The effect of long-term soccer training on left ventricular structure and function in elite male youth soccer players.

AIMS: Cardiac adaptations in elite, male adolescent youth soccer players have been demonstrated in relation to training status. The time course of these adaptations and the delineation of the influence of volatile growth phases from the training effect on these adaptations remain unclear. Consequently, the aims of the study were to evaluate the impact of 3 years of elite-level soccer training on changes in left ventricular (LV) structure and function in a group of highly trained elite youth male soccer players (SP) as they transitioned through the pre-to-adolescent phase of their growth. METHODS: Twenty-two male youth SP from the highest Level of English Premier League Academy U-12 teams were evaluated once a year for three soccer seasons as the players progressed from the U-12 to U-14 teams. Fifteen recreationally active control participants (CON) were also evaluated over the same 3-year period. Two-dimensional transthoracic echocardiography was used to quantify LV structure and function. RESULTS: After adjusting for the influence of growth and maturation, training-induced increases in Years 2 and 3 were noted for: LV end diastolic volume (LVEDV; p = 0.02) and LV end systolic volume (LVESV; p = 0.02) in the SP compared to CON. Training-induced decrements were noted for LV ejection fraction (LVEF; p = 0.006) and TDI-S' (p < 0.001). CONCLUSIONS: An increase in training volume (Years 2 and 3) were aligned with LV volumetric adaptations and decrements in systolic function in the SP that were independent from the influence of rapid somatic growth. Decrements in systolic function were suggestive of a functional reserve for exercise.

EgoActive: Integrated Wireless Wearable Sensors for Capturing Infant Egocentric Auditory-Visual Statistics and Autonomic Nervous System Function 'in the Wild'.

There have been sustained efforts toward using naturalistic methods in developmental science to measure infant behaviors in the real world from an egocentric perspective because statistical regularities in the environment can shape and be shaped by the developing infant. However, there is no user-friendly and unobtrusive technology to densely and reliably sample life in the wild. To address this gap, we present the design, implementation and validation of the EgoActive platform, which addresses limitations of existing wearable technologies for developmental research. EgoActive records the active infants' egocentric perspective of the world via a miniature wireless head-mounted camera concurrently with their physiological responses to this input via a lightweight, wireless ECG/acceleration sensor. We also provide software tools to facilitate data analyses. Our validation studies showed that the cameras and body sensors performed well. Families also reported that the platform was comfortable, easy to use and operate, and did not interfere with daily activities. The synchronized multimodal data from the EgoActive platform can help tease apart complex processes that are important for child development to further our understanding of areas ranging from executive function to emotion processing and social learning.

Effect of long-term soccer training on changes in cardiac function during exercise in elite youth soccer players.

It is unclear what the effect of long-term, high-volume soccer training has on left ventricular (LV) function during exercise in youth soccer players. This study evaluated changes in LV function during submaximal exercise in a group of highly trained male soccer players (SP) as they transitioned over a three-year period from pre-adolescent to adolescent athletes. Data were compared to age- and sex-matched recreationally active controls (CON) over the same time period. Twenty-two SP from two professional English Premier League youth soccer academies (age: 12.0 ± 0.3 years at start of the study) and 15 CON (age: 11.7 ± 0.3 years) were recruited. Two-dimensional echocardiography was used to quantify LV function during exercise at the same submaximal metabolic load (approx. 45%VO2peak ) across the 3 years. After controlling for growth and maturation, there were training-induced changes and superiority (p < 0.001) in cardiac index (QIndex) from year 1 in the SP compared to CON. SP (year 1: 6.13 ± 0.76; year 2: 6.94 ± 1.31; and year 3: 7.20 ± 1.81 L/min/m2 ) compared to CON (year 1: 5.15 ± 1.12; year 2: 4.67 ± 1.04; and year 3: 5.49 ± 1.06 L/min/m2 ). Similar training-induced increases were noted for mitral inflow velocity (E): SP (year 1: 129 ± 12; year 2: 143 ± 16; and year 3: 135 ± 18 cm/s) compared to CON (year 1: 113 ± 10; year 2: 111 ± 12; and year 3: 121 ± 9 cm/s). This study indicated that there was evidence of yearly, training-induced increases in left ventricular function during submaximal exercise independent from the influence of growth and maturation in elite youth SP.

Effect of live-fire training on ventricular-vascular coupling.

INTRODUCTION: Cardiovascular events are a leading cause of firefighter duty-related death, with the greatest risk occurring during or shortly after fire suppression activity. Increased cardiovascular risk potentially manifests from detrimental changes in ventricular function, vascular load, and their interaction, described as ventricular-vascular coupling. PURPOSE: To determine the effect of live-fire training on ventricular-vascular coupling. METHODS: Sixty-eight male (28 [Formula: see text] 7 years, 26.9 [Formula: see text] 3.9 kg/m2) and fifteen female (36 [Formula: see text] 8 years, 24.3 [Formula: see text] 3.9 kg/m2) firefighters completed hemodynamic and cardiac measures before and after 3 h of intermittent live-fire training. Left ventricular function was assessed as ejection fraction (EF) and ventricular elastance (ELV: end systolic pressure [ESP]/end systolic volume) via echocardiography and applanation tonometry-estimated ESP. Vascular load was assessed as arterial elastance (EA: ESP/stroke volume [SV]). Ventricular-vascular coupling (VVC) was quantified as the ratio of EA to ELV and indexed to body surface area (EAI, ELVI). RESULTS: Following firefighting EF decreased (p < 0.01) with no change in ELVI (p = 0.34). SV decreased (p < 0.01) with no change in ESP (p = 0.09), driving a significant increase in EAI (p < 0.01). These changes resulted in a significant increase in the VVC ratio (p < 0.01). CONCLUSION: The findings suggest that firefighting does not alter ventricular elastance but increases arterial elastance in healthy firefighters, resulting in a mismatch between ventricular and vascular systems. This increase in ventricular-vascular coupling ratio and concomitant reduction in ventricular systolic function may contribute to increased cardiovascular risk following live firefighting.

The influence of training status on right ventricular morphology and segmental strain in elite pre-adolescent soccer players.

Cardiac modifications to training are a product of the genetic pre-disposition for adaptation and the repetitive haemodynamic loads that are placed on the myocardium. Elite pre-adolescent athletes are exposed to high-intensity training at a young age with little understanding of the physiological and clinical consequences. It is unclear how right ventricular (RV) structure and function may respond to this type of stimulus. The aim of this study was to compare RV structure and strain across the cardiac cycle and within individual segments in elite soccer players (SP) and controls (CON). METHODS: Twenty-two highly trained, male pre-adolescent SP and 22 age-and sex-matched recreationally active individuals CON were investigated using 2D echocardiography, including myocardial speckle tracking to assess basal, mid-wall, apical and global longitudinal strain and strain rate during systole (SRS) and diastole (SRE and SRA). RESULTS: greater RV cavity size was identified in the SP compared to CON (RVD1 SP: 32.3 ± 3.1 vs. CON: 29.6 ± 2.8 (mm/m2)0.5; p = 0.005). No inter-group differences were noted for peak global RV strain (SP: - 28.6 ± 4.9 vs CON: - 30.3 ± 4.0%, p = 0.11). Lower mid-wall strain was demonstrated in the SP compared to CON (SP: - 27.9 ± 5.8 vs. CON: - 32.2 ± 4.4%, p = 0.007). CONCLUSION: Soccer training has the potential to increase RV size in pre-adolescent players. The unique segmental analyses used in this study have identified inter-group differences that were masked by global strain evaluations. The clinical and physiological implications of these findings warrant further investigation.

Regression of chronic kidney disease in a patient with AL amyloidosis: A case report
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BACKGROUND: AL amyloidosis is a disease that causes significant end-organ damage via deposition of insoluble amyloid fibrils, which cause disruption of normal tissue architecture and function. The mainstay of current treatment employs various chemotherapy regimens, all of which aim to suppress the underlying plasma cell dyscrasia and reduce the production of amyloidogenic precursor proteins. Renal disease is found in between 50 and 80% of sufferers and is often both progressive and irreversible, ultimately leading to end-stage renal failure and death. Recovery from advanced chronic kidney disease is uncommon, however, this case demonstrates that it is possible with ongoing therapy. CASE PRESENTATION: We report the case of a 53-year-old lady with amyloid-induced nephrotic syndrome who underwent intensive chemotherapy. Initially, this lady experienced the gradual decline in renal function typical of the natural history of this disease; her renal function indicated an impending need for dialysis. However, soon after, evidence of recovery became apparent on serum amyloid protein component scintigraphy, measurement of serum free light chains, and measurement of renal parameters. Ultimately, her renal disease was completely resolved. CONCLUSION: This case shows that renal recovery in AL amyloidosis may be possible and also highlights the importance of continued therapy in order to achieve clonal response and recovery of organ function.
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Expert's Choice: 2018's Most Exciting Research in the Field of Pediatric Exercise Science.

This commentary highlights 23 noteworthy publications from 2018, selected by leading scientists in pediatric exercise science. These publications have been deemed as significant or exciting in the field as they (a) reveal a new mechanism, (b) highlight a new measurement tool, (c) discuss a new concept or interpretation/application of an existing concept, or (d) describe a new therapeutic approach or clinical tool in youth. In some cases, findings in adults are highlighted, as they may have important implications in youth. The selected publications span the field of pediatric exercise science, specifically focusing on: aerobic exercise and training; neuromuscular physiology, exercise, and training; endocrinology and exercise; resistance training; physical activity and bone strength; growth, maturation, and exercise; physical activity and cognition; childhood obesity, physical activity, and exercise; pulmonary physiology or diseases, exercise, and training; immunology and exercise; cardiovascular physiology and disease; and physical activity, inactivity, and health.

Left ventricular function during exercise in trained pre-adolescent soccer players.

It is unclear, what the underlying cardiovascular mechanisms are that give rise to the high level of aerobic fitness seen in youth soccer players. The aim of the study was to evaluate global and regional markers of systolic and diastolic function in a group of pre-adolescent soccer players during an incremental exercise test. Twenty-two, male soccer players (SP) from two professional soccer clubs (age: 12.0 ± 0.3 years) volunteered for the study. Fifteen recreationally active boys (CON), of similar age (age: 11.7 ± 0.2 years) were also recruited. All boys underwent a cycle ergometer test to exhaustion. Cardiac dimensions were determined using M-mode echocardiography. During submaximal and maximal exercise, continuous-wave Doppler ultrasound techniques were used to derive stroke volume (SVIndex). Tissue-Doppler imaging was used to quantify systolic (S'adj) and diastolic function (E; E'adj and E/E') at rest and both submaximal and maximal exercise intensities. Speckle tracking echocardiography was used to determine peak longitudinal ε at submaximal exercise intensities. SP demonstrated significantly (P ≤ 0.05) greater peak VO2 values than CON (SP: 48.0 ± 5.0 vs CON: 40.1 ± 7.5 mL/kg/min). Allometrically scaled to body surface area left ventricular end-diastolic volume (LVEDV) was larger (P ≤ 0.05) in the SP (51.3 ± 9.0) compared to CON (44.6 ± 5.8 mL·BSA1.5 ). At the same relative, submaximal exercise intensities, the SP demonstrated greater SVIndex, cardiac output (QIndex), and E. No differences were noted for peak longitudinal ε during submaximal exercise. Factors that augment pre-load and LV volume appear to determine the superior aerobic fitness seen in the soccer players.

Cardiovascular Physiology and Disease in Youth-The Year That Was 2017.

The value of exercise studies in children often resides in defining differences, which might make growing youngsters unique from their mature adult counterparts. Many such physiological and behavioral developmental differences have been identified, emphasizing that children are not, physiologically speaking, simply small adults. The following 2 studies published in the past year were chosen for their importance in contributing to the insights into previously unexplored areas. The first study addresses the influence of exercise on physiological variability, an emerging field that offers to provide important insights into the nature of such responses. The second study concerns the effects of altitude on physiological responses to exercise, an area of considerable importance for the health and physical performance of pediatric athletes, climbers, and residents at high altitude. These studies exemplify the genre of investigations that are essential for advancing our understanding of the link between exercise with physical performance and the well-being of growing children and adolescents.

Cardiovascular Physiology and Disease in Youth-2016.

The two articles in the area of cardiovascular physiology and disease in youth were chosen for commentary because of their exploration of new approaches to the diagnosis and management of cardiovascular derangements in young persons. The first, by Hinds et al., describes the potential clinical importance of detection of cardiovascular changes during exercise testing in adolescent athletes following concussions. This approach might prove useful in establishing safe return-to-play guidelines. The second, a review article by Van De Schoor et al, evaluates the frequency of myocardial scarring in athletes, some of adolescent age, which is a recognized risk factor for sudden cardiac death. These findings support other evidence indicating that sports participation per se might rarely increase the risk of such tragedies. Clearly more research is indicated by the information raised in both of these articles, but their importance to clinical medicine is obvious.

Normative Values for Cardiorespiratory Fitness Testing Among US Children Aged 6-11 years.

BACKGROUND: Nationally representative normative values for cardiorespiratory fitness (CRF) have not been described for US children since the mid 1980s. OBJECTIVE: To provide sex- and age-specific normative values for CRF of US children aged 6-11 years. METHODS: Data from 624 children aged 6-11 years who participated in the CRF testing as part of the 2012 National Health and Nutrition Examination Survey National Youth Fitness Survey, a cross-sectional survey, were analyzed. Participants were assigned to one of three age-specific protocols and asked to exercise to volitional fatigue. The difficulty of the protocols increased with successive age groups. CRF was assessed as maximal endurance time (min:sec). Data analysis was conducted in 2016. RESULTS: For 6-7, 8-9, 10-11 year olds, corresponding with the age-specific protocols, mean endurance time was 12:10 min:sec (95% CI: 11:49-12:31), 11:16 min:sec (95% CI: 11:00-11:31), and 10:01 min:sec (95% CI: 9:37-10:25), respectively. Youth in the lowest 20th percentile for endurance time were more likely to be obese, to report less favorable health, and to report greater than two hours of screen time per day. CONCLUSIONS: These data may serve as baseline estimates to monitor trends over time in CRF among US children aged 6-11 years.

Pediatric Exercise Science: A Brief Overview.

Interest in the physiological responses to exercise unique to the pediatric age group has grown exponentially over the past 50 years. A number of issues surrounding children's exercise have been particularly responsible for this trend, particularly a) recognition of the health benefits of exercise in youth, b) the growing involvement of young persons in highly intense levels of sports play, and c) the role that exercise may play in the diagnosis and management of children with chronic disease. As a consequence, current research to date has provided a comprehensive picture of the features specific to children's response to exercise. Future challenges facing the field of pediatric exercise science involve translating this information into practical guidelines which can be applied to the realms of clinical medical practice, preventive health initiatives, and athletic training regimens which are appropriate for this age group.

Morphologic Features of the "Athlete's Heart" in Children: A Contemporary Review.

Recognizing the cardiac features of athletically trained children bears importance for health care providers and exercise physiologists alike. This literature review reveals that ventricular enlargement and/or hypertrophy are commonly observed in studies of pre- and early-adolescent endurance athletes, yet the magnitude of these features is less than that described in adult athletes. Moreover, the upper range of values in child athletes is sufficiently small that clinical confusion with findings mimicking those in individuals with heart disease should not be expected to occur. In contrast to sex differences in the "athlete's heart" in adults, cardiac structural findings in child athletes are similar in males and females. The extent that cardiac features observed in trained child athletes reflect a response to training or are influenced by genetic preselection remains uncertain.

Cardiac strain during upright cycle ergometry in adolescent males.

Little evidence exists with regard to changes in cardiac strain that occur during submaximal exercise in young males. The aims of the study were to evaluate the changes that occur in longitudinal (L), radial (R), and endocardial circumferential (EC) strain during submaximal upright cycle ergometry and to examine the test-retest reproducibility of these measurements. Fourteen recreationally active, adolescent (age: 17.9 ± 0.7 years) males volunteered for the study. All subjects underwent an incremental (40 W) submaximal cycle ergometer test. L, R, and EC strain values were obtained using speckle tracking, from two-dimensional B-mode images of the left ventricle (LV) during rest and the initial stages of submaximal exercise (40 and 80 W). The average of 6 LV segments was used to determine both peak wall deformation (%) and the time to peak deformation (ms). There was a statistically (P < 0.05) significant increase from rest to submaximal exercise for peak deformation for L, R, and EC strain. There was a statistically significant (P < 0.05) decrease from rest to submaximal exercise for time to peak for L and R and EC strain and between submaximal workloads for time to peak for L strain and EC strain. Coefficients of variation demonstrated reproducibility for upright strain and strain rate measurements similar to published supine measurements. This study has demonstrated that changes in left ventricular wall deformation (L, R and EC strain) that occur during the transition from rest to submaximal exercise can be reliably measured and confirm that a healthy LV has a hyperdynamic response to exercise.

Use of Oxygen Pulse in Predicting Doppler-Derived Maximal Stroke Volume in Adolescents.

Clinical exercise physiologists and physicians administering stress tests in the young have used oxygen pulse as a surrogate measure of stroke volume. It is important to recognize 1) the accuracy of O2 pulse in predicting maximal stroke volume during exercise, and 2) the normal pattern of O2 pulse during a progressive exercise test. This study examined both of these issues in a cohort of 44 healthy adolescent males and females (ages 14-16 years) who performed routine progressive cycle exercise to exhaustion. Gas exchange variables were measured by standard open circuit techniques. Stroke volume at rest and during exercise was assessed by the Doppler ultrasound method. At peak exercise O2 pulse correlated closely with stroke volume (r = .73) with a SEE of 12.6 ml·beat⁻¹. Values of maximal O2 pulse in nonathletic boys and girls were 13.3 ± 2.5 and 11.0 ± 1.7 ml·beat⁻¹, respectively. After the initial workload, a steady rise was observed in O2 pulse, entirely reflecting an increasing arterial venous oxygen difference, with a slope of approximately 4 ml/beat per 100 watts work load. The findings support the use of O2 pulse as a valid predictor of stroke volume during exercise in youth with a moderately high level of accuracy.

Understanding the acetylome: translating targeted proteomics into meaningful physiology.

It is well established that exercise elicits a finely tuned adaptive response in skeletal muscle, with contraction frequency, duration, and recovery shaping skeletal muscle plasticity. Given the power of physical activity to regulate metabolic health, numerous research groups have focused on the molecular mechanisms that sense, interpret, and translate this contractile signal into postexercise adaptation. While our current understanding is that contraction-sensitive allosteric factors (e.g., Ca(2+), AMP, NAD(+), and acetyl-CoA) initiate signaling changes, how the muscle translates changes in these factors into the appropriate adaptive response remains poorly understood. During the past decade, systems biology approaches, utilizing "omics" screening techniques, have allowed researchers to define global processes of regulation with incredible sensitivity and specificity. As a result, physiologists are now able to study substrate flux with stable isotope tracers in combination with metabolomic approaches and to coordinate these functional changes with proteomic and transcriptomic analysis. In this review, we highlight lysine acetylation as an important posttranslational modification in skeletal muscle. We discuss the evolution of acetylation research and detail how large proteomic screens in diverse metabolic systems have led to the current hypothesis that acetylation may be a fundamental mechanism to fine-tune metabolic adaptation in skeletal muscle.

Stroke volume dynamics during progressive exercise in healthy adolescents.

Understanding cardiac responses to exercise in healthy subjects is important in the evaluation of youth with heart disease. This review article incorporates previously published original research from the authors' laboratory to examine changes in stroke volume during progressive exercise which are consistent with a model in which circulatory responses are controlled by alterations in the systemic vascular resistance. Stroke volume dynamics and cardiovascular responses to a progressive upright cycle test were examined in three groups of healthy, untrained adolescent subjects. These indicated a) a progressive decease in systemic vascular resistance, b) little change in stroke volume after an initial rise related to orthostatic changes in ventricular refilling, c) evidence of a constant or slightly declining left ventricular end diastolic filling pressure, d) and increases in markers of ventricular contractility. These observations are consistent with peripheral (vascular resistance) rather than central (cardiac) control of circulation with exercise. Changes in stroke volume during exercise need to be interpreted in respect to alterations in heart rate and myocardial functional capacity.

Pacing strategies of inexperienced children during repeated 800 m individual time-trials and simulated competition.

Prior experience of fatiguing tasks is considered essential to establishing an optimal pacing strategy. This study examined the pacing behavior of inexperienced children during self-paced, 800 m running, both individually and within a competitive environment. Thirteen children (aged 9-11 y) completed a graded-exercise test to volitional exhaustion on a treadmill (laboratory trial), followed by three self-paced, individual 800 m time-trials (Trials 1-3) and one self-paced, competitive 800 m time-trial (Trial 4) on an outdoor athletics track. Ratings of perceived exertion (RPE) and heart rate (HR) were measured throughout all trials. Overall performance time improved from Trial 1-3 (250.1 ± 50.4 s & 242.4 ± 51.5 s, respectively, p < .017). The difference in overall performance time between Trials 3 and 4 (260.5 ± 54.2 s) was approaching significance (p = .06). The pacing strategy employed from the outset was consistent across all trials. These findings dispute the notion that an optimal pacing strategy is learned with exercise experience or training.

Myocardial inotropic response to progressive exercise in healthy subjects: a review.

Assessment of myocardial contractile function during exercise is important in gaining an understanding of the normal mechanics of the cardiovascular responses to exercise stress. Such insights are important in identifying determinants of cardiovascular fitness in athletes as well as assessing patients with heart disease. While obtaining such measurements in the past has been challenging, recent echocardiographic developments offer promise of providing new insights into the nature and magnitude of inotropic changes during exercise. This review provides a state-of-the-art overview of these technologies in light of the current understanding of the role of myocardial contractile function in response to a bout of progressive dynamic exercise.