Cardiac hemodynamics phenotypes and individual responses to training in coronary heart disease patients.

BACKGROUND: In patients with coronary heart disease (CHD), individualized exercise training (ET) programs are strongly recommended to optimize peak oxygen uptake ( V ̇ $$ \dot{\mathrm{V}} $$ O2peak) improvement and prognosis. However, the cardiac hemodynamic factors responsible for a positive response to training remain unclear. The aim of this study was to compare cardiac hemodynamic changes after an ET program in responder (R) versus non-responder (NR) CHD patients. METHODS: A total of 72 CHD patients completed a 3-month ET program and were assessed by cycle ergometer cardiopulmonary exercise test (CPET: V ̇ $$ \dot{\mathrm{V}} $$ O2peak assessment) with impedance cardiography (ICG) for hemodynamic measurements before and after training. Cardiac hemodynamics (e.g., CO, CI, SV, ESV, EDV, and SVR) were measured by ICG during CPET. The R and NR groups were classified using the median change in V ̇ $$ \dot{\mathrm{V}} $$ O2peak (>the median for R and ≤the median for NR). RESULTS: In the R group, V ̇ $$ \dot{\mathrm{V}} $$ O2peak (+17%, p < 0.001), CO, CI, SV, and HR increased by 17%, 17%, 13%, and 5%, respectively (p < 0.05) after the training program. In the NR group, V ̇ $$ \dot{\mathrm{V}} $$ O2peak, CO, CI, and SV increased by 0.5%, 5%, 8%, and 6%, respectively (p < 0.01). The SVR decreased in both groups (-19% in R and -11% in NR, p < 0.001). CONCLUSION: Among CHD patients, the R group showed a better improvement in peak cardiac output via an increase in peak stroke volume and heart rate and a reduced systemic vascular resistance than the NR group. Different cardiac phenotype adaptations and clinical individual responses were identified in CHD patients according to the aerobic fitness responder's status.

Hemodynamic Response to Exercise Training in Heart Failure With Reduced Ejection Fraction Patients.

Background: Supervised exercise training decreases total and cardiac mortality and increases quality of life of heart failure with reduced ejection fraction (HFrEF) patients. However, response to training is variable from one patient to another and factors responsible for a positive response to training remain unclear. The aims of the study were to compare cardiac hemodynamic changes after an exercise training program in responders (R) versus non-responders (NR) HFrEF patients, and to compare different discriminators used to assess response to training. Methods: Seventy-six HFrEF patients (86% males, 57 ± 12 years) completed an exercise training program for 4 weeks. Patients underwent cardiopulmonary exercise testing (CPET) on a cycle ergometer before and after training. Cardiac hemodynamics were measured by impedance cardiography during CPET. The R and NR groups were classified using the median change in peak oxygen uptake (V̇O2peak). Results: There were statistically significant differences in V̇O2peak (+35% vs. -1%, P < 0.0001) and in peaks of ventilation (+30% vs. +2%, P < 0.0001), cardiac output (COpeak) (+25% vs. +4%, P < 0.01), systolic blood pressure (+12% vs. +2%, P < 0.05), diastolic blood pressure (+9% vs. +4%, P < 0.05) and heart rate (+8% vs. +1%, P < 0.01) between R and NR after the training program. V̇O2peak was the best discriminator between R and NR (receiver operating characteristic (ROC) area under the curve (AUC) = 0.83, P < 0.0001), followed by COpeak (ROC AUC = 0.77, P < 0.0001). Conclusion: V̇O2peak is the best discriminator between HFrEF R and NR patients after the training program. Responders showed improvements in peak hemodynamic parameters. These results pave the way for other studies to determine how the individualization of exercise training programs and peak hemodynamic parameters potentially linked to a better positive response status.

Early mobilization of patients with subarachnoid haemorrhage: a national survey of french intensive care units.

OBJECTIVE: To describe French intensive care unit practices regarding the mobilization of patients with subarachnoid haemorrhage. DESIGN: A cross-sectional nationwide survey study. SUBJECTS: Intensivists and physiotherapists or nurses from French intensive care units managing patients with subarachnoid haemorrhage. METHODS: An online questionnaire survey was distributed through the Neurocritical Care and Neuro Anesthesiology French Speaking Society. RESULTS: The response rate was 89%. Of these, 90% did not have a mobilization protocol for patients with subarachnoid haemorrhage. Sixteen percent of departments prohibited all forms of motor physiotherapy for a predefined period. Nineteen percent systematically prohibited out-of-bed mobilization, regardless of the severity of subarachnoid haemorrhage and in the absence of any complication, for a predefined period. The main factors that would delay or interrupt physiotherapy prescription were intracranial hypertension (79%), currently treated vasospasm (59%), and suspicion of vasospasm (44%). Ninety-one percent of the centres identified at least one complication that could be associated with standing upright. These mainly included decreased cerebral perfusion (71%), dislodged external ventricular or lumbar derivations (68%), and haemodynamic instability (65%). CONCLUSION: Mobilization of patients with subarachnoid haemorrhage is heterogeneous among French neuro-intensive care units and several barriers preclude improvement of mobilization practices. Interventional studies assessing mobilization practices, as well as education and training of staff, are crucial to ensure the proper management of patients with subarachnoid haemorrhage and to improve outcomes.

Impact of Early Out-of-Bed Mobilization on Functional Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Cohort Study.

BACKGROUND: Effects of early mobilization are not well documented in patients with aneurysmal subarachnoid hemorrhage (aSAH). Only a few studies have investigated it through progressive mobilization protocols and suggested that it is safe and feasible. This study aimed to determine the impact of early out-of-bed mobilization (EOM) on 3-month functional outcome and cerebral vasospasm (CVS) occurrence in patients with aSAH. METHODS: A retrospective review of consecutive patients admitted to the intensive care unit with a diagnosis of aSAH was performed. EOM was defined as out-of-bed (OOB) mobilization performed before or on day 4 after aSAH onset. The primary outcome was 3-month functional independence (i.e., a modified Rankin Scale below 3) and the occurrence of CVS. RESULTS: A total of 179 patients with aSAH met the inclusion criteria. Thirty-one patients constituted the EOM group, and 148 patients were in the delayed out-of-bed mobilization group. Functional independence was more frequent in the EOM group than in the delayed out-of-bed mobilization group (n = 26 [84%] vs. n = 83 [56%], P = 0.004). In a multivariable analysis, EOM was an independent predictor of functional independence (adjusted odds ratio = 3.11; 95% confidence interval, 1.11-10.36; P < 0.05). The delay between bleeding and first OOB mobilization was also identified as an independent risk factor for the occurrence of CVS (adjusted odds ratio = 1.12; 95% confidence interval = 1.06-1.18, P < 0.001). CONCLUSIONS: EOM was independently associated with favorable functional outcome after aSAH. The delay between bleeding and OOB mobilization was an independent risk factor for reduced functional independence and CVS occurrence. Prospective randomized trials are necessary to confirm these results and improve clinical practice.

Impact of training on combined cardiopulmonary exercise test with stress echocardiography parameters in HFrEF patients.

BACKGROUND: Exercise-based cardiac rehabilitation is recognized to improve quality of life in heart failure patients. However, the effects on the cardiac function are understudied. The main objective was to assess the impact of a 4-week cardiac rehabilitation program on cardiopulmonary exercise testing (CPET) combined with simultaneous echocardiography parameters in chronic heart failure (CHF) patients. The secondary aim was to investigate patients' responses to training. METHODS: Forty-one CHF patients with reduced ejection fraction (29.3 ± 0.1%) underwent CPET and stress echocardiography before and after a 4-week of exercise-training program. Blood parameters, echocardiography and cardiopulmonary parameters were assessed before and after training. Potential echocardiography derived predictive parameters like left and right contractile reserves, left ventricle elastance, end systolic volume and right ventricle S wave response to exercise were also assessed. RESULTS: The training program increased the peak oxygen consumption (VO2) (P < 0.001), the peak systolic blood pressure, the left ventricular outflow tract velocity time integral (P < 0.05) and the circulatory (P < 0.001) and ventilatory (P < 0.01) powers. It also decreased the VE/VCO2 slope (P < 0.001). As the median value of peak VO2 gain was 17%, patients above this value were considered as responders and patients below as non-responders to training. The responders presented a higher left ventricle contractile reserve compared to non-responder patients. The peak left ventricle elastance and peak right ventricle S wave response tended to be higher in responders. CONCLUSION: Combination of CPET and stress echocardiography may contribute to establish the disease severity stratification and to predict response to training in CHF patients with reduced ejection fraction.

Assessing Intracardiac Vortices with High Frame-Rate Echocardiography-Derived Blood Speckle Imaging in Newborns.

The left ventricle (LV) has a unique pattern of hemodynamic filling. During diastole, a rotational body or ring of fluid known as a vortex is formed due to the chiral geometry of the heart. A vortex is reported to have a role in conserving the kinetic energy of blood flow entering into the LV. Recent studies have shown that LV vortices may have prognostic value in describing diastolic function at rest in neonatal, pediatric, and adult populations, and may help with earlier subclinical intervention. However, the visualization and characterization of the vortex remain minimally explored. A number of imaging modalities have been utilized for visualizing and describing intracardiac blood flow patterns and vortex rings. In this article, a technique known as blood speckle imaging (BSI) is of particular interest. BSI is derived from high-frame rate color Doppler echocardiography and provides several advantages over other modalities. Namely, BSI is an inexpensive and noninvasive bedside tool that does not rely on contrast agents or extensive mathematical assumptions. This work presents a detailed step-by-step application of the BSI methodology used in our laboratory. The clinical utility of BSI is still in its early stages, but has shown promise within the pediatric and neonatal populations for describing diastolic function in volume-overloaded hearts. A secondary aim of this study is thus to discuss recent and future clinical work with this imaging technology.

The concordance game: A simple tool to estimate breath hold swimming performance and to teach dynamic apnea.

Introduction: Swimming is composed of several phases. One of them is done underwater in apnea. Although this phase takes an important part of the performance, it is not taught much because of the risk it entails. At the same time, learning apnea can reduce the fear of immersion and, thus, reduce the number of drownings. The pedagogy used in this paper comes from game theory. This paper tested an apnea game based on the agreement between self-prediction and realization of the task. Methods: Considering the preliminary level of the 33 sports students involved, the game offered two choices: swimming apnea over 15 or 20 m with a distribution of payoffs depending on the actual achievement (15 m estimated and less than 20 m performed = + 3 points; 15 m estimated and at least 20 m realized = + 1 points; 20 m predicted and less than 20 m realized = + 2 points; 20 m estimated and at least 20 m realized = + 4 points). Results and discussion: Concordance was favored over discordance, including in the swimmer's comfort zone (15 m). Throughout six apneas the results showed that the structure of this game supports the improvement of the estimation of the distances swum. The "Concordance Game" could be offered in Physical Education or in a sports club to learn to swim a longer distance below the surface without forcing.

Is there a relationship between cardiorespiratory fitness and executive performance as function of mental workload in young adults?

In the current study, we have decided to investigate the relationship between cardiorespiratory fitness and executive functions in young adults as a function of mental workload. To achieve our objectives, we have solicited 29 young adults (18-25 years; 12 women) who have first realized the Random Number Generation (RNG) task with two levels of complexity. After each level of complexity, the participants were asked to report on their perceived difficulty. Secondly, participants performed the RABIT® test, during which oxygen consumption was measured through the Metamax 3B-R2. The results showed that executive performance and perceived difficulty deteriorate with increasing task complexity. Additionally, oxygen consumption increased significantly to reach a peak during the hardest phase of the RABIT® test. Finally, as in previous studies, we could not observe a correlation between cardiorespiratory fitness and executive functions. Our findings support the lack of a direct relationship between cardiorespiratory fitness and executive functions. Future studies should explore the relationship between the composite measure of executive function, hemodynamic activity, and cardiorespiratory fitness in healthy youth and their peers with cardiovascular disease. This will examine an indirect effect of Cardiorespiratory fitness (CRF) on Executive functions (EFs) through brain activity.

Five-Year Trend in Adherence Rate to Aerobic Physical Activity Guidelines among Korean Adults in Metropolitan Cities: 2016-2020 Korea Community Health Survey.

This study investigated the five-year (2016−2020) trend in physical activity adherence rate (PAR)­before and after the onset of the COVID-19 pandemic­and its association with socioeconomic status and community environment among Korean adults. Data were analyzed from the Korea Community Health Survey 2016−2020 concerning adults (19−65 years old) living in seven metropolitan municipalities of South Korea (N = 190,761). The independent variables were socioeconomic status (household income and educational attainment) and community environment (density of physical activity facilities and social cohesion), and the dependent variable was the PAR, as measured by the International Physical Activity Questionnaire-Short Form, a recall-based subjective survey. Multilevel logistic regression models with age, sex, and body mass index as covariates were applied. The results showed that the PAR increased from 37.26% (2016) to 40.84% (2019), during the pre-COVID-19 pandemic, but it sharply decreased to 31.59% (2020) during the COVID-19 confinement (trend p < 0.001); PAR disparities were observed following socioeconomic status, as indicated by household income (trend p < 0.001) and educational attainment (trend p < 0.001). Furthermore, significant moderation effects were observed from socioeconomic status and community environment, but the direction of the effects varied by indicator and COVID-19-related confinement period. Lower educational attainment and higher income were associated with a greater decrease in PAR during the pandemic. This study shows that PAR substantively decreased in South Korea during the COVID-19 pandemic, although it had shown a steady increase through 2019. In addition, PAR disparities by socioeconomic status were found, and socioeconomic status and community environment had distinct influences on PAR trends, depending on their indicators and pre- and post-pandemic periods. Lower educational attainment is associated with greater decreases in PAR during the pandemic, suggesting the necessity for a public campaign to maintain a physically active lifestyle during such social disaster.

Impact of COVID-19 Lockdown on Children's Health in North Africa.

OBJECTIVES: Lockdown measures have been adopted in many countries around the world to control the spread of COVID-19. These measures induced long confinement period that may have had an unintended negative impact on children's life behaviors and health. This study aimed to investigate the impact of behaviors related to COVID-19 confinement on body weight/BMI changes in children from Constantine, Algeria. METHODS: This was a cross-sectional survey based on children aged 5 to 12 years dwelling in any province of Constantine. Parents of children completed an online-distributed questionnaire at two time points (between April and May and anther time between 11th July and 10th august 2020). The questionnaire assessed sociodemographic information, anthropometric data, physical activity, dietary, eating habits, and other factors related to children's lifestyle before and during lockdown. Paired before and during lockdown comparison for each lifestyle multiple statistic tests were performed to assess associations among before and during lockdown data. RESULTS: 275 questionnaires were completed (59.7%). Mean self-reported weight and BMI significantly increased by 1.43 kg and 0.84 kg/meter 2, respectively. Among the examined variables, increased unhealthy food consumption, snacks, number of daily meals taken, low physical activity and increased sedentary behaviors were significantly correlated with higher body weight gain (P < 0.005). These behaviors may not only have a significant impact on the development of childhood obesity but also on the deterioration of the mental state of the children surveyed. CONCLUSION: Restrictive measures during the COVID-19 lockdown, and home confinement, school closure makes children more vulnerable to environmental risks. Results from this study highlight the risk associated with a shift in eating habits, increased dietary intake, decreased physical activity, increased sedentary behaviors, and their impact in exacerbating the gain in body weight and BMI.

The COVID-19 Pandemic Lowers Active Behavior of Patients with Cardiovascular Diseases, Healthy Peoples and Athletes.

AIM: The paper aims to describe the impact of the increasing sedentary lifestyle due to the coronavirus disease-2019 (COVID-19) pandemic restrictions in patients with cardiovascular diseases (CVDs), healthy individuals, and athletes. METHODS: A review of studies investigating the impact of the COVID-19 restrictions on patients with CVDs, healthy subjects, and athletes has been conducted in the PubMed, Medline, and Google Scholar medical databases. RESULTS: The review highlighted the significant decrease of active behavior in patients with CVDs and mainly heart-failure patients, illustrated by a reduction of their daily steps and hours of being active during the COVID-19 pandemic. This review also enlightened a significant increase of the time spent in sedentary behavior and the sleep in healthy individuals. Finally, this review reported that the COVID-19 pandemic restrictions induced detraining periods in athletes, altering their health. These periods might also lead to a decrease of their future performances. CONCLUSIONS: Staying active and maintaining sufficient levels of physical activity during the COVID-19 pandemic are essential to preserve good health, despite the circumstances of quarantine. Alternatives such as completing a cardiac telerehabilitation for CVD patients or training at home for healthy subjects and athletes may be taken into consideration to maintain a regular active behavior in this sanitary context and potential future pandemics.

Is physical activity a future therapy for patients with Marfan syndrome?

INTRODUCTION: The international recommendations tend to avoid physical activity (PA) for patients with Marfan syndrome (MFS). However, exceptions have recently been made in the most recent recommendations for these patients, suggesting benefits from doing PA at low intensity only. Furthermore, there is no evidence that moderate aerobic or weight training can worsen the disease symptoms and increase mortality of MFS patients. The present review sums up the work carried out in the field of PA and MFS. The review aims to (1) identify the different types of exercise testing and training protocols and (2) discuss the feasibility and potentially beneficial nature of PA as an innovative way to manage MFS patients. METHODS: The scientific literature was reviewed using the following words: Marfan syndrome, training, physical activity, evaluation, weight training, arterial disease, aneurysms, lung damage, aortic dissection, rupture. A total of 345 studies were prospected and 43 studies were included. CONCLUSIONS: A limited number of studies were done in humans, however one demonstrated the feasibility of the management of MFS patients with PA. There were potential beneficial effects of PA on arterial structures, but this review also showed deleterious effects when PA was conducted at high intensities, corresponding to 75-85% of the maximal oxygen uptake. However, these effects have only been reported in animal studies.

Effects of a personalized home-based training program among patients suffering from Marfan syndrome: a pilot randomized and controlled study.

Marfan syndrome (MFS) is an autosomal hereditary pathology affecting 1:5000 peoples. Alteration of the fibrillin 1 gene (FBN1) results in haplo-insufficiency of the FBN1 protein mainly altering the vascular system. International recommendations have gradually allowed MFS patients to perform training programs because of its potential benefits. However, to date, there are no data on the effect of a long training period in these patients. The aim of the present study is to investigate the effect of a 3-month personalized home-based training on quality of life (QoL) of patients suffering from MFS. At least 50 MFS patients were included in the study. They were randomly placed into 4 groups: control group; endurance; resistance and endurance + resistance training groups. The training program lasted 3 months and is performed at patients' home. There were 2 training sessions per week telemonitored by a specialist of physical activity and cardiology. Pre and post-training evaluations were performed at the Bichat-Paris Hospital, France. They consisted of assessing psychometrics based on self-administered questionnaires (FiRST, GPAQ, ISP-25, MOS SF-36) and physiological parameters such as the peak oxygen consumption, aorta diameter, cardiac ventricle function and skeletal muscle power at rest and during exercise. Our preliminary results showed an improvement of 50% in QoL, cardiorespiratory fitness and skeletal muscle power in a patient who completed the combined training program. This experimental approach might be a new alternative way for MFS patients' care that may improve their QoL, cardiorespiratory fitness and skeletal muscle power.

Alteration of skeletal and cardiac muscles function in DBA/2J mdx mice background: a focus on high intensity interval training.

Duchenne muscular dystrophy (DMD) is a recessive hereditary myopathy due to deficiency of functional dystrophin. Current therapeutic interventions need more investigation to slow down the progression of skeletal and cardiac muscle weakness. In humans, there is a lack of an adapted training program. In animals, the murine Mdx model with a DBA/2J background (D2-mdx) was recently suggested to present pathological features closer to that of humans. In this study, we characterized skeletal and cardiac muscle functions in males and females D2-mdx mice compared to control groups. We also evaluated the impact of high intensity interval training (HIIT) in these muscles in females and males. HIIT was performed 5 times per week during a month on a motorized treadmill. Specific maximal isometric force production and weakness were measured in the tibialis anterior muscle (TA). Sedentary male and female D2-mdx mice produced lower absolute and specific maximal force compared to control mice. Dystrophic mice showed a decline of force generation during repetitive stimulation compared to controls. This reduction was greater for male D2-mdx mice than females. Furthermore, trained D2-mdx males showed an improvement in force generation after the fifth lengthening contraction compared to sedentary D2-mdx males. Moreover, echocardiography measures revealed a decrease in left ventricular end-diastolic volume, left ventricular ejection volume and left ventricular end-diastolic diameter in sedentary male and female D2-mdx mice. Overall, our results showed a serious muscle function alteration in female and male D2-mdx mice compared to controls. HIIT may delay force loss especially in male D2-mdx mice.

Dexamethasone is associated with early deaths in light chain amyloidosis patients with severe cardiac involvement.

BACKGROUND: Cardiac light chain amyloidosis (AL-CA) patients often die within three months of starting chemotherapy. Chemotherapy for non-immunoglobulin M gammopathy with AL-CA frequently includes bortezomib (Bor), cyclophosphamide (Cy), and dexamethasone (D). We previously reported that NT-ProBNP levels can double within 24h of dexamethasone administration, suggesting a deleterious impact on cardiac function. In this study, we evaluate the role of dexamethasone in early cardiovascular mortality during treatment. METHODS AND FINDINGS: We retrospectively assessed 100 de novo cardiac AL patients (62% male, mean age 68 years) treated at our institute between 2009 and 2018 following three chemotherapy regimens: CyBorDComb (all initiated on day 1; 34 patients), DCyBorSeq (D, day 1; Cy, day 8; Bor, day 15; 17 patients), and CyBorDSeq (Cy, day 1; Bor, day 8; D, day 15; 49 patients). The primary endpoint was cardiovascular mortality and cardiac transplantation at days 22 and 455. At day 22, mortality was 20.6% with CyBorDComb, 23.5% with DCyBorSeq, and 0% with CyBorDSeq (p = 0.003). At day 455, mortality was not significantly different between regimens (p = 0.195). Acute toxicity of dexamethasone was evaluated on myocardial function using a rat model of isolated perfused heart. Administration of dexamethasone induced a decrease in left ventricular myocardium contractility and relaxation (p<0.05), supporting a potential negative inotropic effect of dexamethasone in AL-CA patients with severe cardiac involvement. CONCLUSION: Delaying dexamethasone during the first chemotherapy cycle reduces the number of early deaths without extending survival. It is clear that dexamethasone is beneficial in the long-term treatment of patients with AL-CA. However, the initial introduction of dexamethasone during treatment is critical, but may be associated with early cardiac deaths in severe CA. Thus, it is important to consider the dosage and timing of dexamethasone introduction on a patient-severity basis. The impact of dexamethasone in the treatment of AL-CA needs further investigation.

Mini-Review of Studies Testing the Cardiorespiratory Hypothesis With Near-Infrared Spectroscopy (NIRS): Overview and Perspectives.

The cardiorespiratory hypothesis (CH) is one of the hypotheses used by researchers to explain the relationship between cardiorespiratory fitness and cognitive performance during executive functions. Despite the indubitable beneficial effect of training on brain blood flow and function that may explain the link between physical fitness and cognition and the recognition of the near-infrared spectroscopy (NIRS) as a reliable tool for measuring brain oxygenation, few studies investigated the CH with NIRS. It is still not well understood whether an increase in brain flow by training is translated into an increase in cerebral oxygenation. Thus, the objective of this mini-review was to summarize main results of studies that investigated the CH using the NIRS and to propose future research directions.

Marathon-Induced Cardiac Fatigue: A Review over the Last Decade for the Preservation of the Athletes' Health.

AIM: To provide a state-of-the-art review of the last 10 years focusing on cardiac fatigue following a marathon. METHODS: The PubMed, Bookshelf and Medline databases were queried during a time span of 10 years to identify studies that met the inclusion criteria. Twenty-four studies focusing only on the impact of marathons on the cardiac function and factors involved in cardiac fatigue were included in this review. RESULTS: Sixteen studies focused on the impact of marathons on several biomarkers (e.g., C-reactive protein, cardiac troponin T). Seven studies focused on the left (LV) or right (RV) ventricular function following a marathon and employed cardiac magnetic resonance, echocardiography, myocardial speckle tracking and heart rate variability to analyze global and regional LV or RV mechanics and the impact of the autonomic nervous system on cardiac function. One study focused on serum profiling and its association with cardiac changes after a marathon. CONCLUSIONS: This review reported a negligible impact of marathons on LV and RV systolic and contractile function but a negative impact on LV diastolic function in recreational runners. These impairments are often associated with acute damage to the myocardium. Thus, the advice of the present review to athletes is to adapt their training and have a regular medical monitoring to continue to run marathons while preserving their cardiac health.

Race Analysis of the World's Best Female and Male Marathon Runners.

Background: Beyond the difference in marathon performance when comparing female and male runners, we tested the hypothesis that running strategy does not different according to sex. The goal of the present study is to compare the running strategy between the best female and male marathon performances achieved in the last two years. Methods: Two aspects of the races were analyzed: (i) average speed relative to runner critical speed (CS) with its coefficient of variation and (ii) asymmetry and global tendency of race speed (i.e., the race's Kendall τ ) . Results: The females' best marathons were run at 97.6% ± 3% of CS for the new record (Brigid Kosgei, 2019) and at 96.1% ± 4.4% for the previous record (Paula Radcliffe, 2003). The best male performances (Eliud Kipchoge, 2018 and 2019) were achieved at a lower fraction of CS (94.7% ± 1.7% and 94.1% ± 2.3% in 2018 and 2019, respectively). Eliud Kipchoge (EK) achieved a significant negative split race considering the positive Kendall's τ of pacing (i.e., time over 1 km) ( τ = 0.30; p = 0.007). Furthermore, EK ran more of the average distance below average speed (54% and 55% in 2018 and 2019, respectively), while female runners ran only at 46% below their average speed. Conclusions: The best female and male marathon performances were run differently considering speed time course (i.e., tendency and asymmetry), and fractional use of CS. In addition, this study shows a robust running strategy (or signature) used by EK in two different marathons. Improvement in marathon performance might depend on negative split and asymmetry for female runners, and on higher fractional utilization of CS for male runners.

Metabolic syndrome, leptin-insulin resistance and uric acid: a trinomial foe for Algerian city-dweller adolescents' health.

Background Adolescence is one of the critical periods where increased risk for long-term obesity-related complications is an important health concern. This highlights the need to perform early diagnostics based on precise biomarkers to decrease the risk of complications in adolescents with obesity. Objective To determine the relationships between serum levels of uric acid (UA), leptin and insulin with metabolic syndrome (MS) components in Algerian adolescents. Subjects Nondiabetic adolescents (n = 204). Methods Blood pressure (BP) and anthropometric measurements were performed using standardized techniques. Blood samples were taken for determination of glycemia, triglyceridemia, uricemia, cholesterolemia, leptinemia and insulinemia. Results The rate of MS among an excess weight group was 17.4% [95% confidence interval (CI)]. Serum levels of UA, leptin and insulin were significantly higher in the excess weight group compared to a normal weight group (279.4 ± 86.05 vs. 204.9 ± 50.34 µmol/L and 25.65 ± 14.01 vs. 4.09 ± 2.60 µg/L, p < 0.001; 24.58 ± 13.85 vs. 13.34 ± 6.41 µIU/L, p < 0.05). Serum levels of UA, leptin and insulin were significantly higher in adolescents with MS compared to those without MS (304.86 ± 111.41 vs. 224.72 ± 77.81 µmol/L, 30.26 ± 12.46 vs. 16.93 ± 14.97 µg/L and 30.91 ± 17.30 vs. 18.71 ± 10.14 µIU/L, p < 0.05, respectively). Significant correlations were found between UA and leptin with waist circumference (r = 0.50 and 0.76), diastolic blood pressure (r = 0.58 and 0.43), triglycerides (r = 0.42 and 0.35) and high-density lipoprotein-cholesterol (r = -0.36 and -0.35). Conclusion Serum levels of UA and leptin may be useful biomarkers for early diagnosis of the risk of MS in our Algerian adolescent population.

Voluntary Exercise Improves Cardiac Function and Prevents Cardiac Remodeling in a Mouse Model of Dilated Cardiomyopathy.

Objective: Despite the indubitable beneficial effect of exercise to prevent of cardiovascular diseases, there is still a lack of studies investigating the impact of exercise in non-ischemic dilated cardiomyopathy. Here, we investigated the impact of voluntary exercise on cardiac function in a mouse model of non-ischemic dilated cardiomyopathy (αMHC-MerCreMer:Sf/Sf), induced by cardiac-specific inactivation of the Serum Response Factor. Materials and Methods: Seven days after tamoxifen injection, 20 αMHC-MerCreMer:Sf/Sf mice were assigned to sedentary (n = 8) and exercise (n = 12) groups. Seven additional αMHC-MerCreMer:Sf/Sf mice without tamoxifen injection were used as control. The exercise group performed 4 weeks of voluntary running on wheel (1.8 ± 0.12 km/day). Cardiac function, myocardial fibrosis, and mitochondrial energetic pathways were then blindly assessed. Results: Exercised mice exhibited a smaller decrease of left ventricular (LV) fractional shortening and ejection fraction compared to control mice. This was associated with a lower degree of LV remodeling in exercised mice, as shown by a lower LV end-systolic intrerventricular septal and posterior wall thickness decrease from baseline values compared to sedentary mice. Moreover, exercised mice displayed a reduced gene expression of atrial and brain natriuretic factors. These benefits were associated by a reduced level of myocardial fibrosis. In addition, exercised mice exhibited a higher mitochondrial aconitase, voltage-dependent anion-selective channel 1 and PPAR gamma coactivators-1 alpha proteins levels suggesting that the increase of mitochondrial biogenesis and/or metabolism slowed the progression of dilated cardiomyopathy in exercised animals. Conclusions: In conclusion, our results support the role of voluntary exercise to improve outcomes in non-ischemic dilated heart failure (HF) and also support its potential for a routine clinical use in the future.