Do five screening tools identify the same number of runners who require pre-exercise medical clearance? SAFER XXXIV.

OBJECTIVES: Currently, there are five international screening tools that are recommended to identify individuals who require pre-exercise medical clearance to reduce the risk of medical encounters during exercise. Therefore, the aim was to determine the percentage of race entrants who are advised to obtain pre-exercise medical clearance and the observed agreement between these five different international pre-exercise medical screening tools. METHODS: In all, 76,654 race entrants from the Two Oceans Marathon (2012-2015) that completed an online pre-race screening questionnaire. Five pre-exercise medical screening tools (American Heart Association (AHA), pre-2015 American College of Sport Medicine (ACSM), post-2015 ACSM, Physical Activity Readiness Questionnaire (PAR-Q), and the European Association of Cardiovascular Prevention and Rehabilitation (EACPR)) were retrospectively applied to all participants. The % (95%CI) race entrants requiring medical clearance identified by each tool and the observed agreement between tools (%) was determined. RESULTS: The % entrants requiring medical clearance varied from 6.7% to 33.9% between the five tools: EACPR (33.9%; 33.5-34.3); pre-2015 ACSM (33.9%; 33.5-34.3); PAR-Q (23.2%; 22.9-23.6); AHA (10.0%; 9.7-10.2); post-2015 ACSM (6.7%; 6.5-6.9). The observed agreement was highest between the pre-2015 ACSM and EACPR (35.4%), for pre-2015 ACSM and PAR-Q (24.8%), PAR-Q and EACPR (24.8%), and lowest between the post-2015 ACSM and AHA (4.1%). CONCLUSION: The percentage of race entrants identified to seek medical clearance (and observed agreement) varied considerably between pre-exercise medical screening tools. Further research should determine which tool has the best predictive ability in identifying those at higher risk of medical encounters during exercise.

The Ego Phenomenon and the Doping Problem in Sport: A Historical Conceptual Analysis.

The concept of ego has various meanings in the field of psychology, depending on the paradigmatic and theoretical framework point of departure. The ego phenomenon as operationalized and measured in the theoretical framework of goal orientation will be the contextual framework for a historical conceptual analysis. In the past three decades, research in the theoretical framework of goal orientation has revealed a positive relationship between ego involvement and the tendency to use the prohibited substances to enhance performance in sport. The concept of the ego phenomenon as operationalized within goal orientation theory and meanings attached to the concept can be connected to the historic oriental writings that were written ~2,500 years ago. These attached meanings to the ego phenomenon include elements of extreme competitiveness and outcome orientation, as well as social comparisons and the external norms for the measurement of success and failure. These meanings can be traced back to the classical works involving the Bhagavad Gita, the Tao Te Ching, and the Eastern Origins of Mindfulness that are part of the broader Buddhist philosophical system. Meister Eckhart, a 12th century German theologian, in his significant contribution on the analysis of the having mode as opposed to the being mode also provides insight into the ego phenomenon that can explain why the ego phenomenon can be linked to some of the deeper psychological motives of using the prohibited substances. The researchers in psychology do not yet have a full understanding of why certain athletes dope or have a susceptibility to use the prohibited substances or performance enhancing drugs (PEDs) and thus the motivation for this historical conceptual analysis of the ego phenomenon. Therefore, this article aimed to deepen the understanding of psychological motives of the athletes who exhibit tendencies toward cheating in general and the proclivity to use the prohibited substances.

Effects of a 6-month exercise programme on disease activity, physical and functional parameters in patients with ankylosing spondylitis: Randomised controlled trial.

BACKGROUND: Exercise forms an important component in the management of ankylosing spondylitis (AS). The objective of our study was to determine the effects of a 6-month swimming, land-based stretching, strengthening and breathing exercise intervention in AS patients. METHODS/DESIGN: A total of 29 (14 females, 15 males) patients diagnosed with AS according to the Modified New York Criteria participated in our study. Participants were randomly assigned to an exercise group (ASE) (16 participants) and a control group (ASC) (13 participants). Erythrocyte sedimentation rate and C-reactive protein (CRP); anthropometric measurements; pulmonary function; aerobic capacity; balance; Bath AS Metrology Index; Bath AS Disease Activity Index and the Bath AS Functional Index were assessed. DISCUSSION: Erythrocyte sedimentation rate and CRP did not change notably within or between the groups from pre- to post-intervention. The between group analyses of the physical assessments favoured the ASE with observable improvements in chest expansion (p = 0.002), forced expiration volume (p = 0.012), absolute (p = 0.017) and relative (p = 0.003) maximal oxygen consumption, absolute (p = 0.028) and relative (p = 0.001) physical work capacity. Within the ASE, there is statistical evidence of improvements in 11 of the 19 physical variables. Within the ASC, five of the physical variables deteriorated substantially (p between 0.004 and 0.037) and only balance overall stability on the right improved (p = 0.016). The three functional assessments in the ASE improved (p < 0.007) compared with the ASC post-intervention. A 6-month combined exercise programme may improve physical and functional capacity of AS patients. CONCLUSION: A multimodal exercise intervention may be useful in the management of ankylosing spondylitis. CLINICAL IMPLICATIONS: An unsupervised well -explained exercise programme combining swimming, land-based strengthening and stretching exercises and breathing exercises may be an option for patients with ankylosing spondylitis. TRIAL REGISTRATION: Registration not undertaken at the time of writing.

Effect of Dipole Orientation in Mixed, Charge-Equilibrated Self-assembled Monolayers on Protein Adsorption and Marine Biofouling.

While zwitterionic interfaces are known for their excellent low-fouling properties, the underlying molecular principles are still under debate. In particular, the role of the zwitterion orientation at the interface has been discussed recently. For elucidation of the effect of this parameter, self-assembled monolayers (SAMs) on gold were prepared from stoichiometric mixtures of oppositely charged alkyl thiols bearing either a quaternary ammonium or a carboxylate moiety. The alkyl chain length of the cationic component (11-mercaptoundecyl)-N,N,N-trimethylammonium, which controls the distance of the positively charged end group from the substrate's surface, was kept constant. In contrast, the anionic component and, correspondingly, the distance of the negatively charged carboxylate groups from the surface was varied by changing the alkyl chain length in the thiol molecules from 7 (8-mercaptooctanoic acid) to 11 (12-mercaptododecanoic acid) to 15 (16-mercaptohexadecanoic acid). In this way, the charge neutrality of the coating was maintained, but the charged groups exposed at the interface to water were varied, and thus, the orientation of the dipoles in the SAMs was altered. In model biofouling studies, protein adsorption, diatom accumulation, and the settlement of zoospores were all affected by the altered charge distribution. This demonstrates the importance of the dipole orientation in mixed-charged SAMs for their inertness to nonspecific protein adsorption and the accumulation of marine organisms. Overall, biofouling was lowest when both the anionic and the cationic groups were placed at the same distance from the substrate's surface.

Ad libitum water consumption prevents exercise-associated hyponatremia and protects against dehydration in soldiers performing a 40-km route-march.

BACKGROUND: It remains unclear if ad libitum water drinking, as a hydration strategy, prevents exercise-associated hyponatremia (EAH) during prolonged exercise. The aim of this study was to determine the incidence of EAH within the broader context of fluid regulation among soldiers performing a 40-km route-march ingesting water ad libitum. METHODS: Twenty-eight healthy male soldiers participated in this observational trial. Pre- and post-exercise body mass, blood and urine samples were collected. Blood samples were assessed for serum sodium ([Na+]), glucose, creatinine, urea nitrogen (BUN), plasma osmolality, creatine kinase (CK), and plasma arginine vasopressin (AVP) concentrations. Plasma volume (PV) was calculated using hematocrit and hemoglobin. Urine samples were analyzed for osmolality and [Na+]. Water intake was assessed by weighing bottles before, during and after the march. The mean relative humidity was 55.7% (21.9-94.3%) and the mean dry bulb temperature was 27.1 °C (19.5 °C - 37.0 °C) during the exercise. RESULTS: Twenty-five soldiers (72 ± 10 kg) (Mean ± SD) completed the march in 09:11 ± 00:43 (hr:min). Participants consumed 736 ± 259 ml/h of water and lost 2.8 ± 0.9 kg (4.0% ± 1.4%, P < 0.05) of body mass. Significant (pre-march vs. post-march; P < 0.05) decreases in serum [Na+] (141 mmol/L vs. 136 mmol/L), plasma osmolality (303 mOsmol/kg H2O vs. 298 mOsmol/kg H2O), and serum creatinine (111 µmol/L vs. 101 µmol/L) and urine [Na+] (168 mmol/L vs. 142 mmol/L), as well as significant increases in plasma AVP (2 pg/ml vs. 11 pg/ml), plasma CK (1423 U/L vs. 3894 U/L) and urine osmolality (1035 mOsmol/kg H2O vs. 1097 mOsmol/kg H2O) were found. The soldier (72 kg) with the lowest post-exercise sodium level completed the march in 08:38. He drank 800 ml/h, lost 2% body mass, and demonstrated (pre-post) increases in plasma osmolality (294-314 mOsmol/kg H2O), BUN (20-30 mg/dl), AVP (2-16 pg/ml) and PV (41%). His urine osmolality decreased from 1114 mOsmol/kg H2O to 1110 mOsmol/kg H2O. No participants finished the route-march with a serum [Na+] indicating hypernatremia (range, 134-143 mmol/L). CONCLUSIONS: Ad libitum drinking resulted in 4% body mass loss with a 2 mmol/L serum [Na+] reduction in conjunction with high urine osmolality (> 1000 mOsmol/kg H2O) and plasma AVP. No single hydration strategy likely prevents EAH, but hypernatremia (cellular dehydration) was not seen despite > 2% body mass losses and high urine osmolality.

Fouling-Release Properties of Dendritic Polyglycerols against Marine Diatoms.

Dendritic polyglycerols (PGs) were grafted onto surfaces using a ring-opening polymerization reaction, and the fouling-release properties against marine organisms were determined. The coatings were characterized by spectroscopic ellipsometry, contact angle goniometry, ATR-FTIR, and stability tests in different aqueous media. A high resistance toward the attachment of different proteins was found. The PG coatings with three different thicknesses were tested in a laboratory assay against the diatom Navicula incerta and in a field assay using a rotating disk. Under static conditions, the PG coatings did not inhibit the initial attachment of diatoms, but up to 94% of attached diatoms could be removed from the coatings after exposure to a shear stress of 19 Pa. Fouling release was found to be enhanced if the coatings were sufficiently thick. The excellent fouling-release properties were supported in dynamic field-immersion experiments in which the samples were continually exposed to a shear stress of 0.18 Pa.

Parallelized microfluidic diatom accumulation assay to test fouling-release coatings.

Assessing the efficiency of the next generation of protective marine coatings is highly relevant for their optimization. In this paper, a parallelized microfluidic testing device is presented to quantify the accumulation of a model organism (Navicula perminuta) under constant laminar flow. Using automated microscopy in conjunction with image analysis, the adhesion densities on the tested surfaces could be determined after exposure to a flow of suspended algae for 90 min. The optimized protocol for the assay is presented, and the reproducibility of the densities of attached diatoms was verified on four identical surfaces (self-assembled dodecanethiol monolayers). A set of well-characterized self-assembled monolayers with different chemical terminations was used to validate the performance of the assay and its capability to discriminate diatom accumulation on different surface chemistries under dynamic conditions. The observed trends are in good agreement with previously published results obtained in single channel accumulation and detachment assays. To demonstrate the practical relevance of the dynamic experiment, diatom attachment on four technically relevant silicone coatings with different fouling-release properties could clearly be distinguished.

Dynamic field testing of coating chemistry candidates by a rotating disk system.

Quick and reliable testing is crucial for the development of new fouling release (FR) coatings. Exposure of these coatings to natural multispecies communities is essential in evaluating their efficacy. To this end, we present a rotating disk setup for dynamic field exposure. To achieve a well-defined flow on the surface of the disk, an easy to use sample mounting system was developed that provides a smooth and even surface. We related the angular velocity of the disk to the wall shear stress on the surface with a hydrodynamic model. The wall shear stress was adjusted to values previously found to be suitable to discriminate dynamic diatom attachment on different coating chemistries in the lab. The effect of the dynamic conditions was shown by comparing polystyrene slides under static and dynamic exposure. Using a set of self-assembled monolayers, the discrimination potential of the assay in a multispecies environment was demonstrated.

Amphiphilic Alginates for Marine Antifouling Applications.

Amphiphilic polymers are promising candidates for novel fouling-release coatings for marine applications. We grafted amphiphilic alginates with fluorinated side chains to glass and silicon substrates and characterized the obtained films by contact angle goniometry, spectroscopic ellipsometry, XPS, and ATR-FTIR. The potential to inhibit protein attachment was tested against four different proteins, and intermediate fluorine loadings showed the strongest reduction with respect to hydrophobic, aliphatic controls. A similar trend was observed in dynamic attachment experiments using Navicula perminuta diatoms and settlement experiments with zoospores of the green algae Ulva linza. The results indicate that amphiphilic alginates are promising natural and renewable biomacromolecules that could be included in future protective coating technologies.

Microfluidic accumulation assay probes attachment of biofilm forming diatom cells.

Testing of fouling release (FR) technologies is of great relevance for discovery of the next generation of protective marine coatings. In this paper, an accumulation assay to test diatom interaction under laminar flow with the model organism Navicula perminuta is introduced. Using time lapse microscopy with large area sampling allows determination of the accumulation kinetics of the diatom on three model surfaces with different surface properties at different wall shear stresses. The hydrodynamic conditions within the flow cell are described and a suitable shear stress range to perform accumulation experiments is identified at which statistically significant discrimination of surfaces is possible. The observed trends compare well to published adhesion preferences of N. perminuta. Also, previously determined trends of critical wall shear stresses required for cell removal from the same set of functionalized interfaces shows consistent trends. Initial attachment mediated by extracellular polymeric substances (EPS) present outside the diatoms leads to the conclusion that the FR potential of the tested coating candidates can be deducted from dynamic accumulation experiments under well-defined hydrodynamic conditions. As well as testing new coating candidates for their FR properties, monitoring of the adhesion process under flow provides additional information on the mechanism and geometry of attachment and the population kinetics.

The effectiveness of a range of sports bras in reducing breast displacement during treadmill running and two-step star jumping.

BACKGROUND: The primary aim of the study was to investigate the effectiveness of a range of sports bras in reducing multi-planar breast displacement during treadmill running and a two-step star jump. A secondary aim was to assess the relationship between perceptual bra comfort, bra fit and breast pain and measured breast displacement. METHODS: Seventeen females (mean age 22 years, range 18-31 years) with bra cup sizes B to C volunteered to take part in the study. Three dimensional breast movements were determined for six randomly assigned breast support levels during treadmill running and two-step star jumping. Participants completed a perceptual questionnaire rating bra comfort, bra fit and breast pain. RESULTS: Not all the bras significantly reduced resultant breast movement compared to a control condition. Not all the bras reduced resultant breast movement significantly at all speeds during the treadmill test. A different bra performed best during each of the treadmill running speeds. Perceptual ratings of bra fit and bra comfort were stronger and more reliable predictors of breast pain than breast displacement in our group of relatively small-breasted participants. CONCLUSIONS: Therefore it is apparent that resultant breast movement and the reduction of such movement is a multifaceted function of breast size, bra design and movement/activity type. The variance in bra performance at different treadmill running speeds highlights this fact and indicates that sports bras should be carefully selected to best suit the activity and breast size of the user.

Total Body Water, Electrolyte, and Thermoregulatory Responses to Ad Libitum Water Replacement Using Two Different Water Delivery Systems During a 19-km Route March.

Hands-free hydration systems are often advocated for improved hydration and performance in military populations. The aim was to assess whether such systems indeed result in improved hydration in exercising soldiers. Subjects were required to complete a route march while consuming water ad libitum from either a hydration bladder (BG) or traditional canteen (CG). Water intakes of 538 ml·h⁻¹ (BG) and 533 ml·h⁻¹ (CG) resulted in no differences for changes in body mass, serum [Na], plasma osmolality, total body water, or time required to complete the march. There were no differences between peak exercise core temperature of the BG (38.9° C) and CG (38.7° C) groups. There were no differences between the groups for fluid balance, thermoregulation, or performance. This is a not a surprising finding because the amount of fluid consumed ad libitum is determined by changes in serum osmolality and not the fluid delivery system as often proposed.

Ad libitum vs. restricted fluid replacement on hydration and performance of military tasks.

INTRODUCTION: The primary objective was to evaluate the effect of ad libitum vs. restricted fluid replacement protocol on hydration markers and performance in selected military tasks. The secondary objective was to determine if 300 ml x h(-1) could be considered a safe minimum fluid intake under the experimental conditions. METHODS: Data were collected simulating a route march over 16 km. There were 57 subjects who participated in the study. RESULTS: The mean pre-exercise body mass of the ad libitum group was 70.4 +/- 13.3 (SD) kg compared to 69.3 +/- 8.9 kg in the restricted group. The mean total fluid intake of the ad libitum group was 2.1 +/- 0.9 L compared to 1.2 +/- 0.0 L in the restricted group. The ad libitum and restricted intake groups, respectively, lost a mean of 1.05 kg +/- 0.77 (1.5%) and 1.34 kg +/- 0.37 (1.9%). Calculated sweat rate was 608 +/- 93 ml x h(-1) compared to 762 +/- 162 ml x h(-1) in the ad libitum group. DISCUSSION: There were no significant differences for either urine specific gravity (USG) or urine osmolality (UOsm) before or after the exercise. It is not clear whether fluid intake and calculated sweat rates are causally related or explained by their codependence on a third variable; for example, the exercising metabolic rate. Thus, 300 ml x h(-1) intake could be considered a current safe minimum water intake for soldiers of similar mass under similar experimental conditions, namely similar exercise durations at equivalent exercise intensities in a moderate, dry climate.

Three dimensional musculoskeletal modelling of the abdominal crunch resistance training exercise.

The aim of this study was to evaluate the benefits and limitations of using three dimensional (3D) musculoskeletal modelling (LifeModeler) in assessing the safety and efficacy of exercising on an abdominal crunch resistance training machine. Three anthropometric cases were studied, representing a 5th percentile female, and 50th percentile and 95th percentile male. Results indicated that the LifeModeler default model was capable of solving the forward dynamics simulations without adjustments. The modelling was able to indicate high risk for back injury when performing the abdominal crunch exercise as a result of the unacceptable intervertebral joint loading that occurs during the exercise. Individuals with small anthropometric dimensions such as some females and children cannot be accommodated suitably on the abdominal crunch machine which negatively impacts exercise posture and technique. Hip flexor muscle contribution in the execution of the exercise for the 5th percentile female was substantial thus reducing the efficacy of the exercise in isolating the abdominal muscles.

Exercise Prescription in the Management of Rheumatoid Arthritis

"Background: Over the last few years; the types of exercises prescribed for patients with rheumatoid arthritis (RA) have changed. There is also increasing knowledge on the physical status and physical activity levels of these patients. This article aims to give an overview of the physical status; physical activity levels and appropriate exercise prescription for patients with RA. Method: A literature search was conducted of scientific journals and text; including Medline and PubMed (1980-2012). Literature was selected for its in-depth data and well researched information. Key search terms included ""RA and exercise therapy""; as well as ""physical activity levels and physical status of patients with RA"". Results: The literature indicated that RA has a major impact on physical and psychological health. Over the past decade; there has been growing evidence of the health benefits of physical activity for patients with RA. Despite this evidence; patients with RA are less physically active than the general population. The types of exercises prescribed for patients with RA have changed from the traditionally prescribed isometric and range-of-motion exercises. However; proper choice and appropriate utilisation of exercise is essential in order to provide a therapeutic effect. Conclusion: Although pharmacological interventions have largely improved RA management; exercise therapy remains an important part of treatment. Despite the known benefits of physical activity and exercise; patients with RA are less physically active than the general population."

Three dimensional musculoskeletal modelling of the seated biceps curl resistance training exercise.

The aim of this study was to evaluate the benefits and limitations of using three dimensional (3D) musculoskeletal modelling (LifeModeler) in assessing the safety and efficacy of exercising on a seated biceps curl resistance training machine. Three anthropometric cases were studied, representing a 5th percentile female, 50th percentile and 95th percentile male. Results indicated that the LifeModeler default model was not adequate to solve the forward dynamics simulations. Therefore adjustments had to be made to the default model to successfully complete the forward dynamics simulations. The software was able to sufficiently highlight the shortcomings of the biceps curl machine's engineered adjustability in relation to the anthropometric dimensions of the studied cases, as the 5th percentile female could not be accommodated suitably on the machine. High lumbar spine anterior/posterior shear forces for all anthropometric cases and maximum muscle tensions for the female and 50th percentile male indicate that the seated biceps curl exercise may pose risks for injuries. To conclude, it appears that 3D musculoskeletal modelling can be used to evaluate resistance training equipment such as the seated biceps curl machine. However the limitations as indicated by this study must be taken into consideration, especially when using the default LifeModeler model.

"Going beyond the call of doula": a grounded theory analysis of the diverse roles community-based doulas play in the lives of pregnant and parenting adolescent mothers.

This article presents some of the most salient qualitative results from a larger program evaluation of pregnant and parenting adolescents who participated in a community-based doula program. Using grounded theory analysis, seven problem-solving strategies emerged that doulas apply in helping pregnant and parenting adolescents navigate multiple social and health settings that often serve as barriers to positive maternal- and child-health outcomes. The ethnographic findings of this study suggest that the doulas provide valuable assistance to pregnant and parenting adolescents by addressing social-psychological issues and socio-economic disparities. "Diverse role-taking" results in doulas helping pregnant adolescents navigate more successfully through fragmented social and health service systems that are less supportive of low-income adolescents, who are often perceived to be draining scarce resources. The findings have implications for the roles of community-based doulas assigned to low-income adolescents of color seeking to overcome obstacles and attain better educational and economic opportunities.