Methods to Assess Energy Expenditure of Resistance Exercise: A Systematic Scoping Review.

BACKGROUND: Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the capacity to meaningfully quantify resistance exercise energy expenditure will assist practitioners and researchers in providing nutrition guidance. However, the significant contribution of anaerobic metabolism makes quantifying energy expenditure of resistance exercise challenging. OBJECTIVE: The aim of this scoping review was to investigate the methods used to assess resistance exercise energy expenditure. METHODS: A literature search of Medline, SPORTDiscus, CINAHL and Web of Science identified studies that included an assessment of resistance exercise energy expenditure. Quality appraisal of included studies was performed using the Rosendal Scale. RESULTS: A total of 19,867 studies were identified, with 166 included after screening. Methods to assess energy expenditure included indirect calorimetry (n = 136), blood lactate analysis (n = 25), wearable monitors (n = 31) and metabolic equivalents (n = 4). Post-exercise energy expenditure was measured in 76 studies. The reported energy expenditure values varied widely between studies. CONCLUSIONS: Indirect calorimetry is widely used to estimate energy expenditure. However, given its limitations in quantifying glycolytic contribution, indirect calorimetry during and immediately following exercise combined with measures of blood lactate are likely required to better quantify total energy expenditure. Due to the cumbersome equipment and technical expertise required, though, along with the physical restrictions the equipment places on participants performing particular resistance exercises, indirect calorimetry is likely impractical for use outside of the laboratory setting, where metabolic equivalents may be a more appropriate method.

The impact of 48 h high carbohydrate diets with high and low FODMAP content on gastrointestinal status and symptoms in response to endurance exercise, and subsequent endurance performance.

This study investigated the effects of a high carbohydrate diet, with varied fermentable oligo-, di-, and mono-saccharide and polyol (FODMAP) content, before endurance exercise on gastrointestinal integrity, motility, and symptoms; and subsequent exercise performance. Twelve endurance athletes were provided with a 48 h high carbohydrate (mean ± SD: 12.1 ± 1.8 g kg day-1) diet on two separate occasions, composed of high (54.8 ± 10.5 g day-1) and low FODMAP (3.0 ± 0.2 g day-1) content. Thereafter, participants completed a 2 h steady-state running exercise at 60% of V ˙ O 2 max (22.9 ± 1.2 °C, 46.4 ± 7.9% RH), followed by a 1 h distance performance test. Pre-exercise and every 20 min during steady-state exercise, 100 mL maltodextrin (10% w/v) solution was consumed. A 150 mL lactulose (20 g) solution was consumed 30 min into the distance performance test to determine orocecal transit time (OCTT) during exercise. Blood was collected pre- and post exercise to determine gastrointestinal integrity biomarkers (i.e., I-FABP, sCD14, and CRP). Breath hydrogen (H2) and gastrointestinal symptoms (GIS) were determined pre-exercise, every 15 min, during and throughout recovery. No differences in gastrointestinal integrity biomarkers, OCTT, or distance completed were observed between trials. Pre-exercise total-GIS (1.3 ± 2.9 vs. 4.3 ± 4.4), gut discomfort (9.9 ± 8.1 vs. 15.8 ± 9.0), and upper-GIS (2.8 ± 2.6 vs. 5.7 ± 4.8) during exercise were less severe on high carbohydrate low FODMAP (HC-LFOD) versus high carbohydrate high FODMAP (HC-HFOD) (p < 0.05). Gut discomfort (3.4 ± 4.4 vs. 0.2 ± 0.6) and total-GIS (4.9 ± 6.8 vs. 0.2 ± 0.6) were higher during recovery on HC-LFOD versus HC-HFOD (p < 0.05). The FODMAP content of a 48 h high carbohydrate diet does not impact gastrointestinal integrity or motility in response to endurance exercise. However, a high FODMAP content exacerbates GIS before and during exercise, but this does not impact performance outcomes.

Low Carbohydrate, High Fat Diet Alters the Oral Microbiome without Negating the Nitrite Response to Beetroot Juice Supplementation.

A low carbohydrate, high fat (LCHF) diet in athletes increases fat oxidation but impairs sports performance, potentially due to impaired exercise economy. Dietary nitrate supplementation can improve exercise economy via an increase in nitric oxide production, which is initiated by the reduction of nitrate to nitrite within the oral cavity. This reaction is dependent on the presence of nitrate-reducing oral bacteria, which can potentially be altered by dietary changes, including a LCHF diet. This study explored the effect of a LCHF diet on the oral microbiome and subsequent changes to plasma nitrite concentration following nitrate supplementation. Following five days of LCHF or high carbohydrate (HCHO) control dietary intervention, highly trained male race walkers consumed 140 mL beetroot juice containing 8.4 mmol nitrate; they then provided (a) blood samples for plasma nitrate and nitrite analysis and (b) saliva samples for 16S rRNA sequencing of the oral microbiome. The LCHF diet (n = 13) reduced oral bacterial diversity and changed the relative abundance of the genera Neisseria (+10%), Fusobacteria (+3%), Prevotella (-9%), and Veillonella (-4%), with no significant changes observed following the HCHO diet (n = 11). Following beetroot juice ingestion, plasma nitrite concentrations were higher for the LCHF diet compared to the HCHO diet (p = 0.04). However, the absence of an interaction with the trial (pre-post) (p = 0.71) suggests that this difference was not due to the dietary intervention. In summary, we found an increase in plasma nitrate and nitrite concentrations in response to nitrate supplementation independent of diet. This suggests the oral microbiome is adaptive to dietary changes and can maintain a nitrate reduction capacity despite a decrease in bacterial diversity following the LCHF diet.

Best practice recommendations for body composition considerations in sport to reduce health and performance risks: a critical review, original survey and expert opinion by a subgroup of the IOC consensus on Relative Energy Deficiency in Sport (REDs).

BACKGROUND: The assessment of body composition (BC) in sport raises concern for athlete health, especially where an overfocus on being lighter or leaner increases the risk of Relative Energy Deficiency in Sport (REDs) and disordered eating. METHODS: We undertook a critical review of the effect of BC on performance (29 longitudinal, prospective or intervention studies) and explored current practice related to BC considerations via a follow-up to a 2013 internationally distributed survey. RESULTS: The review found that a higher level of body fat was negatively associated with endurance performance, while a gain in muscle mass resulted in performance benefits across sports. BC did not contribute to early talent identification, and no unique cut-off to signify a performance advantage for BC was identified. BC appears to be one of an array of variables impacting performance, and its influence should not be overstated. The survey (125 practitioners, 61 sports and 26 countries) showed subtle changes in BC considerations over time, such as an increased role for sport dietitian/nutrition practitioners as BC measurers (2013: 54%, 2022: 78%); less emphasis on reporting of body fat percentage (2013: 68%, 2022: 46%) and reduced frequency of BC assessment if ≥every fourth week (2013: 18%, 2022: 5%). Respondents remained concerned about a problematic focus on BC (2013: 69%, 2022: 78%). To address these findings, we provide detailed recommendations for BC considerations, including an overview of preferable BC methodology. CONCLUSIONS: The 'best practice' guidelines stress the importance of a multidisciplinary athlete health and performance team, and the treatment of BC data as confidential medical information. The guidelines provide a health focus around BC, aiming to reduce the associated burden of disordered eating, problematic low energy availability and REDs.

The effect of percentage of ideal body weight on outcomes in ileo-anal pull through for ulcerative colitis.

PURPOSE: Ileo-anal pull through (IAPT) is a commonly performed operation for the surgical management of ulcerative colitis. The effect of body weight on outcomes for patients undergoing this operation has not been extensively studied. METHODS: This was a prospective cohort study at a single tertiary care inflammatory bowel disease (IBD) center. A total of 457 patients who were operated on at the Mount Sinai Medical Center between 1983 and 2015 were included. Demographic characteristics, the patients' body weight at the time of IAPT, and postoperative outcome data were collected. RESULTS: For each patient, body weight was calculated as a percentage of the ideal body weight (IBW) for that patient's height. The mean percentage of ideal body weight was 93.9% with a standard deviation of 20%. The range for the population was 53.1 to 175%. Four hundred forty (96%) of the patients had a weight within two standard deviations of the mean, indicating a normal distribution. Seventy-nine patients developed a Clavien-Dindo class III complication necessitating a procedural treatment. The most common of these was a stricture at the anastomotic site (n = 54). Our study identified an association between a percentage of ideal body weight in the lowest quartile of our population and development of an anastomotic stricture. This association was statistically significant on multivariate analysis. CONCLUSION: Low body weight at the time of ileo-anal pull through for treatment of UC may be a risk factor for development of anastomotic stricture requiring dilation.

Athlete Preferences for Nutrition Education: Development of and Findings from a Quantitative Survey.

Nutrition education (NE) is one of several strategies aimed at enhancing the dietary intake of athletes. This study investigated NE preferences of New Zealand and Australian athletes competing nationally and internationally. Athletes (n = 124, 22 (18, 27) years, female 54.8%) from 22 sports completed an online survey, with responses analysed using descriptive statistics. Teaching techniques considered 'extremely effective' were life examples (47.6% of athletes), hands-on activities (30.6%), and discussions with a facilitator (30.6%). Setting personal nutrition goals was important to most athletes (83.9%), along with two-way feedback with a facilitator (75.0%). General nutrition topics considered 'essential' were energy requirements (52.9%), hydration (52.9%), and nutrient deficiencies (43.3%). Performance topics considered 'essential' were recovery (58.1%), pre-exercise nutrition (51.6%), nutrition during exercise (50.0%), and energy requirements for training (49.2%). Athletes preferred a 'combination of in-person group and one-on-one sessions' (25% of athletes), 'one-on one sessions' (19.2%) and 'in-person group sessions' (18.3%), with only 13.3% interested in 'exclusively online delivery'. Sessions of 31-60 min (61.3% of athletes) held monthly (37.5%) and undertaken with athletes of the same sporting calibre (61.3%) were favoured by the participants. The preferred facilitator was a performance dietitian or nutritionist (82.1% of athletes), who had knowledge of the sport (85.5%), experience in sports nutrition (76.6%), and credibility (73.4%). This research provides novel insights into the factors that need to be considered when designing and implementing nutrition education for athletes.

Carbohydrate knowledge, beliefs, and intended practices, of endurance athletes who report exercise-associated gastrointestinal symptoms.

This study aimed to explore carbohydrate (CHO) knowledge, beliefs, and intended practices of endurance athletes who experience exercise-associated gastrointestinal symptoms (Ex-GIS) compared to those without Ex-GIS. A validated online questionnaire was completed by endurance athletes (n = 201) participating in >60 min of exercise that present with Ex-GIS (n = 137) or without (n = 64). Descriptive statistics were used for parametric and non-parametric data with appropriate significance tests. Associations between categorical data were assessed by Chi-square analysis, and post-hoc Bonferroni tests were applied when significant. A content analysis of open-ended responses was grouped into themes, and quantitative statistics were applied. Participants included runners (n = 114, 57%), triathletes (n = 43, 21%) and non-running sports (n = 44, 21%) who participate in recreational competitive (n = 74, 37%), recreational non-competitive (n = 64, 32%), or competitive regional, national, or international levels (n = 63, 31%). Athletes correctly categorized CHO (x̄ = 92-95%) and non-CHO (x̄ = 88-90%) food and drink sources. On a Likert scale of 1 (strongly disagree) to 5 (strongly agree) athletes typically agree or strongly agree that consuming CHO around key training sessions and competitions enhances athletic performance [median = 4 (IQR, 4-5)], and they intend to consume more CHO around exercise [median = 3 (IQR, 2-3)]. No differences in beliefs and intentions were found among athletes with or without Ex-GIS. To enhance athletic performance, most endurance athletes intend to consume more CHO around exercise. Adequate knowledge of CHO-containing food sources was apparent; however, specific CHO ingestion practices remain to be verified.

Protocol Standardization May Improve Precision Error of InBody 720 Body Composition Analysis.

BACKGROUND: Bioelectrical impedance analysis (BIA) is a popular technique which can be used to track longitudinal changes in body composition. However, precision of the technique has been questioned, especially among athletic populations where small but meaningful changes are often observed. Guidelines exist which attempt to optimize precision of the technique but fail to account for potentially important variables. Standardization of dietary intake and physical activity in the 24 hr prior to assessment has been proposed as an approach to minimizing the error of impedance-derived estimates of body composition. METHODS: Eighteen recreational athletes, male (n = 10) and female (n = 8), underwent two consecutive BIA tests to quantify within-day error, and a third test (the day before or after) to quantify between-day error. All food and fluid intake plus physical activity from the 24 hr prior to the first BIA scan was replicated during the following 24 hr. Precision error was calculated as the root mean square standard deviation, percentage coefficient of variation, and least significant change. RESULTS: There were no significant differences in precision error of within- and between-day fat-free mass, fat mass, and total body water. Differences in precision error of fat-free mass and total body water, but not fat mass, were less than the smallest effect size of interest. CONCLUSION: The 24-hr standardization of dietary intake and physical activity may be an effective approach to minimizing precision error associated with BIA. However, further research to confirm the validity of this protocol compared to nonstandardized or randomized intake is warranted.

Ratcheting Charged Polymers through Symmetric Nanopores Using Pulsed Fields: Designing a Low Pass Filter for Concentrating Polyelectrolytes.

We present a new concept for the separation of DNA molecules by contour length that combines a nanofluidic ratchet, nanopore translocation, and pulsed fields. Using Langevin dynamics simulations, we show that it is possible to design pulsed field sequences to ratchet captured semiflexible molecules in such a way that only short chains successfully translocate, effectively transforming the nanopore process into a low pass molecular filter. We also show that asymmetric pulses can significantly enhance the device efficiency. The process itself can be performed with many pores in parallel, and it should be possible to integrate it directly into nanopore sequencing devices, increasing its potential utility.

Dietary Intake and Body Composition During Ramadan in Athletes: A Systematic Review and Meta-Analysis With Meta-Regression.

The aim of this research was to evaluate the effect of Ramadan observance on dietary intake and body composition in adult athletes. This was a systematic review and meta-analysis. Data sources used were PubMed, Web of Science, Scopus, and Taylor and Francis. Eligibility criteria for selecting studies were as follows: single-group, pre-/post-Ramadan, with or without control group, conducted in athletes aged ≥19 years training at least twice a week, and published in any language before August 25, 2021. Studies assessing dietary intake and/or body composition were deemed eligible. The methodological quality of studies was assessed using QualSyst. Nine studies evaluated dietary intake; 4 of these were rated as strong quality and the remaining as moderate. Of the 17 selected studies evaluating body composition, 7 were of strong quality and the remaining 10 were rated as moderate. Compared to pre-Ramadan, energy (number of studies, K = 7; number of participants, N = 78; g = -0.781; 95% confidence interval [CI], -1.416 to -0.145; p = 0.016), carbohydrate (K = 5; N = 50; g = -1.643; 95% CI, -2.949 to -0.336; p = 0.014), and water (K = 4; N = 39; g = -1.081; 95% CI, -1.371 to -0.790; p = 0.000) intakes decreased during Ramadan. However, fat (K = 5; N = 50; g = -0.472; 95% CI, -1.085 to 0.140; p = 0.131) and protein (K = 5; N = 60; g = -0.574; 95% CI, -1.213 to -0.066; p = 0.079) intakes remained unchanged. Compared to pre-Ramadan, body mass (K = 16; N = 131; g = -0.262; 95% CI, -0.427 to -0.097; p = 0.002) and body fat percentage (K = 8; N = 81; g = -0.197; 95% CI, -0.355 to -0.040; p = 0.014) decreased in the fourth week of Ramadan. Lean body mass did not change during Ramadan (K = 4; N = 45; g = -0.047; 95% CI, -0.257 to 0.162; p = 0.658). Carbohydrate and total water intake decreased with the observance of Ramadan, but fat and protein intake were unchanged. Continued training of athletes during Ramadan was associated with a decreased body mass and body fat percentage, but not lean body mass, toward the end of the fasting month.Key pointsRamadan fasting decreases body mass and body fat percentage of athletes, but not lean body mass.Longer durations of fasting could provoke more pronounced decrements in body mass.Carbohydrate and total water intake decreased during Ramadan in athletes.Future studies, with greater methodological rigor, are required to better discern changes in dietary intake and body composition during Ramadan.Supplemental data for this article is available online at https://doi.org/10.1080/07315724.2021.2000902 .

Impact of 24-Hr Diet and Physical Activity Control on Short-Term Precision Error of Dual-Energy X-Ray Absorptiometry Physique Assessment.

Dual-energy X-ray absorptiometry (DXA) is a popular technique used to quantify physique in athletic populations. Due to biological variation, DXA precision error (PE) may be higher than desired. Adherence to standardized presentation for testing has shown improvement in consecutive-day PE. However, the impact of short-term diet and physical activity standardization prior to testing has not been explored. This warrants investigation, given the process may reduce variance in total body water and muscle solute, both of which can have high daily flux amongst athletes. Twenty (n = 10 males, n = 10 females) recreationally active individuals (age: 30.7 ± 7.5 years; stature: 176.4 ± 9.1 cm; mass: 74.6 ± 14.3 kg) underwent three DXA scans; two consecutive scans on 1 day, and a third either the day before or after. In addition to adhering to standardized presentation for testing, subjects recorded all food/fluid intake plus activity undertaken in the 24 hr prior to the first DXA scan and replicated this the following 24 hr. International Society of Clinical Densitometry recommended techniques were used to calculate same- and consecutive-day PE. There was no significant difference in PE of whole-body fat mass (479 g vs. 626 g) and lean mass (634 g vs. 734 g) between same- and consecutive-day assessments. Same- and consecutive-day PE of whole-body fat mass and lean mass were less than the smallest effect size of interest. Inclusion of 24-hr standardization of diet and physical activity has the potential to reduce biological error further, but this needs to be verified with follow-up investigation.

An exploratory study of the management strategies reported by endurance athletes with exercise-associated gastrointestinal symptoms.

This exploratory study investigated endurance athletes self-reported exercise-associated gastrointestinal symptoms (Ex-GIS) and associated strategies to manage symptomology. Adult endurance athletes with a history of Ex-GIS (n = 137) participating in events ≥ 60 min completed an online validated questionnaire. Respondents included runners (55%, n = 75), triathletes (22%, n = 30), and non-running sports (23%, n = 32), participating at a recreationally competitive (37%, n = 51), recreationally non-competitive (32%, n = 44), and competitive regional/national/international (31%, n = 42) levels. Athletes identified when Ex-GIS developed most frequently either around training (AT), around competitions (AC), or equally around both training (ET) and competitions (EC). Athletes reported the severity of each symptom before, during, and after exercise. Athletes predominantly categorized Ex-GIS severity as mild (< 5/10) on a 0 (no symptoms) to 10 (extremely severe symptoms) visual analog symptomology scale. The Friedman test and post hoc analysis with Wilcoxon signed rank test was conducted with a Bonferroni correction applied to determine differences between repeated measures. The only severe symptom of significance was the urge to defecate during training in the ET group (Z = -0.536, p = 0.01). Ex-GIS incidence was significantly higher during training and competitions in all categories. A content review of self-reported strategies (n = 277) to reduce Ex-GIS indicated popular dietary strategies were dietary fiber reduction (15.2%, n = 42), dairy avoidance (5.8%, n = 16), and a low fermentable oligosaccharides, monosaccharides, and polyols (FODMAP) diet (5.4%, n = 15). In contrast, non-dietary strategies included the use of medications (4.7%, n = 13) and relaxation/meditation (4.0%, n = 11). On a Likert scale of 1-5, the most successful dietary strategies implemented were dietary fiber reduction (median = 4, IQR = 4, 5), low FODMAP diets (median = 4, IQR = 4, 5), dairy-free diets (median = 4, IQR = 4, 5), and increasing carbohydrates (median = 4, IQR = 3, 4). Accredited practicing dietitians were rated as the most important sources of information for Ex-GIS management (n = 29). Endurance athletes use a variety of strategies to manage their Ex-GIS, with dietary manipulation being the most common.

Determinants of Food Choice in Athletes: A Systematic Scoping Review.

BACKGROUND: The individual determinants of food choice have been extensively investigated in the general population, but there have been limited studies in athletes. A better understanding of the food making decisions can help to target interventions that lead to optimal intake for athletes' health and performance. A scoping review will provide an understanding of the sports and settings that have been investigated, the methods and approaches to assessing food choice, as well as the factors influencing food choice. OBJECTIVE: The objective of this review was to map the available evidence on the multi-faceted determinants of food choice in athletes and describe key influences impacting their choices. ELIGIBILITY CRITERIA: Athletes 16 years and over from any country who engage in physical activity with the intent to be competitive. Studies were included if they reported the multi-faceted determinants of food choice as either a primary or secondary outcome. All study designs were considered. SOURCES OF EVIDENCE: This review followed the PRISMA extension for Scoping Reviews. Eleven databases including PubMed, Web of Science (Clarivate Analytics), SPORTDiscus (EBSCO), PsycNET (APA), Health Collection (Informit), CINAHL (EBSCO), the Cochrane Library, ProQuest Dissertations and Theses Global, Trove (National Library of Australia), JBI (Ovid), and Google scholar were searched between September-November 2020 and updated in March 2021. Charting of Data Search results were screened with selected studies extracted into a summary table established a priori by the authors. Study quality was assessed using standardised reporting tools for qualitative and quantitative research designs. The scope and quality of evidence was summarised and reported. RESULTS: A total of 15 studies were included. Qualitative research included one research thesis and six primary research studies using both focus groups and semi-structured interviews. Quantitative research included one research thesis and seven primary research studies with cross-sectional design using different validated and non-validated survey instruments. No longitudinal or intervention studies were found. The majority of studies have been published since 2018 and conducted across multiple countries with either mixed cohorts of athletes or focused on predominately endurance or team sports. The quality of reporting was variable, particularly for qualitative research. Outcomes suggested that performance and health were relevant to athlete food choice, with varying impact of competition season, the level of experience, the culture of the sport, the cultural background or nationality of the athlete, athlete sex and the food environment. CONCLUSION: More research is needed on the multi-faceted determinants of food choice in different cohorts of athletes, particularly females. Future research could explore the relationship between food choice, nutrition knowledge and diet quality or the change in food choice across the phase of the seasons and through injury and illness. Use of validated measurement tools and robust reporting will enable critical interpretation of the study methods and outcomes for use in practice. Registration OSF Registries: Open-ended registration 25th Sept 2020 https://doi.org/10.17605/OSF.IO/4PX2A.

Screening for Low Energy Availability in Male Athletes: Attempted Validation of LEAM-Q.

A questionnaire-based screening tool for male athletes at risk of low energy availability (LEA) could facilitate both research and clinical practice. The present options rely on proxies for LEA such screening tools for disordered eating, exercise dependence, or those validated in female athlete populations. in which the female-specific sections are excluded. To overcome these limitations and support progress in understanding LEA in males, centres in Australia, Norway, Denmark, and Sweden collaborated to develop a screening tool (LEAM-Q) based on clinical investigations of elite and sub-elite male athletes from multiple countries and ethnicities, and a variety of endurance and weight-sensitive sports. A bank of questions was developed from previously validated questionnaires and expert opinion on various clinical markers of LEA in athletic or eating disorder populations, dizziness, thermoregulation, gastrointestinal symptoms, injury, illness, wellbeing, recovery, sleep and sex drive. The validation process covered reliability, content validity, a multivariate analysis of associations between variable responses and clinical markers, and Receiver Operating Characteristics (ROC) curve analysis of variables, with the inclusion threshold being set at 60% sensitivity. Comparison of the scores of the retained questionnaire variables between subjects classified as cases or controls based on clinical markers of LEA revealed an internal consistency and reliability of 0.71. Scores for sleep and thermoregulation were not associated with any clinical marker and were excluded from any further analysis. Of the remaining variables, dizziness, illness, fatigue, and sex drive had sufficient sensitivity to be retained in the questionnaire, but only low sex drive was able to distinguish between LEA cases and controls and was associated with perturbations in key clinical markers and questionnaire responses. In summary, in this large and international cohort, low sex drive was the most effective self-reported symptom in identifying male athletes requiring further clinical assessment for LEA.

Capture and translocation of a rod-like molecule by a nanopore: orientation, charge distribution and hydrodynamics.

We investigate the translocation of rods with different charge distributions using hybrid Langevin dynamics and lattice Boltzmann (LD-LB) simulations. Electrostatic interactions are added to the system using the P3M algorithm to model the electrohydrodynamic interactions (EHI). We first examine the free-solution electrophoretic properties of rods with various charge distributions. Our translocation simulation results suggest that the order parameter is asymmetric during the capture and escape processes despite the symmetric electric field lines, while the impacts of the charge distribution on rod orientation are more significant during the capture process. The capture/threading/escape times are under the combined effects of charge screening, rod orientation, and charge distributions. We also show that the mean capture time of a rod is shorter when it is launched near the wall because rods tend to align along the wall and hence with the local field lines. Remarkably, the orientational capture radius we proposed previously for uniformly charged rods is still valid in the presence of EHI.

Accuracy of body composition measurement techniques across the age span.

This study investigated the acceptable accuracy of common body composition techniques compared with the reference 4-compartment (4C-R) model, which has not been investigated in a sample with diverse characteristics, including age and sex. Techniques included components of the 4C-R model [dual-energy X-ray absorptiometry, air displacement plethysmography, deuterium dilution (DD)] and surrogate compartment models, which utilised bioelectrical impedance spectroscopy (BIS) rather than DD. Men and women (sex = 1:1, 18-85 years, n = 90) completed body composition testing under best-practice guidance. For measurement of individuals, only the reference 3-compartment (3C-R) equation met acceptable error limits (<5% error among individuals) within the a priori cut-point (80%) for fat-free mass (FFM; CV = 0.52%) and fat mass (FM; CV = 1.61%). However, all investigated techniques reached equivalency to the 4C-R model for FFM on average (CV = 0.52-4.31%), but for FM only the 3C and 4C equations that included quantification of total body water (TBW) by DD or BIS reached equivalency overall (CV = 1.61-6.68%). Sex and age minimally influenced accuracy. Only the 3C-R or 4C-R equations are supported for acceptable individual accuracy for both FFM and FM. For group estimates any investigated technique could be used with acceptable accuracy for FFM; however, for FM, inclusion of TBW measurement within a compartment model is necessary. Novelty: Only the referent 3C and 4C models (including deuterium dilution) provide accurate body composition results that are acceptable for measurement of individuals in the general population. For group estimates of lean mass in the general population, compartments models that include TBW must be used for accurate measurement.

Perianal Fistula After Ileoanal Pouch in Patients With Ulcerative Colitis: A Review of 475 Patients Operated on at a Major IBD Center.

BACKGROUND: Ileoanal pouch anastomosis is the surgical treatment of choice for patients with intractable ulcerative colitis. Perianal disease is a feature that is often present in Crohn's disease and infrequently in ulcerative colitis. OBJECTIVE: The aim of this study is to identify the incidence and factors associated with the development of postoperative perianal fistula in patients undergoing ileoanal pouch anastomosis for ulcerative colitis. DESIGN: A prospectively collected database at the time of surgery with subsequent follow-up was utilized. SETTING: The study was conducted at a high-volume single institution. PATIENTS: We studied a series of 475 consecutive patients with preoperative diagnosis of ulcerative colitis who underwent ileoanal pouch anastomosis. MAIN OUTCOME MEASURES: The incidence of postoperative perianal fistula and the factors correlating with its development were primary outcome measures of the study. RESULTS: The overall number of patients developing perianal fistulas was 44 of 475 (9%). Eleven patients with perianal fistula (25%) required return to ileostomy, of which 7 had pouch excision. Patients who developed a postoperative perianal fistula had a younger age at the onset of disease, had a lower age at index surgery, and were more likely to be subsequently classified as indeterminate colitis or Crohn's disease. Patients developing perianal fistulas were also more likely to develop partial dehiscence or stricture of the ileoanal anastomosis. LIMITATIONS: This study spans nearly 40 years during which the surgical procedure evolved. CONCLUSIONS: Young age at the onset of disease, lower age at surgery, and postoperative diagnosis of Crohn's disease and indeterminate colitis were the factors correlating with perianal fistulas. Delayed healing of the ileoanal anastomosis with partial separation and/or stricture also correlated with the onset of perianal fistulas. The severity of rectal inflammation at the time of surgery or the presence of stapled versus handsewn anastomosis did not correlate with the development of perianal fistulas. See Video Abstract at http://links.lww.com/DCR/B705. FSTULA PERIANAL POSTERIOR A RESERVORIO ILEOANAL EN PACIENTES CON COLITIS ULCERATIVA UNA REVISIN DE PACIENTES OPERADOS EN UN CENTRO PRINCIPAL DE EII: ANTECEDENTES:El reservorio ileoanal es el tratamiento quirúrgico de elección para los pacientes con colitis ulcerativa intratable. La enfermedad perianal es una característica que a menudo está presente en la enfermedad de Crohn y con poca frecuencia en la colitis ulcerativa.OBJETIVO:El objetivo del estudio es identificar la incidencia y los factores asociados con el desarrollo de fístula perianal posoperatoria en pacientes sometidos a reservorio ileoanal por colitis ulcerativa.DISEÑO:Base de datos recopilada prospectivamente en el momento de la cirugía con seguimiento subsecuente.ENTORNO CLÍNICO:El estudio se llevó a cabo en una única institución de gran volumen.PACIENTES:Estudiamos una serie de 475 pacientes consecutivos con diagnóstico preoperatorio de colitis ulcerativa a los que se les realizó reservorio ileoanal.PRINCIPALES MEDIDAS DE VALORACIÓN:La incidencia de fístula perianal posoperatoria y los factores que se correlacionan con su desarrollo fueron las principales medidas de resultado del estudio.RESULTADOS:El número total de pacientes que desarrollaron fístulas perianales fue 44 de 475 (9%). Once pacientes con fístula perianal (25%) requirieron volver a la ileostomía, de los cuales 7 tuvieron resección del reservorio. Los pacientes que desarrollaron fístula perianal posoperatoria tenían edad más temprana al inicio de la enfermedad, menor edad en el momento de la cirugía inicial y tenían más probabilidades de ser clasificados posteriormente como colitis indeterminada o enfermedad de Crohn. Los pacientes que desarrollaron fístulas perianales también fueron más propensos a desarrollar dehiscencia parcial o estenosis de la anastomosis ileoanal.LIMITACIONES:Este estudio abarca casi 40 años durante los cuales ha evolucionado el procedimiento quirúrgico.CONCLUSIONES:Edad temprana al inicio de la enfermedad, menor edad al momento de la cirugía, diagnóstico postoperatorio de enfermedad de Crohn y colitis indeterminada fueron los factores que se correlacionaron con las fístulas perianales. El retraso en la cicatrización de la anastomosis ileoanal con separación parcial y/o estenosis también se correlacionó con la aparición de fístulas perianales. La gravedad de la inflamación rectal en el momento de la cirugía o la presencia de anastomosis con grapas versus anastomosis manual no se correlacionó con el desarrollo de fístulas perianales. Consulte Video Resumen en http://links.lww.com/DCR/B705.

Prevalence of Surrogate Markers of Relative Energy Deficiency in Male Norwegian Olympic-Level Athletes.

The syndrome of Relative Energy Deficiency in Sport (RED-S) includes wide-ranging effects on physiological and psychological functioning, performance, and general health. However, RED-S is understudied among male athletes at the highest performance levels. This cross-sectional study aimed to investigate surrogate RED-S markers prevalence in Norwegian male Olympic-level athletes. Athletes (n = 44) aged 24.7 ± 3.8 years, body mass 81.3 ± 15.9 kg, body fat 13.7% ± 5.8%, and training volume 76.1 ± 22.9 hr/month were included. Assessed parameters included resting metabolic rate (RMR), body composition, and bone mineral density by dual-energy X-ray absorptiometry and venous blood variables (testosterone, free triiodothyronine, cortisol, and lipids). Seven athletes (16%) grouped by the presence of low RMR (RMRratio < 0.90) (0.81 ± 0.07 vs. 1.04 ± 0.09, p < .001, effect size 2.6), also showed lower testosterone (12.9 ± 5.3 vs. 19.0 ± 5.3 nmol/L, p = .020) than in normal RMR group. In low RMRratio individuals, prevalence of other RED-S markers (-subclinical-low testosterone, low free triiodothyronine, high cortisol, and elevated low-density lipoprotein) was (N/number of markers): 2/0, 2/1, 2/2, 1/3. Low bone mineral density (z-score < -1) was found in 16% of the athletes, all with normal RMR. Subclinical low testosterone and free triiodothyronine levels were found in nine (25%) and two (5%) athletes, respectively. Subclinical high cortisol was found in 23% of athletes while 34% had elevated low-density lipoprotein cholesterol levels. Seven of 12 athletes with two or more RED-S markers had normal RMR. In conclusion, this study found that multiple RED-S markers also exist in male Olympic-level athletes. This highlights the importance of regular screening of male elite athletes, to ensure early detection and treatment of RED-S.

Increased carbohydrate availability effects energy and nutrient periodisation of professional male athletes from the Australian Football League.

This research aimed to explore the effect of increased carbohydrate availability intervention on energy intake and distribution in professional Australian Football athletes. Six 24-h energy and macronutrient intakes were quantified (n = 19 males; age 24 ± 4 y, stature 187 ± 8 cm, mass 87 ± 9 kg) using photographic food diaries and Foodworks analyses. Energy expenditure was estimated for the same period using GeneActiv accelerometers. During 3 control days, athletes had ad libitum access to food, while the 3 intervention days increased carbohydrate availability, through greater prompting and access to carbohydrate foods. Daily energy intake was higher during intervention (185 ± 40 kJ/kg/d) compared with control (172 ± 31 kJ/kg/d; p < 0.05) but remained below estimated expenditure, and carbohydrate intake was also greater with intervention (5.0 ± 0.2 g/kg/d) than control (4.0 ± 0.2 g/kg/d; p < 0.05). Expenditure was highest during the morning, which coincided with lowest intake on all days, while the intervention was associated with greater carbohydrate intake in the morning (0.6 g/kg, p < 0.05) compared with control. Increasing availability of carbohydrate during high-load training generated a modest increase in carbohydrate and energy intake, and the intervention was most effective in improving carbohydrate intake during mornings. Novelty: Increased access and provision of carbohydrate foods increased carbohydrate consumption and energy intake on high training load days. Daily distribution of energy intake can be modified through actively promoting carbohydrate consumption.

Development and validation of a questionnaire investigating endurance athletes practices to manage gastrointestinal symptoms around exercise.

AIM: To develop and validate a questionnaire investigating endurance athletes' carbohydrate beliefs, knowledge, information sources, and other dietary and non-dietary practices related to exercise-associated gastrointestinal symptoms. METHODS: A questionnaire was developed by a review of relevant literature and sports-related questionnaires, and input from five experienced sports dietitians. Item construct and format was adapted and modified from a previous questionnaire. The modified questionnaire sought information on demographics, nutrition knowledge, beliefs, intended practices, information sources and exercise-associated gastrointestinal symptoms. A five-phase validity process was conducted to determine content, face and construct validity, item difficulty and internal reliability of the questionnaire. The Delphi technique was applied with experts over three anonymous rounds. Items were reviewed to determine whether to keep, modify, or delete, rate the relevance of each item using a content validity index (CVI), and provide comments. A content analysis was conducted on all comments after each round. Online interviews were conducted with a pilot group of endurance athletes (n = 15) to assess item difficulty and feasibility. Nutrition knowledge was compared between pilot group of athletes and experts to determine construct validity and internal consistency. A test-retest process was applied to a second pilot group (n = 8) to verify questionnaire reliability. RESULTS: High CVI (≥.83) and agreement scores were obtained through the Delphi technique. High reliability (r = .942) and acceptable internal consistency (α = .53-.78) of the questionnaire were obtained. CONCLUSIONS: The questionnaire was shown to be a valid and reliable tool that will be of use for clinicians and research purposes.