Professional Endurance Athletes Research Articles

Intrinsic Sinus Node/Atrioventricular Node Dysfunction Requiring Pacemaker Implantation: Role of Former Professional Sport Activity.

Sinus bradycardia and first degree or second degree Mobitz type I atrioventricular (AV) block in an athlete are considered adaptive and reversible phenomena; however, some evidence suggests that they may persist after detraining and become pathological. The aim of the study was to investigate the characteristics of a group of former professional athletes who required pacemaker (PM) implantation for intrinsic (idiopathic) sinus node (SN) dysfunction or AV block in comparison to control groups of sedentary individuals. We included all patients who underwent PM implantation during 2022. Three groups were compared: group 1 including 18 former professional athletes who received a PM for SN dysfunction/AV block in the absence of heart disease; group 2 including the first 20 sedentary individuals without heart disease who underwent PM implantation; and group 3 including all other 323 patients who received PM, the majority with underlying heart diseases. Compared to the non-athlete control group 2, the mean age at diagnosis and at the time of PM implantation of former professional athletes did not show statistically significant differences. However, subgroup analysis revealed significant differences depending on the type of sports discipline: the age at diagnosis and at PM implantation was significantly lower in former endurance athletes than former strength/mixed athletes, control non-athletes, and all other patients. Moreover, former endurance professional athletes exhibited a higher prevalence of second or third degree AV block (78%) as the reason for PM implantation compared to power/mixed athletes (44%). The other clinical characteristics, including echocardiographic parameters, did not differ between former athletes and non-athletes. Former professional endurance athletes with idiopathic SN dysfunction/AV block manifested the disease earlier in the life course compared to former power/mixed athletes and non-athletes. This suggests that bradycardia/AV block caused by intense and prolonged endurance sports may not always be benign and adaptive phenomena.

Training Modifications in Endurance Athletes Due to COVID-19 Restrictions

The aim of this study was to determine which characteristics of recreational, collegiate, and professional endurance athletes were associated with training changes due to COVID-19 safety restrictions. A Qualtrics survey was distributed to endurance athletes around the world from June 2020 to February 2021. Significant differences between athlete characteristics and changes in training status were determined using a Chi-squared test (significance p < 0.05). Approximately 66% of the 331 endurance athletes changed their training due to restrictions. Significant group differences were found for age, sex, prior coaching status, prior use of a training program, and athlete primary sport compared to the whole sample. Understanding these factors may allow athletes/coaches to approach training in a different way to help minimize or prevent the effects of detraining for a greater portion of athletes should a COVID-19 variant or any other pandemic emerge in the future.

Structural and functional characteristics of left ventricular strain in healthy individuals with different physical activity level according to echocardiography

Aim. To determine the structural and functional characteristics of the myocardium in young people with different levels of physical activity (PA).Material and methods. The study included 108 young people without cardiovascular diseases. Seventy-two people were professional endurance athletes (Group A) and 36 were non-athletes (Group non-A). Anthropometric data were evaluated. Transthoracic echocardiography and assessment of left ventricular (LV) longitudinal, radial and circumferential strain, as well as LV twisting, were performed. PA level in non-A group was determined using International Physical Activity Questionnaire (IPAQ).Results. PA level <600 MET-min/week was revealed in 22,3% of participants, moderate PA (from 600 to 1500 MET-min/week) — in 41,7%, and high (3000 MET-min/week) — in 36% of participants of inactive, moderately active and highly active subgroups, respectively. Group A daily PA level was ~15000 MET-min/week. In non-A group, there were no significant differences in echocardiographic parameters in subgroups with different PA levels. Significant differences with group A were revealed. LV diastolic function was within the normal range in all subgroups. The E/A ratio was higher in subgroups with higher PA (maximum in subgroup A). Significant differences were observed between inactive (p=0,027) and athletes/moderately active (p=0,017) subgroups. Longitudinal, radial and circular strain characteristics did not differ in A and non-A groups and were within normal range.Conclusion. In young people without cardiovascular diseases with PA ranges from extremely low to those recommended by WHO, the structural and functional myocardial characteristics were within age normal range and significantly differed from those of professional athletes. In professional athletes, these parameters also remained within the age normal range. Myocardial strain characteristics were within the normal range in all participants

Carbohydrate Intake Practices and Determinants of Food Choices During Training in Recreational, Amateur, and Professional Endurance Athletes: A Survey Analysis.

Carbohydrate (CHO) intake during exercise can optimize endurance performance. However, there is limited information regarding fueling practices of endurance athletes during training. Accordingly, an anonymous German-language online survey was circulated examining the determinants of CHO choices, and intake practices among runners, triathletes, and cyclists during training. Survey questions included predefined answers, and a Likert scale with response of CHO food choice intakes from 1 = never to 5 = always. 1,081 endurance participants (58.0% male, 68.6% aged 18–39 years) of varying competitive levels were included in the analysis. Overall, most participants consumed a combination of commercial sport nutrition products and everyday foods (67.4%, n = 729) with their primary reason that food-first was preferred, but in some exercise scenarios, commercial sport nutrition products were deemed more convenient (61.3%, n = 447). Participants consuming commercial sport nutrition products only (19.3%, n = 209) most often valued their ease of intake during exercise (85.2%, n = 178). Among those consuming everyday foods only (13.2%, n = 143), the most common reason was the perceived importance of eating wholesome foods/natural ingredients (84.6%, n = 121). Between the most frequently consumed CHO sources during training at low-to-moderate intensities (n = 1032), sports drinks (mean ± SD; 2.56 ± 1.33) were consumed significantly more often than bananas (2.27 ± 1.14, p < 0.001), with no significant difference in intake frequency between bananas and traditional muesli/fruit/energy bars (2.25 ± 1.14, p = 0.616). Whereas during high intensities (n = 1,077), sports drinks (3.31 ± 1.51) were significantly more often consumed than gels (2.79 ± 1.37), and gels significantly more often than energy bars (2.43 ± 1.28), all commercial sport nutrition products (all, p < 0.001). Overall, 95.1% (n = 1028) of all participants consumed CHO during training at all exercise intensities, with males (n = 602; 2.35 ± 0.70) consuming significantly more often commercial sport nutrition products than females (n = 424; 2.14 ± 0.79, p < 0.001); females consumed significantly more often everyday foods than males (1.66 ± 0.47 vs. 1.54 ± 0.42, p < 0.001). Most participants used mixed CHO forms during low-to-moderate (87.9%), and high exercise intensities (94.7%). 67.6% (n = 731) of all participants reported guiding their CHO intake rates during training by gut feeling. These large-scale survey findings suggest a preference of endurance participants’ CHO intake during training in liquid form independent of exercise intensities and offer novel insights into CHO intake practices to guide sports nutrition strategies and education.

The Impacts of COVID-19 on Mental Health and Training in US Professional Endurance Athletes.

We examined how professional athletes are affected by COVID-19. Our primary aim was to assess changes in mental health that occurred after COVID-19 restrictions, and our secondary aim was to assess changes in exercise volume and intensity. Cross-sectional study. United States. Strava professional endurance athletes. Participants completed a survey, and a subset of participants consented to have their activity data analyzed. The survey included questions on COVID-19 symptoms, exercise, and mental health, as measured by a modified Patient Health Questionnaire. Participants were asked about 2 periods in 2020: before COVID-19 (January 1-March 14) and during COVID-19 (March 15-August 25), and activity data from both periods were downloaded. Activity data consisted of Global Positioning System and self-reported uploads. One hundred thirty-one male and female Strava athletes were enrolled, and a subset of athletes (n = 114) consented to have their activity data analyzed. During COVID-19 restrictions, 22.2% of participants reported feeling down or depressed and 27.4% of participants reported feeling nervous or anxious at least half the days in a week compared with 3.8% and 4.6% before COVID-19 restrictions, respectively (P < 0.0001). Activity data revealed a significant increase (P < 0.0001) in exercise minutes per day during COVID-19 (mean = 103.00, SD = 42.1) compared with before COVID-19 restrictions (mean = 92.4, SD = 41.3), with no significant changes in intensity. Athletes reported significant increases in feeling down or depressed and nervous or anxious despite an increase in exercise duration during COVID-19. Future research should assess how to support athletes with mental health resources.

A Systematic Review on Markers of Functional Overreaching in Endurance Athletes

The aim of this brief review was to present an overview of noninvasive markers in trained to professional endurance athletes that can reflect a state of functional overreaching. A systematic literature search was conducted in the PubMed, Scopus, and PsycINFO databases. After screening 380 articles, 12 research papers were included for the systematic review. Good consensus was found between the different papers in which noninvasive parameters were able to reflect a state of functional overreaching. Changes in power output (PO), heart rate (HR; [sub]maximal and HR recovery), rating of perceived exertion, and scores in the Daily Analysis of Life Demands for Athletes (DALDA) and/or Profile of Mood States (POMS) were shown to be able to reflect functional overreaching, whereas changes in maximal oxygen uptake and HR-variability parameters were not. Functional overreaching within a maximal performance test was characterized by a decrease in peak PO and a lower maximum HR, whereas a lower mean PO and a lower HR were observed during time trials. Changes in parameters during a standardized submaximal test when functionally overreached were characterized by a higher PO at a fixed HR or a lower HR at a fixed intensity, higher rating of perceived exertion, and a faster HR recovery. Although both the DALDA and POMS were able to reflect functional overreaching, the POMS was not able to differentiate this response from acute fatigue, which makes it unsuitable for accurately monitoring functional overreaching.

Changes in Short-Term and Ultra-Short Term Heart Rate, Respiratory Rate, and Time-Domain Heart Rate Variability Parameters during Sympathetic Nervous System Activity Stimulation in Elite Modern Pentathlonists-A Pilot Study.

Monitoring of markers reflecting cardiac autonomic activity before and during stressful situations may be useful for identifying the physiological state of an athlete and may have medical or performance implications. The study aimed to determine group and individual changes in short-term (5 min) and ultra-short-term (1 min) heart rate (HR), respiratory rate (RespRate), and time-domain heart rate variability (HRV) parameters during sympathetic nervous system activity (SNSa) stimulation among professional endurance athletes. Electrocardiographic recordings were performed in stable measurement conditions (Baseline) and during SNSa stimulation via isometric handgrip in 12 elite modern pentathlonists. Significant increases in short-term HR and decreases in time-domain HRV parameters with no changes in RespRate were observed during SNSa stimulation. Significant differences were observed between Baseline (all minutes) and the last (i.e., 5th) minute of SNSa stimulation for ultra-short-term parameters. Analysis of intra-individual changes revealed some heterogeneity in responses. The study provides baseline responses of HR, RespRate, and time-domain HRV parameters to SNSa stimulation among elite pentathlonists, which may be useful for identifying abnormal responses among fatigued or injured (e.g., concussed) athletes. More attention to individual analysis seems to be necessary when assessing physiological responses to sympathetic stimuli in professional endurance athletes.

HRV-Guided Training for Professional Endurance Athletes: A Protocol for a Cluster-Randomized Controlled Trial.

Physiological training responses depend on sympathetic (SNS) and parasympathetic nervous system (PNS) balance. This activity can be measured using heart rate variability (HRV). Such a measurement method can favor individualized training planning to improve athletes’ performance. Recently, HRV-guided training has been implemented both on professional and amateur sportsmen and sportswomen with varied results. There is a dearth of studies involving professional endurance athletes following a defined HRV-guided training protocol. The objectives of the proposed protocol are: (i) to determine changes in the performance of high-level athletes after following an HRV-guided or a traditional training period and (ii) to determine differences in the athletes’ performance after following both training protocols. This will be a 12-week cluster-randomized controlled protocol in which professional athletes will be assigned to an HRV-based training group (HRV-G) or a traditional-based training group (TRAD-G). TRAD-G will train according to a predefined training program. HRV-G training will depend on the athletes’ daily HRV. The maximal oxygen uptake (VO2max) attained in an incremental treadmill test will be considered as the primary outcome. It is expected that this HRV-guided training protocol will improve functional performance in the high-level athletes, achieving better results than a traditional training method, and thus providing a good strategy for coaches of high-level athletes.

45-LB: Introduction of the Diabetes Exercise Perception (DEEP-1) Questionnaire for Assessing Perceived Attitudes and Challenges in Athletes with Type 1 Diabetes

Background and Aims: Little is known about individual perspectives and challenges faced by elite-level athletes living with type 1 diabetes and where they turn to for advice. Currently, there is no validated tool to assess this. We aimed to generate and pilot test the Diabetes ExErcise Perception (DEEP-1) questionnaire in a group of professional endurance athletes with type 1 diabetes to investigate perceived attitudes and challenges. Methods: The online questionnaire consists of a range of open and closed questions, focusing on 4 key areas related to diabetes management and exercise: 1) Technology; 2) Sleep and Recovery; 3) Glucose Management; and 4) Nutrition. Sixteen professional cyclists with type 1 diabetes (age 27 ± 4 years; HbA1c 6.8 ± 0.5%) were asked to anonymously complete the questionnaire using SurveyMonkey.com. Data were then analyzed descriptively. Results: Fifteen participants responded. In this cohort, 90% showed an interest in using technology for improved exercise performance and 89% for glucose management, although 28% felt unaware of newer technologies. Glucose was perceived as being generally well regulated; however, according to the responses, more attention needs to be focused overnight and pre/during exercise. Sleep quality was rated as an important factor affecting exercise performance by 80% of respondents. 93% of participants identified nutrition as an area for improved performance, with 25% reporting a lack of education in this area. Conclusions: This pilot study highlights the importance of an individualized approach to diabetes management and high-level exercise performance. Future work should validate the DEEP-1 questionnaire in a larger sample size using individuals with a range of physical activity levels. Such a tool may provide a useful and time-efficient means for health care professionals to gain deeper insight into their patients’ attitudes and challenges regarding exercise. Disclosure S.N. Scott: None. F.Y. Fontana: None. C.A. Hayes: Other Relationship; Self; Novo Nordisk A/S. P.H. Lagrou: None. T. Zueger: None. P. Southerland: None. C. Stettler: None.

Combating mental fatigue in soldiers

Mental fatigue impairs both cognitive performance and subsequent physical performance. Mental fatigue can be brought about by the prolonged performance of a single cognitive task, but also by the combined performance of many cognitively demanding activities, as well as tasks that require self-control or prolonged periods of suppressing emotion. Manifestations of mental fatigue include feelings of tiredness, lack of energy and exhaustion, as well as changes in mood states, towards moods such as irritation. Mental fatigue is further exaggerated by conditions commonly experienced by soldiers, such as sleep deprivation. As mental fatigue progresses, continuing a cognitive task becomes difficult, represented by aversion to continue with the present task, a decrease in the level of commitment to the task at hand and increased resistance against further effort. Anecdotal evidence has also noted that mentally fatigued persons become distracted more easily and that lapses in concentration become more frequent. Mental fatigue impairs physical performance, primarily through a reduction in endurance, as well as impacting technical performance, such as soccer passing and goal shooting. Despite consistent findings of a reduction in endurance with mental fatigue, a recent study reported that when compared with recreational cyclists, professional cyclists were more tolerant to mental fatigue. Following a bout of mental exertion, the time trial performance of the professional cyclists was unimpaired, they also significantly outperformed the recreational cyclists on the cognitive task designed to induce mental fatigue. It was suggested that the professional endurance athletes had a greater self-regulatory capacity compared to the recreational athletes, likely due to the amount of time they spend engaged in activities requiring self-regulation such as maintaining a strict diet, refraining from alcohol and committing to long individual training sessions. Although suggested to be partially genetic, many studies have shown that practice of one task of self-regulation will improve performance on another, unrelated task of self-regulation. Self-regulation is a characteristic required for successful performance of endurance sports, studying and training, and persisting with a cognitive task. Consideration of the impact of mental fatigue on physical performance is important in a Defence context. Individuals may be required to perform monotonous tasks for long periods of time, followed by, or concurrent to physical tasks, often with little to no rest. Here we discuss the impact of mental fatigue on physical performance and potential strategies to overcome these performance decrements.

Assessment of Metabolic Flexibility by Means of Measuring Blood Lactate, Fat, and Carbohydrate Oxidation Responses to Exercise in Professional Endurance Athletes and Less-Fit Individuals.

Increased muscle mitochondrial mass is characteristic of elite professional endurance athletes (PAs), whereas increased blood lactate levels (lactatemia) at the same absolute submaximal exercise intensities and decreased mitochondrial oxidative capacity are characteristics of individuals with low aerobic power. In contrast to PAs, patients with metabolic syndrome (MtS) are characterized by a decreased capacity to oxidize lipids and by early transition from fat to carbohydrate oxidation (FATox/CHOox), as well as elevated blood lactate concentration [La-] as exercise power output (PO) increases, a condition termed 'metabolic inflexibility'. The aim of this study was to assess metabolic flexibility across populations with different metabolic characteristics. We used indirect calorimetry and [La-] measurements to study the metabolic responses to exercise in PAs, moderately active individuals (MAs), and MtS individuals. FATox was significantly higher in PAs than MAs and patients with MtS (p<0.01), while [La-] was significantly lower in PAs compared with MAs and patients with MtS. FATox and [La-] were inversely correlated in all three groups (PA: r=-0.97, p<0.01; MA: r=-0.98, p<0.01; MtS: r=-0.92, p<0.01). The correlation between FATox and [La-] for all data points corresponding to all populations studied was r=-0.76 (p<0.01). Blood lactate accumulation is negatively correlated with FATox and positively correlated with CHOox during exercise across populations with widely ranging metabolic capabilities. Because both lactate and fatty acids are mitochondrial substrates, we believe that measurements of [La-] and FATox rate during exercise provide an indirect method to assess metabolic flexibility and oxidative capacity across individuals of widely different metabolic capabilities.

Can intensive exercise harm the heart? You can get too much of a good thing.

Can intensive exercise harm the heart? You can get too much of a good thing.

Comparison of Frequency of Significant Electrocardiographic Abnormalities in Endurance Versus Nonendurance Athletes

Most data assessing the accuracy of electrocardiographic (ECG) screening in identifying cardiac pathology in athletes are derived from relatively unselected cohorts of subjects involved in competitive sports. We hypothesized that the prevalence of ECG abnormalities may be greater in athletes performing the greatest combination of exercise intensity and duration, namely professional endurance athletes. A total of 1,007 male and 254 female elite adult athletes underwent cardiovascular screening inclusive of an electrocardiogram, interpreted using the 2010 European Society of Cardiology guidelines. Training-related ECG changes (group 1) were more common in endurance athletes (EAs) than nonendurance athletes (NEAs; 90.8% vs 86.0%, p= 0.04), as were multiple (≥2) training-related changes (78.9% vs 53.5%, p <0.0001). Group 2 ECG changes (previously considered uncommon and training unrelated) were seen in 18.1% of subjects and were twice as prevalent in EAs compared with NEAs (29.9% vs 15.1%, p <0.0001). Right ventricular hypertrophy (4.4% EAs vs 1.5% NEAs, p <0.005) and deep right precordial T-wave inversion (14.3% EAs vs 4.7% NEAs, p <0.0001) were 3 times as common in EAs. Both group 1 and group 2 changes were similarly prevalent among elite male and female athletes and were more common in EAs regardless of gender. In conclusion, ECG abnormalities are very common in elite athletes and are more common in EAs than NEAs. Right ventricular hypertrophy and deep right precordial T-wave inversion are particularly common in EAs, possibly because of increased structural and/or electrical right ventricular remodeling in this subgroup. The predictive value of ECG screening and criteria for abnormal findings in elite EAs requires specific appraisal.

Rebuttal from Jonatan R. Ruiz, Michael Joyner and Alejandro Lucia

Guash and Nattel argue that a ‘safety threshold’ exists for endurance training, above which the risk of developing pathological cardiovascular conditions increases (Guash & Nattel, 2013). We make five points in rebuttal: Epidemiological data in more than 50,000 Swedes who completed a 90 km cross-country ski race showed a 52% decrease in overall mortality and a 57% reduction in cardiovascular mortality (Farahmand et al. 2003). More protection was seen in individuals who completed more than one race suggesting that exercise-related cardiovascular benefits extend to extreme endurance exercisers. The uniformity of the Swedish medical care and records system makes these data convincing. Intense endurance exercise is associated with increased risk of arrhythmias especially atrial fibrillation (AF), but the Swedish cohort suggests this risk is more modest than previously suspected (Andersen et al. 2013). Importantly, malignant ventricular arrhythmias were low in the skiers. Additionally, lone AF has limited health implications and veteran athletes with arrhythmias still have higher heart rate variability which is protective (Jensen-Urstad et al. 1998). It is unknown if extreme endurance exercise evokes increased coronary calcification. It is known that high cardiorespiratory fitness modulates the increased risk of coronary calcification (LaMonte et al. 2006). Additionally, the coronary vessels of ultramarathon runners are larger than those of controls and vasodilate more (Haskell et al. 1993). Reports on small numbers of master athletes demonstrating ‘cardiac fibrosis’ are countered by studies showing enhanced contractile responses (Seals et al. 1994). There is far too little data on this topic to make meaningful conclusions based on observations reported in small numbers of subjects. Caution is needed when extrapolating provocative data from animal studies to humans. Use of aversive stimulation (tail shock) in rats running at ∼90% of maximum heart rate for 1 h day-1, 5 days week-1 over 16 weeks, is equivalent to the same loads over ∼10 years when translated to humans (Ruiz et al. 2011). Such continuous intense exercise is unrealistic for most humans, including cyclists participating in the Tour de France, where mean cycling time spent at ‘rat intensities’ is below 1 h day-1 (Lucia et al. 2003). Participation in the Tour is in fact associated with increased lifespan (Sanchis-Gomar et al. 2011). Likewise, professional endurance athletes usually live longer and have lower cardiac risk that non-athletes, which is not consistent with the view that intense exercise above a ‘safety threshold leads’ to chronic cardiac damage that limits the longevity benefits of exercise.

Physical activity and physical activity induced energy expenditure in humans: measurement, determinants, and effects

Physical activity is defined as any bodily movement produced by skeletal muscles that results in energy expenditure. The doubly labeled water method for the measurement of total energy expenditure (TEE), in combination with resting energy expenditure, is the reference for physical activity under free-living conditions. To compare the physical activity level (PAL) within and between species, TEE is divided by resting energy expenditure resulting in a figure without dimension. The PAL for sustainable lifestyles ranges between a minimum of 1.1–1.2 and a maximum of 2.0–2.5. The average PAL increases from 1.4 at age 1 year to 1.7–1.8 at reproductive age and declines again to 1.4 at age 90 year. Exercise training increases PAL in young adults when energy balance is maintained by increasing energy intake. Professional endurance athletes can reach PAL values around 4.0. Most of the variation in PAL between subjects can be ascribed to predisposition. A higher weight implicates higher movement costs and less body movement but not necessarily a lower PAL. Changes in physical activity primarily affect body composition and to a lesser extent body weight. Modern man has a similar PAL as a wild mammal of a similar body size.

Comparison of the lipid profile and lipoprotein(a) between sedentary and highly trained subjects

There is consolidated evidence that physical activity exerts beneficial effects on several chronic conditions and longevity, on the basis of its proposed biological effects, especially on lipid profiles. However, debate continues regarding the intensity of activity required for good health, as vigorous physical activity might overwhelm advantageous changes. In addition, little is known so far on the effect of a vigorous and regular aerobic training regimen on emerging markers of cardiovascular risk, such as lipoprotein(a), total/high-density lipoprotein cholesterol ratio and the atherogenic index of plasma. To further investigate this topic, an extensive lipid profile, in accordance with the most recent guidelines issued by the American Heart Association (AHA)/American College of Cardiology (ACC) and the National Cholesterol Education Program (NCEP), was evaluated in 60 healthy male sedentary controls and in a wide population of professional endurance athletes, including 40 male professional cross-country skiers and 102 male professional road cyclists. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides, TC low-density lipoprotein cholesterol (LDL-C) ratio and the atherogenic index of plasma were significantly lower in both categories of professional athletes, whereas the mean HDL-C concentration was significantly higher. The concentration of lipoprotein(a) did not differ significantly between the groups. When compared to current NCEP or AHA/ACC goals, the percentage of patients with undesirable values was statistically different for all parameters tested, apart from lipoprotein(a). According to multiple stepwise logistic regression analysis, lower TC/HDL-C ratio in professional skiers and lower TC/HDL-C ratio and TC in professional cyclists were significantly associated with increased aerobic physical activity. Results of this case-control study confirm that elevated aerobic energy expenditure might be associated with a highly favorable stabilization of most traditional and emerging cardiovascular risk predictors. Therefore, a substantial increase in aerobic physical activity within the population might be recommended to reverse adverse lipid abnormalities, especially in subjects with a higher cardiovascular risk.

Mutations in the hereditary haemochromatosis gene HFE in professional endurance athletes

Background: Hereditary haemochromatosis, a disease that affects iron metabolism, progresses with a greater or lesser tendency to induce iron overload, possibly leading to severe organ dysfunction. Most elite endurance athletes...

Comparison of serum creatinine, uric acid, albumin and glucose in male professional endurance athletes compared with healthy controls

Owing to considerable physical, endocrinological and metabolic adaptations, the analysis of biochemical data in elite and top-class athletes requires caution. With the aim to identify metabolic and biochemical adaptations to particular lifestyle conditions, such as regular and strenuous physical exercise, we measured the concentration of serum albumin, creatinine, uric acid and glucose in 80 male professional cyclists, 37 male members of the Italian national cross-country ski team and 60 male healthy sedentary controls at rest. At variance with earlier investigations, endurance athletes showed significantly decreased concentrations of serum creatinine (controls: 83.1+/-11.0 micromol/l; skiers: 78.0+/-8.4 micromol/l; p<0.05; cyclists: 73.8+/-10.4 micromol/l; p<0.01), uric acid (controls: 362+/-69 micromol/l; skiers: 331 +/-70 micromol/l; p<0.05; cyclists: 312+/-61 micromol/l; p<0.01) and glucose (controls: 5.35+/-0.54 mmol/l; skiers: 4.94+/-0.41 mmol/l; p<0.01; cyclists: 4.94+/-0.42 mmol/l; p<0.01). The concentration of serum albumin was also decreased in athletes, but the difference did not reach statistical significance (controls: 4.76+/-0.26 g/l; skiers: 4.71+/-0.22 g/l; p=0.384; cyclists: 4.68+/-0.22 g/l; p=0.393). Results of the present investigation demonstrate that values of laboratory testing lying outside conventional reference limits calculated on sedentary populations might express physiological adaptations to regular and demanding physical aerobic activity, emphasizing the need for the estimation of reliable reference limits in elite and professional athletes, to avoid equivocal interpretation of results within clinical and anti-doping contests.

Myocardial Stress after Competitive Exercise in Professional Road Cyclists

Based on the determination of cardiac troponin (cTnT), brain natriuretic peptide (BNP), and echocardiographic measurements, recent investigations have reported myocardial damage and reversible cardiac dysfunction after prolonged endurance exercise in apparently healthy subjects. In the present study, we investigated the myocardial stress reaction in professional endurance athletes after strenuous competitive physical exercise. Eleven highly trained male professional road cyclists (age 27 +/- 4 yr; .VO2peak 67 +/- 5 mL.kg-1.min-1; training workload 34,000 +/- 2,500 km.yr-1) were examined. The following parameters were determined before and after one stage of a 5-d professional cycling race: BNP, cTnT (third-generation assay that shows no cross reactivity with skeletal TnT), creatine kinase (CK), creatine kinase MB (CKMB), myoglobin (Myo), and urea. All participants were submitted to a careful cardiac examination including echocardiography and stress ECG. None of the athletes showed pathological findings in the cardiac examination. CK (P < 0.01), CKMB (P < 0.05), and Myo (P < 0.01) were increased after the race. Normal postexercise cTnT levels indicate that the increase in CK, CKMB, and Myo was of noncardiac origin. In contrast, BNP rose significantly from 47.5 +/- 37.5 to 75.3 +/- 55.3 pg.mL-1 (P < 0.01). Pre- and postexercise values of BNP as well as the individual exercise-induced increase in BNP were significantly correlated with age (R2 = 0.68, R2 = 0.66, and R2 = 0.58, respectively; P < 0.05). Strenuous endurance exercise in professional road cyclists does not result in structural myocardial damage. The rise in BNP in older athletes may reflect a reversible, mainly diastolic left ventricular dysfunction. This needs to be confirmed by larger trials including different intensities, sports, and age groups.

Prognostic significance of ventricular extrasystoles in healthy professional athletes: results of a 5-year follow-up.

To assess the natural history of ventricular extrasystoles (VE), a 5-year follow-up of 52 professional endurance athletes was made. All remained well during this period. Forty-four accepted to undergo repeat extensive noninvasive cardiologic examination. In the 23 athletes still in activity at the second study the prevalence of total and complex VE at 24-hour Holter monitoring was substantially unchanged, while in the 21 subjects who had stopped training, complex VE were no longer present (p = 0.01 vs. baseline). Echocardiographic dimensional parameters were significantly higher in the still active athletes than in the no longer active subjects; however, in the latter, left ventricular mass index was still greater than in a group of 40 sedentary subjects previously studied (107 vs. 81 g/m2; p = 0.001). High-intensity physical training does not seem to be harmful in athletes with complex VE, without evidence of underlying cardiac disease.