elicits Additional Physiological Improvements in Male Endurance Athletes.

Int J Environ Res Public Health 2021 04 20;18(8). Epub 2021 Apr 20.

Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, CT 06269, USA.

The purpose of this study was to assess the effectiveness of heat acclimatization (HAz) followed by heat acclimation (HA) on physiological adaptations. 25 male endurance athletes (age 36 ± 12 y, height 178.8 ± 6.39 cm, body mass 73.03 ± 8.97 kg, and VO 57.5 ± 7.0 mL·kg·min) completed HAz and HA. HAz was 3 months of self-directed summer training. In the laboratory, a 5-day HA prescribed exercise to target a hyperthermic zone (HZHA) of T between 38.50 and 39.75 °C for 60 min. Exercise trials were 60 min of running (59% ± 2% VO) in an environmental chamber (wet bulb globe temperature 29.53 ± 0.63 °C) and administered at: baseline, post-HAz, and post-HAz+HA. Measured variables included internal body temperature (T), heart rate (HR), and sweat rate (SR). Repeated measure ANOVAs and post hoc comparisons were used to assess statistically significant ( < 0.05) differences. T was lower post-HAz+HA (38.03 ± 0.39 °C) than post-HAz (38.25 ± 0.42 °C, = 0.009) and baseline (38.29 ± 0.37 °C, = 0.005). There were no differences between baseline and post-HAz ( = 0.479) in T. HR was lower post-HAz (143 ± 12 bpm, = 0.002) and post-HAz+HA (134 ± 11 bpm, < 0.001) than baseline (138 ± 14 bpm). HR was lower post-HAz+HA than post-HAz ( = 0.013). SR was higher post-HAz+HA (1.93 ± 0.47 L·h) than post-HAz (1.76 ± 0.43 L·h, = 0.027). Combination HAz and HA increased physiological outcomes above HAz. This method can be used to improve performance and safety in addition to HAz alone.
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http://dx.doi.org/10.3390/ijerph18084366DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8074339PMC
April 2021

Short term heat acclimation reduces heat strain during a first, but not second, consecutive exercise-heat exposure.

J Sci Med Sport 2021 Apr 6. Epub 2021 Apr 6.

Korey Stringer Institute, Department of Kinesiology, University of Connecticut, USA.

Objectives: Determine whether five days of heat acclimation reduces cardiovascular and thermoregulatory strain during consecutive exercise-heat exposures on the sixth day in the heat.

Design: Pair-matched randomized control trial.

Methods: Twenty-four males completed two, 120min exercise sessions (Session 1, Session 2) in a single day before (Day 1) and after (Day 6) four additional days of exercise in either hot (HOT: 40°C, 40% relative humidity, n=16) or temperate (CON: 23°C, 25% relative humidity, n=8) environments. A mixed-methods heat acclimation approach was implemented. Day 2 consisted of 120min of moderate-high intensity treadmill exercise. Days 3-5 consisted of 90min of moderate-high intensity exercise, with HOT completing this in a hyperthermia clamped manner at rectal temperature ≥38.5°C, and CON<38.5°C.

Results: Session 1 end of exercise rectal temperature and heart rate were lower on Day 6 compared to Day 1 for HOT (p=0.012, p=0.003) but not CON (p=0.152, p=0.437). Session 2 end of exercise rectal temperature was not different between days for HOT (p=0.104) or CON (p=0.275). Session 2 end of exercise heart rate was lower on Day 6 compared to Day 1 for HOT (p=0.004) and CON (p=0.039). Session 1 sweat sensitivity was greater on Day 6 compared to Day 1 for HOT (p=0.039) but not CON (p=0.257). Sweat rate was unchanged for HOT and CON between days during Session 1 (p=0.184, p=0.962) and Session 2 (p=0.051, p=0.793), respectively.

Conclusions: Five days of heat acclimation reduced cardiovascular strain but not thermoregulatory strain during the second, consecutive exercise-heat exposure. CLINICALTRIALS.

Gov Identifier: NCT04053465.
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http://dx.doi.org/10.1016/j.jsams.2021.03.020DOI Listing
April 2021

Effects of cold water immersion on circulating inflammatory markers at the Kona Ironman World Championship.

Appl Physiol Nutr Metab 2021 Jul 28;46(7):719-726. Epub 2021 Jan 28.

Department of Kinesiology, Human Performance Laboratory, University of Connecticut, Storrs, CT, USA.

Cold water immersion (CWI) purportedly reduces inflammation and improves muscle recovery after exercise, yet its effectiveness in specific contexts (ultraendurance) remains unclear. Thus, our aim was to study hematological profiles, systemic inflammation, and muscle damage responses to a specific post-race CWI (vs. control) during recovery after the Ironman World Championship, a culmination of ∼100 000 athletes competing in global qualifying Ironman events each year. Twenty-nine competitors were randomized into either a CWI or control (CON) group. Physiological parameters and blood samples were taken at pre-race, after intervention (POST), and 24 (+1DAY) and 48 hours (+2DAY) following the race. Muscle damage markers (plasma myoglobin, serum creatine kinase) were elevated at POST, +1DAY, and +2DAY, while inflammatory cytokines interleukin (IL)-6, IL-8, and IL-10 and total leukocyte counts were increased only at POST. CWI had no effect on these markers. Numbers of the most abundant circulating cell type, neutrophils, were elevated at POST more so in CWI ( < 0.05, vs. CON). Despite that neutrophil counts may be a sensitive marker to detect subtle effects, CWI does not affect recovery markers 24- and 48-hours post-race (vs. CON). Overall, we determined that our short CWI protocol was not sufficient to improve recovery. Ironman World Championship event increased circulating muscle damage markers, inflammatory markers, and hematological parameters, including circulating immune cell sub-populations that recover 24-48 hours after the race. 12-min CWI post-ultraendurance event affects the absolute numbers of neutrophils acutely, post-race (vs. CON), but does not impact recovery 24- and 48-hours post-race.
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http://dx.doi.org/10.1139/apnm-2020-0602DOI Listing
July 2021

Movement Technique and Standing Balance After Graded Exercise-Induced Dehydration.

J Athl Train 2021 Jan 15. Epub 2021 Jan 15.

Korey Stringer Institute, University of Connecticut, Storrs.

Context: Hypohydration has been shown to alter neuromuscular function. However, the longevity of these impairments remains unclear.

Objective: To examine the effects of graded exercise-induced dehydration on neuromuscular control 24 hours after exercise-induced hypohydration.

Design: Crossover study.

Setting: Laboratory.

Patients Or Other Participants: A total of 23 men (age = 21 ± 2 years, height = 179.8 ± 6.4 cm, mass = 75.24 ± 7.93 kg, maximal oxygen uptake [VO2max] = 51.7 ± 5.5 mL·kg-1·min-1, body fat = 14.2% ± 4.6%).

Intervention(s): Participants completed 3 randomized exercise trials: euhydrated arrival plus fluid replacement (EUR), euhydrated arrival plus no fluid (EUD), and hypohydrated arrival plus no fluid (HYD) in hot conditions (ambient temperature = 35.2°C ± 0.6°C, relative humidity = 31.3% ± 2.5%). Each trial consisted of 180 minutes of exercise (six 30-minute cycles: 8 minutes at 40% VO2max; 8 minutes, 60% VO2max; 8 minutes, 40% VO2max; 6 minutes, passive rest) followed by 60 minutes of passive recovery.

Main Outcome Measure(s): We used the Landing Error Scoring System and Balance Error Scoring System (BESS) to measure movement technique and postural control at pre-exercise, postexercise and passive rest (POSTEX), and 24 hours postexercise (POST24). Differences were assessed using separate mixed-design (trial × time) repeated-measures analyses of variance.

Results: The magnitude of hypohydration at POSTEX was different among EUR, EUD, and HYD trials (0.2% ± 1%, 3.5% ± 1%, and 5% ± 0.9%, respectively; P < .05). We observed no differences in Landing Error Scoring System scores at pre-exercise (2.9 ± 1.6, 3.0 ± 2.1, 3.0 ± 2.0), POSTEX (3.3 ± 1.5, 3.0 ± 2.0, 3.1 ± 1.9), or POST24 (3.3 ± 1.9, 3.2 ± 1.4, 3.3 ± 1.6) among the EUD, EUR, and HYD trials, respectively (P = .90). Hydration status did not affect BESS scores (P = .11), but BESS scores at POSTEX (10.4 ± 1.1) were greater than at POST24 (7.7 ± 0.9; P = .03).

Conclusions: Whereas exercise-induced dehydration up to 5% body mass did not impair movement technique or postural control 24 hours after a prolonged bout of exercise in a hot environment, postural control was impaired at 60 minutes after prolonged exercise in the heat. Consideration of the length of recovery time between bouts of exercise in hot environments is warranted.
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http://dx.doi.org/10.4085/1062-6050-0436.19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901584PMC
January 2021

Progression of human subjective perceptions during euhydration, mild dehydration, and drinking.

Physiol Behav 2021 02 23;229:113211. Epub 2020 Oct 23.

Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, United States. Electronic address:

Thirst motivates consumption of water necessary for optimal health and cognitive-physiological functions. Other than thirst, little is known about coexisting perceptions and moods that provide information to the brain and participate in body water homeostasis. The purpose of this investigation was to observe perceptions, somatic sensations, and moods during controlled changes of hydration status. During routine daily activities interspersed with laboratory visits, 18 healthy young men (age, 23±3 y; body mass, 80.13±10.61 kg) self-reported hourly ratings (visual analog scales, VAS) of 17 subjective perceptions, across two 24-h periods (ad libitum food and water intake while euhydrated; water restriction with dry food intake [WR]) and during a 30-min rehydration session (R, 1.46±0.47 L water intake). At the end of WR, body mass loss reached 1.67 kg (2.12%). Distinct perceptions were identified during euhydration, WR and immediately after R. Starting approximately 4 h after WR began (body mass loss of ∼0.5%), perceptual changes included progressively intensifying ratings of thirst, mouth dryness, desire for water, and pleasantness of drinking. In comparison, immediately after R, participants reported a reversal of the perceptions observed during WR (above) plus cooler thermal sensation, increased satisfaction, and stomach fullness. These VAS ratings suggested that aversive moods contributed to drinking behavior and supported previously published animal studies. In conclusion, this investigation delineates previously unreported perceptions and their evolution (e.g., appearance, extinction, time course) that motivated drinking during WR and discouraged overdrinking after R.
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http://dx.doi.org/10.1016/j.physbeh.2020.113211DOI Listing
February 2021

Inputs to Thirst and Drinking during Water Restriction and Rehydration.

Nutrients 2020 Aug 24;12(9). Epub 2020 Aug 24.

Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA.

Current models of afferent inputs to the brain, which influence body water volume and concentration via thirst and drinking behavior, have not adequately described the interactions of subconscious homeostatic regulatory responses with conscious perceptions. The purpose of this investigation was to observe the interactions of hydration change indices (i.e., plasma osmolality, body mass loss) with perceptual ratings (i.e., thirst, mouth dryness, stomach emptiness) in 18 free-living, healthy adult men (age, 23 ± 3 y; body mass, 80.09 ± 9.69 kg) who participated in a 24-h water restriction period (Days 1-2), a monitored 30-min oral rehydration session (REHY, Day 2), and a 24-h ad libitum rehydration period (Days 2-3) while conducting usual daily activities. Laboratory and field measurements spanned three mornings and included subjective perceptions (visual analog scale ratings, VAS), water intake, dietary intake, and hydration biomarkers associated with dehydration and rehydration. Results indicated that total water intake was 0.31 L/24 h on Day 1 versus 2.60 L/24 h on Day 2 (of which 1.46 L/30 min was consumed during REHY). The increase of plasma osmolality on Day 1 (297 ± 4 to 299 ± 5 mOsm/kg) concurrent with a body mass loss of 1.67 kg (2.12%) paralleled increasing VAS ratings of thirst, desire for water, and mouth dryness but not stomach emptiness. Interestingly, plasma osmolality dissociated from all perceptual ratings on Day 3, suggesting that morning thirst was predominantly non-osmotic (i.e., perceptual). These findings clarified the complex, dynamic interactions of subconscious regulatory responses with conscious perceptions during dehydration, rehydration, and reestablished euhydration.
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http://dx.doi.org/10.3390/nu12092554DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7551505PMC
August 2020

Resistance Training and Milk-Substitution Enhance Body Composition and Bone Health in Adolescent Girls.

J Am Coll Nutr 2021 Mar-Apr;40(3):193-210. Epub 2020 Jun 10.

Department of Human Sciences, The Ohio State University, Columbus, Ohio, USA.

Increased soft-drink consumption has contributed to poor calcium intake with 90% of adolescent girls consuming less than the RDA for calcium. The purpose of this investigation was to determine the independent and additive effects of two interventions (milk and resistance training) on nutrient adequacy, body composition, and bone health in adolescent girls. The experimental design consisted of four experimental groups of adolescent girls 14-17 years of age: (1) Milk + resistance training [MRT];  = 15; (2) Resistance training only [RT];  = 15; (3) Milk only [M]  = 20; (4) Control [C]  = 16. A few significant differences were observed at baseline between the groups for subject characteristics. Testing was performed pre and post-12 week training period for all groups. Milk was provided (3, 8 oz servings) for both the MRT and the M groups. The MRT group and the RT groups performed a supervised periodized resistance training program consisting of supervised one-hour exercise sessions 3 d/wk (M, W, F) for 12 wk. Baseline dietary data was collected utilizing the NUT-P-FFQ and/or a 120 item FFQ developed by the Fred Hutchinson Cancer Research Center (Seattle, Washington). Body composition was measured in the morning after an overnight fast using dual-energy X-ray absorptiometry (DXA) with a total body scanner (Prodigy, Lunar Corporation, Madison, WI). A whole body scan for bone density and lumbar spine scans were performed on all subjects. Maximal strength of the upper and lower body was assessed via a one-repetition maximum (1-RM) squat and bench press exercise protocols. Significance was set at  ≤ 0.05. Significant differences in nutrient intakes between groups generally reflected the nutrient composition of milk with greater intakes of protein and improved nutrient adequacy for several B vitamins, vitamin A, vitamin D, calcium, magnesium, phosphorus, potassium, and zinc. Mean calcium intake was 758 and 1581 mg/d, in the non-milk and milk groups, respectively, with 100% of girls in the milk groups consuming > RDA of 1300 mg/d. There were no effects of milk on body composition or muscle performance, but resistance training had a main effect and significantly increased body mass, lean body mass, muscle strength, and muscle endurance. There was a main effect of milk and resistance training on several measures of bone mineral density (BMD). Changes in whole body BMD in the M, RT, MRT, and CON were 0.45, 0.52, 1.32, and -0.19%, respectively ( < 0.01). Over the course of 12 weeks the effects of 1300 mg/d of calcium in the form of fluid milk combined with a heavy resistance training program resulted in the additive effects of greater nutrient adequacy and BMD in adolescent girls. While further studies are needed, combining increased milk consumption with resistance training appears to optimize bone health in adolescent girls.
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http://dx.doi.org/10.1080/07315724.2020.1770636DOI Listing
June 2020

Impact of Nutrient Intake on Hydration Biomarkers Following Exercise and Rehydration Using a Clustering-Based Approach.

Nutrients 2020 Apr 30;12(5). Epub 2020 Apr 30.

University of Connecticut, Storrs, CT 06269, USA.

We investigated the impact of nutrient intake on hydration biomarkers in cyclists before and after a 161 km ride, including one hour after a 650 mL water bolus consumed post-ride. To control for multicollinearity, we chose a clustering-based, machine learning statistical approach. Five hydration biomarkers (urine color, urine specific gravity, plasma osmolality, plasma copeptin, and body mass change) were configured as raw- and percent change. Linear regressions were used to test for associations between hydration markers and eight predictor terms derived from 19 nutrients merged into a reduced-dimensionality dataset through serial k-means clustering. Most predictor groups showed significant association with at least one hydration biomarker: 1) Glycemic Load + Carbohydrates + Sodium, 2) Protein + Fat + Zinc, 3) Magnesium + Calcium, 4) Pinitol, 5) Caffeine, 6) Fiber + Betaine, and 7) Water; potassium + three polyols, and mannitol + sorbitol showed no significant associations with any hydration biomarker. All five hydration biomarkers were associated with at least one nutrient predictor in at least one configuration. We conclude that in a real-life scenario, some nutrients may serve as mediators of body water, and urine-specific hydration biomarkers may be more responsive to nutrient intake than measures derived from plasma or body mass.
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http://dx.doi.org/10.3390/nu12051276DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7282025PMC
April 2020

Acute Kidney Injury Biomarker Responses to Short-Term Heat Acclimation.

Int J Environ Res Public Health 2020 02 19;17(4). Epub 2020 Feb 19.

Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, CT 06269, USA.

The combination of hyperthermia, dehydration, and strenuous exercise can result in severe reductions in kidney function, potentially leading to acute kidney injury (AKI). We sought to determine whether six days of heat acclimation (HA) mitigates the rise in clinical biomarkers of AKI during strenuous exercise in the heat. Twenty men completed two consecutive 2 h bouts of high-intensity exercise in either hot ( = 12, 40 °C, 40% relative humidity) or mild ( = 8, 24 °C, 21% relative humidity) environments before (PreHA) and after (PostHA) 4 days of 90-120 min of exercise per day in a hot or mild environment. Increased clinical biomarkers of AKI (CLINICAL) was defined as a serum creatinine increase ≥0.3 mg·dL or estimated glomerular filtration rate (eGFR) reduction >25%. Creatinine similarly increased in the hot environment PreHA (0.35 ± 0.23 mg·dL) and PostHA (0.39 ± 0.20 mg·dL), with greater increases than the mild environment at both time points (0.11 ± 0.07 mg·dL, 0.08 ± 0.06 mg·dL, ≤ 0.001), respectively. CLINICAL occurred in the hot environment PreHA ( = 9, 75%), with fewer participants with CLINICAL PostHA ( = 7, 58%, = 0.007), and no participants in the mild environment with CLINICAL at either time point. Percent change in plasma volume was predictive of changes in serum creatinine PostHA and percent changes in eGFR both PreHA and PostHA. HA did not mitigate reductions in eGFR nor increases in serum creatinine during high-intensity exercise in the heat, although the number of participants with CLINICAL was reduced PostHA.
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http://dx.doi.org/10.3390/ijerph17041325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7068478PMC
February 2020

Exploring determinants of, and interventions for, delayed presentation of women with breast symptoms: A systematic review.

Eur J Oncol Nurs 2020 Feb 16;44:101677. Epub 2019 Oct 16.

Mother and Infant Research Unit, School of Nursing and Health Sciences, University of Dundee, UK.

Purpose: Behaviour change interventions are more likely to be effective if they are sensitive to contextual determinants of behaviour. Delayed presentation of women with breast symptoms is a concern for both high-income and low- and medium-income countries. Our aim was to integrate evidence on determinants of time to presentation of women with breast symptoms with complementary evidence on interventions for promoting early presentation.

Methods: A systematic review was conducted according to PRISMA guidelines. Ten electronic databases were searched for relevant articles published between 1985 to May 2019. Pre-defined selection criteria were applied to retrieved records. Evidence on interventions, and on determinants were integrated through sequential explanatory synthesis design.

Results: Of the 4185 documents retrieved, 11 intervention studies and 10 determinants studies were included in the synthesis. Overall, evidence on interventions is of low quality, while that on determinants is of medium quality. Intervention studies were mostly individual-level with almost exclusive focus on breast cancer awareness among postmenopausal women in high-income countries. Synthesis of evidence on determinants resulted in 10 domains. Juxtaposing the evidence on determinants of time to presentation of women with breast symptoms with that of the interventions to promote early presentation shows a mismatch between them.

Conclusions: Whilst there is strong evidence that women with breast symptoms face multi-level influences to presentation, current interventions have focused almost exclusively on breast cancer awareness in high-income countries. High quality multi-level interventions are required to promote early presentation of symptomatic women in different socio-cultural and economic settings.
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http://dx.doi.org/10.1016/j.ejon.2019.101677DOI Listing
February 2020

Practical Hydration Solutions for Sports.

Nutrients 2019 Jul 9;11(7). Epub 2019 Jul 9.

Department of Kinesiology, University of Alabama, Tuscaloosa, AL 35487, USA.

Personalized hydration strategies play a key role in optimizing the performance and safety of athletes during sporting activities. Clinicians should be aware of the many physiological, behavioral, logistical and psychological issues that determine both the athlete's fluid needs during sport and his/her opportunity to address them; these are often specific to the environment, the event and the individual athlete. In this paper we address the major considerations for assessing hydration status in athletes and practical solutions to overcome obstacles of a given sport. Based on these solutions, practitioners can better advise athletes to develop practices that optimize hydration for their sports.
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http://dx.doi.org/10.3390/nu11071550DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6682880PMC
July 2019

Exacerbated heat strain during consecutive days of repeated exercise sessions in heat.

J Sci Med Sport 2019 Oct 18;22(10):1084-1089. Epub 2019 Jun 18.

Korey Stringer Institute, Department of Kinesiology, University of Connecticut, United States.

Objectives: An exercise session in a hot environment may increase thermal strain during subsequent exercise sessions on the same and consecutive days. Therefore, this study was conducted to determine lasting physiological strain from moderate-high intensity, intermittent exercise in heat on subsequent exercise.

Design: Repeated measures laboratory study.

Methods: Seventeen healthy, recreationally active men (age: 22±3 y, maximal oxygen consumption: 54.6±5.3mLkgmin) underwent two intermittent moderate-high intensity aerobic exercise sessions separated by 2h of rest one day, followed by one session 24h later in a 40°C, 40% relative humidity environment. Heart rate, rectal temperature, heat stress perception, and environmental symptoms were assessed.

Results: 100%, 35%, and 71% of participants completed the full exercise protocol during the first exercise session, second exercise session, and the following day, respectively. Exercising heart rate and rectal temperature were greater during the second exercise session (189±11bpm, 38.80±0.47°C) than the first identical exercise session (180±17bpm, p=0.004; 38.41±0.52°C, p=0.001), respectively. Immediate post-exercise heart rate, rectal temperature, thirst, thermal sensation, fatigue, and perceived exertion were similar among exercise sessions despite a shorter exercise duration during the second exercise session (93±27min, p=0.001) and the following day (113±12min, p=0.032) than the first exercise session (120±0min).

Conclusions: Moderate-high-intensity intermittent exercise in the heat resulted in greater heat strain during a second exercise session the same day, and exercise the subsequent day.
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http://dx.doi.org/10.1016/j.jsams.2019.06.003DOI Listing
October 2019

Cold-water immersion blunts and delays increases in circulating testosterone and cytokines post-resistance exercise.

Eur J Appl Physiol 2019 Aug 20;119(8):1901-1907. Epub 2019 Jun 20.

Department of Human Sciences, The Ohio State University, 305 Annie & John Glenn Ave, Columbus, OH, 43210, USA.

Introduction: Cold-water immersion (CWI) is often used to promote recovery by reducing exercise-induced muscle damage, soreness, and inflammation. However, recent reports have cautioned that CWI may attenuate the adaptive response to resistance training.

Purpose: To determine the effect of post resistance-exercise CWI on circulating free testosterone (T) and cytokine (IL-6 and TNF-α) response.

Methods: Using a randomized and counterbalanced repeated-measures design, 11 resistance-trained men completed two workouts (6 sets of 10 repetitions of back squats at 80% of maximum load) a week apart after which they took part in either 15 min of CWI (15 °C) or passive recovery. T, IL-6, and TNFα were measured in blood samples taken before (PRE) and 5 (5POST), 15 (15POST), 30 (30POST), and 60 (60POST) min post-exercise and compared between treatments and over time.

Results: For T, a significant interaction effect of condition over time (p = 0.030) as well as greater relative concentrations of T in CON (Δ9.2%) than CWI (Δ-0.5%, p = 0.049) at 30POST were observed. In addition, at 60POST, T dropped below PRE values in CWI (Δ-10.4%, p = 0.028) but not in CON (Δ-1.6%, p = 0.850). A suppressed cytokine response was observed after CWI in IL-6 at 30POST (CWI: Δ4.9%, CON: Δ47.5%, p = 0.041) and TNFα at 15POST (CWI: Δ5.3%, CON: Δ17.0%, p = 0.022).

Conclusions: CWI blunted the T and cytokine response after a bout of resistance exercise. These results indicate that CWI results in an altered anabolic response and may help to explain the previous observation of attenuated hypertrophy when CWI is used after resistance exercise.
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http://dx.doi.org/10.1007/s00421-019-04178-7DOI Listing
August 2019

Intermittent exercise-heat exposures and intense physical activity sustain heat acclimation adaptations.

J Sci Med Sport 2019 Jan 19;22(1):117-122. Epub 2018 Jun 19.

Department of Human Sciences, The Ohio State University, United States.

Objectives: To determine if intermittent exercise-heat exposures (IHE) every fifth day sustain heat acclimation (HA) adaptations 25 days after initial HA.

Design: Randomized control trial.

Methods: Sixteen non-heat acclimatized men heat acclimated during 10-11 days of exercise in the heat (40°C, 40% RH). A heat stress test (120min, 45% V˙O) before (Pre HA) and after HA (Post HA) in similar hot conditions assessed HA status. Pair-matched participants were randomized into a control group (CON; n=7) that exercised in a temperate environment (24°C, 21%RH) or IHE group (n=9) that exercised in a hot environment (40°C, 40%RH) every fifth day for 25 days following HA (+25d) with out-of-laboratory exercise intensity and duration recorded. Both groups completed +25d in the hot condition.

Results: Both groups heat acclimated similarly (p>0.05) evidenced by lower heart rate (HR), thermoregulatory, physiological, and perceptual responses (perceived exertion, fatigue, thermal sensation) Pre HA vs. Post HA (p≤0.05). At +25d, post-exercise HR (p=0.01) and physiological strain index (p<0.05) but neither T (p=0.18) nor sweat rate (p=0.44) were lower in IHE vs. CON. In IHE only, post-exercise T and perceptual responses at Post HA and +25d were lower than Pre HA (p≤0.01). +25d post-exercise epinephrine was higher in CON vs. IHE (p=0.04). Exercise intensity during out-of-lab exercise and +25d post-exercise HR were correlated (r=-0.89, p=0.02) in IHE.

Conclusions: Exercise-heat exposures every fifth day for 25 days and regular intense physical activity after HA sustained HR and T adaptations and reduced perceptual and physiological strain during exercise-heat stress ∼1 month later.
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http://dx.doi.org/10.1016/j.jsams.2018.06.009DOI Listing
January 2019

Monitoring Blood Biomarkers and Training Load Throughout a Collegiate Soccer Season.

J Strength Cond Res 2019 Nov;33(11):3065-3077

Korey Stringer Institute, Department of Kinesiology, University of Connecticut, Storrs, Connecticut.

Huggins, RA, Fortunati, AR, Curtis, RM, Looney, DP, West, CA, Lee, EC, Fragala, MS, Hall, ML, and Casa, DJ. Monitoring blood biomarkers and training load throughout a collegiate soccer season. J Strength Cond Res 33(11): 3065-3077, 2019-This observational study aimed to characterize the responses of a comprehensive panel of biomarkers, observed ranges, training load (TL) metrics, and performance throughout the collegiate soccer season (August-November). Biomarkers (n = 92) were collected before the start of pre-season (PS), in-season weeks (W)1, W4, W8, and W12 in NCAA Division I male soccer players (n = 20, mean ± SD; age = 21 ± 1 years, height = 180 ± 6 cm, body mass = 78.19 ± 6.3 kg, body fat = 12.0 ± 2.6%, VO2max 51.5 ± 5.1 ml·kg·min). Fitness tests were measured at PS, and W12 and TL was monitored daily. Changes in biomarkers and performance were calculated via separate repeated-measures analysis of variance. Despite similar fitness (p > 0.05), endocrine, muscle, inflammatory, and immune markers changed over time (p < 0.05). Total and free testosterone was lower in W1 vs. PS, whereas free cortisol remained unchanged at PS, W1, and W4 (>0.94 mg·dL). Oxygen transport and iron metabolism markers remained unchanged except for HCT (W1 vs. PS) and total iron binding capacity (W8-W12 vs. W1). Hepatic markers albumin, globulin, albumin:globulin, and total protein levels were elevated (p < 0.05) at W12 vs. W1, whereas aspartate aminotransferase and alanine aminotransferase levels were elevated at W1-W12 and W8-W12 vs. PS, respectively. Vitamin E, zinc, selenium, and calcium levels were elevated (p < 0.05) at W12 vs. W1, whereas Vitamin D was decreased (p < 0.05). Fatty acids and cardiovascular markers (omega-3 index, cholesterol:high-density lipoprotein [HDL], docosahexenoic acid, low-density lipoprotein [LDL], direct LDL, non-HDL, ApoB) were reduced at W1 vs. PS (p ≤ 0.05). Immune, lipid, and muscle damage biomarkers were frequently outside clinical reference ranges. Routine biomarker monitoring revealed subclinical and clinical changes, suggesting soccer-specific reference ranges. Biomarker monitoring may augment positive adaptation and reduce injuries from stressors incurred during soccer.
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http://dx.doi.org/10.1519/JSC.0000000000002622DOI Listing
November 2019

Interactions of Gut Microbiota, Endotoxemia, Immune Function, and Diet in Exertional Heatstroke.

J Sports Med (Hindawi Publ Corp) 2018 16;2018:5724575. Epub 2018 Apr 16.

Oncology Nutrition, Hartford Hospital Cancer Institute, Hartford, CT 06102, USA.

Exertional heatstroke (EHS) is a medical emergency that cannot be predicted, requires immediate whole-body cooling to reduce elevated internal body temperature, and is influenced by numerous host and environmental factors. Widely accepted predisposing factors (PDF) include prolonged or intense exercise, lack of heat acclimatization, sleep deprivation, dehydration, diet, alcohol abuse, drug use, chronic inflammation, febrile illness, older age, and nonsteroidal anti-inflammatory drug use. The present review links these factors to the human intestinal microbiota (IM) and diet, which previously have not been appreciated as PDF. This review also describes plausible mechanisms by which these PDF lead to EHS: endotoxemia resulting from elevated plasma lipopolysaccharide (i.e., a structural component of the outer membrane of Gram-negative bacteria) and tissue injury from oxygen free radicals. We propose that recognizing the lifestyle and host factors which are influenced by intestine-microbial interactions, and modifying habitual dietary patterns to alter the IM ecosystem, will encourage efficient immune function, optimize the intestinal epithelial barrier, and reduce EHS morbidity and mortality.
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http://dx.doi.org/10.1155/2018/5724575DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5926483PMC
April 2018

Renal stress and kidney injury biomarkers in response to endurance cycling in the heat with and without ibuprofen.

J Sci Med Sport 2018 Dec 16;21(12):1180-1184. Epub 2018 May 16.

Human Performance Laboratory, University of Connecticut, United States.

Exercise, especially in the heat, can contribute to acute kidney injury, which can expedite chronic kidney disease onset. The additional stress of ibuprofen use is hypothesized to increase renal stress.

Objectives: To observe the effects of endurance cycling in the heat on renal function. Secondarily, we investigated the effect of ibuprofen ingestion on kidney stress.

Design: Randomized, placebo controlled and observational methods were utilized.

Methods: Forty cyclists (52±9y, 21.7±6.5% body fat) volunteered and completed an endurance cycling event (5.7±1.2h) in the heat (33.2±5.0°C, 38.4±10.7% RH). Thirty-five participants were randomized to ingest a placebo (n=17) or 600mg ibuprofen (n=18) pre-event. A blood sample was drawn before and following the event. Serum creatinine was assessed by colorimetric assay. An ELISA was used to measure serum neutrophil gelatinase-associated lipocalin. Fractional excretion of sodium was calculated after urinary and serum electrolyte analyses.

Results: Placebo versus ibuprofen groups contributed no significant difference in any variable (p>0.05). Serum creatinine significantly increased from pre- (0.52±0.14mg/dL) to post-event (0.88±0.21mg/dL; p<0.001). Serum neutrophil gelatinase-associated lipocalin significantly increased (pre: 68.51±17.54ng/mL; post: 139.12±36.52ng/mL; p<0.001) and fractional excretion of sodium was significantly reduced from pre- (0.52±0.24%) to post-event (0.27±0.18%; p<0.001).

Conclusions: Changes in renal biomarkers suggest mild acute kidney injury and reduced kidney function during a single bout of endurance cycling in the heat, without influence from moderate ibuprofen ingestion.
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http://dx.doi.org/10.1016/j.jsams.2018.05.003DOI Listing
December 2018

Adrenal Stress and Physical Performance During Military Survival Training.

Aerosp Med Hum Perform 2018 Feb;89(2):99-107

Department of Kinesiology, The Ohio State University, Columbus OH, USA.

Introduction: The purpose of this research was to evaluate neuroendocrine and physical performance responses in sailors and Marines undergoing U.S. Navy Survival, Evasion, Resistance, and Escape (SERE) training.

Methods: Participants were 20 men (Age: 25.3 ± 3.6 yr; Height: 178.1 ± 6.1 cm; Weight: 83.7 ± 12.6 kg). Men were further split into high fit (N = 10) and low fit (N = 10) subgroups based on physical fitness test scores. Blood samples were obtained at baseline (T1), stress (T2), and recovery (T3) timepoints, and were analyzed for plasma epinephrine, plasma norepinephrine, plasma dopamine, serum cortisol, serum testosterone, and plasma neuropeptide Y. Vertical jump and handgrip tests were performed at T1 and T2.

Results: Stress hormone concentrations were significantly elevated at T2, with a concomitant reduction in testosterone concentrations. NPY concentrations did not increase at T2, but decreased significantly at T3. Subjects maintained performance on vertical jump and handgrip tests from T1 to T2. Significant between group differences were observed in norepinephrine (high fit: 3530.64 ± 2146.54 pmol · L-1, low fit: 4907.16 ± 3020.85 pmol · L-1) and NPY (high fit: 169.30 ± 85.89 pg · ml-1, low fit: 123.02 ± 88.86 pg · ml-1) concentrations at T3.

Conclusion: This study revealed that despite significant increases in stress hormone concentrations in all subjects during SERE, fitter subjects exhibited differential hormonal responses during recovery, with quicker return of norepinephrine and NPY to baseline concentrations. This suggests physical fitness level may have a protective effect in recovery from periods of high stress military training.Szivak TK, Lee EC, Saenz C, Flanagan SD, Focht BC, Volek JS, Maresh CM, Kraemer WJ. Adrenal stress and physical performance during military survival training. Aerosp Med Hum Perform. 2018; 89(2):99-107.
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http://dx.doi.org/10.3357/AMHP.4831.2018DOI Listing
February 2018

Ceragenin CSA13 Reduces Clostridium difficile Infection in Mice by Modulating the Intestinal Microbiome and Metabolites.

Gastroenterology 2018 05 31;154(6):1737-1750. Epub 2018 Jan 31.

Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, California. Electronic address:

Background & Aims: Clostridium difficile induces intestinal inflammation by releasing toxins A and B. The antimicrobial compound cationic steroid antimicrobial 13 (CSA13) has been developed for treating gastrointestinal infections. The CSA13-Eudragit formulation can be given orally and releases CSA13 in the terminal ileum and colon. We investigated whether this form of CSA13 reduces C difficile infection (CDI) in mice.

Methods: C57BL/6J mice were infected with C difficile on day 0, followed by subcutaneous administration of pure CSA13 or oral administration of CSA13-Eudragit (10 mg/kg/d for 10 days). Some mice were given intraperitoneal vancomycin (50 mg/kg daily) on days 0-4 and relapse was measured after antibiotic withdrawal. The mice were monitored until day 20; colon and fecal samples were collected on day 3 for analysis. Blood samples were collected for flow cytometry analyses. Fecal pellets were collected each day from mice injected with CSA13 and analyzed by high-performance liquid chromatography or 16S sequencing; feces were also homogenized in phosphate-buffered saline and fed to mice with CDI via gavage.

Results: CDI of mice caused 60% mortality, significant bodyweight loss, and colonic damage 3 days after infection; these events were prevented by subcutaneous injection of CSA13 or oral administration CSA13-Eudragit. There was reduced relapse of CDI after administration of CSA13 was stopped. Levels of CSA13 in feces from mice given CSA13-Eudragit were significantly higher than those of mice given subcutaneous CSA13. Subcutaneous and oral CSA13 each significantly increased the abundance of Peptostreptococcaceae bacteria and reduced the abundance of C difficile in fecal samples of mice. When feces from mice with CDI and given CSA13 were fed to mice with CDI that had not received CSA13, the recipient mice had significantly increased rates of survival. CSA13 reduced fecal levels of inflammatory metabolites (endocannabinoids) and increased fecal levels of 4 protective metabolites (ie, citrulline, 3-aminoisobutyric acid, retinol, and ursodeoxycholic acid) in mice with CDI. Oral administration of these CSA13-dependent protective metabolites reduced the severity of CDI.

Conclusions: In studies of mice, we found the CSA13-Eudragit formulation to be effective in eradicating CDI by modulating the intestinal microbiota and metabolites.
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http://dx.doi.org/10.1053/j.gastro.2018.01.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5927842PMC
May 2018

Adding Resistance Training to the Standard of Care for Inpatient Substance Abuse Treatment in Men With Human Immunodeficiency Virus Improves Skeletal Muscle Health Without Altering Cytokine Concentrations.

J Strength Cond Res 2018 Jan;32(1):76-82

1Applied Physiology Laboratory, Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, Texas;2Department of Biological Sciences, University of North Texas, Denton, Texas;3Department of Kinesiology, Texas Woman's University, Denton, Texas; and4Department of Kinesiology, University of Connecticut, Storrs, Connecticut.

Vingren, JL, Curtis, JH, Levitt, DE, Duplanty, AA, Lee, EC, McFarlin, BK, and Hill, DW. Adding resistance training to the standard of care for inpatient substance abuse treatment in men with human immunodeficiency virus improves skeletal muscle health without altering cytokine concentrations. J Strength Cond Res 32(1): 76-82, 2018-Substance abuse and human immunodeficiency virus (HIV) infection can independently lead to myopathy and related inflammatory alterations; importantly, these effects seem to be additive. Resistance training (RT) can improve muscle health in people living with HIV (PLWH), but the efficacy of this intervention has not been examined for PLWH recovering from substance abuse. The purpose of this study was to determine the effect of RT on muscle health markers (mass, strength, and power) and basal circulating biomarkers for men living with HIV undergoing substance abuse treatment. Men living with HIV undergoing 60-day inpatient substance abuse treatment completed either RT (3×/wk) or no exercise training (control) for 6 weeks. Muscle mass, strength, and power, and fasting circulating cytokines (interferon γ, tumor necrosis factor-α, interleukin (IL)-1β, IL-2, IL-4, IL-6, and IL-10), vascular cellular adhesion molecule-1, and cortisol were measured before (PRE) and after (POST) the 6-week period. Both groups received the standard of care for HIV and substance abuse treatment determined by the inpatient facility. Muscle mass, strength, and power increased (p ≤ 0.05) from PRE to POST for RT but were unchanged for control. No differences were found for circulating biomarkers. Adding RT to the standard of care for substance abuse treatment improved aspects of muscle health (mass, strength, and power) in men living with HIV. These improvements are associated with a lower risk of a number of health conditions. Therefore, practitioners should consider implementing RT interventions as part of substance abuse treatment programs in this population to help manage long-term health.
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http://dx.doi.org/10.1519/JSC.0000000000002289DOI Listing
January 2018

CSA13 inhibits colitis-associated intestinal fibrosis via a formyl peptide receptor like-1 mediated HMG-CoA reductase pathway.

Sci Rep 2017 11 27;7(1):16351. Epub 2017 Nov 27.

Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California Los Angeles, Los Angeles, CA, 90095, USA.

Many Crohn's disease (CD) patients develop intestinal strictures, which are difficult to prevent and treat. Cationic steroid antimicrobial 13 (CSA13) shares cationic nature and antimicrobial function with antimicrobial peptide cathelicidin. As many functions of cathelicidin are mediated through formyl peptide receptor-like 1 (FPRL1), we hypothesize that CSA13 mediates anti-fibrogenic effects via FPRL1. Human intestinal biopsies were used in clinical data analysis. Chronic trinitrobenzene sulfonic acid (TNBS) colitis-associated intestinal fibrosis mouse model with the administration of CSA13 was used. Colonic FPRL1 mRNA expression was positively correlated with the histology scores of inflammatory bowel disease patients. In CD patients, colonic FPRL1 mRNA was positively correlated with intestinal stricture. CSA13 administration ameliorated intestinal fibrosis without influencing intestinal microbiota. Inhibition of FPRL1, but not suppression of intestinal microbiota, reversed these protective effects of CSA13. Metabolomic analysis indicated increased fecal mevalonate levels in the TNBS-treated mice, which were reduced by the CSA13 administration. CSA13 inhibited colonic HMG-CoA reductase activity in an FPRL1-dependent manner. Mevalonate reversed the anti-fibrogenic effect of CSA13. The increased colonic FPRL1 expression is associated with severe mucosal disease activity and intestinal stricture. CSA13 inhibits intestinal fibrosis via FPRL1-dependent modulation of HMG-CoA reductase pathway.
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http://dx.doi.org/10.1038/s41598-017-16753-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5703874PMC
November 2017

Fidaxomicin and OP-1118 Inhibit Clostridium difficile Toxin A- and B-Mediated Inflammatory Responses via Inhibition of NF-κB Activity.

Antimicrob Agents Chemother 2018 01 21;62(1). Epub 2017 Dec 21.

Center for Inflammatory Bowel Diseases, Vatche and Tamar Manoukian Division of Digestive Diseases, David Geffen School of Medicine at the University of California, Los Angeles, Los Angeles, California, USA

causes diarrhea and colitis by releasing toxin A and toxin B. In the human colon, both toxins cause intestinal inflammation and stimulate tumor necrosis factor alpha (TNF-α) expression via the activation of NF-κB. It is well established that the macrolide antibiotic fidaxomicin is associated with reduced relapses of infection. We showed that fidaxomicin and its primary metabolite OP-1118 significantly inhibited toxin A-mediated intestinal inflammation in mice and toxin A-induced cell rounding We aim to determine whether fidaxomicin and OP-1118 possess anti-inflammatory effects against toxin A and toxin B in the human colon and examine the mechanism of this response. We used fresh human colonic explants, NCM460 human colonic epithelial cells, and RAW264.7 mouse macrophages to study the mechanism of the activity of fidaxomicin and OP-1118 against toxin A- and B-mediated cytokine expression and apoptosis. Fidaxomicin and OP-1118 dose-dependently inhibited toxin A- and B-induced TNF-α and interleukin-1β (IL-1β) mRNA expression and histological damage in human colonic explants. Fidaxomicin and OP-1118 inhibited toxin A-mediated NF-κB phosphorylation in human and mouse intestinal mucosae. Fidaxomicin and OP-1118 also inhibited toxin A-mediated NF-κB phosphorylation and TNF-α expression in macrophages, which was reversed by the NF-κB activator phorbol myristate acetate (PMA). Fidaxomicin and OP-1118 prevented toxin A- and B-mediated apoptosis in NCM460 cells, which was reversed by the addition of PMA. PMA reversed the cytoprotective effect of fidaxomicin and OP-1118 in toxin-exposed human colonic explants. Fidaxomicin and OP-1118 inhibit toxin A- and B-mediated inflammatory responses, NF-κB phosphorylation, and tissue damage in the human colon.
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http://dx.doi.org/10.1128/AAC.01513-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5740352PMC
January 2018

Blood Hemostatic Changes During an Ultraendurance Road Cycling Event in a Hot Environment.

Wilderness Environ Med 2017 Sep 22;28(3):197-206. Epub 2017 Jul 22.

Department of Military & Emergency Medicine, Uniformed Services University of Health Sciences, Bethesda, MD (Drs Kupchak and Deuster, Mr Kazman).

Objective: This study aims to examine blood hemostatic responses to completing a 164-km road cycling event in a hot environment.

Methods: Thirty-seven subjects (28 men and 9 women; 51.8±9.5 [mean±SD] y) completed the ride in 6.6±1.1 hours. Anthropometrics (height, body mass [taken also during morning of the ride], percent body fat [%]) were collected the day before the ride. Blood samples were collected on the morning of the ride (PRE) and immediately after (IP) the subject completed the ride. Concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers (platelet factor 4, β-thromboglobulin, von Willebrand factor antigen, thrombin-antithrombin complex, thrombomodulin, and D-Dimer) were measured. Associations between changes from PRE- to IP-ride were examined as a function of event completion time and subject characteristics (demographics and anthropometrics).

Results: All blood hemostatic markers increased significantly (P < .001) from PRE to IP. After controlling for PRE values, finishing time was negatively correlated with platelet factor 4 (r = 0.40; P = .017), while percent body fat (%BF) was negatively correlated with thrombin-antithrombin complex (r = -0.35; P = .038) and to thrombomodulin (r = -0.36; P = .036). In addition, male subjects had greater concentrations of thrombin-antithrombin complex (d = 0.63; P < .05) and natural logarithm thrombomodulin (d = 6.42; P < .05) than female subjects.

Conclusion: Completing the 164-km road cycling event in hot conditions resulted in increased concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers in both men and women. Although platelet activation and coagulation occurred, the fibrinolytic system markers also increased, which appears to balance blood hemostasis and may prevent clot formation during exercise in a hot environment.
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http://dx.doi.org/10.1016/j.wem.2017.05.002DOI Listing
September 2017

Biomarkers in Sports and Exercise: Tracking Health, Performance, and Recovery in Athletes.

J Strength Cond Res 2017 10;31(10):2920-2937

1Department of Kinesiology, University of Connecticut, Storrs, Connecticut; 2Quest Diagnostics, Madison, New Jersey; 3Department of Health, Human Performance, & Recreation, University of Arkansas, Fayetteville, Arkansas; 4Department of Biomedical Engineering and Mechanics, Virginia Tech University, Blacksburg, Virginia; and 5Department of Kinesiology, California State University, Fresno, California.

Biomarker discovery and validation is a critical aim of the medical and scientific community. Research into exercise and diet-related biomarkers aims to improve health, performance, and recovery in military personnel, athletes, and lay persons. Exercise physiology research has identified individual biomarkers for assessing health, performance, and recovery during exercise training. However, there are few recommendations for biomarker panels for tracking changes in individuals participating in physical activity and exercise training programs. Our approach was to review the current literature and recommend a collection of validated biomarkers in key categories of health, performance, and recovery that could be used for this purpose. We determined that a comprehensive performance set of biomarkers should include key markers of (a) nutrition and metabolic health, (b) hydration status, (c) muscle status, (d) endurance performance, (e) injury status and risk, and (f) inflammation. Our review will help coaches, clinical sport professionals, researchers, and athletes better understand how to comprehensively monitor physiologic changes, as they design training cycles that elicit maximal improvements in performance while minimizing overtraining and injury risk.
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http://dx.doi.org/10.1519/JSC.0000000000002122DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5640004PMC
October 2017

Round Table on Malignant Hyperthermia in Physically Active Populations: Meeting Proceedings.

J Athl Train 2017 Apr 7;52(4):377-383. Epub 2017 Mar 7.

Department of Health, Human Performance, and Recreation, University of Arkansas, Fayetteville.

Context:   Recent case reports on malignant hyperthermia (MH)-like syndrome in physically active populations indicate potential associations among MH, exertional heat stroke (EHS), and exertional rhabdomyolysis (ER). However, an expert consensus for clinicians working with these populations is lacking.

Objective:   To provide current expert consensus on the (1) definition of MH; (2) history, etiology, and pathophysiology of MH; (3) epidemiology of MH; (4) association of MH with EHS and ER; (5) identification of an MH-like syndrome; (6) recommendations for acute management of an MH-like syndrome; (7) special considerations for physically active populations; and (8) future directions for research.

Setting:   An interassociation task force was formed by experts in athletic training, exercise science, anesthesiology, and emergency medicine. The "Round Table on Malignant Hyperthermia in Physically Active Populations" was convened at the University of Connecticut, Storrs, September 17-18, 2015.

Conclusions:   Clinicians should consider an MH-like syndrome when a diagnosis of EHS or ER cannot be fully explained by clinical signs and symptoms presented by a patient or when recurrent episodes of EHS or ER (or both) are unexplained. Further research is required to elucidate the genetic and pathophysiological links among MH, EHS, and ER.
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http://dx.doi.org/10.4085/1062-6050-52.2.06DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402536PMC
April 2017

The effects of different exercise training modalities on plasma proenkephalin Peptide F in women.

Peptides 2017 05 3;91:26-32. Epub 2017 Mar 3.

Department of Human Sciences, The Ohio State University, Columbus, OH, United States.

Due to the important interactions of proenkephalin fragments (e.g., proenkephalin [107-140] Peptide F) to enhance activation of immune cells and potentially combat pain associated with exercise-induced muscle tissue damage, we examined the differential plasma responses of Peptide F to different exercise training programs. Participants were tested pre-training (T1), and after 8 weeks (T2) of training. Fifty-nine healthy women were matched and then randomly assigned to one of four groups: heavy resistance strength training (STR, n=18), high intensity endurance training (END, n=14), combined strength and endurance training (CMB, n=17), or control (CON, n=10). Blood was collected using a cannula inserted into a superficial vein in the antecubital fossa with samples collected at rest and immediately after an acute bout of 6 X 10 RM in a squat resistance exercise before training and after training. Prior to any training, no significant differences were observed for any of the groups before or after acute exercise. With training, significant (P≤0.95) elevations were observed with acute exercise in each of the exercise training groups and this effect was significantly greater in the CMB group. These data indicate that in untrained women exercise training will not change resting of plasma Peptide F concentrations unless both forms of exercise are performed but will result in significant increases in the immediate post-exercise responses. Such findings appear to indicate adrenal medullary adaptations opioid production significantly altered with exercise training.
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http://dx.doi.org/10.1016/j.peptides.2017.02.006DOI Listing
May 2017

Exertional Hyponatremia and Serum Sodium Change During Ultraendurance Cycling.

Int J Sport Nutr Exerc Metab 2017 Apr 6;27(2):139-147. Epub 2016 Oct 6.

Introduction: Exertional hyponatremia (EH) during prolonged exercise involves all avenues of fluid-electrolyte gain and loss. Although previous research implicates retention of excess fluid, EH may involve either loss, gain, or no change of body mass. Thus, the etiology, predisposing factors, and recommendations for prevention are vague-except for advice to avoid excessive drinking.

Purpose: This retrospective field study presents case reports of two unacquainted recreational cyclists (LC, 31y and AM, 39 years) who began exercise with normal serum electrolytes but finished a summer 164-km ride (ambient, 34±5°C) with a serum [Na+] of 130 mmol/L.

Methods: To clarify the etiology of EH, their pre- and post-exercise measurements were compared to a control group (CON) of 31 normonatremic cyclists (mean ± SD; 37±6 years; 141±3 mmol Na+/L).

Results: Anthropomorphic characteristics, exercise time, and post-exercise ratings of thermal sensation, perceived exertion and muscle cramp were similar for LC, AM and CON. These two hyponatremic cyclists consumed a large and similar volume of fluid (191 and 189 ml/kg), experienced an 11 mmol/L decrease of serum [Na+], reported low thirst sensations; however, LC gained 3.1 kg (+4.3% of body mass) during 8.9 hr of exercise and AM maintained body mass (+0.1kg, +0.1%, 10.6h). In the entire cohort (n = 33), post-event serum [Na+] was strongly correlated with total fluid intake (R = 0.45, p < .0001), and correlated moderately with dietary sodium intake (R=0.28, p = .004) and body mass change (R = 0.22, p = .02). Linear regression analyses predicted the threshold of EH onset (<135 mmol Na+/L) as 168 ml fluid/kg.

Conclusions: The wide range of serum [Na+] changes (+6 to -11 mmol/L) led us to recommend an individualized rehydration plan to athletes because the interactions of factors were complex and idiosyncratic.
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http://dx.doi.org/10.1123/ijsnem.2016-0135DOI Listing
April 2017

Effect of Caffeine on Perceived Soreness and Functionality Following an Endurance Cycling Event.

J Strength Cond Res 2017 Mar;31(3):638-643

1Human Performance Laboratory, University of Arkansas, Fayetteville, Arkansas; 2Applied Physiology Laboratory, University of North Texas, Denton, Texas; 3EXOS, Phoenix, Arizona; 4Human Performance Lab, University of Connecticut, Storrs, Connecticut; 5University of Hartford, West Hartford, Connecticut; and 6Midwestern State University, Wichita Falls, Texas.

Caldwell, AR, Tucker, MA, Butts, CL, McDermott, BP, Vingren, JL, Kunces, LJ, Lee, EC, Munoz, CX, Williamson, KH, Armstrong, LE, and Ganio, MS. Effect of caffeine on perceived soreness and functionality following an endurance cycling event. J Strength Cond Res 31(3): 638-643, 2017-Caffeine can reduce muscle pain during exercise; however, the efficacy of caffeine in improving muscle soreness and recovery from a demanding long-duration exercise bout has not been established. The purpose of this study was to investigate the effects of caffeine intake on ratings of perceived muscle soreness (RPMS) and perceived lower extremity functionality (LEF) following the completion of a 164-km endurance cycling event. Before and after cycling RPMS (1-to-6; 6 = severe soreness) and LEF (0-to-80; 80 = full functionality) were assessed by questionnaires. Subjects ingested 3 mg/kg body mass of caffeine or placebo pills in a randomized, double-blind fashion immediately after the ride and for the next 4 mornings (i.e., ∼800 hours) and 3 afternoons (i.e., ∼1200 hours). Before each ingestion, RPMS and LEF were assessed. Afternoon ratings of LEF were greater with caffeine ingestion the first day postride (65.0 ± 6.1 vs. 72.3 ± 6.7; for placebo and caffeine, respectively; p = 0.04), but at no other time points (p > 0.05). The caffeine group tended to have lower overall RPMS in the afternoon versus placebo (i.e., main effect of group; 1.1 ± 0.2 vs. 0.5 ± 0.2; p = 0.09). Afternoon RPMS for the legs was significantly lower in the caffeine group (main effect of caffeine; 1.3 ± 0.2 vs. 0.5 ± 0.3; p = 0.05). In conclusion, ingesting caffeine improved RPMS for the legs, but not LEF in the days following an endurance cycling event. Athletes may benefit from ingesting caffeine in the days following an arduous exercise bout to relieve feelings of soreness and reduced functionality.
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http://dx.doi.org/10.1519/JSC.0000000000001608DOI Listing
March 2017

Pro- and anti-inflammatory cytokine responses to a 164-km road cycle ride in a hot environment.

Eur J Appl Physiol 2016 Oct 13;116(10):2007-15. Epub 2016 Aug 13.

Applied Physiology Laboratory, Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, 1155 Union Circle #310769, Denton, TX, 76203-5017, USA.

Purpose: The purpose of this study was to examine the circulating cytokine response to a recreational 164-km road cycling event in a high ambient temperature and to determine if this response was affected by self-paced exercise time to completion.

Methods: Thirty-five men and five women were divided into tertiles based on time to complete the cycling event: slowest (SLOW), moderate (MOD), and fastest (FAST) finishers. Plasma samples were obtained 1-2 h before (PRE) and immediately after (IP) the event. A high-sensitivity multiplex assay kit was used to determine the concentration of plasma anti-inflammatory cytokines (IL-4, IL-5, IL-10, IL-13) and pro-inflammatory cytokines (IL-1β, IL-2, IL-6, IL-7, IL-8, IL-12, GM-CSF, IFN-γ, and TNF-α).

Results: The concentration of plasma IL-10 increased significantly (p < 0.05) in FAST and MOD groups and had no change in the SLOW group in response to a 164-km cycling event in the hot environment. Other cytokine responses were not influenced by the Time to completion. Pro-inflammatory cytokines IL-1β, IL-2, GM-CSF, and TNF-α decreased; whereas, IL-6 and IL-8 increased from PRE to IP. Additionally, anti-inflammatory cytokines IL-4 and IL-13 decreased.

Conclusions: Completion of a 164-km cycling event induced substantial changes in circulating pro- and anti-inflammatory cytokine concentrations. Time to completion appears to have a greater influence on the systemic IL-10 response than the environmental condition; however, it is possible that a threshold for absolute intensity must be reached for environmental conditions to affect the IL-10 response to exercise. Thus, cyclists from the FAST/MOD groups appear more likely to experience an acute transient immune suppression than cyclists from the SLOW group.
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http://dx.doi.org/10.1007/s00421-016-3452-5DOI Listing
October 2016