Compression Socks Reduce Running-Induced Intestinal Damage.

ABSTRACT: Zadow, EK, Edwards, KH, Kitic, CM, Fell, JW, Adams, MJ, Singh, I, Kundur, A, Johnstone, ANB, Crilly, J, Bulmer, AC, Halson, SL, and, and Wu, SSX. Compression socks reduce running-induced intestinal damage. J Strength Cond Res 36(9): 2461-2464, 2022-Exercise is associated with a reduction in splanchnic blood flow that leads to the disruption of intestinal epithelium integrity, contributing to exercise-induced gastrointestinal syndrome. Strategies that promote intestinal blood flow during exercise may reduce intestinal damage, which may be advantageous for subsequent recovery and performance. This study aimed to explore if exercise-associated intestinal damage was influenced by wearing compression garments, which may improve central blood flow. Subjects were randomly allocated to wear compression socks ( n = 23) or no compression socks (control, n = 23) during a marathon race. Blood samples were collected 24 hours before and immediately after marathon and analyzed for intestinal fatty acid-binding protein (I-FABP) concentration as a marker of intestinal damage. The magnitude of increase in postmarathon plasma I-FABP concentration was significantly greater in control group (107%; 95% confidence interval [CI], 72-428%) when compared with runners wearing compression socks (38%; 95% CI, 20-120%; p = 0.046; d = 0.59). Wearing compression socks during a marathon run reduced exercise-associated intestinal damage. Compression socks may prove an effective strategy to minimize the intestinal damage component of exercise-induced gastrointestinal syndrome.

Association between a delay in driving licensure and driving while impaired and riding with an impaired driver among emerging adults.

BACKGROUND: Teens who delay driving licensure may not be subject to graduated driver licensing restrictions that are known to reduce crash risk. We explored the association of delay in licensure with driving while impaired (DWI) and riding with an impaired driver (RWI) among emerging adults. METHODS: Data from the NEXT Generation Health Study, starting with 10th grade (2009-2010), were analyzed. The outcome variables were Wave 7 (W7) self-reported DWI and RWI as dichotomous variables. The independent variable was delay in licensure. Covariates included sex, urbanicity, race/ethnicity, family structure, parent education, family affluence, teen's highest education, minimum legal drinking age laws, and onset age of alcohol use. Descriptive analysis and logistic regressions were conducted. RESULTS: Of 2525 participants eligible for licensure, 887 reported a delay in licensure by 1-2 years (38.9%, weighted) and 1078 by > 2 years (30.3% weighted) across 7 waves. In W7, 23.5% (weighted and hereafter, 5.6% once, 17.8% ≥twice) of participants reported DWI and 32.42% (5.6% once, 25.4% ≥twice) reported RWI. Logistic regressions showed no overall significant association of delay in licensure with either W7 RWI or W7 DWI. However, in stratified analyses, among African American youth, delay in licensure was positively associated with DWI (OR = 2.41, p = 0.03) and RWI (OR = 2.72, p = 0.05). Among those with ≤ high school or lower education by W7, delayed licensure was positively associated with RWI (OR = 2.51, p < 0.01). CONCLUSIONS: While in the overall sample, delayed licensure did not appear to be associated with DWI or RWI, our findings suggest that delayed licensure may be of concern to teen risk of DWI and RWI among African Americans and among those with lower educational attainment. Furthermore, as two-thirds of youth delayed licensure, more research is needed to determine whether this is more of a positive (i.e., protective) factor by reducing their exposure to crash risk or a negative (i.e., risk) factor due to their missing important driver safety stages of graduated driver licensing.

Deep vein thrombosis in a well-trained masters cyclist, is popliteal vein entrapment syndrome to blame?

Whilst athletes are the epitome of health, venous thromboembolisms (VTE) including deep vein thrombosis and pulmonary embolism have been demonstrated to occur in well-trained athletes. VTE is frequently misdiagnosed and poorly treated within this population, often resulting in career or life-threatening ramifications. Furthermore, VTE risk rises with increasing age (> 40 years), potentially affecting masters athletes. A 44-year-old well-trained male cyclist volunteered to participate in a research project investigating the influence of exercise on haemostasis in well-trained athletes. The cyclist presented with elevated D-Dimer levels both pre- (2251 ng/mL) and post-exercise (2653 ng/mL). The cyclist reported constant mild-pain in the left mid-calf region, with a cold tingling sensation in their left foot. Diagnosis of DVT was confirmed via a DVT squeeze test and Doppler ultrasound, with the clot located in the left popliteal vein. During the research project, the cyclist was exposed to numerous thrombogenic risk factors including travel, dehydration, prolonged sitting and exercise. The DVT in the popliteal vein may have resulted from repetitive movements associated with cycling. Additionally, hypertrophy of the gastrocnemius muscle may have impinged the vein. When diagnosing DVT within a cycling population, PVES should not be overlooked as a contributing factor.

The effect of an ultra-endurance running race on heart rate variability.

PURPOSE: The aim of this study was to investigate the effect of an ultra-marathon on heart rate variability (HRV) and psychometric indices in endurance runners. In addition, we aimed to determine the magnitude of change and subsequent recovery for 7 days following the race. METHODS: Recreationally trained runners (n = 13 (8M); age = 36.6 ± 7.6 years; height = 174 ± 9 cm; weight = 70.5 ± 9.3 kg) completed measures of HRV upon waking in the morning for 1 week prior to and 1 week following a 64-km running race. Profile of mood states, wellbeing, and muscular soreness were also measured throughout the study period to further contextualise recovery. RESULTS: An increase in heart rate accompanied by decreased LnSDNN, LnRMSSD, LnLF, LnHF, and LnLF/HF from baseline were observed 1 day post-race (p < 0.05). Indices of HRV had returned to baseline on day 2 of recovery. Perceptual fatigue and muscle soreness increased post-race (immediately following and on day 1 of recovery) (p < 0.05) and took until day 5 of recovery to return to baseline. CONCLUSION: The results indicate that cardiac autonomic control is significantly altered in response to a 64 km ultra-marathon. Specifically, parasympathetic activity is suppressed. The change in autonomic control was relatively short-lived, and parasympathetic-related indices had returned to baseline 2 days after the event. Subjective measures of fatigue and wellbeing suggest that athletes were not completely recovered until day 5 post-event, with muscular soreness remaining prominent during this period. A combination of physiological and psychological parameters is important to contextualise recovery in ultra-endurance runners.

Mixed-method evaluation of a community-wide physical activity program in Launceston, Australia.

ISSUE ADDRESSED: Physical inactivity is a leading risk factor for disease burden and premature mortality. Interventions to increase physical activity are common, though few examples of multi-strategy, wide-scale community programs exist. Active Launceston is a community-wide program aimed at improving health and well-being through physical activity. We report on the process evaluation of Active Launceston and changes in community physical activity participation between 2008 and 2015, as a measure of program effectiveness. METHODS: Mixed-method evaluation of Active Launceston combined process evaluation-consisting of participant numbers, socio-demographic characteristics, campaign awareness, focus groups and stakeholder interviews-with impact evaluation consisting of a random-sample cross-sectional serial telephone survey. RESULTS: Active Launceston attracted 11 887 attendees, participating in 30 342 sessions, amounting to 38 088 hours of physical activity between 2008 and 2015. Participant focus groups highlighted benefits including increased engagement in exercise, better health and social connectedness. While telephone surveys found the proportion of people participating in any physical activity in the last 12 months to be similar between the 3 years (2008, 77.7%; 2012, 77.1%; 2015, 73.6%), a higher proportion participated in vigorous physical activity in 2012 and 2015 compared to 2008 (P < 0.01), when adjusting for age and gender differences. A higher proportion also achieved sufficient activity for health in 2015 compared to 2008 (P = 0.01). CONCLUSIONS: Mixed-method evaluation suggests Active Launceston is an effective community-wide program supporting community members to engage in regular physical activity and increase levels of social engagement. SO WHAT?: This work provides a model for implementing high-reach, community-wide interventions that improve physical activity outcomes.

Complexities of Young Driver Injury and Fatal Motor Vehicle Crashes.

We offer a perspective on the literature discussing the importance of driving for youth, the complexities of learning to drive, and the risks of driving which lead to motor vehicle crashes (MVCs). Specifically, we discuss important underlying reasons why some adolescents and young adults may be more susceptible to engaging in driving behaviors which result in fatal MVCs; the leading cause of death among 15 to 20 y/o. Some of the factors known to lead to crash fatalities span the domains of cognitive development, distraction, alcohol/drug use, psychosocial development and peer influence, and young driver inexperience. While advancements in driver training, traffic safety legislation, vehicle safety engineering, and emergency/trauma care have helped reduce the prevalence of crashes, we suggest that natural brain maturation which occurs during adolescence and young adulthood may hold unique susceptibilities for young driver crashes. As such, we discuss the importance in using a multidisciplinary research approach, and specifically neuroscience methods, to develop a more compressive understanding of crash risk factors among young drivers. By using a multidisciplinary approach when studying young drivers, we can advance the injury and prevention science as well as inform relevant policies, innovative technologies, comprehensive training and intervention programs which will develop safer young drivers sooner.

Acquired and Genetic Thrombotic Risk Factors in the Athlete.

While athletes are often considered the epitome of health due to their physique and lowered potential for metabolic and cardiovascular diseases, they may also be at risk for the onset and development of venous thromboembolism (VTE). In an attempt to achieve and remain competitive, athletes are frequently exposed to numerous athlete-specific risk factors, which may predispose them to VTE through the disruption of factors associated with Virchow's triad (i.e., hypercoagulability, venous stasis, and vessel wall injury). Indeed, hypercoagulability within an athletic population has been well documented to occur due to a combination of multiple factors including exercise, dehydration, and polycythemia. Furthermore, venous stasis within an athletic population may occur as a direct result of prolonged periods of immobilization experienced when undertaking long-distance travels for training and competition, recovery from injury, and overdevelopment of musculature. While all components of Virchow's triad are disrupted, injury to the vessel wall has emerged as the most important factor contributing to thrombosis formation within an athletic population, due to its ability to influence multiple hemostatic mechanisms. Vessel wall injury within an athletic population is often related to repetitive microtrauma to the venous and arterial walls as a direct result of sport-dependent trauma, in addition to high metabolic rates and repetitive blood monitoring. Although disturbances to Virchow's triad may not be detrimental to most individuals, approximately 1 in 1,000 athletes will experience a potentially fatal post-exercise thrombotic incidence. When acquired factors are considered in conjunction with genetic predispositions to hypercoagulability present in some athletes, an overall increased risk for VTE is present.

Combined Carbohydrate and Protein Ingestion During Australian Rules Football Matches and Training Sessions Does Not Reduce Fatigue or Accelerate Recovery Throughout a Weeklong Junior Tournament.

Lee, NA, Fell, JW, Pitchford, NW, Hall, AH, Leveritt, MD, and Kitic, CM. Combined carbohydrate and protein ingestion during Australian rules football matches and training sessions does not reduce fatigue or accelerate recovery throughout a weeklong junior tournament. J Strength Cond Res 32(2): 344-355, 2018-Australian rules football (ARF) is a physically demanding sport that can induce high levels of fatigue. Fatigue may be intensified during periods where multiple matches are played with limited recovery time. Combined carbohydrate and protein (CHO + PRO) intake during physical activity may provide performance and recovery benefits. The aim of this study was to investigate whether CHO + PRO ingestion during ARF matches and training sessions throughout a tournament would enhance performance or recovery in comparison with CHO-only ingestion. Australian rules football players (n = 21) competing in a 7-day national tournament participated in this randomized and double-blinded study. Beverages containing either CHO (n = 10) or CHO + PRO (n = 11) were provided during matches (day 1, day 4, and day 7) and training sessions (day 2 and day 3). Countermovement jumps (CMJs), ratings of muscle soreness, and autonomic function were assessed throughout the tournament. Gastrointestinal tract (GI) discomfort was measured after matches. Countermovement jump peak velocity increased in the CHO + PRO group (p = 0.01) but not in the CHO group. There were no differences in the other CMJ variables. In both groups, muscle soreness increased from days 0 and 1 to day 2 (p ≤ 0.05) but did not remain elevated. R-R intervals (time elapsed between successive peaks in QRS complexes) increased in both groups from day 1 to day 7 (mean difference = 59.85 ms, p < 0.01). Postmatch GI discomfort was not different (p > 0.05) between groups. When daily dietary protein is adequate (>1.8 g·kg·d), the ingestion of CHO + PRO during matches and training sessions throughout a tournament does not reduce muscle soreness nor have clear benefits for neuromuscular recovery or modulate autonomic function in junior ARF athletes, compared with that of CHO alone.

Estimation of the Potential Effectiveness of Lowering the Blood Alcohol Concentration (BAC) Limit for Driving from 0.08 to 0.05 Grams per Deciliter in the United States.

BACKGROUND: In 2013, the National Transportation Safety Board (NTSB) issued a report recommending that states lower the illegal blood alcohol concentration (BAC) limit for driving from 0.08 to 0.05 g/dl. The NTSB concluded that there is a strong evidence-based foundation for a BAC limit of 0.05 or lower. Most industrialized nations have already enacted a 0.05 illegal BAC limit. This study was undertaken to contribute to the scientific evidence as to whether lowering the BAC limit to 0.05 will be an effective alcohol policy in the United States. METHODS: We accomplished our objective by: (i) conducting a meta-analysis of qualifying international studies to estimate the range and distribution of the most likely effect size from a reduction to 0.05 BAC or lower; (ii) translating this synthesis toward estimating the effects of reducing the current 0.08 BAC limit to 0.05 in the United States; and (iii) estimating the life-saving benefits of the proposed 0.03 reduction in the driving limit from 0.08 to 0.05 BAC. RESULTS: In our meta-analysis of studies on lowering the BAC limit in general, we found a 5.0% decline in nonfatal alcohol-related crashes, a 9.2% decline in fatal alcohol-related crashes from lowering the BAC to 0.08, and an 11.1% decline in fatal alcohol-related crashes from lowering the BAC to 0.05 or lower. We estimate that 1,790 lives would be saved each year if all states adopted a 0.05 BAC limit. CONCLUSIONS: This study provides strong evidence of the relationship between lowering the BAC limit for driving and the general deterrent effect on alcohol-related crashes.

Case Study: Utilizing a Low FODMAP Diet to Combat Exercise-Induced Gastrointestinal Symptoms.

Athletes employ various dietary strategies in attempts to attenuate exercise-induced gastrointestinal (GI) symptoms to ensure optimal performance. This case-study outlines one of these GI-targeted approaches via the implementation of a short-term low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) diet, with the aim to attenuate persistent running specific GI symptoms in a recreationally competitive multisport athlete (male, 86 kg, 57.9 ml·kg·min-1 V02max, 10-15 hr/week training, with no diagnosed GI disorder). Using a single-blinded approach a habitual diet was compared with a 6-day low FODMAP intervention diet (81 ± 5g vs 7.2 ± 5.7g FODMAP s/day) for their effect on GI symptoms and perceptual wellbeing. Training was similar during the habitual and dietary intervention periods. Postexercise (During) GI symptom ratings were recorded immediately following training. Daily GI symptoms and the Daily Analysis of Life Demands for Athletes (DALDA) were recorded at the end of each day. Daily and During GI symptom scores (scale 0-9) ranged from 0-4 during the habitual dietary period while during the low FODMAP dietary period all scores were 0 (no symptoms at all). DALDA scores for worse than normal ranged from 3-10 vs 0-8 in the habitual and low FODMAP dietary periods, respectively, indicating improvement. This intervention was effective for this GI symptom prone athlete; however, randomized-controlled trials are required to assess the suitability of low FODMAP diets for reducing GI distress in other symptomatic athletes.

Commercial Hype Versus Reality: Our Current Scientific Understanding of Gluten and Athletic Performance.

Recent explosion in the prevalence of gluten-free athletes, exacerbated by unsubstantiated commercial health claims, has led to some professional athletes touting gluten-free diet as the secret to their success. Forty-one percent of athletes report adhering to a gluten-free diet (GFD), which is four-fold higher than the population-based clinical requirements. Many nonceliac athletes believe that gluten avoidance improves gastrointestinal well-being, reduces inflammation, and provides an ergogenic edge, despite the fact that limited data yet exist to support any of these benefits. There are several plausible associations between endurance-based exercise and gastrointestinal permeability whereby a GFD may be beneficial. However, the implications of confounding factors, including the risks of unnecessary dietary restriction, financial burden, food availability, psychosocial implications, alterations in short-chain carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), and other wheat constituents emphasize the need for further evaluation.

The Reliability of Strength Tests Performed In Elevated Shoulder Positions Using a Handheld Dynamometer.

CONTEXT: The reliable measurement of shoulder strength is important when assessing athletes involved in overhead activities. Swimmers' shoulders are subject to repetitive humeral elevation and consequently have a high risk of developing movement-control issues and pain. Shoulder-strength tests performed in positions of elevation assist with the detection of strength deficits that may affect injury and performance. The reliability of isometric strength tests performed in positions of humeral elevation without manual stabilization, which is a typical clinical scenario, has not been established. OBJECTIVE: To establish the relative and absolute intrarater reliability of shoulder-strength tests functional to swimming in 3 body positions commonly used in the clinical setting. DESIGN: Repeated-measures reliability study. SETTING: Research laboratory. SUBJECTS: 15 university students and staff (mean ± SD age 24 ± 8.2 y). INTERVENTION: Isometric shoulder-strength tests were performed in positions of humeral elevation (flexion and extension in 140° abduction in the scapular plane, internal and external rotation in 90° abduction) on subjects without shoulder pain in supine, prone, and sitting. Subjects were tested by 1 examiner with a handheld dynamometer and retested after 48 h. MAIN OUTCOME MEASURES: Relative reliability (ICC3,1) values with 95% CI. Absolute reliability was reported by minimal detectable change (MDC). RESULTS: Good to excellent intrarater reliability was found for all shoulder-strength tests (ICC .87-.99). Intrarater reliability was not affected by body position. MDC% was <16% for every test and ≤11% for tests performed in supine. CONCLUSIONS: Shoulder flexion, extension, and internal- and external-rotation strength tests performed in humeral elevation demonstrated excellent to good intrarater reliability regardless of body position. A strength change of more than 15% in any position can be considered meaningful.

[What do we know about the exercise-related transient abdominal pain ?] / Que sait-on sur le « point de côté ¼ lié à l'effort ?

Exercise-related transient abdominal pain or « side stitch ¼ is a very common problem among athletes, whatever their level of participation. This pain may be present in different areas of the abdomen, even in the shoulder, usually well localized, and described as cramping or stabbing depending on the severity. The etiology is still debated, with many possible theories. It is a benign problem but other pathologies, often more severe, must be excluded in case of any atypical presentation. There are simple preventive measures recommended. This pain usually disappears within minutes by slowing or stopping the effort and / or using different methods without scientific validation until now.

La douleur abdominale transitoire liée à l'effort ou « point de côté ¼ est un problème fréquemment rencontré chez les sportifs, qu'ils soient débutants ou confirmés. Cette douleur peut être présente dans différentes zones de l'abdomen, voire même les épaules, le plus souvent bien localisée, décrite comme une crampe ou « coup de couteau ¼ selon la sévérité. L'étiologie est encore débattue, avec de multiples théories possibles. Il s'agit d'un problème bénin mais d'autres pathologies, souvent plus graves, doivent être exclues devant toute présentation atypique. Il existe des mesures préventives simples à conseiller. Cette douleur disparaît généralement en quelques minutes en ralentissant ou stoppant l'effort et / ou à l'aide de différentes méthodes, sans validation scientifique à ce jour.

The Utility of Including the Strengths of Underage Drinking Laws in Determining Their Effect on Outcomes.

BACKGROUND: To control underage drinking in the United States, which has been associated with an estimated 5,000 deaths and 2.6 million injuries or other harm annually, each state has developed a unique set of laws. Previous research examining these laws' effectiveness has frequently focused on the laws' existence without considering variance in sanctions, enforcement, or exemptions. METHODS: We scored 20 minimum legal drinking age 21 (MLDA-21) laws for their strengths and weaknesses based on (i) sanctions for violating the law, (ii) exceptions or exemptions affecting application, and (iii) provisions affecting the law or enforcement. We then replicated a 2009 study of the effects of 6 MLDA-21 laws in 3 different ways (using identical structural equation modeling): Study 1-8 additional years of data, no law strengths; Study 2-years from the original study, added law strengths; Study 3-additional years, law strengths, serving as an update of the 6 laws' effects. RESULTS: In all 3 studies-and the original study-keg registration laws were associated with both an unexpected significant increase (+11%, p < 0.001) in underage drinking-driver ratios and a notable 25% reduction in per capita beer consumption-opposing results that are difficult to explain. In Study 3, possession and purchase laws were associated with a significant decrease in underage drinking-driver fatal crash ratios (-4.9%, p < 0.001; -3.6%, p < 0.001, respectively). Similarly, zero tolerance and use and lose laws were associated with reductions in underage drinking-driver ratios (-2.8%, p < 0.001; -5.3%, p < 0.001, respectively). CONCLUSIONS: Including strengths and weaknesses of underage drinking laws is important when examining their effects on various outcomes as the model fit statistics indicated. We suggest that this will result in more accurate and more reliable estimates of the impact of the laws on various outcome measures.

Relationship of impaired-driving enforcement intensity to drinking and driving on the roads.

BACKGROUND: It is principally the area of enforcement that offers the greatest opportunity for reducing alcohol-impaired driving in the near future. How much of a reduction in drinking and driving would be achieved by how much improvement in enforcement intensity? METHODS: We developed logistic regression models to explore how enforcement intensity (6 different measures) related to the prevalence of weekend nighttime drivers in the 2007 National Roadside Survey who had been drinking (blood alcohol concentration [BAC] ≥ 0.00 g/dl), who had BACs ≥ 0.05 g/dl, and who were driving with an illegal BAC ≥ 0.08 g/dl. RESULTS: Drivers on the roads in our sample of 30 communities who were exposed to fewer than 228 traffic stops per 10,000 population aged 18 and older had 2.4 times the odds of being BAC positive, 3.6 times the odds of driving with a BAC ≥ 0.05, and 3.8 times the odds of driving with a BAC ≥ 0.08 compared to those drivers on the roads in communities with more than 1,275 traffic stops per 10,000 population. Drivers on the roads in communities with fewer than 3.7 driving under the influence (DUI) arrests per 10,000 population had 2.7 times the odds of BAC-positive drivers on the roads compared to communities with the highest intensity of DUI arrest activity (>38 DUI arrests per 10,000 population). CONCLUSIONS: The number of traffic stops and DUI arrests per capita were significantly associated with the odds of drinking and driving on the roads in these communities. This might reflect traffic enforcement visibility. The findings in this study may help law enforcement agencies around the country adjust their traffic enforcement intensity to reduce impaired driving in their community.

Confounding compression: the effects of posture, sizing and garment type on measured interface pressure in sports compression clothing.

The purpose of this investigation was to measure the interface pressure exerted by lower body sports compression garments, in order to assess the effect of garment type, size and posture in athletes. Twelve national-level boxers were fitted with sports compression garments (tights and leggings), each in three different sizes (undersized, recommended size and oversized). Interface pressure was assessed across six landmarks on the lower limb (ranging from medial malleolus to upper thigh) as athletes assumed sitting, standing and supine postures. Sports compression leggings exerted a significantly higher mean pressure than sports compression tights (P < 0.001). Oversized tights applied significantly less pressure than manufacturer-recommended size or undersized tights (P < 0.001), yet no significant differences were apparent between different-sized leggings. Standing posture resulted in significantly higher mean pressure application than a seated posture for both tights and leggings (P < 0.001 and P = 0.002, respectively). Pressure was different across landmarks, with analyses revealing a pressure profile that was neither strictly graduated nor progressive in nature. The pressure applied by sports compression garments is significantly affected by garment type, size and posture assumed by the wearer.

Exploring the popularity, experiences, and beliefs surrounding gluten-free diets in nonceliac athletes.

Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popular despite a paucity of supportive medical or ergogenic evidence. This study aimed to quantify the demographics of NCA and determine associated experiences, perceptions, and sources of information related to GFD. Athletes (n = 910, female = 528, no gender selected = 5) completed a 17-question online survey. Forty-one percent of NCA respondents, including 18-world and/or Olympic medalists, follow a GFD 50-100% of the time (GFD > 50): only 13% for treatment of reported medical conditions with 57% self-diagnosing their gluten sensitivity. The GFD > 50 group characteristics included predominantly endurance sport athletes (70.0%) at the recreationally competitive level (32.3%), between 31 and 40 years of age (29.1%). Those who follow a GFD > 50 reported experiencing, abdominal/gastrointestinal (GI) symptoms alone (16.7%) or in conjunction with two (30.7%) or three (35.7%) additional symptoms (e.g., fatigue) believed to be triggered by gluten. Eighty-four percent of GFD > 50 indicated symptom improvement with gluten-removal. Symptom-based and non-symptom-based self-diagnosed gluten-sensitivity (56.7%) was the primary reason for adopting a GFD. Leading sources of GFD information were online (28.7%), trainer/coach (26.2%) and other athletes (17.4%). Although 5-10% of the general population is estimated to benefit clinically from a GFD a higher prevalence of GFD adherence was found in NCA (41.2%). Prescription of a GFD among many athletes does not result from evidence-based practice suggesting that adoption of a GFD in the majority of cases was not based on medical rationale and may be driven by perception that gluten removal provides health benefits and an ergogenic edge in NCA.

Aortic reservoir characteristics and brain structure in people with type 2 diabetes mellitus; a cross sectional study.

BACKGROUND: Central hemodynamics help to maintain appropriate cerebral and other end-organ perfusion, and may be altered with ageing and type 2 diabetes mellitus (T2DM). We aimed to determine the associations between central hemodynamics and brain structure at rest and during exercise in people with and without T2DM. METHODS: In a sample of people with T2DM and healthy controls, resting and exercise measures of aortic reservoir characteristics (including excess pressure integral [P(excess)]) and other central hemodynamics (including augmentation index [AIx] and aortic pulse wave velocity [aPWV]) were recorded. Brain volumes (including gray matter volume [GMV] and white matter lesions [WML]) were derived from magnetic resonance imaging (MRI) scans. Multivariable linear regression was used to study the associations of hemodynamic variables with brain structure in the two groups adjusting for age, sex, daytime systolic BP (SBP) and heart rate. RESULTS: There were 37 T2DM (63 ± 9 years; 47% male) and 37 healthy individuals (52 ± 8 years; 51% male). In T2DM, resting aPWV was inversely associated with GMV (standardized ß = -0.47, p = 0.036). In healthy participants, resting P(excess) was inversely associated with GMV (ß = -0.23, p = 0.043) and AIx was associated with WML volume (ß = 0.52, p = 0.021). There were no associations between exercise hemodynamics and brain volumes in either group. CONCLUSIONS: Brain atrophy is associated with resting aortic stiffness in T2DM, and resting P(excess) in healthy individuals. Central vascular mechanisms underlying structural brain changes may differ between healthy individuals and T2DM.

The effect of a caffeinated mouth-rinse on endurance cycling time-trial performance.

The purpose of this study was to investigate if acute caffeine exposure via mouth-rinse improved endurance cycling time-trial performance in well-trained cyclists. It was hypothesized that caffeine exposure at the mouth would enhance endurance cycling time-trial performance. Ten well-trained male cyclists (mean ± SD: 32.9 ± 7.5 years, 74.7 ± 5.3 kg, 176.8 ± 5.1cm, VO2peak = 59.8 ± 3.5 ml·kg⁻¹·min⁻¹) completed two experimental time-trials following 24 hr of dietary and exercise standardization. A randomized, double-blind, placebo-controlled, cross-over design was employed whereby cyclists completed a time-trial in the fastest time possible, which was equivalent work to cycling at 75% of peak aerobic power output for 60 min. Cyclists were administered 25 ml mouth-rinses for 10 s containing either placebo or 35 mg of anhydrous caffeine eight times throughout the time-trial. Perceptual and physiological variables were recorded throughout. No significant improvement in time-trial performance was observed with caffeine (3918 ± 243 s) compared with placebo mouth-rinse (3940 ± 227 s). No elevation in plasma caffeine was detected due to the mouth-rinse conditions. Caffeine mouth-rinse had no significant effect on rating of perceived exertion, heart rate, rate of oxygen consumption or blood lactate concentration. Eight exposures of a 35 mg dose of caffeine at the buccal cavity for 10s does not significantly enhance endurance cycling time-trial performance, nor does it elevate plasma caffeine concentration.