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Purpose: Wetsuits have been shown to change swim biomechanics and, thus, increase performance, but not all athletes are comfortable with their use because of possible modifications in motor coordination. The aim of this study was to evaluate the effects of wetsuit use on biomechanical, physiological, and perceptual variables. Methods: Eleven national- and international-level triathletes, familiar with wetsuit use, performed 7 × 200-m front crawl at constant preset speed twice, with and without a full wetsuit. The trunk incline (TI) and index of coordination (IdC) were measured stroke by stroke using video analysis. Stroke, breaths, and kick count, and timing (as breathing/kick action per arm-stroke cycle); stroke length (SL); and underwater length were analyzed using inertial-measurement-unit sensors. Heart rate (HR), rating of perceived exertion (RPE), and swimming comfort were monitored during the task. Results: A lower TI; IdC; number of strokes, kicks, and breaths; HR; and RPE for each 200 m were found in wetsuit compared with swimsuit condition. Higher values of SL and underwater length were found in wetsuit, whereas no differences were found in swimming comfort and timing of kicks and breaths. An increase for swimsuit condition in number of strokes and breaths, HR, and RPE was found during the task compared with the first 200 m. Conclusion: Wetsuit use reduces TI and, thus, drag; increases propelling proficiency; and shows lower fatigability, without modifying motor coordination, compared with swimsuit use at the same speed. The use of a wetsuit during training sessions is recommended to increase comfort and the positive effects on performance.

Introduction The etiology of sudden cardiac death (SCD) in young people continues to attract much attention. This meta-analysis aimed to identify the most frequent causes of SCD in individuals aged ≤35 years, the differences between athletes and non-athletes and geographic areas. Methods Studies published between 01/01/1990 and 01/31/2020 and evaluating post-mortem the aetiology of SCD in young individuals (≤35 years) were included. Individuals were divided into athletes and non-athletes. Studies that did not report separate data between athletes and non-athletes were excluded. Results Thirty-four studies met the inclusion criteria, and a total population of 5,060 victims of SCD were analyzed (2,890 athletes, 2,170 non-athletes). Comparing the causes of SCD between athletes and non-athletes, non-ischemic left ventricular scar (NILVS) (5.1% vs. 1.1%, p=0.01) was more frequent in the former, while coronary artery disease (CAD) (19.6% vs. 9.1%, p=0.009), arrhythmogenic cardiomyopathy (ACM) (11.5% vs. 4.7%, p=0.03) and channelopathies (8.4% vs. 1.9%, p=0.02) were more frequent in the latter. In studies published in the last decade, hypertrophic cardiomyopathy (HCM) (p=0.002), dilated cardiomyopathy (p=0.047), and anomalous origin of coronary arteries (AOCA) (p=0.009) were more frequently the causes of SCD in athletes while aortic dissection (0.022) was the cause in non-athletes. HCM (p=0.01) and AOCA (p=0.004) were more frequently the causes of SCD in the US while ACM (p=0.001), structurally normal heart (p=0.02), and channelopathies (p=0.02) were more frequent in Europe. Conclusions Among the causes of SCD, NILVS was the more frequent cause in athletes, while CAD, ACM and channelopathies were more frequent causes in non-athletes. The causes of SCD differ between the US and Europe.

Exercise training is highly recommended in current guidelines on primary and secondary prevention of cardiovascular disease (CVD). This is based on the cardiovascular benefits of physical activity and structured exercise, ranging from improving the quality of life to reducing CVD and overall mortality. Therefore, exercise should be treated as a powerful medicine and critical component of the management plan for patients at risk for or diagnosed with CVD. A tailored approach based on the patient’s personal and clinical characteristics represents a cornerstone for the benefits of exercise prescription. In this regard, the use of cardiopulmonary exercise testing is well-established for risk stratification, quantification of cardiorespiratory fitness and ventilatory thresholds for a tailored, personalised exercise prescription. The aim of this paper is to provide a practical guidance to clinicians on how to use data from cardiopulmonary exercise testing towards personalised exercise prescriptions for patients at risk of or with CVD.

BackgroundSARS-CoV-2 infection might be associated with cardiac complications in low-risk populations, such as in competitive athletes. However, data obtained in adults cannot be directly transferred to preadolescents and adolescents who are less susceptible to adverse clinical outcomes and are often asymptomatic.ObjectivesWe conducted this prospective multicentre study to describe the incidence of cardiovascular complications following SARS-CoV-2 infection in a large cohort of junior athletes and to examine the effectiveness of a screening protocol for a safe return to play.MethodsJunior competitive athletes suffering from asymptomatic or mildly symptomatic SARS-CoV-2 infection underwent cardiac screening, including physical examination, 12-lead resting ECG, echocardiogram and exercise ECG testing. Further investigations were performed in cases of abnormal findings.ResultsA total of 571 competitive junior athletes (14.3±2.5 years) were evaluated. About half of the population (50.3%) was mildly symptomatic during SARS-CoV-2 infection, and the average duration of symptoms was 4±1 days. Pericardial involvement was found in 3.2% of junior athletes: small pericardial effusion (2.6%), moderate pericardial effusion (0.2%) and pericarditis (0.4%). No relevant arrhythmias or myocardial inflammation was found in subjects with pericardial involvement. Athletes with pericarditis or moderate pericardial effusion were temporarily disqualified, and a gradual return to play was achieved after complete clinical resolution.ConclusionsThe prevalence of cardiac involvement was low in junior athletes after asymptomatic or mild SARS-CoV-2 infection. A screening strategy primarily driven by cardiac symptoms should detect cardiac involvement from SARS-CoV-2 infection in most junior athletes. Systematic echocardiographic screening is not recommended in junior athletes.

Background Although structured exercise training is strongly recommended in cardiac patients, uncertainties exist about the methods for determining exercise intensity (EI) and their correspondence with effective EI obtained by ventilatory thresholds. We aimed to determine the first (VT1 ) and second ventilatory thresholds (VT2 ) in cardiac patients, sedentary subjects, and athletes comparing VT1 and VT2 with EI defined by recommendations. Methods We prospectively enrolled 350 subjects (mean age: 50.7±12.9 years; 167 cardiac patients, 150 healthy sedentary subjects, and 33 competitive endurance athletes). Each subject underwent ECG, echocardiography, and cardiopulmonary exercise testing. The percentages of peak VO2 , peak heart rate (HR), and HR reserve were obtained at VT1 and VT2 and compared with the EI definition proposed by the recommendations. Results VO2 at VT1 corresponded to high rather than moderate EI in 67.1% and 79.6% of cardiac patients, applying the definition of moderate exercise by the previous recommendations and the 2020 guidelines, respectively. Most cardiac patients had VO2 values at VT2 corresponding to very-high rather than high EI (59.9% and 50.3%, by previous recommendations and 2020 guidelines, respectively). A better correspondence between ventilatory thresholds and recommended EI domains was observed in healthy subjects and athletes (90% and 93.9%, respectively). Conclusions EI definition based on percentages of peak HR and peak VO2 may misclassify the effective EI, and the discrepancy between the individually determined and the recommended EI is particularly relevant in cardiac patients. A ventilatory threshold-based rather than a range-based approach is advisable to define an appropriate level of EI.

Despite the common belief that sleep quality at altitude is poor, the scientific evidence to support this notion is still modest. Therefore, the purpose of the present study was to evaluate possible changes of actigraphy-based and subjective sleep parameters in a group of elite open-water swimmers during a 14-day altitude training camp (ATC) at 1500 m. The study subjects were five Olympic-level open-water swimmers (mean age: 25.0 ± 3.2 years; 3 females and 2 males). All subjects wore a wrist activity monitor and filled a sleep diary for 18 consecutive nights, 4 nights before and 14 nights during ATC. The data were then analyzed at four different time points: before ATC (PRE), the first two days of ATC (T1), and after one (T2) and two weeks of ATC (T3). Training load, assessed as the covered distance (km), session rating of perceived exertion (sRPE), and heart rate (HR), was monitored during the week before and the first and second week of ATC. No significant differences in objective and subjective scores of sleep quality were detected, whereas the sleep onset time (p = 0.018; η2p = 0.83, large) and sleep offset time (p < 0.001; η2p = 0.95, large) significantly differed among PRE, T1, T2, and T3: elite athletes started to sleep and woke up ≃ 1 h earlier the first two days of ATC compared to PRE (sleep onset time: p = 0.049; sleep offset time: p = 0.016). Further, an increase in the training volume during the two weeks of the ATC was observed, with the most time spent in a low-intensity regime and an increase in time spent in a high-intensity regime compared to PRE. Sleep quality was not negatively influenced by a 14-day altitude training camp at 1500 m in a group of Olympic-level elite swimmers despite an increase in perceived exertion during training sessions. Nonetheless, early sleep onset and sleep offset times were observed for the first two nights of ATC: elite athletes started to sleep and woke up ≃ 1 h earlier compared to the baseline nights.

Post-acute sequelae of coronavirus disease 19 (COVID-19) (PASC) describe a wide range of symptoms and signs involving multiple organ systems occurring after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, representing a growing health problem also in the world of sport and the athletic population. Patients with PASC have new, returning, or persisting symptoms four or more weeks after the infection. Among the most frequent symptoms, patients complain of fatigue, dyspnea, exercise intolerance, and reduced functional capacity that interfere with everyday life activity. The role of exercise programs in PASC patients will be identified, and upcoming studies will establish the magnitude of their benefits. However, the benefits of exercise to counteract these symptoms are well known, and an improvement in cardiopulmonary fitness, functional status, deconditioning, and quality of life can be obtained in these patients, as demonstrated in similar settings. Based on this background, this review aims to summarise the current evidence about the PASC syndrome and the benefit of exercise in these patients and to provide a practical guide for the exercise prescription in PASC patients to help them to resume their functional status, exercise tolerance, prior activity levels, and quality of life, also considering the athletic population and their return to play and sports competitions.

Purpose: To analyze training-intensity distribution (TID) using different independent monitoring systems for internal training load in a group of elite open-water swimmers. Methods: One hundred sixty training sessions were monitored in 4 elite open-water swimmers (2 females and 2 males: 23.75 [4.86] y, 62.25 [6.18] kg, 167 [6.68] cm) during 5 weeks of regular training. Heart-rate-based methods, such as time in zone (TIZ), session goal (SG), and hybrid (SG/TIZ), were used to analyze TID. Similarly to SG/TIZ, a new hybrid approach, the rating of perceived exertion (RPE)/TIZ for a more accurate analysis of TID was used. Moreover, based on the 3-zone model, the session ratings of perceived exertion of the swimmers and the coach were compared. Results: Heart-rate- and RPE-based TID methods were significantly different in quantifying Z1 (P = .012; effect size [ES] = 0.490) and Z2 (P = .006; ES = 0.778), while no difference was observed in the quantification of Z3 (P = .428; ES = 0.223). The heart-rate-based data for Z1, Z2, and Z3 were 83.2%, 7.4%, and 8.1% for TIZ; 80.8%, 8.3%, and 10.8% for SG/TIZ; and 55%, 15.6%, and 29.4% for SG. The RPE-based data were 70.9%, 19.9%, and 9.2% for RPE/TIZ% and 41.2%, 48.9%, and 9.7% for the session rating of perceived exertion. No differences were observed between the coach’s and the swimmers’ session ratings of perceived exertion in the 3 zones (Z1: P = .663, ES = −0.187; Z2: P = .110, ES = 0.578; Z3: P = .149, ES = 0.420). Conclusion: Using RPE-based TID methods, Z2 was significantly larger compared with Z1. These results show that RPE-based TID methods in elite open-water swimmers are affected by both intensity and volume.

Cardiovascular diseases are the leading cause of death in high-income countries. Exercise prescription is an effective tool for primary and secondary cardiovascular prevention and the cardiovascular benefits of physical activity are well established, ranging from improving the quality of life to reducing mortality. A tailored approach based on patient's personal and clinical characteristics represents a cornerstone for the benefits of exercise prescription. The use of cardiopulmonary exercise testing is well-established for a tailored exercise prescription, as ventilatory thresholds allow to define exercise intensity in a highly individualized manner.

The 10-km open-water swimming race is an endurance event that takes place in lakes, rivers, or sea and has been an Olympic event since 2008. The aim of the present brief report is to describe training volume and intensity distribution of elite open-water swimmers during the 2016 Olympic season, verifying if, in order to maximize performance, most of the training would be performed at low intensities.Eight elite Italian open-water swimmers (3 male and 5 female; 25 [2] y, 1.74 [0.05] m, 68.26 [8.17] kg) specialized in distances between 5 and 25 km participated in the study. Training load was determined using an online training diary. Training intensity was categorized according to the 3-zone model: Z1, light intensity; Z2, moderate intensity; and Z3, high intensity. Session rating of perceived exertion was used to quantify training-intensity distribution. This method assigns the entire session into a single intensity zone based on the rating of perceived exertion recorded 30 min posttraining.Total yearly training volume was 3576.93 (272.390) km (3220.80-4041.97), distributed across 446 (37) (397-484) sessions monitored during the 2016 Olympic season. Training-intensity distribution in each zone was 76.83% (8.11%) in Z1, 17.70% (6.79%) in Z2, and 5.47% (5.93%) in Z3.High volumes in Z1 appear to be an important training method used by elite open-water swimmers. However, future research is necessary to study the effects of different training-intensity distribution on open-water swimming performances.

Funding Acknowledgements Type of funding sources: None. Introduction. The etiology of sudden cardiac death (SCD) in young people is still debated. The aim of this meta-analysis was to identify the most frequent causes of SCD in individuals aged ≤35 years, the differences between athletes and nonathletes and among geographic areas. Methods. Studies published between 01/01/1990 and 01/31/2020 and evaluating post-mortem the etiology of SCD in young individuals (≤35 years) were included. Individuals were divided in athletes and nonathletes. Studies that did not report separately data between athletes and nonathletes were excluded. Results. Thirty-four studies met the inclusion criteria and a total population of 5,060 victims of SCD were analysed (2,890 athletes, 2,170 nonathletes). Structurally normal heart, hypertrophic cardiomyopathy (HCM), idiopathic left ventricular hypertrophy, and anomalous origin of coronary arteries (AOCA) were the most frequent causes of SCD in athletes while coronary artery disease (CAD), arrhythmogenic cardiomyopathy (ACM), and channelopathies were frequent causes of SCD in nonathletes. The number of SCDs due to ischemic heart disease (19.6% vs. 9.1%, p = 0.009), ACM (11.5% vs. 4.7%, p = 0.03) and channelopathies (8.4% vs. 1.9%, p = 0.02) was higher in nonathletes comparing with athletes. SCD due to non-ischemic left ventricular scar (5.1% vs. 1.1%, p = 0.01) was more frequent in athletes. HCM (p = 0.01) and AOCA (p = 0.004) were more frequently cause of SCD in US while ACM (p = 0.001), structurally normal heart (p = 0.02), and channelopathies (p = 0.02) in Europe. Conclusions. Structurally normal heart, HCM, AOCA were frequent causes of SCD in athletes while CAD, ACM and channelopathies in nonathletes. The causes of SCD differ between US and Europe.

Funding Acknowledgements Type of funding sources: None. Background. Although structured exercise training is strongly recommended in cardiac patients, uncertainties exist about the methods for determining exercise intensity (EI) and their correspondence with effective EI obtained by ventilatory thresholds. We aimed to determine the first (VT1) and second ventilatory threshold (VT2) in cardiac patients, sedentary subjects and athletes comparing VT1 and VT2 with EI defined by recommendations. Methods. We prospectively enrolled 350 subjects (mean age: 50.7 ± 12.9 years; 167 cardiac patients, 150 healthy sedentary subjects, 33 competitive endurance athletes). Each subject underwent ECG, echocardiography, and cardiopulmonary exercise testing. The percentages of peak VO2, peak heart rate (HR), and HR reserve were obtained at VT1 and VT2, and compared with EI definition proposed by the recommendations. Results. VO2 at VT1 corresponded to high rather than moderate EI in 67.1% and in 79.6% of cardiac patients, applying the definition of moderate exercise by the previous recommendations and the 2020 guidelines, respectively. Most of cardiac patients had VO2 values at VT2 corresponding to very-high rather than high EI (59.9% and 50.3%, by previous recommendations and 2020 guidelines, respectively). A better correspondence between ventilatory-thresholds and recommended EI domains was observed in healthy subjects and in athletes (90% and 93.9%, respectively). Conclusions. EI definition based on percentages of peak HR and peak VO2 may misclassify the effective EI and the discrepancy between the individually determined and the recommended EI is particularly relevant in cardiac patients. A ventilatory threshold-based rather than a range-based approach is advisable in order to define an appropriate level of EI. Abstract Figure.

Funding Acknowledgements Type of funding sources: None. Background. Premature ventricular beats (PVBs) are not an unusual finding and their interpretation is sometimes challenging. Unfortunately, few data on the characteristics of PVBs that correlate with the risk of an underlying heart disease are available in athletes. Objectives. The aim of this prospective study was to investigate the diagnostic and prognostic value of PVBs characteristics in competitive athletes. Methods. From a cohort of 1,751 athletes evaluated at our sports cardiology centre, we enrolled 112 competitive athletes Results. The majority (79%) of athletes exhibited monomorphic PVBs with a fascicular or infundibular pattern (common morphologies). A definitive diagnosis of cardiac disease was reached in 26 athletes (23% of the entire population) and correlated with uncommon PVBs morphology (p Conclusions. Infundibular and fascicular PVBs were the most common morphologies observed in athletes with ventricular arrhythmias referred for cardiological evaluation. Morphology and complexity of PVBs, but not their number, predicted the probability of an underlying disease. Athletes with PVBs and negative investigation showed a good prognosis. Abstract Figure.

Background We intended to verify through time-motion analysis the characteristics of the sequences of actions in terms of occurrence during water polo matches: number, duration, and possible relationships with technical-tactical aspects. Methods Water polo matches played at the 18th FINA World Championships 2019 were chosen for examination, and the analysis involved both single actions and Trains of Actions (ToAs). A ToA is a sequence of actions that occurs during the match without actual game interruption. Results A total of 1261 game actions were evaluated in the 17 matches analyzed. In 89% of cases the actions occurred in ToAs while in 11% of cases they took place as single actions. On average, each match included 74.4±5.3 actions; of these, only 7.9±3.4 (C.I. at 95%: lower bound 6.1 and upper bound 9.6) were single actions while 66.2±5.5 occurred in sequences (ToA2 = 29.6 ± 9.0%; ToA3 = 26.1 ± 9.7%; ToA4 = 16.5 ± 10.6%). The winning team performed on average more actions than the losing one (42.1±6.1 vs 32.0±6.4; effect size: 1.67; p value: 0.001). The ToAs had different compositions, from 2 to 18 actions, and then very different durations, from about 1 minute up to 8 minutes. 66% of goals were scored after ToAs and 34% after single actions. Conclusions The study of ToAs provides useful information on the physiological demand of the game, which may help to plan and organize physical training making it as specific as possible. The description of ToAs, can help coaches to better define the game scenario and understand which technical and tactical measures are needed to improve game organization.

The etiology of sudden cardiac death (SCD) in young people continues to attract much attention. This meta-analysis aimed to identify the most frequent causes of SCD in individuals aged ≤35 years, the differences between athletes and non-athletes and geographic areas.Studies published between 01/01/1990 and 01/31/2020 and evaluating post-mortem the aetiology of SCD in young individuals (≤35 years) were included. Individuals were divided into athletes and non-athletes. Studies that did not report separate data between athletes and non-athletes were excluded.Thirty-four studies met the inclusion criteria, and a total population of 5,060 victims of SCD were analyzed (2,890 athletes, 2,170 non-athletes). Comparing the causes of SCD between athletes and non-athletes, non-ischemic left ventricular scar (NILVS) (5.1% vs. 1.1%, p=0.01) was more frequent in the former, while coronary artery disease (CAD) (19.6% vs. 9.1%, p=0.009), arrhythmogenic cardiomyopathy (ACM) (11.5% vs. 4.7%, p=0.03) and channelopathies (8.4% vs. 1.9%, p=0.02) were more frequent in the latter. In studies published in the last decade, hypertrophic cardiomyopathy (HCM) (p=0.002), dilated cardiomyopathy (p=0.047), and anomalous origin of coronary arteries (AOCA) (p=0.009) were more frequently the causes of SCD in athletes while aortic dissection (0.022) was the cause in non-athletes. HCM (p=0.01) and AOCA (p=0.004) were more frequently the causes of SCD in the US while ACM (p=0.001), structurally normal heart (p=0.02), and channelopathies (p=0.02) were more frequent in Europe.Among the causes of SCD, NILVS was the more frequent cause in athletes, while CAD, ACM and channelopathies were more frequent causes in non-athletes. The causes of SCD differ between the US and Europe.

The aim of the present study was to test the effect of carbohydrate ingestion, simulating a 10-km open water race competition on energy cost (Csw), perceived exertion (RPE), heart rate (HR), stroke rate (SR) and performance. We hypothesized that carbohydrate ingestion would reduce Csw and RPE in elite open water swimmers (OW-swimmers) and improve performance. Eight elite OW-swimmers swam for 3 × 30 min with 20-s of interval necessary to collect data in the swimming flume at a pre-set pace corresponding to their 10-km race pace, followed by a time to exhaustion test (TTE) at 100% of the peak oxygen uptake (V̇O2peak). During the set, OW-swimmers ingested 45-g of carbohydrates (CHO) in 550-mL of water (8% solution) during each of the two intervals or a placebo solution (PLA). HR, RPE, V̇O2 and SR were measured. Shapiro-Wilk test was used to verify the normal distribution of data. Two-way repeated measures ANOVA and t-test was performed (p

Objectives The COVID-19 pandemic has shocked the sports world because of the suspension of competitions and the spread of SARS-CoV-2 among athletes. After SARS-CoV-2 infection, cardio-pulmonary complications can occur and, before the resumption of sports competitions, a screening has been recommended. However, few data are available and discrepancies exist in the screening modalities. We conducted this prospective study to investigate the incidence of cardiovascular consequences following SARS-CoV-2 infection in young adult competitive athletes and the appropriate screening strategies for a safe return-to-play. Methods Ninety competitive athletes (24 ± 10 years) after asymptomatic or mildly symptomatic SARS-CoV-2 infection were screened by physical examination, blood testing, spirometry, 12‑lead resting ECG, 24-h ambulatory ECG monitoring, echocardiogram, and cardiopulmonary exercise testing (CPET). Results Sixty-four athletes (71.1%) were male, and most (76.7%) were mildly symptomatic. After SARS-CoV-2 infection, spirometry and resting ECG were normal in all athletes. Ambulatory ECG monitoring demonstrated

BACKGROUND: Anterior T-wave inversion (aTWI) can be a common electrical sign in cardiomyopathies but also a benign feature regressing with age in healthy children. Unfortunately, little is known about the age of positivisation of aTWI and its determinants in children and longitudinal data are not available. The aim of this longitudinal study was to identify the age and determinants of positivisation of aTWI in healthy children. METHODS: ATWI was observed in 331 healthy children. They were evaluated yearly until positivisation for a maximum period of 4 years. Positivisation of aTWI was observed in 312 children (94%). The weight, height/length and their respective percentiles at birth and at the time of positivisation of aTWI and weeks of gestation at birth were collected. RESULTS: Positivisation of aTWI occurred at a mean age of 13.0±2.0 years. When aTWI became positive, the majority of children had a height between 51° and 75° or over the 75° percentile. At the multivariate logistic regression analysis height, weight, percentiles of height and weight at the time of positivisation were identified as the strongest independent predictors of the positivisation of aTWI. No correlation was found for prematurity and anthropometrics characteristics at birth. CONCLUSIONS: ATWI is a common feature of pediatric ECG, usually regressing with age. Height, weight, percentiles of height and weight at the time of positivisation were identified as determinants of TWI positivisation. These simple anthropometric characteristics should be used in addition to chronological age in order to interpret aTWI in children.

Cancer and cardiovascular diseases are the leading causes of death in high-income countries. Cardiovascular complications can be found in cancer patients, being the result of so-called ‘cardio-toxicity’. Therefore, it becomes essential to thoroughly investigate the origin of cardiac damage and the strategy to prevent it or to reverse the negative remodelling associated with cardiotoxicity. In this review the beneficial effects of physical exercise in cancer patients were analysed, particularly to prevent cardio-toxicity before its clinical manifestation. According to the relevance of exercise, we suggest strategies for exercise prescription with a tailored approach in these patients. In conclusion, physical exercise seems to be a promising and effective treatment for cancer patients during and after therapy and seems to counteract the negative effects induced by drugs on the cardiovascular system. Exercise prescription should be tailored according to patient’s individual characteristics, to the drugs administered, to the personal history, and to his/her response to exercise, taking into account that different types of training can be prescribed according also to the patient’s choice. A cardiological evaluation including exercise testing is essential for an appropriate prescription of exercise in these patients.

Premature ventricular beats (PVBs) are not an unusual finding and their interpretation is sometimes challenging. Unfortunately, few data on the characteristics of PVBs that correlate with the risk of an underlying heart disease are available in athletes.The aim of this prospective study was to investigate the diagnostic and prognostic value of PVBs characteristics in competitive athletes.From a cohort of 1751 athletes evaluated at our sports cardiology centre, we enrolled 112 competitive athletes40 years of age (mean age 21 ± 10 years) and with no known heart disease referred for PVBs. All athletes underwent physical examination, ECG, 12‑lead ambulatory ECG monitoring, exercise testing, and echocardiography. Further investigations including cardiac magnetic resonance were performed for abnormal findings at first-line evaluation or for specific PVBs characteristics.The majority (79%) of athletes exhibited monomorphic PVBs with a fascicular or infundibular pattern (common morphologies). A definitive diagnosis of cardiac disease was reached in 26 athletes (23% of the entire population) and correlated with uncommon PVBs morphology (p 0.001) and arrhythmia complexity (p 0.001). The number of PVBs/24-h was lower in athletes with cardiac disease than in those with normal heart (p 0.05). During the follow-up a spontaneous reduction of PVBs and no adverse events were observed.Infundibular and fascicular PVBs were the most common morphologies observed in athletes with ventricular arrhythmias referred for cardiological evaluation. Morphology and complexity of PVBs, but not their number, predicted the probability of an underlying disease. Athletes with PVBs and negative investigation showed a good prognosis.

Purpose: Although wearing a wetsuit while swimming, when permitted, is primarily for safety reasons (ie, to protect against hypothermia), changes in buoyancy, biomechanics, and exercise performance have been reported. This narrative review covers the benefits of different wetsuit models on performance in swimming and triathlon. Methods: A computer search of online databases was conducted to locate relevant published research until March 2021. After the screening process, 17 studies were selected for analysis. Results: Most of the selected studies involved pool swimmers or triathletes completing short or middle distances in a pool while using a full or a long sleeveless wetsuit. Swimming with wetsuit elicited significant improvements in performance (maximum 11%), mainly by decreasing drag and energy cost, by increasing buoyancy, and by affecting technique. Different rates of change in each factor were found according to swimming ability and wetsuit model. In addition, wearing a wetsuit was often rated as uncomfortable by athletes. Conclusions: Although improvement in swimming performance by wearing a wetsuit has been reported in the literature, the amplitude of the improvement remains questionable. The enhancement in swimming performance is attributable merely to improvements in propulsion proficiency and buoyancy, as well as a reduction in drag. The extent to which athletes are familiar with the use of a wetsuit, their swimming ability, and the wetsuit model may play important roles in this improvement. More studies simulating competition and comparing elite versus nonelite athletes are needed.

In water polo competitions, teams play four periods, each period consisting of eight minutes of actual playing time: a total of 32 minutes (Standard Actual Play Time, SAPT). Substitutions are permitted and a player may be substituted several times. The aim of this article was to provide reference data on played time, taking into consideration the field play position of the players. 352 male water polo players of 18 different nationalities were studied during two consecutive FINA World Championships. 180 games were analyzed and 1980 measurements of the game Measured Actual Play Time (MAPT) were taken. A time density index (DI) was calculated for each athlete using SAPT and MAPT. No statistically significant differences between the field positions were found with regard to age, as was the case in relation to teams between Game MAPT, Tournament MAPT and DI. However, when looking at the diverse field positions (field players, FP; center forward, CF; center back, CB), there were statistically significant differences: Game MAPT FPvsCB p = 0.03 and FPvsCF p = 0.03; Tournament MAPT FPvsCB p = 0.03; DI FPvsCB p = 0.03 and FPvsCF p = 0.04. In these competitions the water polo player had on average a MAPT value of 17.4 ± 6.1 min (54.6 ± 9.5% DI); there were athletes who played 2.3 min (7.1% DI) and others who played up to 31.6 min (95.3% DI). The MAPT in water polo is extremely variable among athletes and must be considered for a correct performance analysis. High-level water polo players require different training strategies depending on their MAPT.

Purpose: The sensation of fatigue experienced at a certain point of the race is an important factor in the regulation of pacing. The rating of perceived exertion (RPE) is considered one of the main mediators utilized by athletes to modify pacing. The aim was to analyze the relationship between pacing and RPE of elite open water swimmers during national indoor pool championships. Methods: A total of 17 elite open water swimmers (males, n = 9; females, n = 8) agreed to provide RPE every 500 m during the finals of the national championships 5-km indoor pool race. Time splits, stroke rate, and RPE were collected every 500 m. The Hazard score was calculated by multiplying the momentary RPE by the remaining fraction of the race. Athletes were placed in one of two categories: medalists or nonmedalists. For all variables, separate mixed analysis of variances (P ≤ .05) with repeated measures were used considering the splits (ie, every 500 m) as within-subjects factor and the groups (ie, medalists and nonmedalists) as between-subjects factor. Results: Average swimming speed showed a significant main effect for split for both males and females (P P = .032). RPE increased in both groups (P Conclusions: The results of the present study show different pacing strategies adopted by medalists and nonmedalists despite a similar RPE.

Purpose: Motor outputs are governed by dynamics organized around stable states and spontaneous transitions: we seek to investigate the swimmers’ motor behavior flexibility as a function of speed and aquatic environment manipulations. Method: Eight elite male swimmers partook an eight-level incremental test (4% increment from 76% to 104% of their mean speed on 200 m front crawl) in a quasi-static aquatic environment (pool). Swimmers then partook another incremental test at similar effort in a dynamic aquatic environment (swimming flume) up to maximal speed. Stroke rate (SR), index of coordination (IdC) and intersegmental coupling of the upper limbs were computed from the inertial sensors located on the upper limbs and the sacrum. Results: With speed increase, SR values presented a steeper linear increase in the pool than in the flume. IdC values increased also in the pool but remained stable in the flume. Individual SR and IdC vs. speed increase displayed second-order polynomial dynamics, indicative of adaptive flexibility with a range of extremum values more restricted in the flume. Finally, a reduction of the in-phase coordination pattern was noted with flume speed increase. Conclusions: Action possibilities were strongly constrained in the flume at the highest speeds as the fluid flow led to discontinuity in the propulsive actions of the upper limbs and lack of in-phase inter-segmental coordination. This highlights that the behavioral flexibility was restricted in the flume in comparison to the pool, in which the exploitation of opportunities for action involved a larger number of degrees of freedom in the movement.

This study aims to assess the correspondence between session rating of perceived exertion (sRPE) breakpoints with both the first lactate threshold (LT1) and the second lactate threshold (LT2) in elite open water swimmers (OWS). Six elite OWS of the National Olympic Team specialized in distances between 5 and 25 km participated to the study. OWS performed a set of 6 times 500 m incremental swimming step test during which blood lactate concentration (BLC), split time (ST), stroke frequency (SF), and rating of perceived exertion (RPE) were collected. To assess the corresponding breakpoints, we considered LT1 as the highest workload not associated with rise in BLC and LT2 as the increase of 2mM above LT1. According to the LT1 and LT2, the identified zones were: Z1 &le, 3, Z2 between 4 and 6, Z3 &ge, 7. In conclusion, the intensity zones determined for OWS resulted different from what previously reported for other endurance disciplines.

The benefits of physical activity are well established, leading to both cardiovascular and non-cardiovascular benefits, improving quality of life and reducing mortality. Despite such striking body of evidence, patients with hypertrophic cardiomyopathy are often discouraged by health professionals to practice physical activity and personalised exercise prescription is an exception rather than the rule. As a result, hypertrophic cardiomyopathy patients are on average less active and spend significantly less time at work or recreational physical activity than the general population. Exercise restriction derives from the evidence that vigorous exercise may occasionally trigger life-threatening arrhythmias and sudden cardiac death. However, while participation in competitive sports should be prudentially denied, hypertrophic cardiomyopathy patients can benefit from the positive effects of regular physical activity, aimed to reduce the risk of comorbidities and improve the quality of life. Based on this rationale, exercise should be prescribed and titrated just like a drug in hypertrophic cardiomyopathy patients, considering individual characteristics, symptoms, past medical history, objective individual response to exercise, previous training experience and stage of disease. Type, frequency, duration, and intensity should be defined on a personal basis. Yet exercise prescription in hypertrophic cardiomyopathy and its long-term effects represent major gaps in our current knowledge and require extensive research. We here review existing evidence regarding benefits and hazards of physical activity, with specific focus on viable modalities for tailored and safe exercise prescription in these patients, highlighting future developments and relevant research targets.

Background. Endurance sports practice has significantly increased over the last decades, with a growing proportion of master athletes. However, concerns exist regarding the potential proarrhythmic effects induced by ultra-endurance sports. This study aimed to analyse the acute effects of an ultramarathon race on atrial remodelling and supraventricular arrhythmias in a population of master athletes. Methods. Master athletes participating in an ultramarathon (50 km, 600 m of elevation gain) with no history of heart disease were recruited. A single-lead ECG was recorded continuously from the day before to the end of the race. Echocardiography and 12-lead resting ECG were performed before and immediately at the end of the race. Results. The study sample consisted of 68 healthy non-professional master athletes. Compared with baseline, P wave voltage was higher after the race (p < 0.0001), and more athletes developed ECG criteria for right atrial enlargement (p < 0.0001). Most of the athletes (97%) had ≥1 premature atrial beats (PAB) during the 24-h monitoring, also organised in triplets (17%) and non-sustained supraventricular tachycardias (NSSVTs) (19%). In contrast, exercise-induced PABs, triplets, and NSSVTs were rare. One athlete developed acute atrial fibrillation during the race. After the race, no significant differences were found in biatrial dimensions. Biatrial function, estimated by peak atrial longitudinal and contraction strains, were normal both before and after the race. Conclusions. In master athletes running an ultramarathon, acute exercise-induced atrial dysfunction was not detected, and exercise-induced supraventricular arrhythmias were uncommon. These results did not confirm the hypothesis of an acute atrial dysfunction induced by ultra-endurance exercise.

This study assessed perception-action coupling in expert swimmers by focusing on their upper limb inter-segmental coordination in front crawl. To characterize this coupling, we manipulated the fluid flow and compared trials performed in a swimming pool and a swimming flume, both at a speed of 1.35ms-1. The temporal structure of the stroke cycle and the spatial coordination and its variability for both hand/lower arm and lower arm/upper arm couplings of the right body side were analyzed as a function of fluid flow using inertial sensors positioned on the corresponding segments. Swimmers' perceptions in both environments were assessed using the Borg rating of perceived exertion scale. Results showed that manipulating the swimming environment impacts low-order (e.g., temporal, position, velocity or acceleration parameters) and high-order (i.e., spatial-temporal coordination) variables. The average stroke cycle duration and the relative duration of the catch and glide phases were reduced in the flume trial, which was perceived as very intense, whereas the pull and push phases were longer. Of the four coordination patterns (in-phase, anti-phase, proximal and distal: when the appropriate segment is leading the coordination of the other), flume swimming demonstrated more in-phase coordination for the catch and glide (between hand and lower arm) and recovery (hand/lower arm and lower arm/upper arm couplings). Conversely, the variability of the spatial coordination was not significantly different between the two environments, implying that expert swimmers maintain consistent and stable coordination despite constraints and whatever the swimming resistances. Investigations over a wider range of velocities are needed to better understand coordination dynamics when the aquatic environment is modified by a swimming flume. Since the design of flumes impacts significantly the hydrodynamics and turbulences of the fluid flow, previous results are mainly related to the characteristics of the flume used in the present study (or a similar one), and generalization is subject to additional investigations.

Background Twelve-lead electrocardiogram (ECG) is an established tool in the evaluation of adult athletes, providing information about life-threatening cardiovascular diseases such as long-QT syndrome. However, changes induced by development challenge the interpretation of ECG in the paediatric population, particularly for the repolarisation phase. The aim of this prospective, longitudinal study was to determinate the distribution of QT interval in children practicing sport and to evaluate changes in QT duration during preadolescence. Methods A final population of 1473 children practising sport (mean age: 12.0±1.8 years, interval 7–15 years) was analysed. Each athlete was evaluated at baseline, mid-term and end of the study with a mean follow-up of 3±1 years. QT interval was corrected with Bazett (B) and Fridericia (F) formulae. Results At baseline QTcB was 412±25ms and QTcF 387±21ms, with no changes during follow-up. Ten children (0.68%) had an abnormal QTc. In children with QTc ≥480ms confirmed both by Bazett and Fridericia formulae, QT duration persisted abnormal during the follow-up and children were disqualified. Conversely, children with borderline QTc intervals (>460 and Dynamic changes in QT interval duration Baseline Mid-term FU Long-term FU p value Intervallo QT 343±25 345±24* 346±25* Conclusions QT duration does not change over time in children with normal duration. A minority of children has a QT ≥480ms; in these subjects QT interval remains prolonged during the follow-up. Conversely, in children with borderline QT, mid-term follow-up is useful to identify a normalization during the growth. Clinicians should take into account that the use of Bazett and Fridericia correction formulae is not interchangeable and that Fridericia formula should be preferred when resting HR is higher than 80 bpm.

Background Exercise-induced enlargement of cardiac chambers is commonly observed in competitive athletes. However, ventricular dilatation is also a common phenotypic expression of life-threatening cardiomyopathies. The use of cardiac magnetic resonance (CMR) for the exclusion of pathology is growing. However, normal reference values have not been established for athletes. The aim of this meta-analysis was to derive normal reference values of biventricular size and function estimated by CMR in competitive athletes. Methods We conducted a systematic review of English-language studies in the MEDLINE, Scopus, and Cochrane databases investigating biventricular size and function by CMR in athletes. Athletes were divided into endurance, combined, and mixed groups according to the sport practiced. The potential impact of training volume was also evaluated. Results Twenty-seven studies and 983 competitive athletes were included for CMR quantification of biventricular size and function. In this review, normal reference values are presented for biventricular size and function to be applied to male competitive athletes according to the disciplines practiced. A significant impact of training volume was demonstrated for the right ventricle: athletes practicing the largest number of training hours per week were those exhibiting the greatest degree of right ventricular remodeling (Figure 1). Notably, biventricular function was not significantly affected by training volume. Figure 1 Conclusions The present meta-analysis defines the normal limits of biventricular size and function estimated by CMR in competitive athletes. The authors suggest using these normal reference values as an alternative to standard upper limits derived from the general population when interpreting CMR images in athletes.

BACKGROUND Some concerns exist about possible detrimental effects on cardiac function of ultra-endurance competitions. The aim of this study was to evaluate the acute effects of an ultramarathon by comparing pre- and post-race 12-lead ECG features. METHODS A total of 301 competitive athletes (mean age: 48 ± 9 years) running a 50-km ultramarathon were analyzed. Twelve-lead ECG was collected the day before the race and immediately at the finish line. According to the Italian law, athletes could have participated only after undergoing pre-participation screening that ruled out the presence of an underlying heart disease. RESULTS After the race a significant increase in P-wave voltage (P

Open-water swimming (OWS) is an outdoor endurance discipline that takes place in oceans, seas, rivers and lakes. OWS involves physiological issues and environmental challenges not typically seen in other events within aquatic sports. However, performance in OWS is determined/affected by the specific challenges of aquatic locomotion; this chapter will thus be introduced by general principles regarding the bioenergetics and biomechanics of swimming with a specific focus on the physiological and biomechanical determinants of endurance speed. When compared to other endurance disciplines, in conventional OWS races sex differences in performance are rather low. Pacing strategies in OWS depend, among other factors, on the benefits of drafting. OWS is in fact a head-to-head competition where finishing position rather than finishing time is important and where the differences between the winner and the other competitors may be only marginal. A common risk in OWS is hypothermia; according to the American Heart Association hypothermia is defined as a core body temperature below 35°C.

Background: It has been shown that the fastest open-water swimmers (OW-swimmers) increase significantly the speed in the last split of the open-water events. The aim of the present work was to determine if the fastest OW-swimmers have a higher speed in the middle- and long-distance pool swimming events, and to develop a multivariate model that can predict the medalist group in the 10-km competition. Methods: A total of 484 athletes (252-males and 232-females) were included in the analysis. Swimmers were divided into four groups based on their finishing position in the competition. For each swimmer, the absolute best performance (PB) of 200, 400, 800 and 1500-meter in long course, the seasonal best performance (SPB) obtained before the open-water events and critical velocity (CV) were analyzed. Multivariate analysis of variance (MANOVA) was used to detect significant differences between groups and discriminant analysis was used to predict a grouping variable. Results: All the variables analyzed were significantly different between groups (p &lt, 0.001). The first discriminant function correctly classified 50% of the overall female and male swimmers. Conclusion: Fastest OW-swimmers have a higher speed in middle- and long-distance pool swimming events. Further studies should include different anthropometric and physiological variables to increase the accuracy of classification.

Swimming is a challenging locomotion, involving the coordination of upper and lower limbs to propel the body forward in a highly resistive aquatic environment. During front crawl, freestyle stroke, alternating rotational motion of the upper limbs above and below the waterline, is coordinated with alternating lower limb pendulum actions. The aim of this study was to investigate the upper to lower limbs coordination dynamics of eight male elite front crawlers while increasing swimming speed and disturbing the aquatic environment (i.e., pool vs. flume). Upper to lower limb frequency ratios, coordination, coupling strength, and asymmetry were computed from data collected by inertial measurement units. Significant speed effect was observed, leading to transitions from 1∶1 to 1∶3 frequency ratios (1∶3 overrepresented), whereas 1∶2 frequency ratio was rarely used. Flume swimming led to a significant lower coupling strength at low speeds and higher asymmetries, especially at the highest speeds, probably related to the flume dynamic environment.

Aims Twelve-lead electrocardiogram (ECG) is an established tool in the evaluation of athletes, providing information about life-threatening cardiovascular diseases, such as long QT syndrome. However, the interpretation of ECG is sometimes challenging in children, particularly for the repolarization phase. The aim of this prospective, longitudinal study was to determinate the distribution of QT interval in children practicing sport and to evaluate changes in QT duration overtime. Methods and results A population of 1473 preadolescents practising sport (12.0 ± 1.8 years, 7–15 years) was analysed. Each athlete was evaluated at baseline, mid-term, and end of the study (mean follow-up: 3 ± 1 years). QT interval was corrected with Bazett (B) and Fridericia (F) formulae. At baseline QT interval corrected with the Bazett formula (QTcB) was 412 ± 25 ms and QT interval corrected with the Fridericia formula (QTcF) 387 ± 21 ms, with no changes during follow-up. Ten children (0.68%) had an abnormal QTc. In those with QTcB and QTcF ≥480 ms, QTc duration persisted abnormal during the follow-up and they were disqualified. Conversely, children with 460 ms < (QTcB) Conclusion Normal QTc interval does not change over time in preadolescents. A minority of them has a QTc ≥480 ms; in these subjects, QTc interval remains prolonged. The use of Bazett and Fridericia correction formulae is not interchangeable and the Fridericia correction should be preferred in preadolescents with a resting HR ≥82 b.p.m.

Professional karate is a sport activity requiring both physical and psychological skills that have been associated with a better “global neural efficacy.” By means of resting state functional magnetic resonance imaging (rs-fMRI), we investigated the neural correlates of cognitive and kinematic abilities in a group of 14 professional karateka and 14 heathy matched controls. All subjects underwent an extensive cognitive test battery for the identification of individual multidimensional cognitive profile and rs-fMRI scans investigating functional connectivity (FC). Moreover, kinematic performances in athletes were quantified by the Ergo-Mak, an integrated system developed for measuring motor reactivity, strength, and power of athletic gestures. Karateka performed significantly better than controls in the visual search task, an ability linked with increased positive correlations in FC between the right superior parietal lobe and bilateral occipital poles. Kinematic performances of athletic feats were sustained by increased positive correlations between subcortical (cerebellum and left thalamus) and cortical (inferior frontal cortex, superior parietal cortex, superior temporal cortex) regions. An unexpected FC increase between auditory and motor-related areas emerged in karateka, possibly reflecting a cross-modal coupling due to the continuous exposure to either internal or external auditory cues, positing this sensory channel as a possible target for novel training strategies. Results represent a further step in defining brain correlates of “neural efficiency” in these athletes, whose brain can be considered a model of continuous plastic train-related adaptation.

Cycling stage racing is a heavy and strenuous endurance event and it has been recognized that such exercise can affect the hormonal asset of hypothalamic–pituitary–adrenal (HPA) and hypothalamic–pituitary–testicular (HPT) axis. However, in cycling, literature on such changes is scarce and published data have been derived from small samples of athletes. The aims of study were to provide normative values for serum hormonal steroid values, changes in serum hormonal steroids and assess any relationships between a riders’ performance and their hormonal profile before and after the stage race. Male elite professional cyclists (n = 93) competing in the 2010 GiroBio 10-day stage race participated in this study. Blood chemistry measurements included cortisol (C), testosterone (T), free testosterone (fT) and sex hormone binding globulin (SHBG). Data are expressed as mean ± SD. Serum concentration of C and fT were lower at the end of GiroBio [C (nmol L−1): 559.34 ± 95.71 vs 469.59 ± 51.12; fT (pmol ml−1): 63.91 ± 27.85 vs 37.51 ± 17.86]. These serum hormonal (mean values ± 2SD) values may be near the physiological ceiling for elite cyclists. There was inverse correlation among average final speed and pre-competition serum concentration of T (r = −0.265, p = 0.01); average final speed was negatively correlated with riders body mass pre and post the 10-day stage event. In conclusion, pre-GiroBio serum C levels could be a useful benchmark to preserve riders’ health and, moreover, our data confirm that the strenuous effort sustained by riders during a stage race induces appreciable changes in the hormonal profile. In addition, our data suggest that lower levels of T could represent favourable prerequisite to cope better in a cycling stage race.

Most of the cerebral functions are asymmetrically represented in the two hemispheres. Moreover, dexterity and coordination of the distal segment of the dominant limbs depend on cortico-motor lateralization. In this study, we investigated whether postural control may be also considered a lateralized hemispheric brain function. To this aim, 15 young subjects were tested in standing position by measuring center of pressure (COP) shifts along the anteroposterior axis (COP-Y) during dynamic posturography before and after continuous Theta Burst Stimulation (cTBS) intervention applied to the dominant or non-dominant M1 hand area as well as to the vertex. We show that when subjects were expecting a forward platform translation, the COP-Y was positioned significantly backward or forward after dominant or non-dominant M1 stimulation, respectively. We postulate that cTBS applied on M1 may have disrupted the functional connectivity between intra- and interhemispheric areas implicated in the anticipatory control of postural stability. This study suggests a functional asymmetry between the two homologous primary motor areas, with the dominant hemisphere playing a critical role in the selection of the appropriate postural control strategy.

The aim of the present study was to test the effectiveness of carbohydrate (CHO) feeding supplemented every 2.5-km, as in official races, on the performance, rating of perceived exertion (RPE), and glycaemia during a 10-km intermittent training workout in elite open-water swimmers. A randomized crossover design was used. Participants completed two 10-km intermittent training sessions (20 &times, 500-m). The relative velocity was expressed in percentage of a single 500-m. Glycaemia was monitored by continuous glucose monitoring. Participants had to ingest either 1 L of tap water (WAT, 0.50 L&middot, h&minus, 1) or 120 g of CHO in the form of 8% solution (60 g&middot, 1). The 15-point RPE scale was used during the trials. A two-way ANOVA for repeated measures was performed (p &lt, 0.05). The relative velocity of each 500-m was not significantly different between the two trials. No significant differences emerged in the relative velocity of the last 500-m between trials. Average RPE was not statistically different between the two trials (11 &plusmn, 3 in WAT and 12 &plusmn, 3 in CHO). In the last 500-m, glycaemia was significantly higher in the CHO trial (5.92 &plusmn, 0.47 mmol&middot, L&minus, 1 in CHO, 5.61 &plusmn, 0.61 mmol&middot, 1 in WAT). CHO ingestion did not improve performance or affect RPE during a 10-km intermittent training in elite open-water swimmers.

Purpose: Different aspects of pacing in endurance events have been investigated, however, there are very limited information on pacing strategies during open-water swimming. The aim was to describe and compare the pacing profile used by male and female open-water swimmers (OW-swimmers) during the 5-, 10- and 25 km races in the main international competitions. Methods: A total of 438 performances were analysed for 5 km, 579 for 10 km and 189 for 25 km, from 2012 to 2017. Swimmers were divided into four groups based on finishing time. G1 whose finishing times were within 0.5% of the winner’s time, G2 between 0.51% and 1% slower than winner’s time; G3 between 1.1% and 2% slower than winner’s time; G4 over 2% of winner’s time. Kolmogorov–Smirnov test was used to verify the normal distribution of data and repeated measures ANOVA was performed. Results: G1 adopted a negative pacing and significantly increased the speed in the last split compared with the other groups during the 5-, 10- and 25-km races in both malesand females (p

T-wave inversion (TWI) is rare in athlete's heart but is a common manifestation in cardiomyopathies. Although TWI has been extensively investigated in adult athletes, the ability of this ECG pattern to distinguish between a physiological variant and a developing heart muscle disease in children is controversial. The aim of this longitudinal study was to establish the prevalence, changes and clinical significance of TWI in a large cohort of pre-adolescent athletes.2227 children (mean age 12.3 ± 2.0 years) undergoing sports preparticipation screening were included. Children with TWI underwent yearly follow-up until the positivisation of TWI for a maximum follow-up of 4 years.Among 2227 children, 358 (16%) had TWI. Children with TWI were younger (11.4 ± 2.1 vs. 12.5 ± 2.0 years, p 0.0001) and had a lower BSA than children without TWI (p 0.0001). 97% of children showed anterior TWI while only 3% had infero-lateral TWI. Anterior TWI became positive in 94% of children during the 4-year follow-up (p 0.0001 vs. baseline) and the remaining 6% did not show abnormal clinical findings. Conversely, in the group of 9 children with infero-lateral TWI, only 1 showed normalisation during follow-up (p = 0.81) and 1 was found to have a cardiomyopathy.Anterior TWI is common in children and generally becomes positive by the age of 14 years. Conversely, infero-lateral TWI is rare, persistent and may be associated with structural heart disease. Therefore, infero-lateral TWI should not be interpreted as physiologically related to age, development or training and children with infero-lateral TWI should remain under strict clinical surveillance.

Objectives The aim of this meta-analysis was to derive normal reference values of biventricular size and function estimated by cardiac magnetic resonance (CMR) in competitive athletes. Background Exercise-induced enlargement of cardiac chambers is commonly observed in competitive athletes. However, ventricular dilatation is also a common phenotypic expression of life-threatening cardiomyopathies. The use of CMR for the exclusion of pathology is growing. However, normal reference values have not been established for athletes. Methods The authors conducted a systematic review of English-language studies in the MEDLINE, Scopus, and Cochrane databases investigating biventricular size and function by CMR in athletes. Athletes were divided into endurance, combined, and mixed groups according to the sport practiced. The potential impact of training volume was also evaluated. Results Twenty-seven studies and 983 competitive athletes were included for CMR quantification of biventricular size and function. In this review, normal reference values are presented for biventricular size and function to be applied to male competitive athletes according to the disciplines practiced. A significant impact of training volume was demonstrated for the right ventricle: athletes practicing the largest number of training hours per week were those exhibiting the greatest degree of right ventricular remodeling. Notably, biventricular function was not significantly affected by training volume. Conclusions The present meta-analysis defines the normal limits of biventricular size and function estimated by CMR in competitive athletes. The authors suggest using these normal reference values as an alternative to standard upper limits derived from the general population when interpreting CMR images in athletes.