Evaluation of nocturnal vs. morning measures of heart rate indices in young athletes

Purpose The purpose of this study was to compare heart rate (HR) and heart rate variability in young endurance athletes during nocturnal sleep and in the morning; and to assess whether changes in these values are associated with changes in submaximal running (SRT) and counter-movement jump (CMJ) performance. Methods During a three-week period of similar training, eleven athletes (16 ± 1 years) determined daily HR and heart rate variability (RMSSD) during sleep utilizing a ballistocardiographic device (Emfit QS), as well as in the morning with a HR monitor (Polar V800). Aerobic fitness and power production were assessed employing SRT and CMJ test. Results Comparison of the average values for week 1 and week 3 revealed no significant differences with respect to nocturnal RMSSD (6.8%, P = 0.344), morning RMSSD (13.4%, P = 0.151), morning HR (-3.9 bpm, P = 0.063), SRT HR (-0.7 bpm, P = 0.447), SRT blood lactate (4.9%, P = 0.781), CMJ (-4.2%, P = 0.122) or training volume (16%, P = 0.499). There was a strong correlation between morning and nocturnal HRs during week 1 (r = 0.800, P = 0.003) and week 3 (r = 0.815, P = 0.002), as well as between morning and nocturnal RMSSD values (for week 1, r = 0.895, P<0.001 and week 3, r = 0.878, P = 0.001). Conclusion This study concluded that HR and RMSSD obtained during nocturnal sleep and in the morning did not differ significantly. In addition, weekly changes in training and performance were small indicating that fitness was similar throughout the 3-week period of observation. Consequently, daily measurement of HR indices during nocturnal sleep provide a potential tool for long-term monitoring of young endurance athletes.

Acute impact of an endurance race on biventricular and biatrial myocardial strain in competitive male and female triathletes evaluated by feature-tracking CMR

Objectives Cardiac adaptation in endurance athletes is a well-known phenomenon, but the acute impact of strenuous exercise is rarely reported on. The aim of this study was to analyze the alterations in biventricular and biatrial function in triathletes after an endurance race using novel feature-tracking cardiac magnetic resonance (FT-CMR). Methods Fifty consecutive triathletes (45 ± 10 years; 80% men) and twenty-eight controls were prospectively recruited, and underwent 1.5-T CMR. Biventricular and biatrial volumes, left ventricular ejection fraction (LVEF), FT-CMR analysis, and late gadolinium imaging (LGE) were performed. Global systolic longitudinal (GLS), circumferential (GCS), and radial strain (GRS) were assessed. CMR was performed at baseline and following an endurance race. High-sensitive troponin T and NT-proBNP were determined. The time interval between race completion and CMR was 2.3 ± 1.1 h (range 1–5 h). Results Post-race troponin T (p < 0.0001) and NT-proBNP (p < 0.0001) were elevated. LVEF remained constant (62 ± 6 vs. 63 ± 7%, p = 0.607). Post-race LV GLS decreased by tendency (− 18 ± 2 vs. − 17 ± 2%, p = 0.054), whereas GCS (− 16 ± 4 vs. − 18 ± 4%, p < 0.05) and GRS increased (39 ± 11 vs. 44 ± 11%, p < 0.01). Post-race right ventricular GLS (− 19 ± 3 vs. − 19 ± 3%, p = 0.668) remained constant and GCS increased (− 7 ± 2 vs. − 8 ± 3%, p < 0.001). Post-race left atrial GLS (30 ± 8 vs. 24 ± 6%, p < 0.0001) decreased while right atrial GLS remained constant (25 ± 6 vs. 24 ± 6%, p = 0.519). Conclusions The different alterations of post-race biventricular and biatrial strain might constitute an intrinsic compensatory mechanism following an acute bout of endurance exercise. The combined use of strain parameters may allow a better characterization of ventricular and atrial function in endurance athletes. Key Points • Triathletes demonstrate a decrease of LV global longitudinal strain by tendency and constant RV global longitudinal strain following an endurance race. • Post-race LV and RV global circumferential and radial strains increase, possibly indicating a compensatory mechanism after an acute endurance exercise bout. • Subgroup analyses of male triathletes with focal myocardial fibrosis did not demonstrate alterations in biventricular and biatrial strain after an endurance race.

Symptomatic second-degree atrioventricular block in a recreational athlete

This case study provides an example of bradycardia associated with an increase in exercise training in a recreational athlete. Although recognised among high-level endurance athletes, this case demonstrates the potential negative effects of exercise on the heart in a patient participating in the levels of exercise recommended by Public Health England. It adds weight to the ongoing discussion of the incomplete understanding of the level of exercise needed to induce pathological changes in cardiac physiology. We discuss the investigations that led us to our diagnosis, highlighting the importance of a detailed exercise history in patients who present with palpitations and provide a potential explanation of how this phenomenon may have occurred. Currently, bradycardia induced by exercise has been managed through pacemaker insertion or complete cessation of exercise. This report demonstrates effective treatment through a period of exercise cessation and slow reintroduction of exercise training.

Inducing low energy availability in trained endurance male athletes results in poorer explosive power

Purpose Low energy availability in males needs more original research to understand its health and performance consequences. The aim of the study was to induce low energy availability in previously healthy male endurance athletes by reducing energy availability by 25% for 14 consecutive days and measure any potential changes in performance, health, mental state or energy markers. Methods Energy availability was reduced in 12 trained, well-trained and elite endurance athletes by increasing energy expenditure and controlling energy intake. After intervention, health was assessed by blood draw, body composition was measured, energy markers by measuring resting energy expenditure, performance with three specific tests (measuring endurance, agility and explosive power) and two questionnaires were used for psychological assessment (the Three Factor Eating Questionnaire and Well-being questionnaire). Results Reduced energy availability (22.4 ± 6.3 kcal/kg FFM/day) caused significantly lower haemoglobin values (t(12) = 2.652, p = 0.022), there was a tendency for lower iron and IGF-1 (p = 0.066 and p = 0.077, respectively). Explosive power was reduced (t(12) = 4.570, p = 0.001), lactate metabolism was altered and athletes reported poorer well-being (t(12) = 2.385, p = 0.036). Cognitive restriction was correlated with energy availability (r = 0.528, p = 0.039). Conclusion This is the first research providing direct evidence that suboptimal energy availability negatively impacts explosive power before hormonal changes occur in male endurance athletes. It is also the first to show direct association of low energy availability and higher cognitive restriction. We also observed worse well-being and lower haemoglobin values. 25% of energy availability reduction as not enough to elicit changes in resting energy expenditure.

Long-term within- and between-subject biological variation of 29 routine laboratory measurands in athletes

Objectives Within- and between-subject biological variation (BV) estimates have many applications in laboratory medicine. However, robust high-quality BV estimates are lacking for many populations, such as athletes. This study aimed to deliver BV estimates of 29 routine laboratory measurands derived from a Biological Variation Data Critical Appraisal Checklist compliant design in a population of high-endurance athletes. Methods Eleven samples per subject were drawn from 30 triathletes monthly, during a whole sport season. Serum samples were measured in duplicate for proteins, liver enzymes, lipids and kidney-related measurands on an Advia2400 (Siemens Healthineers). After outlier and homogeneity analysis, within-subject (CVI) and between-subject (CVG) biological variation estimates were delivered (CV-ANOVA and log-ANOVA, respectively) and a linear mixed model was applied to analyze the effect of exercise and health related variables. Results Most CVI estimates were similar or only slightly higher in athletes compared to those reported for the general population, whereas two- to three-fold increases were observed for amylase, ALT, AST and ALP. No effect of exercise and health related variables were observed on the CVI estimates. For seven measurands, data were not homogeneously distributed and BV estimates were therefore not reported. Conclusions The observation of higher CVI estimates in athletes than what has been reported for the general population may be related to physiological stress over time caused by the continuous practice of exercise. The BV estimates derived from this study could be applied to athlete populations from disciplines in which they exercise under similar conditions of intensity and duration.

Right heart exercise-training-adaptation and remodelling in endurance athletes

Long-term sports training leads to myocardial adaptations, with remodelling of the heart chambers. However, while myocardial adaptations of the left heart are well described, remodelling of the right heart and its impact on the development of arrhythmias is still debated. To conduct a systematic review on right ventricle (RV) and right atrium (RA) structural and functional changes in athletes who participate in long-term endurance training. Systematic review. A systematic literature search was conducted. All the articles reporting right heart echocardiographic (ECHO) and cardiac magnetic resonance (CMR) parameters evaluated in endurance athletes and sedentary subjects were considered eligible. A multivariate analysis was conducted to investigate whether age, sex, body surface area (BSA), intensity of training are associated with RV ECHO, CMR parameters and RA ECHO parameters. A positive association between age and right atrium area (RAA) (P = 0.01) was found. This is a negative association to RV E/A (P = 0.004), and RV end diastolic diameter (RVED) longitudinal (P = 0.01). A positive association between BSA and RVED middle (P = 0.001), as well between BSA and RAA (P = 0.05) was found, along with a negative association with RV E/A (P = 0.002). A positive association between intensity of training and RV end systolic area (RVESA) (P = 0.03), RV end diastolic volume indexed (RVEDVI) (P = 0.01), RV end systolic volume indexed (RVESVI) (P = 0.01) was found, along with a negative association with ejection fraction (EF %) (P = 0.01). Endurance athletes demonstrated an association between RV remodelling and age, BSA and intensity of training.

Impact of Probiotics on the Performance of Endurance Athletes: A Systematic Review

Background: Probiotic supplements contain different strains of living microorganisms that promote the health of the host. These dietary supplements are increasingly being used by athletes to improve different aspects such as athletic performance, upper respiratory tract infections (URTIs), the immune system, oxidative stress, gastrointestinal (GI) problems, etc. This study aimed to identify the current evidence on the management of probiotics in endurance athletes and their relationship with sports performance. Methods: A systematic review of the last five years was carried out in PubMed, Scopus, Web of science, Sportdiscus and Embase databases. Results: Nine articles met the quality criteria. Of these, three reported direct benefits on sports performance. The remaining six articles found improvements in the reduction of oxidative stress, increased immune response and decreased incidence of URTIs. There is little scientific evidence on the direct relationship between the administration of probiotics in endurance athletes and sports performance. Conclusions: Benefits were found that probiotics could indirectly influence sports performance by improving other parameters such as the immune system, response to URTIs and decreased oxidative stress, as well as the monitoring of scheduled workouts.

Planificación dietético-nutricional para una prueba de mountain bike de XCO: estudio de caso (Nutritional planning for an XCO mountain bike event: Case study)

El cross country es una modalidad del ciclismo de mountain bike (MTB), cuyas competiciones se caracterizan por dar un determinado número de vueltas a un circuito con una distancia desde 6-9km hasta 40-200km. En estos eventos, es importante planificar una estrategia dietético-nutricional para mitigar la aparición de resultados adversos relacionados con la nutrición. El objetivo de este estudio fue realizar la planificación dietético-nutricional de un ciclista de MTB que disputa una competición de cross country. El ciclista es un varón de 27 años (VO2max=74.46 ml•kg-1•min-1; PAM=420W; altura=1.81m; peso=78.6kg; % masa grasa=9.47, sumatorio de pliegues=61.9mm) con 3 años de experiencia en el entrenamiento y competición de pruebas MTB a nivel regional. La intervención tuvo lugar en el gabinete Alinua de la Universidad de Alicante, cuya finalidad fue mejorar la composición corporal y elaborar una programación dietético-nutricional para disputar una carrera de MTB el 23-2-2020 en la provincia de Alicante. La intervención incluía las recomendaciones para deportistas de resistencia y se dividió en un periodo de preparación, periodo de 3 semanas previas a la carrera y periodo competitivo. El participante realizó satisfactoriamente la prueba, se adhirió a la planificación, y no manifestó ningún problema. Para un ciclista, afrontar un evento de estas características con éxito requiere de un asesoramiento teórico-práctico y una programación dietético-nutricional de manera individualizada que trate de contribuir nutricionalmente antes, durante y después de la práctica del ejercicio, así como aminorar la posible aparición de contratiempos que puedan poner en riesgo el rendimiento y la salud. Abstract. Cross Country is a modality of mountain bike cycling (MTB), whose competitions are characterized by giving a certain number of laps to a circuit with a distance from 6-9km to 40-200km. In these events, it is important to plan a dietetic-nutritional strategy to mitigate the appearance of nutrition-related adverse outcomes. The purpose of the study was to plan the dietetic-nutritional planning of a MTB cyclist who competes in a Cross Country competition. The cyclist is a 27-year-old male (VO2max=74.46 ml•kg-1•min-1; MAP=420W; height=1.81m; weight=78.6kg; % fat mass=9.47; sum of 8 skinfolds=61.9mm) with 3 years of experience in training and competing in MTB events at a regional level. The intervention took place in the Alinua cabinet of the University of Alicante, whose purpose was to improve the body composition and to elaborate a dietetic-nutritional program to dispute a MTB race on 23-2-2020 in the province of Alicante. The intervention included the recommendations for endurance athletes and was divided into a preparation period, a period of 3 weeks before the race and a competitive period. Finally, the participant successfully completed the race according to the planning and did not manifest any problems. For a cyclist, facing an event of these characteristics successfully requires theoretical-practical advice and dietary-nutritional programming in an individualized way that tries to contribute at a nutritional level before, during and after physical exercise, as well as to reduce the possible appearance of setbacks that may jeopardize performance and health.