Dynamic and stationary monitoring of air pollutant exposures and dose during marathons

Marathon running significantly increases breathing volumes and, consequently, air pollution inhalation doses. This is of special concern for elite athletes who ventilate at very high rates. However, race organizers and sport governing bodies have little guidance to support events scheduling to protect runners. A key limitation is the lack of hyper-local, high temporal resolution air quality data representative of exposure along the racecourse. This work aimed to understand the air pollution exposures and dose inhaled by athletes, by means of a dynamic monitoring methodology designed for road races. Air quality monitors were deployed during three marathons, monitoring nitrogen dioxide (NO2), ozone (O3), particulate matter (PMx), air temperature, and relative humidity. One fixed monitor was installed at the Start/Finish line and one mobile monitor followed the women elite runner pack. The data from the fixed monitors, deployed prior the race, described daily air pollution trends. Mobile monitors in combination with heatmap analysis facilitated the hyper-local characterization of athletes' exposures and helped identify local hotspots (e.g., areas prone to PM resuspension) which should be preferably bypassed. The estimation of inhaled doses disaggregated by gender and ventilation showed that doses inhaled by last finishers may be equal or higher than those inhaled by first finishers for O3 and PMx, due to longer exposures as well as the increase of these pollutants over time (e.g., 58.2 ± 9.6 and 72.1 ± 23.7 μg of PM2.5 for first and last man during Rome marathon). Similarly, men received significantly higher doses than women due to their higher ventilation rate, with differences of 31-114 μg for NO2, 79-232 μg for O3, and 6-41 μg for PMx. Finally, the aggregated data obtained during the 4 week- period prior the marathon can support better race scheduling by the organizers and provide actionable information to mitigate air pollution impacts on athletes' health and performance.

Sports and Immunity, from the recreational to the elite athlete

The pivotal role of the immune system in physical activity is well-established. While interactions are complex, they tend to constitute discrete immune responses. Moderate intensity exercise causes leukocytosis with a mild anti-inflammatory cytokine profile and immunoenhancement. Above a threshold of intensity, lactate-mediated IL-6 release causes a proinflammatory state followed by a depressed inflammatory state, which stimulates immune adaptation and longer term cardiometabolic enhancement. Exercise-related immune responses are modulated by sex, age and immunonutrition. At all ability levels, these factors collectively affect the immune balance between enhancement or overload and dysfunction. Excessive training, mental stress or insufficient recovery risks immune cell exhaustion and hypothalamic pituitary axis (HPA) stress responses causing immunodepression with negative impacts on performance or general health. Participation in sport provides additional immune benefits in terms of ensuring regularity, social inclusion, mental well-being and healthier life choices in terms of diet and reduced smoking and alcohol, thereby consolidating healthy lifestyles and longer term health. Significant differences exist between recreational and professional athletes in terms of inherent characteristics, training resilience and additional stresses arising from competition schedules, travel-related infections and stress. Exercise immunology examines the central role of immunity in exercise physiology and straddles multiple disciplines ranging from neuroendocrinology to nutrition and genetics, with the aim of guiding athletes to train optimally and safely. This review provides a brief outline of the main interactions of immunity and exercise, some influencing factors, and current guidance on maintaining immune health.

Muscle injuries in athletics during the 2020 Tokyo Olympic Games: differences between heats and finals

BACKGROUND

The aim of this study was to analyze muscle injuries and their related risk factors during the Athletics events of the 2020 Tokyo Olympic Games including the differences in muscle injury rates between heats and finals.

METHODS

We included and analyzed in this study muscle injuries diagnosed by either magnetic resonance imaging, ultrasound, or physical examinations by at least two physicians, from Athletics athletes participating at the 2020 Tokyo Olympic Games. Data from electronic medical records, including sex, nationality, event, and the round (heat vs. final) during which the muscle injury occurred and the air temperature in the stadium, measured every five minutes during the competition were extracted.

RESULTS

Among the 1631 athletes who competed, a total of 36 athletes (20 males and 16 females) were diagnosed with a muscle injury during the 2020 Tokyo Olympic Games. Among them, 24 occurred during heats (1.47 per 100 athletes) and 12 during finals (2.20 per 100 athletes) (P=0.25). Logistic regression analysis revealed that the geographic region of athletes' origin was a factor associated with muscle injury, with the highest muscle injury rate being in athletes from Africa (odds ratio [OR]=4.74, 95% confidence interval [CI]) = 1.75 to 12.82) and North America (OR=3.02, 95%CI=1.27 to 7.20). For male athletes, competing in finals was a risk factor to sustain a muscle injury (OR=2.55, 95%CI=1.01 to 6.45).

CONCLUSIONS

During the 2020 Olympic Games, muscle injury rate was higher in finals than in heats, reaching statistical significance in male athletes.

The Biological Basis of Sex Differences in Athletic Performance: Consensus Statement for the American College of Sports Medicine

ABSTRACT

Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%-30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, but remains low in females. The primary goal of this consensus statement is to provide the latest scientific knowledge and mechanisms for the sex differences in athletic performance. This review highlights the differences in anatomy and physiology between males and females that are primary determinants of the sex differences in athletic performance and in response to exercise training, and the role of sex steroid hormones (particularly testosterone and estradiol). We also identify historical and nonphysiological factors that influence the sex differences in performance. Finally, we identify gaps in the knowledge of sex differences in athletic performance and the underlying mechanisms, providing substantial opportunities for high-impact studies. A major step toward closing the knowledge gap is to include more and equitable numbers of women to that of men in mechanistic studies that determine any of the sex differences in response to an acute bout of exercise, exercise training, and athletic performance.

Thermoregulatory responses during road races in hot-humid conditions at the 2019 Athletics World Championships

Purpose: To characterise thermoregulatory and performance responses of elite road-race athletes, while competing in hot, humid, night-time conditions during the 2019 IAAF World Athletic Championships. Method: Male and female athletes, competing in the 20 km racewalk (n=20 males, 24 females), 50 km racewalk (n=19 males, 8 females) and marathon (n=15 males, 22 females) participated. Exposed mean skin (T_sk) and continuous core body (T_c) temperature were recorded with infrared thermography and ingestible telemetry pill, respectively. Results: The range of ambient conditions (recorded roadside) were 29.3-32.7°C air temperature, 46-81 % relative humidity, 0.1-1.7 m∙s^-1 air velocity and 23.5-30.6°C wet bulb globe temperature. T_c increased by 1.5 ± 0.1°C but mean T_sk decreased by 1.5 ± 0.4°C over the duration of the races. T_sk and T_c changed most rapidly at the start of the races and then plateaued, with T_c showing a rapid increase again at the end, in a pattern mirroring pacing. Performance times were between 3 to 20 % (mean = 113 ± 6%) longer during the championships compared to the personal best (PB) of athletes. Overall mean performance relative to PB was correlated with the wet-bulb globe temperature (WBGT) of each race (R² = 0.89), but not with thermophysiological variables (R² ≤ 0.3). Conclusion: As previously reported in exercise heat stress, in this field study T_c rose with exercise duration, whereas T_sk showed a decline. The latter contradicts the commonly recorded rise and plateau in laboratory studies at similar ambient temperatures, but without realistic air movement.

Injury acknowledgement by reduction of sports load in world-leading athletics (track and field) athletes varies with their musculoskeletal health literacy and the socioeconomic environment

Objective

Although injury burden prompts elite athletics (track and field) athletes to engage in injury management, little is known about their health literacy. We investigated musculoskeletal (MS) health literacy in world-leading athletics athletes and associations with prechampionship injury acknowledgement by reduction of training load in different socioeconomic environments.

Methods

Adult and youth athletics athletes (n=1785) preparing for World Championships were invited to complete the Literacy in Musculoskeletal Problems instrument and report acknowledgement of injury by reduction in training load during prechampionship tapering. Their socioeconomic standing was estimated through the Human Development Index of their home country. Demographic differences were examined using χ2tests and determinants of injury acknowledgement assessed using logistic regression.

Results

Complete data were obtained from 780 athletes (43.7%) with 26% demonstrating sufficient MS health literacy, higher in adult (41%) than youth (13%) athletes (p<0.001). Adult athletes at the uppermost socioeconomic level showed higher MS health literacy than athletes at lower socioeconomic levels (p<0.001). At the uppermost socioeconomic level, adult athletes with sufficient MS health literacy had increased likelihood of acknowledging an injury by reduction in training load compared with peers demonstrating insufficient MS health literacy (OR=2.45; 95% CI 1.33–4.53). Athletes at middle socioeconomic levels with sufficient MS health literacy had decreased likelihood for acknowledging an injury during tapering (OR=0.29; 95% CI 0.11–0.78).

Conclusions

The prevalence of sufficient MS health literacy in world-leading athletics athletes is low. Associations between MS health literacy and injury acknowledgement in these athletes vary with the resourcefulness of the socioeconomic environment, implying that health literacy and resources for medical and performance support should be ascertained concurrently.

Vulnerability and stressors on the pathway to depression in a global cohort of young athletics (track and field) athletes

This research set out to identify pathways from vulnerability and stressors to depression in a global population of young athletes. Retrospective data were collected at age 18-19 years from Athletics athletes (n = 1322) originating from Africa, Asia, Europe, Oceania, and the Americas. We hypothesised that sports-related and non-sports-related stressors in interaction with structural vulnerability instigate depression. Path modelling using Maximum likelihood estimation was employed for the data analysis. Depression caseness and predisposition were determined using the WHO-5 instrument. Thirty-six percent of the athletes (n = 480) returned complete data. Eighteen percent of the athletes reported lifetime physical abuse, while 11% reported sexual abuse. Forty-five percent of the athletes had recently sustained an injury. The prevalence of depression caseness was 5.6%. Pathways to depression caseness were observed from female sex (p = 0.037) and injury history (p = 0.035) and to predisposition for depression also through exposure to a patriarchal society (p = 0.046) and physical abuse (p < 0.001). We conclude that depression in a global population of young athletes was as prevalent as previously reported from general populations, and that universal mental health promotion in youth sports should include provision of equal opportunities for female and male participants, injury prevention, and interventions for abuse prevention and victim support.

Cardiovascular effects of doping substances, commonly prescribed medications and ergogenic aids in relation to sports: a position statement of the sport cardiology and exercise nucleus of the European Association of Preventive Cardiology

The use of substances and medications with potential cardiovascular effects among those practicing sports and physical activity has progressively increased in recent years. This is also connected to the promotion of physical activity and exercise as core aspects of a healthy lifestyle, which has led also to an increase in sport participation across all ages. In this context, three main users' categories can be identified, (i) professional and amateur athletes using substances to enhance their performance, (ii) people with chronic conditions, which include physical activity and sport in their therapeutic plan, in association with prescribed medications, and (iii) athletes and young individuals using supplements or ergogenic aids to integrate their diet or obtaining a cognitive enhancement effect. All the substances used for these purposes have been reported to have side effects, among whom the cardiovascular consequences are the most dangerous and could lead to cardiac events. The cardiovascular effect depends on the type of substance, the amount, the duration of use, and the individual response to the substances, considering the great variability in responses. This Position Paper reviews the recent literature and represents an update to the previously published Position Paper published in 2006. The objective is to inform physicians, athletes, coaches, and those participating in sport for a health enhancement purpose, about the adverse cardiovascular effects of doping substances, commonly prescribed medications and ergogenic aids, when associated with sport and exercise.

Joint position statement of the International Federation of Sports Medicine (FIMS) and European Federation of Sports Medicine Associations (EFSMA) on the IOC framework on fairness, inclusion and non-discrimination based on gender identity and sex variations

The IOC recently published its framework on fairness, inclusion and non-discrimination based on gender identity and sex variations. This framework is drafted mainly from a human rights perspective, with less consideration for medical/scientific issues. The framework places the onus for gender eligibility and classification entirely on the International Federations (IFs), even though most will not have the capacity to implement the framework. The position of no presumption of advantage is contrary to the 2015 IOC consensus. Implementation of the 2021 framework will be a major challenge for IFs that have already recognised the inclusion of trans and women athletes with differences of sexual development (DSD) using a scientific/medical solution. The potential consequences for sports that need to prioritise fairness or safety could be one of two extremes (1) exclusion of all transgender or DSD athletes on the grounds of advantage or (2) self-identification that essentially equates to no eligibility rules. Exclusion of all transgender or DSD athletes is contrary to the Olympic charter and unlawful in many countries. While having no gender eligibility rules, sport loses its meaning and near-universal support. Athletes should not be under pressure to undergo medical procedures or treatment to meet eligibility criteria. However, if an athlete is fully informed and consents, then it is their free choice to undergo carefully considered or necessary interventions for gender classification for sport to compete fairly and safely in their chosen gender. Free choice is a fundamental human right, but so is the right to fair and safe competition.

The use of infrared thermography for the dynamic measurement of skin temperature of moving athletes during competition; methodological issues

Objective. To investigate the use of infrared thermography (IRT) for skin temperature measurement of moving athletes during competition and its sensitivity to factors that are traditionally standardised.Approach. Thermograms were collected for 18 female athletes during the 20 km racewalk at the 2019 World Athletics Championships, with a medium-wave, cooled indium antimonide medium wave infrared band (MWIR) and a long-wave, uncooled microbolometer longwave infrared band (LWIR) infrared camera.Main results. The MWIR provided greater clarity images of motion due to a shorter exposure and response time and produced a higher percentage of acceptable images. Analysing acceptable images only, the LWIR and WMIR produced good levels of agreement, with a bias of -0.1 ± 0.6 °C in mean skin temperature for the LWIR. As the surface area of an ROI was reduced, the measured temperature became less representative of the whole ROI. Compared to measuring the whole area ROI, a single central pixel produced a bias of 0.3 ± 0.3 °C (MWIR) and 0.1 ± 0.4 °C (LWIR) whilst using the maximum and minimum temperature pixels resulted in deviations of 1.3 ± 0.4 °C and -1.1 ± 0.3 °C (MWIR) and 1.2 ± 0.3 °C and -1.3 ± 0.4 °C (LWIR). The sensitivity to air and reflected temperatures was lower for the LWIR camera, due to the higher emissivity of skin in its wavelength.Significance. IRT provides an appropriate tool for the measurement of skin temperature during real-world competition and critically during athlete motion. The cheaper LWIR camera provides a feasible alternative to the MWIR in low rate of motion scenarios, with comparable precision and sensitivity to analysis. However, the LWIR is limited when higher speeds prevent the accurate measurement and ability to capture motion.

Evolution of distance running shoes: performance, injuries, and rules

Over the last 50 years, the development of running shoes has been mainly focused on improving the protection and comfort of the runner and her/his foot. Although there have been tentative attempts by companies to make shoes a tool for improving athletic performance, this goal has only recently been achieved. Indeed, the year 2016 was a real turning point when Nike launched its first shoe benefiting from the advanced footwear technology. Advanced footwear technology (AFT) mostly consists of an increased sole thickness, a curved and stiff plate embedded or below the shoe midsole, and an outsole with a marked concave shape. This innovation turned to a game changer in the world of distances running performance. Indeed, between 2016 and 2019, many male and female runners broke personal best times, national records, area, and world records in distance from 5 km to the marathon. The present article aimed at describing the magnitude of these performance enhancements in distance running as well as and the possible underlying performance-enhancement mechanisms associated with the advanced footwear technology. It also reviewed the existing literature on the safety aspects of "classical" construction shoes and AFT shoes. It concluded on a possible shoe mechanical tests-based protocol to maintain fair distance running competitions while not totally preventing manufacturers to innovate, and some thoughts on the nature and goals of further studies to be conducted to assess the safety (macro- and micro-traumatic) AFT in both elite and recreational runner populations.

'The Little Engine That Could': A Qualitative Study of Medical Service Access and Effectiveness among Adolescent Athletics Athletes Competing at the Highest International Level

Little is known about provision of medical services to adolescents prior to participating in international top-level sports. This study aimed to investigate experiences of medical service provision among high-level adolescent athletics (track and field) athletes from three continents. A thematic narrative analysis was applied to data collected from 14 athletes by semi-structured interviews. Although competing at the highest international level, these adolescent athletes had difficulties making sense of symptoms of ill health, especially on their own. With increasing exercise loads, the athletes’ medical support needs had extended beyond the capacity of parents and local communities. As there was no organized transfer of the responsibility for medical support to sports organizations, the athletes often had to manage their health problems by themselves. There were major variations among the adolescent athletes with regards to medical service access and quality. The services used ranged from sophisticated computer-assisted biomechanical analyses to traditional healers. Decreased exercise load was the common sports injury treatment. The results of this study demonstrate how the ethical standards underpinning youth sports as well as the equal provision of medical services to adolescents are challenged across the world. Further research on health service provision to adolescent top-level athletes is warranted.

Overtraining Syndrome (OTS) and Relative Energy Deficiency in Sport (RED-S): Shared Pathways, Symptoms and Complexities

The symptom similarities between training-overload (with or without an Overtraining Syndrome (OTS) diagnosis) and Relative Energy Deficiency in Sport (RED-S) are significant, with both initiating from a hypothalamic-pituitary origin, that can be influenced by low carbohydrate (CHO) and energy availability (EA). In this narrative review we wish to showcase that many of the negative outcomes of training-overload (with, or without an OTS diagnosis) may be primarily due to misdiagnosed under-fueling, or RED-S, via low EA and/or low CHO availability. Accordingly, we undertook an analysis of training-overload/OTS type studies that have also collected and analyzed for energy intake (EI), CHO, exercise energy expenditure (EEE) and/or EA. Eighteen of the 21 studies (86%) that met our criteria showed indications of an EA decrease or difference between two cohorts within a given study (n = 14 studies) or CHO availability decrease (n = 4 studies) during the training-overload/OTS period, resulting in both training-overload/OTS and RED-S symptom outcomes compared to control conditions. Furthermore, we demonstrate significantly similar symptom overlaps across much of the OTS (n = 57 studies) and RED-S/Female Athlete Triad (n = 88 studies) literature. It is important to note that the prevention of under-recovery is multi-factorial, but many aspects are based around EA and CHO availability. Herein we have demonstrated that OTS and RED-S have many shared pathways, symptoms, and diagnostic complexities. Substantial attention is required to increase the knowledge and awareness of RED-S, and to enhance the diagnostic accuracy of both OTS and RED-S, to allow clinicians to more accurately exclude LEA/RED-S from OTS diagnoses.

Lifetime Prevalence of Verbal, Physical, and Sexual Abuses in Young Elite Athletics Athletes

To examine prevalence of verbal, physical, and sexual abuses in young elite athletes, a cross sectional questionnaire-based survey was conducted during the World Athletics under 20 World Championships. This questionnaire aimed at distinguishing between abuses perpetrated in the context of Athletics from those which were unrelated to Athletics. Four hundred and eighty athletes (52.3%, male) from North America, South America, Europe, Africa, Asia, and Oceania took part in the electronic anonymous survey. Outside Athletics setting, no gender difference was found for the prevalence of verbal, physical, and sexual abuses. However, 45 males (18% of the male population) and 34 females (15% of the female population) athletes reported sexual abuse. Asian athletes reported a slightly higher rate of sexual abuse; three quarters of them being non-touching abuses. Inside Athletics setting, no gender difference was found for the prevalence of verbal, physical, and non-touching sexual abuses. However, 58 males (23%) and 47 females (21%) reported verbal abuses. Thirty-one males (12%) and 20 females (9%) reported physical abuses, whereas 30 males (12%) and 17 females (7%) reported sexual abuses. Physical abuses were slightly more frequent in Asia and in Africa and less frequent in South America. Sexual abuses inside Athletics also differed over regions, and were unexpectedly twice more frequent than expected in Asia and slightly less frequent than expected in Europe. Friends and partners were identified as the more frequent (>50%) abusers outside or inside the Athletics settings, whereas outside Athletics and inside Athletics, coaches were identified as sexual abuse perpetrators in 8 and 25% of cases, respectively. The prevalence of verbal, physical, or sexual abuses is high but consistent with what has been reported in United Kingdom, Norway, Canada, and Sweden at national level in recreational or elite athletes. Sexual abuse, including touching or penetrative abuses, occurred significantly more often in male athletes when compared to female athletes. This finding invites healthcare and social workers, and policymakers to also consider the risk of sexual abuse of young male athletes in Athletics. These results also call for longitudinal studies on young elite athletes.

Prehospital management of exertional heat stroke at sports competitions: International Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020

Objectives

This document aimed to summarise the key components of exertional heat stroke (EHS) prehospital management.

Methods

Members of the International Olympic Committee Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020 summarised the current best practice regarding the EHS prehospital management.

Results

Sports competitions that are scheduled under high environmental heat stress or those that include events with high metabolic demands should implement and adopt policy and procedures for EHS prehospital management. The basic principles of EHS prehospital care are: early recognition, early diagnosis, rapid, on-site cooling and advanced clinical care. In order to achieve these principles, medical organisers must establish an area called the heat deck within or adjacent to the main medical tent that is optimised for EHS diagnosis, treatment and monitoring. Once admitted to the heat deck, the rectal temperature of the athlete with suspected EHS is assessed to confirm an elevated core body temperature. After EHS is diagnosed, the athlete must be cooled on-site until the rectal temperature is below 39°C. While cooling the athlete, medical providers are recommended to conduct a blood analysis to rule out exercise-associated hyponatraemia or hypoglycaemia, provided that this can be safely performed without interrupting cooling. The athlete is transported to advanced care for a full medical evaluation only after the treatment has been provided on-site.

Conclusions

A coordination of care among all medical stakeholders at the sports venue, during transport, and at the hospital is warranted to ensure effective management is provided to the EHS athlete.

Effect of Advanced Shoe Technology on the Evolution of Road Race Times in Male and Female Elite Runners

The influence of advanced footwear technology (thickness of light midsole foam and rigid plate) on distance running performances was analyzed during an 8-year period. Analysis of variance was used to measure effects of time, gender, shoe technology, and East African origin on male and female top 20 or top 100 seasonal best times in 10-kilometer races, half-marathons, and marathons. In both genders and three distance-running events, seasonal best times significantly decreased from 2017, which coincided with the introduction of the advanced footwear technology in distance running. This performance improvement was of similar magnitude in both East African and non-East African elite runners. In female elite athletes, the magnitudes (from 1.7 to 2.3%) of the decrease in seasonal best times between 2016 and 2019 were significantly higher than in their male counterparts (from 0.6 to 1.5%). Analyses of variance confirmed that the adoption of the advanced footwear technology significantly improved the top 20 seasonal best times in female half marathons and marathons and male marathons, with the improvements being more pronounced in females and in long-distance running events. The adoption of this new shoe technology improved female marathon time by ~2 min and 10 s, which represents a significant increase in performance (1.7%).

Meteorological Risks in Doha 2019 Athletics World Championships: Health Considerations From Organizers

The Doha 2019 IAAF World Championships represent a challenge for athletes, workforce and spectators who could compete, work or attend under likely extreme meteorological conditions. This short article summarizes the methodology used by the IAAF and the Local Organizing Committee doctors to analyze and reduce risks, while complying as much as possible with existing recommendations or policies. The main steps to be completed are identification and description of weather-related risks, description and whenever possible testing of all their possible mitigation measures during test events, revision of these risks once mitigation implemented, and finally drafting a contingency plan for remaining exceptional and impactful occurrences. Such risk management methodology could apply to other sports, ideally from the host city selection to the delivery of the competitive event.

Enhanced Skeletal Muscle Oxidative Capacity and Capillary-to-Fiber Ratio Following Moderately Increased Testosterone Exposure in Young Healthy Women

Background: Recently, it was shown that exogenously administered testosterone enhances endurance capacity in women. In this study, our understanding on the effects of exogenous testosterone on key determinants of oxygen transport and utilization in skeletal muscle is expanded.

Methods: In a double-blinded, randomized, placebo-controlled trial, 48 healthy active women were randomized to 10 weeks of daily application of 10 mg of testosterone cream or placebo. Before and after the intervention, VO₂ max, body composition, total hemoglobin (Hb) mass and blood volumes were assessed. Biopsies from the vastus lateralis muscle were obtained before and after the intervention to assess mitochondrial protein abundance, capillary density, capillary-to-fiber (C/F) ratio, and skeletal muscle oxidative capacity.

Results: Maximal oxygen consumption per muscle mass, Hb mass, blood, plasma and red blood cell volumes, capillary density, and the abundance of mitochondrial protein levels (i.e., citrate synthase, complexes I, II, III, IV-subunit 2, IV-subunit 4, and V) were unchanged by the intervention. However, the C/F ratio, specific mitochondrial respiratory flux activating complex I and linked complex I and II, uncoupled respiration and electron transport system capacity, but not leak respiration or fat respiration, were significantly increased following testosterone administration compared to placebo.

Conclusion: This study provides novel insights into physiological actions of increased testosterone exposure on key determinants of oxygen diffusion and utilization in skeletal muscle of women. Our findings show that higher skeletal muscle oxidative capacity coupled to higher C/F ratio could be major contributing factors that improve endurance performance following moderately increased testosterone exposure.

Athletes' exposure to air pollution during World Athletics Relays: A pilot study

Potential adverse consequences of exposure to air pollutants during exercise include decreased lung function, and exacerbation of asthma and exercise-induced bronchoconstriction. These effects are especially relevant for athletes and during international competitions, as they may impact athletic performance. Thus, assessing and mitigating exposure to air pollutants during exercising should be encouraged in sports venues. A comprehensive air quality assessment was carried out during the World Relays Yokohama 2019, in the stadium and the warm-up track. The pilot included on-line and off-line instrumentation for gaseous and particulate pollutants and meteorological parameters, and the comparison with local reference data. Air quality perception and exacerbation of symptoms of already-diagnosed diseases (mainly respiratory and cardiovascular) were assessed by athletes by means of questionnaires during training sessions. Median NO₂ concentrations inside the stadium (25.6-31.9 μgm^-3) were in the range of the Yokohama urban background, evidencing the impact of urban sources (e.g., traffic) on athletes' exposure during training and competition. The assessment of hourly air pollutant trends was identified as a valuable tool to provide guidance to reduce atheletes' exposure, by identifying the periods of the day with lowest ambient concentrations. This strategy could be adopted to define training and competition schedules, and would have special added value for athletes with respiratory conditions. Personal exposure to polycyclic aromatic hydrocarbons was quantified through wearable silicone wristbands, and showed highly variability across volunteers. The wristbands are a simple approach to assess personal exposure to potentially toxic organic compounds. Further research would be necessary with regard to specific air pollutants that may trigger or exacerbate respiratory conditions typical of the athlete community. The availability of high time-resolved exposure data in the stadiums opens up the possibility to calculate doses of specific pollutants for individual athletes in future athletics events, to understand the impact of environmental factors on athletic performance.

[Does sport practice have an impact on the immune status ?]

Does sport practice have an impact on the immune status ? Both sports and physical activity alter our immune system. Intense/prolonged acute exercise triggers an immunosuppression period which lasts longer in unfit individuals. Although regular and well-designed workloads show immunostimulant and protective effects towards infectious diseases, highly-trained and elite athletes are definitively more vulnerable to microbial aggressions.

Efficacy of pre-participation cardiac evaluation recommendations among athletes participating in World Athletics Championships

Background

Athletes competing in athletics (track and field) at international level may be participating with underlying undiagnosed life-threatening cardiovascular conditions. Our objective was to analyse variations in pre-participation cardiac evaluation prevalence among athletes participating in two International Association of Athletics Federations (IAAF) World Athletics Championships, with regard to the human developmental level and global region of their home countries, as well as athletes' age category, gender, event group and medical insurance type.

Design

Cross-sectional web-based survey.

Methods

A total of 1785 athletes competing in the IAAF World Under 18 Championships Nairobi 2017 and World Championships London 2017 were invited to complete a pre-participation health questionnaire investigating the experience of a pre-participation cardiac examination.

Results

A total of 704 (39%) of the athletes participated. Among these, 59% (60% of women; 58% of men) reported that they had been provided at least one type of pre-participation cardiac evaluation. Athletes from very high income countries, Europe and Asia, showed a higher prevalence of at least one pre-participation cardiac evaluation.

Conclusions

The prevalence of pre-participation cardiac evaluation in low to middle income countries, and the African continent in particular, needs urgent attention. Furthermore, increases in evaluation prevalence should be accompanied by the development of cost-effective methods that can be adopted in all global regions.

Medical encounters (including injury and illness) at mass community-based endurance sports events: an international consensus statement on definitions and methods of data recording and reporting

Mass participation endurance sports events are popular but a large number of participants are older and may be at risk of medical complications during events. Medical encounters (defined fully in the statement) include those traditionally considered 'musculoskeletal' (eg, strains) and those due to 'illness' (eg, cardiac, respiratory, endocrine). The rate of sudden death during mass endurance events (running, cycling and triathlon) is between 0.4 and 3.3 per 100 000 entrants. The rate of other serious medical encounters (eg, exertional heat stroke, hyponatraemia) is rarely reported; in runners it can be up to 100 times higher than that of sudden death, that is, between 16 and 155 per 100 000 race entrants. This consensus statement has two goals. It (1) defines terms for injury and illness-related medical encounters, severity and timing of medical encounters, and diagnostic categories of medical encounters, and (2) describes the methods for recording data at mass participation endurance sports events and reporting results to authorities and for publication. This unifying consensus statement will allow data from various events to be compared and aggregated. This will inform athlete/patient management, and thus make endurance events safer.

Androgens and athletic performance of elite female athletes

PURPOSE OF REVIEW

During the last decades androgens have been used illicitly by athletes of both genders. Because of some obvious ethical limitations, mechanisms underlying the performance-enhancing effects of these hormone or drugs, as well as the magnitude of their effects, have been poorly addressed. This review aims to combine findings from field and from the laboratory to provide new insights into the ergogenic properties of endogenous or exogenous androgens on female athletes.

RECENT FINDINGS

Results obtained from recent neuropsychological studies indicated that testosterone, and not the sex chromosomes, is responsible for the sexual differentiation of visuospatial neural activation. These findings could explain how males and hyperandrogenic females benefit from androgens performance-enhancing effects in sports where visuospatial abilities are closely linked to better performance. Another study conducted on elite female athletes showed that, in some athletic events, where muscle power is of critical importance, individuals with the highest free testosterone concentration significantly outperformed competitors with the lowest free testosterone concentration.

SUMMARY

In some sport events, female athletes with high or very high androgen levels (whether it is from endogenous or exogenous origin) have an estimated competitive benefit of 2-5% over those with androgen levels within the normal female range. These findings are to be taken into account in the actual controversy about eligibility of females with hyperandrogenism to compete in women's sports.

The impact of sleeping with reduced glycogen stores on immunity and sleep in triathletes

PURPOSE

We investigated the effects of a 3-week dietary periodization on immunity and sleep in triathletes.

METHODS

21 triathletes were divided into two groups with different nutritional guidelines during a 3-week endurance training program including nine twice a day sessions with lowered (SL group) or maintained (CON group) glycogen availability during the overnight recovery period. In addition to performance tests, sleep was monitored every night. Systemic and mucosal immune parameters as well as the incidence of URTI were monitored every week of the training/nutrition protocol. Two-ways ANOVA and effect sizes were used to examine differences in dependent variables between groups at each time point.

RESULTS

The SL group significantly improved 10 km running performance (-1 min 13 s, P < 0.01, d = 0.38), whereas no improvement was recorded in the CON group (-2 s, NS). No significant changes in white blood cells counts, plasma cortisol and IL-6 were recorded over the protocol in both groups. The vitamin D status decreased in similar proportions between groups, whereas salivary IgA decreased in the SL group only (P < 0.05, d = 0.23). The incidence of URTI was not altered in both groups. All participants in both groups went to bed earlier during the training program (SL -20 min, CON -27 min, P < 0.05, d = 0.28). In the SL group, only sleep efficiency slightly decreased by 1.1 % (P < 0.05, d = 0.25) and the fragmentation index tended to increase at the end of the protocol (P = 0.06).

CONCLUSION

Sleeping and training the next morning regularly with reduced glycogen availability has minimal effects on selected markers of immunity, the incidence of URTI and sleeping patterns in trained athletes.

Women with hyperandrogenism in elite sports: scientific and ethical rationales for regulating

The recent implementation by some major sports-governing bodies of policies governing eligibility of females with hyperandrogenism to compete in women's sports has raised a lot of attention and is still a controversial issue. This short article addresses two main subjects of controversy: the existing scientific basis supporting performance enhancing of high blood T levels in elite female athletes, and the ethical rationale and considerations about these policies. Given the recently published data about both innate and acquired hyperandrogenic conditions and their prevalence in elite female sports, we claim that the high level of androgens are per se performance enhancing. Regulating women with clinical and biological hyperandrogenism is an invitation to criticism because biological parameters of sex are not neatly divided into only two categories in the real world. It is, however, the responsibility of the sports-governing bodies to do their best to guarantee a level playing field to all athletes. In order not cloud the discussions about the policies on hyperandrogenism in sports, issues of sports eligibility and therapeutic options should always be considered and explained separately, even if they may overlap. Finally, some proposals for refining the existing policies are made in the present article.

The microbiota: an exercise immunology perspective

The gut microbiota consists of a cluster of microorganisms that produces several signaling molecules of a hormonal nature which are released into the blood stream and act at distal sites. There is a growing body of evidence indicating that microbiota may be modulated by several environmental conditions, including different exercise stimulus, as well some pathologies. Enriched bacterial diversity has also been associated with improved health status and alterations in immune system, making multiple connections between host and microbiota. Experimental evidence has shown that reduced levels and variations in the bacterial community are associated with health impairments, while increased microbiota diversity improves metabolic profile and immunological responses. So far, very few controlled studies have focused on the interactions between acute or chronic exercise and the gut microbiota. However, some preliminary experimental data obtained from animal studies or probiotics studies show some interesting results at the immune level, indicating that the microbiota also acts like an endocrine organ and is sensitive to the homeostatic and physiological changes associated with exercise. Thus, our review intends to shed some light on the interaction between gut microbiota, exercise and immunomodulation.

Serum androgen levels in elite female athletes

OBJECTIVE

Prior to the implementation of the blood steroidal module of the Athlete Biological Passport, we measured the serum androgen levels among a large population of high-level female athletes as well as the prevalence of biochemical hyperandrogenism and some disorders of sex development (DSD).

METHODS AND RESULTS

In 849 elite female athletes, serum T, dehydroepiandrosterone sulphate, androstenedione, SHBG, and gonadotrophins were measured by liquid chromatography-mass spectrometry high resolution or immunoassay. Free T was calculated. The sampling hour, age, and type of athletic event only had a small influence on T concentration, whereas ethnicity had not. Among the 85.5% that did not use oral contraceptives, 168 of 717 athletes were oligo- or amenorrhoic. The oral contraceptive users showed the lowest serum androgen and gonadotrophin and the highest SHBG concentrations. After having removed five doped athletes and five DSD women from our population, median T and free T values were close to those reported in sedentary young women. The 99th percentile for T concentration was calculated at 3.08 nmol/L, which is below the 10 nmol/L threshold used for competition eligibility of hyperandrogenic women with normal androgen sensitivity. Prevalence of hyperandrogenic 46 XY DSD in our athletic population is approximately 7 per 1000, which is 140 times higher than expected in the general population.

CONCLUSION

This is the first study to establish normative serum androgens values in elite female athletes, while taking into account the possible influence of menstrual status, oral contraceptive use, type of athletic event, and ethnicity. These findings should help to develop the blood steroidal module of the Athlete Biological Passport and to refine more evidence-based fair policies and recommendations concerning hyperandrogenism in female athletes.

Molecular diagnosis of 5α-reductase deficiency in 4 elite young female athletes through hormonal screening for hyperandrogenism

CONTEXT

Although a rare occurrence, previously undiagnosed disorders of sex development (DSD) with hyperandrogenism are sometimes detected by hormonal screening during the international sports competitions. Identifying the cause of XY,DSD raises medical and ethical concerns, especially with regard to issues of the eligibility to compete.

OBJECTIVE

The aim of this study was to determine whether the detection of high plasma T in young elite female athletes during hormonal screening would reveal an unsuspected XY DSD.

SETTING

The study was performed in the Nice and Montpellier University Hospitals (France), which collaborate as reference centers for DSD in elite athletes on behalf of sports governing bodies.

PATIENTS

Four cases of elite young athletes with female phenotypes but high plasma T detected during hormonal screening were investigated for undiagnosed XY DSD.

MAIN OUTCOME MEASURES

Evaluation of clinical, biological, radiological (magnetic resonance imaging and dual-energy x-ray absorptiometry) and genetic characteristics was conducted.

RESULTS

The 4 athletes presented as tall, slim, muscular women with a male bone morphotype, no breast development, clitoromegaly, partial or complete labial fusion, and inguinal/intralabial testes. All reported primary amenorrhea. The hormonal analysis evidenced plasma T within the male range, the karyotype was 46, XY, and molecular analysis of the 5α-reductase type 2 (srd5A2) gene identified a homozygotic mutation in 2 cases, a heterozygotic compound in 1 case, and a deletion in 1 case.

CONCLUSION

5α-Reductase deficiency should be investigated in elite young female athletes with primary amenorrhea and high male T levels detected during antidoping programs to identify undiagnosed XY DSD.

Position statement. Part two: Maintaining immune health

The physical training undertaken by athletes is one of a set of lifestyle or behavioural factors that can influence immune function, health and ultimately exercise performance. Others factors including potential exposure to pathogens, health status, lifestyle behaviours, sleep and recovery, nutrition and psychosocial issues, need to be considered alongside the physical demands of an athlete's training programme. The general consensus on managing training to maintain immune health is to start with a programme of low to moderate volume and intensity; employ a gradual and periodised increase in training volumes and loads; add variety to limit training monotony and stress; avoid excessively heavy training loads that could lead to exhaustion, illness or injury; include non-specific cross-training to offset staleness; ensure sufficient rest and recovery; and instigate a testing programme for identifying signs of performance deterioration and manifestations of physical stress. Inter-individual variability in immunocompetence, recovery, exercise capacity, non-training stress factors, and stress tolerance likely explains the different vulnerability of athletes to illness. Most athletes should be able to train with high loads provided their programme includes strategies devised to control the overall strain and stress. Athletes, coaches and medical personnel should be alert to periods of increased risk of illness (e.g. intensive training weeks, the taper period prior to competition, and during competition) and pay particular attention to recovery and nutritional strategies.

Time-frequency analysis of heart rate variability reveals cardiolocomotor coupling during dynamic cycling exercise in humans

To test the hypothesis that cycling exercise modulates heart rate variability (HRV), we applied a short-time Fourier transform on the electrocardiogram of subjects performing a maximal graded cycling test. A pedaling frequency component (PFC) in HRV was continuously observed over the time course of the exercise test and extracted from R-R interval series obtained from 15 healthy subjects with a heterogeneous physical fitness, exercising at three different pedaling frequency ( n = 5): 70, 80, and 90 rpm. From 30 to 50% of the maximal power output (Pmax), in the 90 rpm group, spectral aliasing caused PFC to overlap with the respiratory sinus arrhythmia (RSA) band, significantly overestimating the PFC amplitude ( APFC). In the meantime, APFC did not increase significantly from its minimal values in the 70 rpm (∼1.26 ms) and 80 rpm (∼1.20 ms) groups. Then, from 60 to 100% maximal power output (Pmax), workload increase caused a significant ∼2.8-, ∼3.3-, and ∼3.4-fold increase in APFC in the 70, 80, and 90 rpm groups, respectively, with no significant difference between groups. At peak exercise, APFC accounted for ∼43, ∼39, and ∼49% of the total HRV in the 70, 80, and 90 rpm groups, respectively. Our findings indicate that cycling continuously modulates the cardiac chronotropic response to exercise, inducing a new component in HRV, and that workload increase during intense exercise further accentuates this cardiolocomotor coupling. Moreover, because PFC and RSA overlapped at low workloads, methodological care should be taken in future studies aiming to quantify RSA as an index of parasympathetic activity.

Airway inflammation and upper respiratory tract infection in athletes: is there a link?

Upper Respiratory Tract Infection (URTI) is regarded as the most common medical condition affecting both highly trained and elite athletes, in particular those participating in endurance events. The causes of these disturbances, also occurring during training, remain unclear. Viruses such as rhinovirus, adenovirus and para-influenza virus are frequently reported as the source of URTI. However, in a few comprehensive laboratory and epidemiological studies which reported at least a 30% incidence of URTI, no identifiable pathogens were either reported or studied. A recent, longitudinal study investigated symptomatology and pathogenic etiology in sedentary controls, recreational and elite athletes. The highest incidence of URTI occurred in elite athletes. However; only 11 out of 37 illness episodes overall had pathogenic origins, and most of the unidentified upper respiratory illnesses were shorter in duration and less severe than infectious ones. This concept of inflammation without infection in athletes is quite new and leads us to consider other explanatory pathophysiological conditions. Increases in airway neutrophils, eosinophils and lymphocytes have been described under resting conditions in endurance sports, swimmers and cross-country skiers. These inflammatory patterns may be due to pollutants or chlorine-related compounds in swimmers. After intense exercise similar airways cellular profiles have been reported, with a high amount of bronchial epithelial cells. This increase in airway inflammatory cells in athletes can result from a hyperventilation-induced increase in airway osmolarity stimulating bronchial epithelial cells to release chemotactic factors. Fortunately, in most cases, these inflammatory cells express rather low level of adhesion molecules, explaining why airway inflammation may appear blunted in athletes despite numerous inflammatory cellular elements. However it can be hypothesized that a transient loss of control of this local inflammation, due to various external physico-chemical strains, might occur. This might account for some of the unidentified upper respiratory illnesses.

A new modeling of the overlapping T wave for the efficient estimation of the P-R intervals during exercise and recovery

The analysis of the heart period series is a difficult task especially under graded exercise conditions. Having a good tool to characterize the P-R and R-R intervals, i.e. a good method of time delay estimation, would carry out a better knowledge of the neural activity during exercise and recovery in the field of pacemaker's design. Unfortunately, for the P-R intervals, the problem of estimation has been rarely addressed. In this paper, we propose a new method for estimating the P-R intervals based on an iterative Maximum-Likelihood approach. The main contribution is to take into account the overlapping T wave on ECG recorded during exercise. The goal of this study is to compute a model of the T wave which overlaps the P wave and then to cancel this influence before the determination of the P-R intervals.

Time-Varying Analysis Methods and Models for the Respiratory and Cardiac System Coupling in Graded Exercise

The analysis of heart period series is a difficult task especially under graded exercise conditions. From all the information present in these series, we are the most interested in the coupling between respiratory and cardiac systems, known as respiratory sinus arrythmia. In this paper, we show that precise patterns concerning the respiratory frequency can be extracted from the heart period series. An evolutive model is introduced in order to achieve tracking of the main respiratory-related frequencies and their time-varying amplitudes. Since respiration acts to modulate the sinus rhythm, we relate the frequencies and amplitudes to this modulation by analyzing in detail its nonlinear transformation giving the heart period signal. This analysis is performed assuming stationary conditions but also in the realistic case where the mean heart period, the amplitude, and the frequency of the respiration are time-varying. Since this paper is devoted to the theoretical and complete presentation of the method used in a physiological study published elsewhere, the capabilities of our method will be illustrated in a realistic simulated case.

Muscle performance in patients with Crohn's disease in clinical remission

BACKGROUND

Because patients with Crohn's disease (CD) often show increased energy expenditure, nutritional deficiencies, and general fatigue, all which may persist after a flare, we hypothesized that CD could alter muscle mass and function. This study aimed to assess muscle strength and endurance in CD patients in clinical remission and the influencing factors.

METHODS

Forty-one outpatients (17 men and 24 women; age, 37 +/- 10 yr), in remission (CD Activity Index < 150) for > 3 months, and 25 age-matched healthy controls (10 men and 15 women; age, 37 +/- 13 yr) were evaluated. Evaluation included a sit-up test, hand-grip strength test, hand-grip endurance test, lower limb strength test, and lower limb endurance test (LE), as well as a measure of physical activity.

RESULTS

No significant difference was found between CD and control groups regarding weight, height, body mass index, fat mass, and fat-free mass. Strength performance was lower in CD subjects compared with controls, particularly for lower limb indexes: lower limb strength test (-24.6%, P < 0.001), LE (-25.8%, P < 0.001), and sit-up test (-25.1%, P < 0.001). Previous disease severity, disease duration, the cumulative dose of glucocorticosteroids, current inflammation, and global habitual physical activity did not affect muscle performance. A recent use of steroids improved LE.

CONCLUSIONS

CD patients in clinical remission have decreased muscle function that may affect their quality of life. This pattern is reflected by reduced strength and endurance indexes, particularly for lower limbs. The reasons for these changes need further study. Strength training should be assessed in these patients.

Influences of breathing patterns on respiratory sinus arrhythmia in humans during exercise

Persistence of respiratory sinus arrhythmia (RSA) has been described in humans during intense exercise and attributed to an increase in ventilation. However, the direct influence of ventilation on RSA has never been assessed. The dynamic evolution of RSA and its links to ventilation were investigated during exercise in 14 healthy men using an original modeling approach. An evolutive model was estimated from the detrended and high-pass-filtered heart period series. The instantaneous RSA frequency (FRSA, in Hz) and amplitude (ARSA, in ms) were then extracted from all recordings. A(RSA) was calculated with short-time Fourier transform. First, measurements of FRSA and ARSA were performed from data obtained during a graded and maximal exercise test. Influences of different ventilation regimens [changes in tidal volume (VT) and respiratory frequency (FR)] on ARSA were then tested during submaximal [70% peak O2 consumption (VO2peak)] rectangular exercise bouts. Under graded and maximal exercise conditions, ARSA decreased from the beginning of exercise to 61.9 +/- 3.8% VO2peak and then increased up to peak exercise. During the paced breathing protocol, normoventilation (69.4 +/- 8.8 l/min), hyperventilation (81.8 +/- 8.3 l/min), and hypoventilation (56.4 +/- 6.2 l/min) led to significantly (P < 0.01) different ARSA values (3.8 +/- 0.5, 4.6 +/- 0.8, and 2.9 +/- 0.5 ms, respectively). In addition, no statistical difference was found in ARSA when ventilation was kept constant, whatever the FR-VT combinations. Those results indicate that RSA persists for all exercise intensities and increases during the highest intensities. Its persistence and increase are strongly linked to both the frequency and degree of lung inflation, suggesting a mechanical influence of breathing on RSA.

Effects of long duration exercise on cognitive function, blood glucose, and counterregulatory hormones in male cyclists

Electrocortical effects of long duration exercise on cognitive function were investigated by analyzing P300 amplitude and latency changes during a 3-h cycling exercise. P300 components were measured in 12 well-trained cyclists and blood glucose, cortisol, insulin, glycerol, and free fatty acids (FFAs) epinephrine and norepinephrine were analyzed. Results indicated that P300 components were affected by exercise with a temporary increase in amplitude between the 1st and the 2nd hour and an increase in latency after 2 h of exercise concomitant with some hormonal changes, including an increase in cortisol and epinephrine and a decrease in blood glucose. These findings suggest a combined effect of arousal and central fatigue on electrocortical indices of cognitive function during acute physical exercise.

Ageing and muscle: the effects of malnutrition, re-nutrition, and physical exercise

Because of the metabolic changes caused by ageing, malnutrition is accompanied by a preferential loss of fat-free mass in the elderly, and it exaggerates the physiological loss of body cell mass, muscle mass and muscle function observed in the aged. Exercise training has positive anabolic effects even in the frail elderly, and may improve the effect of re-nutrition in malnourished elderly patients.