36 results on '"Sims ST"'
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2. Working on Ideas that Matter: Engaging Students Through Innovation and Entrepreneurship.
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Louis, Blake Sims St.
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- *
ENTREPRENEURSHIP , *MIDDLE school teachers - Abstract
The article offers information on engaging students through innovation and entrepreneurship (I&E). It mentions that I&E develop valuable solutions for people; and also mentions that human-centred design is core to this work and emphasises the crucial inclusion of those affected by the problem in all aspects of idea development.
- Published
- 2020
3. The effect of a cold beverage during an exercise session combining both strength and energy systems development training on core temperature and markers of performance
- Author
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LaFata Danielle, Carlson-Phillips Amanda, Sims Stacy T, and Russell Elizabeth M
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Hydration ,Dehydration ,Euhydration ,Core temperature ,Thermoregulation ,Performance ,Cold water ,Exercise ,Nutrition. Foods and food supply ,TX341-641 ,Sports medicine ,RC1200-1245 - Abstract
Abstract Background Although studies have investigated the effects of hydration on performance measures, few studies have investigated how the temperature of the ingested liquid affects performance and core temperature during an exercise session. The hypothesis of the present study was that cold water would improve thermoregulation and performance as measured by bench repetitions to fatigue, broad jump for force and power and total time to exhaustion for cardiovascular fitness Methods Forty-five, physically fit, adult males (30.28 ± 5.4 yr, 1.77 ± 7.8 m, 83.46 ± 11.5 kg; 13.7 ± 4.8 %BF; 49.8 ± 6.3 ml/kg/min V02) completed two 60-minute exercise sessions. Subjects consumed either COLD (4°C) or room temperature (RT) water (22°C) in randomized order. Core temperature was measured every 15 minutes throughout each trial using a digestible thermometer. Three performance tests were performed upon completion of the exercise session: bench press to fatigue, standing broad jump, and bicycle time to exhaustion Results Although both groups significantly increased their core temperature (p Conclusion Drinking cold water can significantly mediate and delay the increase in core body temperature during an exercise session in a moderate climate with euhydrated subjects. The ingestion of COLD improved performance for 49% and 51% of the participants in the broad jump and TTE performance tests respectively, but did not reach statistical significance. Moreover, although minimal, subjects experienced a decrease in performance on the bench press during the COLD.
- Published
- 2012
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4. International society of sports nutrition position stand: ketogenic diets.
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Leaf A, Rothschild JA, Sharpe TM, Sims ST, Macias CJ, Futch GG, Roberts MD, Stout JR, Ormsbee MJ, Aragon AA, Campbell BI, Arent SM, D'Agostino DP, Barrack MT, Kerksick CM, Kreider RB, Kalman DS, and Antonio J
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- Humans, Body Composition, Ketosis, Sports Nutritional Sciences, Dietary Carbohydrates administration & dosage, Exercise physiology, Physical Endurance physiology, Diet, Ketogenic, Athletic Performance physiology, Sports Nutritional Physiological Phenomena
- Abstract
Position Statement: The International Society of Sports Nutrition (ISSN) provides an objective and critical review of the use of a ketogenic diet in healthy exercising adults, with a focus on exercise performance and body composition. However, this review does not address the use of exogenous ketone supplements. The following points summarize the position of the ISSN., 1. A ketogenic diet induces a state of nutritional ketosis, which is generally defined as serum ketone levels above 0.5 mM. While many factors can impact what amount of daily carbohydrate intake will result in these levels, a broad guideline is a daily dietary carbohydrate intake of less than 50 grams per day., 2. Nutritional ketosis achieved through carbohydrate restriction and a high dietary fat intake is not intrinsically harmful and should not be confused with ketoacidosis, a life-threatening condition most commonly seen in clinical populations and metabolic dysregulation., 3. A ketogenic diet has largely neutral or detrimental effects on athletic performance compared to a diet higher in carbohydrates and lower in fat, despite achieving significantly elevated levels of fat oxidation during exercise (~1.5 g/min)., 4. The endurance effects of a ketogenic diet may be influenced by both training status and duration of the dietary intervention, but further research is necessary to elucidate these possibilities. All studies involving elite athletes showed a performance decrement from a ketogenic diet, all lasting six weeks or less. Of the two studies lasting more than six weeks, only one reported a statistically significant benefit of a ketogenic diet., 5. A ketogenic diet tends to have similar effects on maximal strength or strength gains from a resistance training program compared to a diet higher in carbohydrates. However, a minority of studies show superior effects of non-ketogenic comparators., 6. When compared to a diet higher in carbohydrates and lower in fat, a ketogenic diet may cause greater losses in body weight, fat mass, and fat-free mass, but may also heighten losses of lean tissue. However, this is likely due to differences in calorie and protein intake, as well as shifts in fluid balance., 7. There is insufficient evidence to determine if a ketogenic diet affects males and females differently. However, there is a strong mechanistic basis for sex differences to exist in response to a ketogenic diet.
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- 2024
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5. Optimizing Soldier Counseling: Multi-Source, Mixed-Method Evaluation of a Developmental Counseling Training for Mid-Grade Level Leaders.
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Novosel-Lingat JEM, Kirk MA, Coaxum MC, Harris PL, Sappenfield KB, Hertzman WU, Sims ST, Allard YS, and Knust SK
- Abstract
Introduction: In accordance with ADP 6-22-001 and ATP 6-22.1, counseling is the process routinely executed by Army leaders to develop, mentor, and coach subordinate Soldiers and Army civilians within their organization. When implemented effectively, the counseling process can be utilized to produce capable, resilient, and satisfied subordinates who are prepared and motivated to meet mission-essential responsibilities. Training opportunities that specifically focus on optimizing this key leader competence, particularly with non-commissioned officers, are limited. The Directorate of Prevention, Resilience and Readiness (Headquarters, Department of the Army, G-9) offers a specific training, the Counseling Enhancement Workshop, and requested an evaluation to determine the effectiveness of the current training and identify opportunities for improvement., Materials and Methods: A longitudinal 360-degree approach was deployed as a common multisource methodology intended to produce triangulated feedback from participants, as well as their subordinates and supervisors. Quantitative surveys and qualitative structured interviews were conducted. Performance psychology professional facilitators who train this workshop were also administered a questionnaire to capture instructional feedback. Measures include a knowledge assessment of the workshop content, Counseling Self-Efficacy Survey, as well as original measures related to the workshop experience. Completed written developmental counseling forms and observations from the evaluation team were also reviewed to ensure fidelity of the training implementation and delivery. The current study reports on survey responses from participants and facilitators., Results: Results suggested a strong and positive correlation between the pre- and post-workshop Counseling Self-Efficacy Scale. Because of a small sample size, data were analyzed as planned but interpreted with caution because of limited validity. There was a significant increase between the pre- and post-tests knowledge comprehension test scores. Facilitators reported confidence in teaching resilience skills, but not coaching Soldiers to apply those skills as part of the developmental counseling process., Conclusions: The Army counseling process can be utilized to produce capable, resilient, and satisfied subordinates who are prepared and motivated to meet mission-essential responsibilities. Quantitative results on the content of the CEW present opportunities for meaningful training that increases leaders' confidence in delivering counseling sessions, as well as mastering specific skills that benefit the subordinate Soldier and improve unit health. Furthermore, performance psychology professionals provided feedback on focus areas to meet the instructional objective of the training more efficiently and effectively. Ultimately, the counseling process is considered the most important tool available to current leaders to build the capacity of future leaders and an investment in the training to enhance these skills will provide great returns to the U.S. Army as a whole., (Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2024. This work is written by (a) US Government employee(s) and is in the public domain in the US.)
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- 2024
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6. An End-User Evaluation of Blast Overpressure and Accelerative Impact Body-Worn Sensors.
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Smith CD, Reddy MK, Sims ST, Conen KM, and Krauss SW
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- Humans, Male, Adult, Female, Military Personnel statistics & numerical data, Qualitative Research, Blast Injuries, Middle Aged, Wearable Electronic Devices standards, Wearable Electronic Devices statistics & numerical data, Explosions statistics & numerical data, United States, Focus Groups methods
- Abstract
Introduction: Blast overpressure and accelerative impact can produce concussive-like symptoms in service members serving both garrison and deployed environments. In an effort to measure, document, and improve the response to these overpressure and impact events, the U.S. Army Medical Material Development Activity is evaluating body-worn sensors for use by the Joint Conventional Force. In support, the WRAIR completed a qualitative end-user evaluation with service members from high-risk mission occupational specialties to determine the potential needs, benefits, and challenges associated with adopting body-worn sensors into their job duties., Materials and Methods: WRAIR staff led hour-long semi-structured focus groups with 156 Army, Navy, and Marine Corps participants, primarily representing infantry, combat engineer, explosive ordnance disposal, artillery, mortar, and armor job specialties. Topics included their sensor needs, concepts of operations, and recommended design features for implementing sensors into the force. Dialogue from each focus group was audio recorded and resulting transcripts were coded for thematic qualitative analysis using NVivo software., Results: Users recommended a single, unobtrusive, rugged, multi-directional sensor that could be securely mounted to the helmet and powered by a battery type (such as rechargeable lithium or disposable alkaline batteries) that was best suited for their garrison and field/deployed environments. The sensors should accurately measure low-level (∼1.0 pounds per square inch) blasts and maintain a record of cumulative exposures for each service member. Discussions supported the need for immediate, actionable feedback from the sensor with the option to view detailed blast or impact data on a computer. There were, however, divergent opinions on security issues regarding wireless versus wired data transfer methods. Participants also expressed a need for the exposure data to integrate with their medical records and were also willing to have their data shared with leadership, although opinions differed on the level of echelon and if the data should be identifiable. Regarding accountability, users did not want to be held fiscally liable for the sensors and recommended having the unit be responsible for maintenance and distribution. Concerns about being held fiscally liable, being overly burdened, and having one's career negatively impacted were listed as factors that could decrease usage. Finally, participants highlighted the importance of understanding the purpose and function of the sensors and supported a corresponding training module., Conclusions: Participating service members were generally willing to adopt body-worn sensors into their garrison and deployed activities. To maximize adoption of the devices, they should be convenient to use and should not interfere with service members' job tasks. Providing a clear understanding of the benefits (such as incorporating exposure data into medical records) and the function of sensors will be critical for encouraging buy-in among users and leaders. Incorporating end-user requirements and considering the benefits and challenges highlighted by end users are important for the design and implementation of body-worn sensors to mitigate the risks of blast overpressure and accelerative impact on service members' health., (Published by Oxford University Press on behalf of the Association of Military Surgeons of the United States 2024. This work is written by (a) US Government employee(s) and is in the public domain in the US.)
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- 2024
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7. Differences in Injury Profiles Between Female and Male Athletes Across the Participant Classification Framework: A Systematic Review and Meta-Analysis.
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Hardaker NJ, Hume PA, and Sims ST
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- Humans, Female, Male, Sex Factors, Anterior Cruciate Ligament Injuries, Athletes, Risk Factors, Athletic Injuries epidemiology
- Abstract
Background: Female sex is a significant determinant of anterior cruciate ligament (ACL) injury. It is not understood if sex is a key determinant of other sports-related injuries., Objective: The aim of this systematic review was to identify where differences in injury profiles are most apparent between the sexes in all sports across the six-tiered participant classification framework., Methods: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and the 'implementing PRISMA in Exercise, Rehabilitation, Sport medicine and SporTs science'(PERSiST) guidance. The databases PubMed, CINAHL, Web of Science, SPORTDiscus, Medline, Scopus, Cochrane Library and EBSCO were searched from database inception to 24 April 2023. Longitudinal, prospective and retrospective cohort studies and cross-sectional and descriptive epidemiology studies that used standard injury data collection were included. Studies were excluded if injuries were not medically diagnosed and if injuries were not reported and/or analysed by sex. Two reviewers independently extracted data and assessed study quality using the Downs and Black checklist., Results: Overall, 180 studies were included (8 tier-5, 40 tier-4, 98 tier-3, 30 tier-2, 5 tier-1 studies; one study included data in two tiers). Of those, 174 studies were of moderate quality and six studies were of limited quality. In sex-comparable sports, there was moderate evidence that female athletes had greater risk of knee injury (relative risk (RR) 2.7; 95% CI 1.4-5.5), foot/ankle injuries (RR 1.25; 95% CI 1.17-1.34), bone stress injury (RR 3.4; 95% CI 2.1-5.4) and concussion (RR 8.46; 95% CI 1.04-68.77) than male athletes. Male athletes were at increased risk of hip/groin injuries (RR 2.26; 95% CI 1.31-3.88) and hamstring injuries (RR 2.4; 95% CI 1.8-3.2) compared with females, particularly in dynamic sports. Male athletes were 1.8 (1.37-2.7) to 2.8 (2.45-3.24) times more likely to sustain acute fractures than female athletes, with the highest risk in competition., Discussion: Most studies in all cohorts were of moderate quality (mean/range of scores tier-5: 17 ± 2.2 [14-20], tier-4: 16.9 ± 1.9 [11-21], tier-3: 16.9 ± 1.5 [11-20], tier-2: 16.3 ± 2.2 [11-20], tier-1 studies: 15.6 ± 1.3 [14-17] out of 28 on the Downs and Black checklist), with only six studies of limited quality. Female athletes' propensity for bone stress injuries highlights opportunities to reinforce development of optimal bone health during adolescence and to outline the effects of energy availability. Earlier strength development and exposure to neuromuscular training programmes and modification of skill development in female athletes may be effective strategies for reducing lower limb injury risk. Key components of neuromuscular training programmes could be beneficial for reducing hip/groin and hamstring injury risk in male athletes. There may be a need for sex-specific prevention and return-to-sport protocols for sports-related concussion in female athletes., Conclusions: Female sex was a key determinant of sports-related injuries beyond ACL injury including foot/ankle injury, bone stress injury and sports-related concussion. Male sex was a key determinant of hip/groin, hamstring injury and upper limb injury., Trial Registry: PROSPERO registration number: CRD42017058806 (last updated on 7th June 2023)., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)
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- 2024
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8. Pre-sleep feeding, sleep quality, and markers of recovery in division I NCAA female soccer players.
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Greenwalt CE, Angeles E, Vukovich MD, Smith-Ryan AE, Bach CW, Sims ST, Zeleny T, Holmes KE, Presby DM, Schiltz KJ, Dupuit M, Renteria LI, and Ormsbee MJ
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- Humans, Female, Sleep Quality, Retrospective Studies, Sleep, Athletes, Soccer physiology
- Abstract
Pre-sleep nutrition habits in elite female athletes have yet to be evaluated. A retrospective analysis was performed with 14 NCAA Division I female soccer players who wore a WHOOP, Inc. band - a wearable device that quantifies recovery by measuring sleep, activity, and heart rate metrics through actigraphy and photoplethysmography, respectively - 24 h a day for an entire competitive season to measure sleep and recovery. Pre-sleep food consumption data were collected via surveys every 3 days. Average pre-sleep nutritional intake (mean ± sd: kcals 330 ± 284; cho 46.2 ± 40.5 g; pro 7.6 ± 7.3 g; fat 12 ± 10.5 g) was recorded. Macronutrients and kcals were grouped into high and low categories based upon the 50
th percentile of the mean to compare the impact of a high versus low pre-sleep intake on sleep and recovery variables. Sleep duration ( p = 0.10, 0.69, 0.16, 0.17) and sleep disturbances ( p = 0.42, 0.65, 0.81, 0.81) were not affected by high versus low kcal, PRO, fat, CHO intake, respectively. Recovery ( p = 0.81, 0.06, 0.81, 0.92), RHR ( p = 0.84, 0.64, 0.26, 0.66), or HRV ( p = 0.84, 0.70, 0.76, 0.93) were also not affected by high versus low kcal, PRO, fat, or CHO consumption, respectively. Consuming a small meal before bed may have no impact on sleep or recovery.- Published
- 2023
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9. International society of sports nutrition position stand: nutritional concerns of the female athlete.
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Sims ST, Kerksick CM, Smith-Ryan AE, Janse de Jonge XAK, Hirsch KR, Arent SM, Hewlings SJ, Kleiner SM, Bustillo E, Tartar JL, Starratt VG, Kreider RB, Greenwalt C, Rentería LI, Ormsbee MJ, VanDusseldorp TA, Campbell BI, Kalman DS, and Antonio J
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- Female, Humans, Male, Progesterone, Athletes, Amino Acids, Creatine, Sports
- Abstract
Based on a comprehensive review and critical analysis of the literature regarding the nutritional concerns of female athletes, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Female athletes have unique and unpredictable hormone profiles, which influence their physiology and nutritional needs across their lifespan. To understand how perturbations in these hormones affect the individual, we recommend that female athletes of reproductive age should track their hormonal status (natural, hormone driven) against training and recovery to determine their individual patterns and needs and peri and post-menopausal athletes should track against training and recovery metrics to determine the individuals' unique patterns. 2. The primary nutritional consideration for all athletes, and in particular, female athletes, should be achieving adequate energy intake to meet their energy requirements and to achieve an optimal energy availability (EA); with a focus on the timing of meals in relation to exercise to improve training adaptations, performance, and athlete health. 3. Significant sex differences and sex hormone influences on carbohydrate and lipid metabolism are apparent, therefore we recommend first ensuring athletes meet their carbohydrate needs across all phases of the menstrual cycle. Secondly, tailoring carbohydrate intake to hormonal status with an emphasis on greater carbohydrate intake and availability during the active pill weeks of oral contraceptive users and during the luteal phase of the menstrual cycle where there is a greater effect of sex hormone suppression on gluconogenesis output during exercise. 4. Based upon the limited research available, we recommend that pre-menopausal, eumenorrheic, and oral contraceptives using female athletes should aim to consume a source of high-quality protein as close to beginning and/or after completion of exercise as possible to reduce exercise-induced amino acid oxidative losses and initiate muscle protein remodeling and repair at a dose of 0.32-0.38 g·kg
-1 . For eumenorrheic women, ingestion during the luteal phase should aim for the upper end of the range due to the catabolic actions of progesterone and greater need for amino acids. 5. Close to the beginning and/or after completion of exercise, peri- and post-menopausal athletes should aim for a bolus of high EAA-containing (~10 g) intact protein sources or supplements to overcome anabolic resistance. 6. Daily protein intake should fall within the mid- to upper ranges of current sport nutrition guidelines (1.4-2.2 g·kg-1 ·day-1 ) for women at all stages of menstrual function (pre-, peri-, post-menopausal, and contraceptive users) with protein doses evenly distributed, every 3-4 h, across the day. Eumenorrheic athletes in the luteal phase and peri/post-menopausal athletes, regardless of sport, should aim for the upper end of the range. 7. Female sex hormones affect fluid dynamics and electrolyte handling. A greater predisposition to hyponatremia occurs in times of elevated progesterone, and in menopausal women, who are slower to excrete water. Additionally, females have less absolute and relative fluid available to lose via sweating than males, making the physiological consequences of fluid loss more severe, particularly in the luteal phase. 8. Evidence for sex-specific supplementation is lacking due to the paucity of female-specific research and any differential effects in females. Caffeine, iron, and creatine have the most evidence for use in females. Both iron and creatine are highly efficacious for female athletes. Creatine supplementation of 3 to 5 g per day is recommended for the mechanistic support of creatine supplementation with regard to muscle protein kinetics, growth factors, satellite cells, myogenic transcription factors, glycogen and calcium regulation, oxidative stress, and inflammation. Post-menopausal females benefit from bone health, mental health, and skeletal muscle size and function when consuming higher doses of creatine (0.3 g·kg-1 ·d-1 ). 9. To foster and promote high-quality research investigations involving female athletes, researchers are first encouraged to stop excluding females unless the primary endpoints are directly influenced by sex-specific mechanisms. In all investigative scenarios, researchers across the globe are encouraged to inquire and report upon more detailed information surrounding the athlete's hormonal status, including menstrual status (days since menses, length of period, duration of cycle, etc.) and/or hormonal contraceptive details and/or menopausal status.- Published
- 2023
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10. Heating Up to Keep Cool: Benefits and Persistence of a Practical Heat Acclimation Protocol in Elite Female Olympic Team-Sport Athletes.
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Fenemor SP, Driller MW, Gill ND, Anderson B, Casadio JR, Sims ST, and Beaven CM
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- Humans, Female, Body Temperature Regulation, Acclimatization physiology, Athletes, Hot Temperature, Exercise physiology, Heating
- Abstract
Purpose: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program., Methods: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay)., Results: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by -0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by -0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41)., Conclusions: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus.
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- 2023
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11. Editorial: Highlights in sport and exercise nutrition 2021/22.
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Nieman DC, Sims ST, Wentz LM, and Mariscal-Arcas M
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Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
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- 2023
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12. Advancing feminist innovation in sport studies: A transdisciplinary dialogue on gender, health and wellbeing.
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Thorpe H, Bekker S, Fullagar S, Mkumbuzi N, Nimphius S, Pape M, Sims ST, and Travers A
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Athlete health and wellbeing requires a holistic, multidimensional approach to understanding, supporting, and treating individual athletes. Building more supportive, inclusive, and equitable environments for the health and wellbeing of women and gender expansive people further requires gender-responsive approaches that promote broader cultural change. Feminist sport and exercise medicine practitioners, sports scientists, and social science researchers are increasingly coming together in their efforts to do this work. However, working across disciplines inevitably includes an array of ontological, epistemological, and political challenges. In this paper, we offer a curated 'dialogue' with a group of feminist scholars engaged in research and practice across disciplines, bringing them together to discuss some of the most pressing gendered issues in sport today (i.e., ACL injury, concussion, menstruation in sport, mental health, gender categories). In so doing, we amplify the voices of those working (empirically and clinically) at the disciplinary intersections of gender, sport and health, and learn about some of the current and future possibilities for transdisciplinary innovations and strategies for building (responsiveness to) cultural change., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Thorpe, Bekker, Fullagar, Mkumbuzi, Nimphius, Pape, Sims and Travers.)
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- 2023
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13. The Influence of Full-Time Holistic Support Delivered by a Sports Nutritionist on Within-Day Macronutrient Distribution in New Zealand Provincial Academy Rugby Union Players.
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Roberts CJ, Gill ND, Beaven CM, Posthumus LR, and Sims ST
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- Humans, New Zealand, Energy Intake physiology, Nutrients, Football physiology, Nutritionists
- Abstract
Dietary intake is an important consideration for rugby union ('rugby') players to ensure substrate provision for optimal performance and facilitate recovery. Within-day meal distribution is especially important for athletes, particularly those with congested schedules and multiple daily training sessions. In the present study, 10 provincial academy rugby players engaged in a holistic support protocol informed by behaviour-change techniques led by a full-time sports nutritionist. Dietary intake was estimated during a 4-week monitoring and 4-week intervention period using the remote food photography method on one high-volume training day (two training sessions) and two low-volume training days (≤1 training session) per week. Lean body mass did not change significantly in response to the intervention. Significant increases were observed for protein on both low-volume (breakfast, AM snack, evening snack) and high-volume (post-gym, AM snack, evening snack) training days. Carbohydrate intake post-intervention was significantly greater at the pre-gym eating occasion but lower at PM snack and dinner eating occasions on high-volume days. These data suggest that incorporating a holistic support protocol led by a sports nutritionist can influence within-day nutrient intake in rugby players; however, no change to lean body mass was observed, and the influence of these changes in nutrient intake on performance and recovery warrants further investigation.
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- 2022
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14. High Prevalence of Iron Deficiency Exhibited in Internationally Competitive, Non-Professional Female Endurance Athletes-A Case Study.
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Sims ST, Mackay K, Leabeater A, Clarke A, Schofield K, and Driller M
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- Humans, Female, Prevalence, Iron metabolism, Ferritins, Transferrin metabolism, Hemoglobins analysis, Athletes, C-Reactive Protein metabolism, Anemia, Iron-Deficiency epidemiology, Iron Deficiencies
- Abstract
Background: While iron deficiency is commonly discussed in populations of professional female athletes, less is known about highly trained, sub-elite female athletes (e.g., those winning international age-group competitions) who generally have less access to medical and allied health support., Methods: Thirteen non-professional highly trained female endurance athletes provided training diaries and completed a blood test, where iron markers of haemoglobin (Hb), haematocrit (Hct), C-reactive protein (Crp), serum iron, serum ferritin, and transferrin were assessed. Resting metabolic rate (RMR) and body composition using dual-energy X-ray absorptiometry (DXA) were also obtained. Participants were classified as iron deficient (ID) if serum ferritin was <30 ug/L serum ferritin., Results: Six of the 13 females were classified as ID. Serum iron, ferritin, Hb, Hct, and ferrin were greater in the ID group ( p < 0.05). Crp resulted in large to very large correlations with serum iron ( r = -0.72), serum ferritin ( r = -0.66), and transferrin ( r = 0.70)., Conclusions: In this population of highly trained female athletes, 46% were diagnosed with sub-optimal iron levels, which could have lasting health effects and impair athletic performance. The need for more education and support in non-professional athletes regarding iron deficiency is strongly advised.
- Published
- 2022
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15. Case Study: Energy Availability and Endocrine Markers in Elite Male Track Cyclists.
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Schofield KL, Thorpe H, and Sims ST
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- Adult, Athletes, Body Composition, Cross-Sectional Studies, Energy Intake, Energy Metabolism, Humans, Male, Young Adult, Basal Metabolism, Dietary Proteins
- Abstract
Aim: To highlight energy availability status, resting metabolic rate measures, dietary protein intake, and testosterone concentration in 4 elite male track cycling athletes (mean [SD]: age: 20.8 [1.5] y, body mass: 76.3 [3.6] kg, height: 181.8 [2.9] cm)., Method: A cross-sectional observation included measures of energy availability (energy intake minus exercise energy expenditure, divided by fat-free mass), resting metabolic rate from indirect calorimetry, dietary protein intake from food records, blood analysis to assess sex hormone status, and performance markers., Results: Midrange testosterone (16.9-19.8 nmol/L), lowered resting metabolic rate ratio (0.76-0.98), varied luteinizing hormone (4-10 U/L), and suboptimal energy availability (26-41 kcal/kg fat-free mass/d, range) were observed in the male track cyclists. Protein intakes ranged from 2.0 g to 2.8 g protein/kg/d., Conclusion: The current cohort may have within-day energy deficiency, putting them in a catabolic state.
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- 2022
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16. Where are all the men? Low energy availability in male cyclists: A review.
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Schofield KL, Thorpe H, and Sims ST
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- Humans, Male, Sports Nutritional Physiological Phenomena, Athletes psychology, Bicycling physiology, Bicycling psychology, Bone Density physiology, Endocrine System physiology, Energy Intake physiology, Energy Metabolism physiology
- Abstract
Most of the low energy availability (LEA) research has been conducted in female populations. The occurrence of LEA in male athletes is not well known, even with an understanding of the components involved in and contributing to LEA. Cycling is a major risk factor for LEA due to inherent sports characteristics: low impact, high energy demands, and a common perception that leanness is a performance advantage. The purpose of this review is to discuss the cycling-specific studies that have documented components of RED-S. The review demonstrates male cyclists (1) experience energy deficits daily, weekly and throughout a season; (2) exhibit lower bone mineral density at the spine compared to the hip, and low bone mineral density correlating with LEA and; (3) demonstrate downregulation of the endocrine system with elevated cortisol, reduced testosterone and insulin-like growth factor 1. The complexity of LEA is further explored by the socio-psychological contribution that may impact eating behaviours, and therefore increase the risk of developing LEA. Future research directions include applying multifaceted research methods to gain a greater understanding of this syndrome and the effect of LEA on male cyclists.
- Published
- 2021
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17. Patterns of endogenous and exogenous ovarian hormone modulation on recovery metrics across the menstrual cycle.
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Sims ST, Ware L, and Capodilupo ER
- Abstract
Introduction: As the number of female athletes competing rises globally, training methodologies should reflect sex differences across critical metrics of adaptation to training. Surrogate markers of the autonomic nervous system (ANS) used for monitoring training load are heart rate variability (HRV) and resting heart rate (RHR). The aim was to investigate ovarian hormone effects on standard recovery metrics (HRV, RHR, respiratory rate (RR) and sleep duration) across a large population of female athletes., Methods: A retrospective study analysed 362 852 days of data representing 13 535 menstrual cycles (MC) from 4594 respondents (natural MC n=3870, BC n=455, progestin-only n=269) for relationships and/or differences between endogenous and exogenous ovarian hormones on ANS., Results: HRV and return to baseline (recovery) decreased as resting HR and RR increased (p<0.001) from the early follicular to the late luteal phase of the MC. Patterning was paradoxical across phases for users of combined hormonal contraception (BC) as compared with the patterning of the MC. HRV and recovery start elevated and drop off quickly during the withdrawal bleed, rising through the active pill weeks (p<0.001). Progestin-only users had similar patterning as the MC. The relationship between normalised recovery and previous day strain is modulated by birth control type. BC exhibited steeper declines in recovery with additional strain-normalised recovery decreases by an additional 0.0055±0.00135 (p<0.001) per unit of strain; with no significant difference between MC and progestin-only (p=0.19)., Conclusion: The patterning of ANS modulation from ovarian hormones is significantly different between naturally cycling women and those on BC, with the patterning dependent on the type of contraception used., Competing Interests: Competing interests: Two of the authors (ERC, LW) are affiliated to the commercial company WHOOP, however, this does not alter the authors’ adherence to BJSM policies on sharing data and materials., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2021
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18. Biological and Socio-Cultural Factors Have the Potential to Influence the Health and Performance of Elite Female Athletes: A Cross Sectional Survey of 219 Elite Female Athletes in Aotearoa New Zealand.
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Heather AK, Thorpe H, Ogilvie M, Sims ST, Beable S, Milsom S, Schofield KL, Coleman L, and Hamilton B
- Abstract
Health is a pre-requisite for optimal performance yet the parameters which govern health and performance of elite female athletes are little understood. The aim of this study was to quantify the health status of elite female athletes, and understand sociocultural factors influencing that status. The survey addressed demographic, health and athletic performance history, training load, contraceptive use, sport-specific appearance and performance pressures, and communication barriers. Three hundred and fifty-seven elite New Zealand female athletes were recruited to complete an on-line survey. Two hundred and nineteen athletes completed the survey. Oligomenorrhea/amenorrhea had been diagnosed in only 12% of athletes compared with 50% of athletes not on hormonal contraception who reported symptoms consistent with this diagnosis. Stress fractures and iron deficiency were common and associated with oligomenorrhoea/amenorrhea ( P = 0.002), disordered eating ( P = 0.009) or menorrhagia ( P = 0.026). Athletes involved in individual sports ( P = 0.047) and with higher training volumes ( P < 0.001) were more likely to report a medical illness. Seventy-three percent of athletes felt pressured by their sport to alter their physical appearance to conform to gender ideals with 15% engaging in disordered eating practices. Barriers to communicating female health issues included male coaches and support staff, and lack of quality information pertaining to health. Elite female athletes may fail to reach peak performance due to specific health issues and undiagnosed pathology. Sociocultural factors influence the effectiveness of support of female's health and performance. Organizational and cultural change is required if elite female athletes are to combine optimal health with best performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Heather, Thorpe, Ogilvie, Sims, Beable, Milsom, Schofield, Coleman and Hamilton.)
- Published
- 2021
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19. Menstrual cycle and thermoregulation during exercise in the heat: A systematic review and meta-analysis.
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Giersch GEW, Morrissey MC, Katch RK, Colburn AT, Sims ST, Stachenfeld NS, and Casa DJ
- Subjects
- Female, Follicular Phase, Humans, Luteal Phase, Body Temperature Regulation, Exercise physiology, Hot Temperature, Menstrual Cycle
- Abstract
Research conducted on exercise in the heat has been largely conducted in males, leaving women understudied. Of research including women, results are inconsistent on the impact of menstrual cycle phase on thermoregulation., Objectives: The purpose of this systematic review is to quantify published investigations in thermal physiology that include menstrual cycle comparisons and assess aggregate data of investigations that include menstrual cycle variation and aerobic exercise in the heat., Methods: 367 research articles were identified via systematic review and inclusion criteria and yielded 9 papers included in this analysis for a total number of 83 research subjects. Effect size estimates (Hedge's g) were utilized for initial (pre-exercise) and post-exercise internal body temperature (rectal or esophageal, T
int ), sweat rate, mean skin temperature, and exercise heart rate., Results: Pooled effect size showed significantly greater initial Tint (1.231±0.186, p<0.01) and post-exercise Tint (0.455±0.153, p<0.01) in the luteal compared to follicular phases. No significant differences were present in mean skin temperature, sweat rate, or exercise heart rate across menstrual phases in analyses of aggregate data., Conclusions: The limited available data suggest that observed increases in initial Tint in the luteal phase are maintained throughout and post-exercise without an observed impact in sweat rate or mean skin temperature., (Copyright © 2020 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)- Published
- 2020
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20. Hepcidin and iron: novel findings for elite female rugby Sevens players.
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Smith S, Sims ST, Thorpe H, Baker D, Haszard J, Badenhorst C, and Black KE
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- Adult, Athletes statistics & numerical data, C-Reactive Protein analysis, Female, Ferritins blood, Football statistics & numerical data, Humans, Iron Deficiencies, Longitudinal Studies, Young Adult, Hepcidins blood, Iron blood
- Abstract
Background: Iron deficiency is a common deficiency disease worldwide with athletes at increased risk., Methods: A proposed new mechanism of exercise-induced iron deficiency in athletes involves the iron-regulatory hormone hepcidin, however, there is limited information on this amongst elite athletes. This study describes iron status in elite female rugby Sevens players., Results: Blood samples were collected at the start and mid-season and analyzed for serum iron, serum ferritin (SF), soluble transferring receptor (sTfR), high sensitivity C-reactive Protein (hsCRP) and hepcidin. Of the 17 players 18% were iron deficient (SF<30 µg/L) with 29-35% of players with sub-optimal iron stores at some point during the study (SF<45 µg/L). Serum hepcidin was strongly correlated with SF (r=0.61, P=0.0001)., Conclusions: Some elite female rugby Sevens players have sub-optimal iron stores over the course of a season.
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- 2020
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21. The Validity of Resting Metabolic Rate-Prediction Equations and Reliability of Measured RMR in Female Athletes.
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Mackay KJ, Schofield KL, Sims ST, McQuillan JA, and Driller MW
- Abstract
The aim of the current study was to; 1) assess the test-retest reliability of an indirect calorimetry analyzer (Parvo Medics TrueOne), and 2) compare measured RMR with three RMR-predictive (pRMR) equations in female athletes. In part one, 12 recreationally-exercising women (mean ± SD; age 27.5 ± 12.3 y) performed two RMR assessments, on separate days, utilising the Parvo Medics TrueOne analyser. In part two, 25 recreationally-exercising women to sub-elite athletes (mean ± SD; age 30.1 ± 10.2 y) underwent an RMR assessment using the Parvo Medics TrueOne analyser, which was compared to three calculated pRMR equations (Harris-Benedict (H-B), Mifflin-St Jeor (M), World Health Organisation (WHO)). eTest-retest reliability for the TrueOne analyser was deemed acceptable (CV = 5.3%, ICC = 0.92). The validity of pRMR when compared to measured RMR showed low levels of agreement in all 3 predictive equations (M: CV = 21.4%, TEE = 269 kcal.day
-1 , r = 0.16, WHO: CV = 21.5%, TEE = 270 kcal.day-1 , r = 0.13 H-B: CV = 21.6%, TEE = 270 kcal.day-1 , r = 0.13). The Parvo Medics TrueOne analyser is a reliable tool for measuring RMR. Caution should be taken when using pRMR equations in female athletes as they do not take into account the likely differences in fat free mass in these populations.- Published
- 2019
22. Resting metabolic rate prediction equations and the validity to assess energy deficiency in the athlete population.
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Schofield KL, Thorpe H, and Sims ST
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Athletes, Body Composition physiology, Body Mass Index, Calorimetry, Indirect methods, Female, Humans, Male, Middle Aged, Young Adult, Basal Metabolism physiology, Energy Metabolism physiology, Sports physiology
- Abstract
New Findings: What is the topic of this review? We review the issues with using predicted resting metabolic rate equations in athletic populations. What advances does it highlight? The use of dated predicted resting metabolic rate equations is not appropriate for athletic populations until more studies have been conducted among these unique populations., Abstract: Resting metabolic rate (RMR) is the amount of energy the body uses at rest. A suppressed RMR has been correlated with low energy availability and therefore used as an indicator of an individual's energy state. Furthermore, confounding identification of low energy availability within an athletic population are the physiological measures required, which can be time consuming and require professional expertise. To negate the demands of laboratory protocols in measuring RMR, predicted RMR (
p RMR) equations were developed. Caution should be exercised when applying thep RMR equations for determining low energy availability in athletes owing to the population used to develop the equations and the higher metabolic cost of fat-free mass, thus elevated RMR, associated with athletes. Moreover, a low ratio of measured RMR top RMR is often used as an alternative marker for energy deficiency. Predictive equations should implement fat-free mass within the algorithm when estimating RMR in athletic populations. The purpose of this paper is to describep RMR equation development and the issues associated with use ofp RMR equations for athletic populations. As professional sport increases, validation ofp RMR equations in the modern athlete population is needed to monitor energy availability for athletic health and performance., (© 2019 The Authors. Experimental Physiology © 2019 The Physiological Society.)- Published
- 2019
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23. Myths and Methodologies: Reducing scientific design ambiguity in studies comparing sexes and/or menstrual cycle phases.
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Sims ST and Heather AK
- Subjects
- Adaptation, Physiological physiology, Athletes, Contraceptives, Oral pharmacology, Estrogens metabolism, Exercise physiology, Female, Humans, Menstrual Cycle drug effects, Menstrual Cycle metabolism, Progesterone metabolism, Sex Characteristics, Sports physiology, Menstrual Cycle physiology
- Abstract
New Findings: What is the topic of this review? We review methodological considerations for the inclusion of women in sex and menstrual cycle phase comparison studies. What advances does it highlight? Improving the methodological design for studies exploring sex differences, menstrual cycle phase differences and/or endogenous versus exogenous female sex hormones will help to close the gap in our understanding of the effects of endogenous and exogenous hormones on exercise science and sports medicine outcomes., Abstract: In recent years, the increase in scientific literature exploring sex differences has been beneficial to both clinicians and allied health science professionals, although female athletes are still significantly under-represented in sport and exercise science research. Women have faced exclusion throughout history though the complexities of sociocultural marginalization and biomedical disinterest in women's health. These complexities have contributed to challenges of studying women and examining sex differences. One underlying complexity to methodological design may be hormonal perturbations of the menstrual cycle. The biphasic responses of oestrogen and progesterone across the menstrual cycle significantly influence physiological responses, which contribute to exercise capacity and adaptation in women. Moreover, oral contraceptives add complexity through the introduction of varying concentrations of circulating exogenous oestrogen and progesterone, which may moderate physiological adaptations to exercise in a different manner to endogenous ovarian hormones. Thus, applied sport and exercise science research focusing on women remains limited, in part, by poor methodological design that does not define reproductive status. By highlighting specific differences between phases with regard to hormone perturbations and the systems that are affected, methodological inconsistencies can be reduced, thereby improving scientific design that will enable focused research on female athletes in sports science and evaluation of sex differences in responses to exercise. The aims of this review are to highlight the differences between endogenous and exogenous hormone profiles across a standard 28-32 day menstrual cycle, with the goal to improve methodological design for studies exploring sex differences, menstrual cycle phase differences and/or endogenous versus exogenous female sex hormones., (© 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.)
- Published
- 2018
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24. Fluid intake behavior in athletes during typical training bouts.
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Buoite Stella A, Francescato MP, Sims ST, and Morrison SA
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- Adolescent, Adult, Analysis of Variance, Child, Female, Humans, Male, Practice Guidelines as Topic, Retrospective Studies, Self Report, Young Adult, Athletes statistics & numerical data, Drinking Behavior, Exercise physiology, Exercise psychology
- Abstract
Background: Hydration habits during training may differ depending on sports mode and individual characteristics. The aim of this study was to assess fluid intake behavior in a wide sample of Italian athletes during their regular training., Methods: Data on hydration habits during training were collected from a random sample of competitive athletes. Hydration strategies and personal characteristics were queried via questionnaire, including athletes' quantity and type of fluid ingested during a typical training bout, sport characteristics (e.g. mode and training duration), and whether their coach encouraged them to drink during trainings., Results: Three hundred and fifty-two competitive athletes participated to the study; two hundred eighty-nine athletes correctly completed all survey items (age: 8-63 years, median: 21±13 years). Athletes were involved in international (3.1%), national (34.1%) and regional (44.9%) competitions. Median fluid intakes during training were 0.25 L/h; 150 athletes reported fluid intake below the median, whilst 23 athletes (6.5% of total sample) reported fluid intake at or above currently published exercise hydration guidelines (NATA and ACSM). Binary logistic regression indicated that the number of pauses to drink (B=0.771, P=0.000), duration of a typical training bout (B=-2.237, P=0.000), and a coach's encouragement to drink (B=0.601, P=0.030) were each associated with fluid consumption above or below the median value., Conclusions: Athletes across all disciplines reported drinking less fluid during training than currently espoused in hydration guidelines. A coach's encouragement to drink, the number of pauses during training, and bout duration each influence total fluid volume consumed, regardless of competition level, sex or the age of an athlete.
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- 2017
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25. Lower skin cancer risk in women with higher body mass index: the women's health initiative observational study.
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Tang JY, Henderson MT, Hernandez-Boussard T, Kubo J, Desai M, Sims ST, Aroda V, Thomas F, McTiernan A, and Stefanick ML
- Subjects
- Age Factors, Aged, Cohort Studies, Female, Humans, Logistic Models, Middle Aged, Obesity epidemiology, Risk Factors, United States epidemiology, Women's Health, Body Mass Index, Melanoma epidemiology, Skin Neoplasms epidemiology
- Abstract
The unclear relationship of obesity to incident melanoma and nonmelanoma skin cancer (NMSC) risks was evaluated in the large, geographically diverse longitudinal, prospective Women's Health Initiative (WHI) observational study. Risks of melanoma and NMSC in normal weight women were compared with risks in overweight [body mass index (BMI) = 25-29.0 kg/m(2)] and obese (BMI ≥ 30 kg/m(2)) women, using Cox proportional hazards models for melanoma and logistic regression for NMSC. Over a mean 9.4 years of follow-up, there were 386 melanoma and 9,870 NSMC cases. Risk of melanoma did not differ across weight categories (P = 0.86), whereas in fully adjusted models, NMSC risk was lower in overweight [OR, 0.93; 95% confidence interval (CI), 0.89-0.99] and obese (OR, 0.85; 95% CI, 0.80-0.91) women (P < 0.001). Excess body weight was not associated with melanoma risk in postmenopausal women but was inversely associated with NMSC risk, possibly due to lower sun exposure in overweight and obese women. This supports previous work demonstrating the relationship between excess body weight and skin cancer risk., (©2013 AACR.)
- Published
- 2013
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26. Low-fat diet and skin cancer risk: the women's health initiative randomized controlled dietary modification trial.
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Gamba CS, Stefanick ML, Shikany JM, Larson J, Linos E, Sims ST, Marshall J, Van Horn L, Zeitouni N, and Tang JY
- Subjects
- Aged, Cohort Studies, Feeding Behavior, Female, Humans, Incidence, Middle Aged, Postmenopause metabolism, Risk Factors, Treatment Outcome, Diet, Fat-Restricted statistics & numerical data, Dietary Fats administration & dosage, Skin Neoplasms epidemiology
- Abstract
Background: Large cohort studies have reported no relationship between dietary fat and nonmelanoma skin cancer (NMSC), although a low-fat diet intervention reduced NMSC risk in a small clinical trial. In animal studies, skin tumor development has been reduced by low-fat diet. We evaluated the effect of a low-fat dietary pattern on NMSC and melanoma in the Women's Health Initiative Dietary Modification trial., Methods: Postmenopausal women aged 50 to 79 years (n = 48,835) were randomly assigned to the low-fat dietary pattern intervention (n = 19,541) or comparison group (n = 29,294). The intervention goals included decreasing fat intake to 20% or less of calories, increasing vegetable and fruit intake, and increasing grain intake. Self-reported incident NMSC (n = 4,907) and physician-adjudicated incident melanoma (n = 279) were ascertained every 6 months., Results: Over 8.1 years of follow-up, the low-fat diet intervention did not affect overall incidence of NMSC [HR 0.98; 95% confidence interval (CI), 0.92-1.04] or melanoma (HR, 1.04; 95% CI, 0.82-1.32). In subgroup analyses of melanoma risk, baseline fat intake interacted significantly with group assignment (Pinteraction = 0.006). Among women with higher baseline fat intake, the dietary intervention significantly increased risk (HR, 1.48; 95% CI, 1.06-2.07), whereas, among women with lower baseline fat intake, the intervention tended to reduce melanoma risk (HR, 0.72; 95% CI, 0.50-1.02)., Conclusions: In this large randomized trial, a low-fat dietary pattern did not affect overall incidence of NMSC or melanoma., Impact: A low-fat diet does not reduce incidence of NMSC, but an interaction between baseline fat intake and dietary intervention on melanoma risk warrants further investigation.
- Published
- 2013
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27. Changes in physical activity and body composition in postmenopausal women over time.
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Sims ST, Kubo J, Desai M, Bea J, Beasley JM, Manson JE, Allison M, Seguin RA, Chen Z, Michael YL, Sullivan SD, Beresford S, and Stefanick ML
- Subjects
- Absorptiometry, Photon, Adipose Tissue physiology, Aged, Aged, 80 and over, Female, Humans, Longitudinal Studies, Middle Aged, Prospective Studies, Body Composition physiology, Exercise physiology, Postmenopause physiology
- Abstract
Purpose: Higher physical activity (PA) has been associated with greater attenuation of body fat gain and preservation of lean mass across the lifespan. These analyses aimed to determine relationships of change in PA to changes in fat and lean body mass in a longitudinal prospective study of postmenopausal women., Methods: Among 11,491 women enrolled at three Women's Health Initiative clinical centers who were selected to undergo dual-energy x-ray absorptiometry, 8352 had baseline body composition measurements, with at least one repeated measure at years 1, 3, and 6. PA data were obtained by self-report at baseline and 3 and 6 yr of follow-up. Time-varying PA effect on change in lean and fat mass during the 6-yr study period for age groups (50-59 yr, 60-69 yr, and 70-79 yr) was estimated using mixed effects linear regression., Results: Baseline PA and body composition differed significantly among the three age groups. The association of change in fat mass from baseline and time-varying PA differed across the three age groups (P = 0.0006). In women age 50-59 yr, gain in fat mass from baseline was attenuated with higher levels of PA. Women age 70-79 yr lost fat mass at all PA levels. In contrast, change in lean mass from baseline and time-varying PA did not differ by age group (P = 0.1935)., Conclusions: The association between PA and change in fat mass varies by age group, with younger, but not older, women benefiting from higher levels of aerobic PA. Higher levels of aerobic activity are not associated with changes in lean mass, which tends to decrease in older women regardless of activity level. Greater attention to resistance training exercises may be needed to prevent lean mass loss as women age.
- Published
- 2013
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28. Relationship of sedentary behavior and physical activity to incident cardiovascular disease: results from the Women's Health Initiative.
- Author
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Chomistek AK, Manson JE, Stefanick ML, Lu B, Sands-Lincoln M, Going SB, Garcia L, Allison MA, Sims ST, LaMonte MJ, Johnson KC, and Eaton CB
- Subjects
- Age Factors, Aged, Body Mass Index, Cardiovascular Diseases physiopathology, Cohort Studies, Female, Humans, Incidence, Middle Aged, Multivariate Analysis, Overweight epidemiology, Postmenopause physiology, Prognosis, Proportional Hazards Models, Prospective Studies, Risk Assessment, Survival Rate, Time Factors, United States, Cardiovascular Diseases epidemiology, Cardiovascular Diseases etiology, Motor Activity physiology, Sedentary Behavior, Women's Health
- Abstract
Objectives: The aim of this study was to examine the independent and joint associations of sitting time and physical activity with risk of incident cardiovascular disease (CVD)., Background: Sedentary behavior is recognized as a distinct construct beyond lack of leisure-time physical activity, but limited data exist on the interrelationship between these 2 components of energy balance., Methods: Participants in the prospective Women's Health Initiative Observational Study (n = 71,018), 50 to 79 years of age and free of CVD at baseline (1993 to 1998), provided information on sedentary behavior, defined as hours of sitting/day, and usual physical activity at baseline and during follow-up through September 2010. First CVD (coronary heart disease or stroke) events were centrally adjudicated., Results: Sitting ≥10 h/day compared with ≤5 h/day was associated with increased CVD risk (hazard ratio: 1.18, 95% confidence interval: 1.09 to 1.29) in multivariable models including physical activity. Low physical activity was also associated with higher CVD risk (p for trend < 0.001). When women were cross-classified by sitting time and physical activity (p for interaction = 0.94), CVD risk was highest in inactive women (≤1.7 metabolic equivalent task-h/week) who also reported ≥10 h/day of sitting. Results were similar for coronary heart disease and stroke when examined separately. Associations between prolonged sitting and risk of CVD were stronger in overweight versus normal weight women and women 70 years of age and older compared with younger women., Conclusions: Prolonged sitting time was associated with increased CVD risk, independent of leisure-time physical activity, in postmenopausal women without a history of CVD. A combination of low physical activity and prolonged sitting augments CVD risk., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)
- Published
- 2013
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29. Physical activity and body mass: changes in younger versus older postmenopausal women.
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Sims ST, Larson JC, Lamonte MJ, Michael YL, Martin LW, Johnson KC, Sarto GE, and Stefanick ML
- Subjects
- Aged, Body Mass Index, Female, Humans, Middle Aged, Waist-Hip Ratio, Body Weight physiology, Motor Activity physiology, Postmenopause physiology
- Abstract
Purpose: The study's purpose was to investigate the relationship of sedentary (≤ 100 MET · min · wk(-1)), low (>100-500 MET · min · wk(-1)), moderate (>500-1200 MET · min · wk(-1)), and high (>1200 MET · min · wk(-1)) habitual physical activity with body weight, body mass index, and measures of fat distribution (waist-to-hip ratio) in postmenopausal women by age decades., Methods: A prospective cohort study of 58,610 postmenopausal women age 50-79 yr weighed annually during 8 yr at one of 40 US clinical centers was analyzed to determine the relationship of high versus low habitual physical activity with changes in body weight and fat distribution by age group., Results: Among women age 50-59 yr, there was significant weight loss in those expending >500-1200 MET · min · wk(-1) (coefficient = -0.30, 95% confidence interval = -0.53 to -0.07) compared with the group expending ≤ 100 MET · min · wk(-1). Among women age 70-79 yr, higher physical activity was associated with less weight loss (coefficient = 0.34, 95% confidence interval = 0.04-0.63). Age at baseline significantly modified the association between physical activity and total weight change, whereas baseline body mass index did not., Conclusions: High habitual physical activity is associated with less weight gain in younger postmenopausal women and less weight loss in older postmenopausal women. These findings suggest that promoting physical activity among postmenopausal women may be important for managing body weight changes that accompany aging.
- Published
- 2012
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30. Sex differences in the prevalence of peripheral artery disease in patients undergoing coronary catheterization.
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Sadrzadeh Rafie AH, Stefanick ML, Sims ST, Phan T, Higgins M, Gabriel A, Assimes T, Narasimhan B, Nead KT, Myers J, Olin J, and Cooke JP
- Subjects
- Aged, Ankle Brachial Index, California epidemiology, Coronary Artery Disease epidemiology, Cross-Sectional Studies, Female, Humans, Logistic Models, Male, Middle Aged, New York City epidemiology, Odds Ratio, Peripheral Arterial Disease diagnosis, Prevalence, Risk Assessment, Risk Factors, Severity of Illness Index, Sex Factors, Coronary Angiography, Coronary Artery Disease diagnostic imaging, Peripheral Arterial Disease epidemiology
- Abstract
To determine whether there are sex differences in the prevalence of peripheral artery disease, we performed an observational study of 1014 men and 547 women, aged ≥ 40 years, referred for elective coronary angiography. Women were slightly older, more obese, had higher low-density lipoprotein cholesterol (LDL-C) levels and systolic blood pressure (BP), and were more likely to be African American. Women had higher high-density lipoprotein cholesterol (HDL-C) levels, lower diastolic BP, and were less likely to smoke or to have a history of cardiovascular disease. Women had less prevalent (62% vs 81%) and less severe coronary artery disease (CAD) (p < 0.001 for both) by coronary angiography, but more prevalent peripheral artery disease (PAD) as determined by the ankle-brachial index (ABI) than men (23.6% versus 17.2%). Independent predictors of lower ABI were female sex, black race, older age, tobacco use, CAD, diabetes, and triglyceride level. In a full multivariable logistic regression model, women had a risk-adjusted odds ratio for PAD of 1.78 (95% CI 1.25-2.54) relative to men. Among patients referred for coronary angiography, women have less prevalent and less severe CAD, but more prevalent PAD, a sex difference that is not explained by traditional cardiovascular disease risk factors or CAD severity. Clinical Trial Registration-URL: http://clinicaltrials.gov. Unique identifier: NCT00380185.
- Published
- 2010
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31. Gendered innovations: a new approach for nursing science.
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Sims ST, Stefanick ML, Kronenberg F, Sachedina NA, and Schiebinger L
- Subjects
- Female, Humans, Male, Nursing Research, Sex Factors
- Abstract
Considerable sex and gender bias has been recognized within the field of medicine. Investigators have used sex and gender analysis to reevaluate studies and outcomes and generate new perspectives and new questions regarding differential diagnoses and treatments of men and women. Sex and gender analysis acts as an experimental control to provide critical scientific rigor; researchers who ignore it risk ignoring a possible source of error in past, current, and future science. In this article, the authors introduce some tools of sex and gender analysis and illustrate the concept of gendered innovations by demonstrating through examples how this type of analysis has profoundly enhanced human knowledge in health and disease. The authors also provide recommendations for incorporating the concepts of sex and gender analysis into nursing education and research.
- Published
- 2010
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32. Endogenous and exogenous female sex hormones and renal electrolyte handling: effects of an acute sodium load on plasma volume at rest.
- Author
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Sims ST, Rehrer NJ, Bell ML, and Cotter JD
- Subjects
- Adult, Arginine Vasopressin metabolism, Bicycling physiology, Body Water metabolism, Contraceptives, Oral, Hormonal pharmacology, Ethinyl Estradiol pharmacology, Female, Follicular Phase physiology, Hormones physiology, Humans, Levonorgestrel pharmacology, Luteal Phase physiology, Models, Statistical, Osmotic Pressure, Progestins pharmacology, Electrolytes metabolism, Gonadal Steroid Hormones pharmacology, Kidney metabolism, Plasma Volume drug effects, Rest physiology, Sodium pharmacology
- Abstract
This study was conducted to investigate effects of an acute sodium load on resting plasma volume (PV) and renal mechanisms across the menstrual cycle of endurance-trained women with natural (NAT) or oral contraceptive pill (OCP) controlled cycles. Twelve women were assigned to one of two groups, according to their usage status: 1) OCP [n = 6, 29 yr (SD 6), 59.4 kg (SD 3.2)], or 2) NAT [n = 6, 24 yr (SD 5), 61.3 kg (SD 3.6)]. The sodium load was administered as a concentrated sodium chloride/citrate beverage (164 mmol Na(+)/l, 253 mosmol/kgH(2)O, 10 ml/kg body mass) during the last high-hormone week of the OCP cycle (OCP(high)) or late luteal phase of the NAT cycle (NAT(high)) and during the low-hormone sugar pill week of OCP (OCP(low)) or early follicular phase of the NAT cycle (NAT(low)). The beverage ( approximately 628 ml) was ingested in seven portions across 60 min. Over the next 4 h, PV expanded more in the low-hormone phase for both groups (time-averaged change): OCP(low) 6.1% (SD 1.1) and NAT(low) 5.4% (SD 1.2) vs. OCP(high) 3.9% (SD 0.9) and NAT(high) 3.5% (SD 0.8) (P = 0.02). The arginine vasopressin increased less in the low-hormone phase [1.63 (SD 0.2) and 1.30 pg/ml (SD 0.2) vs. 1.82 (SD 0.3) and 1.57 pg/ml (SD 0.5), P = 0.0001], as did plasma aldosterone concentration ( approximately 64% lower, P = 0.0001). Thus PV increased more and renal hormone sensitivity was decreased in the low-hormone menstrual phase following sodium/fluid ingestion, irrespective of OCP usage.
- Published
- 2008
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33. Differences in wearer response to garments for outdoor activity.
- Author
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Laing RM, Sims ST, Wilson CA, Niven BE, and Cruthers NM
- Subjects
- Adult, Animals, Body Mass Index, Heart Rate, Humans, Male, Pilot Projects, Wool, Adaptation, Physiological, Clothing, Environment, Hot Temperature adverse effects, Motor Activity, Skin Temperature physiology
- Abstract
The performance of garments for outdoor activity was compared. Three fabrics, each in garments for the upper body, matched garment/wearer dimensions, were worn by 10 athletically 'well-trained' males under controlled conditions (hot 32 +/- 2 degrees C, 20 +/- 2% relative humidity (RH); cold 8 +/- 2 degrees C, 40 +/- 2% RH) with physical (instrumental) and sensory responses obtained during the trials. Differences in human responses to the fabrics/garments included heart rate, core temperature during run (hot, cold), rest (hot) and walk (cold), heat content of the body, humidity under garments during rest and run and time to onset of sweating. No such differences were identified for change in body mass, core temperature during walk (hot) and rest (cold), skin temperature, temperature of skin covered by the garment, humidity under the garments during walk or for any perceptions (thermal sensations, thermal comfort of torso, exertion, wetness). The garment in single jersey wool fabric performed best in both hot and cold conditions. Effects of garments on wearers are often related to properties of the fabrics from which the garments are made. This study shows that only some differences in fabric properties result in measurable thermophysiological and perceptual responses of the garment wearers and underlines the difficulty in predicting performance of garments/persons from laboratory tests on fabrics.
- Published
- 2008
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34. Preexercise sodium loading aids fluid balance and endurance for women exercising in the heat.
- Author
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Sims ST, Rehrer NJ, Bell ML, and Cotter JD
- Subjects
- Adult, Arginine Vasopressin blood, Beverages, Contraceptives, Oral pharmacology, Cross-Over Studies, Double-Blind Method, Estrogens physiology, Female, Humans, Menstrual Cycle physiology, Osmolar Concentration, Physical Endurance physiology, Sodium administration & dosage, Sodium blood, Water-Electrolyte Balance physiology, Exercise physiology, Hot Temperature, Physical Endurance drug effects, Sodium pharmacology, Water-Electrolyte Balance drug effects
- Abstract
This study was conducted during the high-hormone phase of both natural and oral contraceptive pill (OCP)-mediated menstrual cycles to determine whether preexercise ingestion of a concentrated sodium beverage would increase plasma volume (PV), reduce physiological strain, and aid endurance of moderately trained women cycling in warm conditions. Thirteen trained cyclists [peak O(2) uptake 52 ml x kg(-1) x min(-1) (SD 2), age 26 yr (SD 6), weight 60.8 kg (SD 5)] who were oral contraceptive users (n = 6) or not (n = 7) completed this double-blind, crossover experiment. Cyclists ingested a concentrated-sodium (High Na(+): 164 mmol Na(+)/l) or low-sodium (Low Na(+): 10 mmol Na(+)/l) beverage (10 ml/kg) before cycling to exhaustion at 70% Peak O(2) uptake in warm conditions (32 degrees C, 50% relative humidity, air velocity 4.5 m/s). Beverage (approximately 628 ml) was ingested in seven portions across 60 min beginning 105 min before exercise, with no additional fluid given until the end of the trial. Trials were separated by one to two menstrual cycles. High Na(+) increased PV (calculated from hematocrit and hemoglobin concentration) before exercise, whereas Low Na(+) did not [-4.4 (SD 1.1) vs. -1.9% (SD 1.3); 95% confidence interval: for the difference 5.20, 6.92; P < 0.0001], and it involved greater time to exhaustion [98.8 (SD 25.6) vs. 78.7 (SD 24.6) min; 95% confidence interval: 13.3, 26.8; P < 0.0001]. Core temperature rose more quickly with Low Na(+) [1.6 degrees C/h (SD 0.2)] than High Na(+) [1.2 degrees C/h (SD 0.2); P = 0.04]. Plasma [AVP], [Na(+)] concentration, and osmolality, and urine volume, [Na(+)], and osmolality decreased with sodium loading (P < 0.05) independent of pill usage. Thus preexercise ingestion of a concentrated sodium beverage increased PV, reduced thermoregulatory strain, and increased exercise capacity for women in the high-hormone phase of natural and oral contraceptive pill-mediated menstrual cycles, in warm conditions.
- Published
- 2007
- Full Text
- View/download PDF
35. Sodium loading aids fluid balance and reduces physiological strain of trained men exercising in the heat.
- Author
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Sims ST, van Vliet L, Cotter JD, and Rehrer NJ
- Subjects
- Adult, Cross-Over Studies, Double-Blind Method, Humans, Male, Middle Aged, Monitoring, Physiologic, New Zealand, Placebos, Exercise physiology, Hot Temperature, Physiological Phenomena physiology, Sodium administration & dosage, Water-Electrolyte Balance physiology
- Abstract
Purpose: This study was conducted to determine whether preexercise ingestion of a highly concentrated sodium beverage would increase plasma volume (PV) and reduce the physiological strain of moderately trained males running in the heat., Methods: Eight endurance-trained (.VO2max: 58 mL.kg(-1).min(-1) (SD 5); 36 yr (SD 11)) runners completed this double-blind, crossover experiment. Runners ingested a high-sodium (High Na+: 164 mmol Na+.L(-1)) or low-sodium (Low Na+: 10 mmol Na+.L(-1)) beverage (10 mL.kg(-1)) before running to exhaustion at 70% .VO2max in warm conditions (32 degrees C, 50% RH, V(a) approximately equal to 1.5 m.s(-1)). Beverages (approximately 757 mL) were ingested in seven portions across 60 min beginning 105 min before exercise. Trials were separated by 1-3 wk. Heart rate and core and skin temperatures were measured throughout exercise. Urine and venous blood were sampled before and after drinking and exercise., Results: High Na+ increased PV before exercise (4.5% (SD 3.7)), calculated from Hct and [Hb]), whereas Low Na+ did not (0.0% (SD 0.5); P = 0.04), and involved greater time to exercise termination in the six who stopped because of an ethical end point (core temperature 39.5 degrees C: 57.9 min (SD 6) vs 46.4 min (SD 4); P = 0.04) and those who were exhausted (96.1 min (SD 22) vs 75.3 min (SD 21); P = 0.03; High Na+ vs Low Na+, respectively). At equivalent times before exercise termination, High Na+ also resulted in lower core temperature (38.9 vs 39.3 degrees C; P = 0.00) and perceived exertion (P = 0.01) and a tendency for lower heart rate (164 vs 174 bpm; P = 0.08)., Conclusions: Preexercise ingestion of a high-sodium beverage increased plasma volume before exercise and involved less thermoregulatory and perceived strain during exercise and increased exercise capacity in warm conditions.
- Published
- 2007
- Full Text
- View/download PDF
36. Vaginal gonococcal cultures in sexual abuse evaluations: evaluation of selective criteria for preteenaged girls.
- Author
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Ingram DL, Everett VD, Flick LA, Russell TA, and White-Sims ST
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Disease Transmission, Infectious, Evaluation Studies as Topic, Female, Gonorrhea microbiology, Gonorrhea transmission, Humans, Infant, Male, Medical History Taking, Prospective Studies, Urine microbiology, Child Abuse, Sexual diagnosis, Gonorrhea diagnosis, Neisseria gonorrhoeae isolation & purification, Vagina microbiology
- Abstract
Objective: Accurate selective criteria could limit the number of vaginal cultures for Neisseria gonorrhoeae performed on preteenaged girls as part of their sexual abuse evaluations. This study was performed to determine whether the published selective criteria by the American Academy of Pediatrics (AAP) Committee on Child Abuse and Neglect and by Siegel et al would have accurately detected all cases of vaginal gonococcal infections in our large study population., Methods: We prospectively studied girls, ages 1 to 12 years, who were referred to our Child Sexual Abuse Team (CSAT) at Wake Medical Center in Raleigh, NC, between July 1, 1976 to July 1, 1996, for sexual abuse evaluations which were performed using a protocol that included collecting historical information, a sexual abuse interview, and a detailed genital examination which included a vaginal culture for N gonorrhoeae., Results: Our study population consisted of 2898 girls of whom 2731 (94%) had vaginal cultures successfully performed for N gonorrhoeae. There were 84 girls with vaginal gonococcal infections, 80 of whom had a vaginal discharge. The four girls without a vaginal discharge included two with a history of having vaginal intercourse with an alleged perpetrator with gonorrhea, one with N gonorrhoeae isolated from a urine culture, and one whose preteenaged sister had gonorrhea. All of the 84 girls would have been identified using the selective culturing criteria of the AAP Committee on Child Abuse and Neglect: culturing when epidemiologically indicated (interpreted as the girl having another sexually transmitted disease [STD], a child sibling, child household member, a close child associate or a perpetrator with a known STD) or when the history and/or physical findings suggest the possibility of oral, genital, or rectal contact, or Siegel et al's more selective criteria: only culturing prepubertal girls for N gonorrhoeae if there is a vaginal discharge at the time of presentation or if there is a high risk for STD acquisition, defined as having a STD diagnosed, a sibling with a STD, contact with a perpetrator known to have a STD, contact with multiple perpetrators, or Tanner stage III or above., Conclusion: Both the selective criteria of the AAP Committee on Child Abuse and Neglect and the more selective criteria of Siegel et al as we interpreted them were accurate when applied to identifying girls with vaginal gonococcal infections in our study population.
- Published
- 1997
- Full Text
- View/download PDF
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