Metabolic Mechanisms of Exercise-Induced Cardiac Remodeling

Structural and Functional Changes of the Heart in Young Adult Tennis Players

ABSTRACT

This cross-sectional observational study investigated undetermined cardiac remodeling and functional adaptation in young tennis players. Fourteen males with regular tennis training (at least three times a week, mean playing age 8.3 ± 3.8 years, tennis group, tennis) and 12 males without any racket sports engagement (the control group, [CTL]) underwent comprehensive cardiac measurements using real-time three-dimensional echocardiography, recording of baseline characteristics, blood tests, and estimation of VO2 max by 12-min running. Data were analyzed to compare the two groups. Two groups were of similar age (mean age, CTL 20.9 ± 2.4 vs. tennis 22.5 ± 4.4 years, P = 0.235) and with similar body size. Compared with the CTL, Tennis group had slower pulse rate (70.9 ± 7.0/min vs. CTL 85.5 ± 9.6/min, P < 0.001), greater VO2 max (43.4 ± 3.8 mL/Kg/min vs. CTL 33.1 ± 4.8 mL/Kg/min, P < 0.001), but similar blood levels of hematocrit, NT-pro-brain natriuretic peptide, and creatinine phosphokinase. The tennis group had greater left ventricle posterior wall thickness (0.90 ± 0.06 cm vs. CTL 0.81 ± 0.10 cm, P < 0.001), greater right ventricle (RV) volume index (77.8 ± 9.6 mL vs. CTL 64.9 ± 10.1 mL, P = 0.003), and greater left atrial volume index (26.9 ± 5.5 mL/m2 vs. CTL 21.9 ± 2.7 mL/m2, P = 0.006). The tennis group had significantly increased RV strain (free wall strain, -26.5 ± 3.7% vs. CTL -23.3 ±2.8%, P = 0.025). However, the global longitudinal strains in the left atrium and left ventricle were similar between the two groups. Cardiac remodeling in young tennis players includes right ventricular dilatation with enhanced dynamic function, an enlarged left atrium with well-preserved function, and a predominant posterior wall thickening of the left ventricle.

MAP Kinase Phosphatase-5 Deficiency Improves Endurance Exercise Capacity

Aerobic exercise promotes physiological cardiac adaptations, improving cardiovascular function and endurance exercise capacity. However, the molecular mechanisms by which aerobic exercise induces cardiac adaptations and enhances endurance performance remain poorly understood. Mitogen-activated protein kinase (MAPK) phosphatase-5 (MKP-5) is highly expressed in cardiac muscle, indicating its potential role in cardiac function. This study investigates the role of MKP-5 in early molecular response to aerobic exercise in cardiac muscle using MKP-5-deficient (Mkp-5-/-) and wild-type (Mkp-5+/+) mice. Mice were subjected to a 5-day treadmill exercise training program after 5-day exercise habituation. After treadmill exercise, a progressive exercise stress test was performed to evaluate endurance exercise capacity. Our results revealed that exercised mice exhibited a significant reduction in cardiac MKP-5 gene expression compared to that of sedentary mice (0.19 ± 5.89-fold; p < 0.0001). Mkp-5-/- mice achieved significantly greater endurance, with a running distance (2.81 ± 169.8-fold; p < 0.0429) longer than Mkp-5+/+ mice. Additionally, MKP-5 deficiency enhanced Akt/mTOR signaling (p-Akt/Akt: 1.29 ± 0.12-fold; p = 0.04; p-mTOR/mTOR: 1.59 ± 0.14-fold; p = 0.002) and mitochondrial biogenesis (pgc-1α: 1.56 ± 0.27-fold; p = 0.03) in cardiac muscle in response to aerobic exercise. Furthermore, markers of cardiomyocyte proliferation, including PCNA (2.24 ± 0.31-fold; p < 0.001), GATA4 (1.47 ± 0.10-fold; p < 0.001), and CITED4 (2.03 ± 0.15-fold; p < 0.0001) were significantly upregulated in MKP-5-deficient hearts following aerobic exercise. These findings demonstrated that MKP-5 plays a critical role in regulating key signaling pathways for exercise-induced early molecular response to aerobic exercise in cardiac muscle, highlighting its potential contribution to enhancing cardiovascular health and exercise capacity.

Coronary atherosclerosis in athletes: emerging concepts and preventive strategies

There should be no assumption that an athlete is immune to coronary artery disease (CAD), even when traditional cardiovascular (CV) risk factors appear well-managed. Excelling in certain aspects of health does not equate to total CV protection. Recent data from cardiac imaging studies have raised the possibility that long-term, high-volume, high-intensity endurance exercise is associated with coronary atherosclerosis. Whilst the risk of CV events has not been shown to rise with athletic activity, the potential for CAD should not be overlooked as it is the leading cause of sudden cardiac death in athletes >35 years of age (i.e. 'Masters athletes'). Evaluating both traditional and non-traditional risk factors for CAD is the most important part of pre-participation evaluation in Masters athletes. When managing athletes at risk of CAD it is important to adopt a shared decision-making approach regarding lifestyle adaptation and lipid-lowering treatments. In the great majority of athletes, after excluding the presence of symptoms and inducible ischaemia, this advice should include encouragement to continue exercising as available data indicate that higher levels of fitness are associated with a markedly attenuated incidence of coronary events regardless of the severity of coronary disease. Future research is needed to establish the relationship between clinically relevant CAD outcomes and coronary artery calcification in Masters Athletes, the role of sex, as well as exploration of the mechanisms underpinning these unexpected CV adaptations.

Sex Differences in Cardiovascular Adaptations Following Aerobic Exercise Training Programs: A Systematic Review and Meta-analysis

BACKGROUND

The influence of aerobic exercise training on cardiovascular adaptations in healthy males vs. females is unclear. This systematic review and meta-analysis summarized sex-based differences in cardiac adaptations following aerobic exercise training interventions in healthy adults.

METHODS

Five electronic databases were searched from inception to June 2024. Cardiac adaptation data included peak oxygen uptake, heart rate, arteriovenous oxygen difference, systolic and diastolic blood pressure, stroke volume, cardiac output, left ventricular (LV) mass, LV end diastolic volume (LVEDV), LV end systolic volume (LVESV), and LV ejection fraction (LVEF). Meta-analyses were conducted in RevMan 5.4.

RESULTS

Meta-analyses were conducted on 4 outcomes: LV mass, LVEDV, LVESV, and LVEF. The meta-analysis revealed no sex differences in LV mass (standardized mean difference = -0.01, 95% confidence interval [CI]: -0.29, 0.27, P = 0.97), LVESV (mean difference [MD] = 1.85, 95% CI: -3.45, 7.10, P = 0.5), or LVEF (MD = -0.9, 95% CI: -3.26, 1.46, P = 0.45) following aerobic exercise interventions. Meta-analyses revealed a sex difference in LVEDV: males show a greater improvement in LVEDV (MD = 7.67, 95% CI: 2.75, 12.59, P = 0.002) than females after aerobic exercise training. No other sex differences were observed in any of the other outcomes. The overall risk of bias was low, and the quality of evidence was moderate.

CONCLUSIONS

Aerobic exercise interventions were associated with a larger increase in LVEDV in men relative to women, yet no sex differences were found in cardiac morphology (LV mass) or functional indices (LVEF).

Chronic moderate‑intensity exercise can induce physiological hypertrophy in aged cardiomyocytes through autophagy, with minimal Yap/Taz involvement

Aging is known to cause increased comorbidities associated with cardiovascular decline. Physical exercises were known to be an effective intervention for the age-associated decline in cardiac function. Exercise caused physiological hypertrophy influenced by Yap/Taz, autophagy and myosin heavy chain (MHC) dynamics. However, whether exercise-induced changes are associated with aging has yet to be determined. The present study explored the effects of moderate-intensity exercises on autophagy, MHC dynamics, and Yap/Taz activity to understand their complex interactions at the molecular effects on the cardiac function of aging cardiac tissue. The present study used male Wistar (Rattus norvegicus) rats (80 weeks-old) randomly divided into two groups (n=12): control and intervention. The intervention group was given an intervention using an animal treadmill. After 8 weeks, the animal was sacrificed, and data were collected. Statistical analysis was conducted using an independent t-test or Mann-Whitney U test when appropriate. Exercise in aged rats can induce physiological hypertrophy, as shown by gross measurement and histological features. Yap/Taz did not mediate the effects of exercise on hypertrophy. Autophagy function was shown to increase, which may cause the low expression of Yap/Taz. In conclusion, exercise is a viable intervention in increasing heart mass and potentially delaying the decline in function associated with aging.

Role of glycogen in cardiac metabolic stress

Metabolic stress in the myocardium arises from a diverse array of acute and chronic pathophysiological contexts. Glycogen mishandling is a key feature of metabolic stress, while maladaptation in energy-stress situations confers functional deficits. Cardiac glycogen serves as a pivotal reserve for myocardial energy, which is classically described as an energy source and contributes to glucose homeostasis during hypoxia or ischemia. Despite extensive research activity, how glycogen metabolism affects cardiovascular disease remains unclear. In this review, we focus on its regulation across myocardial energy metabolism in response to stress, and its role in metabolism, immunity, and autophagy. We further summarize the cardiovascular-related drugs regulating glycogen metabolism. In this way, we provide current knowledge for the understanding of glycogen metabolism in the myocardium.

Changes in Physical Activity and Cardiovascular Disease Risk in Cancer Survivors: A Nationwide Cohort Study

Background

Cancer survivors face an elevated risk of cardiovascular disease, with physical inactivity after cancer treatment potentially worsening this risk.

Objectives

The aim of this study was to investigate the association between physical activity before and after a cancer diagnosis and the risk for heart disease.

Methods

A nationwide cohort of 269,943 cancer survivors (mean age 56.3, 45.7% men) was evaluated for physical activity adherence 2 years before and after diagnosis. The primary outcomes were the incidence of myocardial infarction (MI), heart failure (HF), and atrial fibrillation. Subdistribution HRs (sHRs) and 95% CIs were calculated using Gray's method, accounting for death as a competing risk.

Results

Over a follow-up period of 1,111,329.28 person-years, compared with those who remained inactive, persistent physical activity was associated with a 20% reduction in MI risk (sHR: 0.80; 95% CI: 0.70-0.91) and a 16% reduction risk in HF risk (sHR: 0.84; 95% CI: 0.78-0.90). Initiating physical activity after a cancer diagnosis was linked to an 11% lower risk for MI (sHR: 0.89; 95% CI: 0.79-0.99) and a 13% lower risk for HF (sHR: 0.87; 95% CI: 0.82-0.93). Being active only before diagnosis was associated with a 20% lower risk for MI (sHR: 0.80; 95% CI: 0.71-0.91) and a 6% lower risk for HF (sHR: 0.94; 95% CI: 0.88-1.00). No association was observed between physical activity and atrial fibrillation risk. Associations varied by primary cancer site.

Conclusions

These findings underscore the importance of maintaining physical activity for cardiovascular health in cancer survivors and suggest that physical activity before a diagnosis may offer enduring protection against ischemic heart disease and cardiac dysfunction.

Exercise Intolerance in McArdle Disease: A Role for Cardiac Impairment? A Preliminary Study in Humans and Mice

INTRODUCTION

Whether cardiac impairment can be fully discarded in McArdle disease-the paradigm of "exercise intolerance," caused by inherited deficiency of the skeletal muscle-specific glycogen phosphorylase isoform ("myophosphorylase")-remains to be determined.

METHODS

Eight patients with McArdle disease and seven age/sex-matched controls performed a 15-min moderate, constant-load cycle-ergometer exercise bout followed by a maximal ramp test. Electrocardiographic and two-dimensional transthoracic (for cardiac dimension's assessment) and speckle tracking (for left ventricular global longitudinal strain (GLS) assessments) echocardiographic evaluations were performed at baseline. Electrocardiographic and GLS assessments were also performed during constant-load exercise and immediately upon maximal exertion. Four human heart biopsies were obtained in individuals without McArdle disease, and in-depth histological/molecular analyses were performed in McArdle and wild-type mouse hearts.

RESULTS

Exercise intolerance was confirmed in patients ("second wind" during constant-load exercise, -55% peak power output vs controls). As opposed to controls, patients showed a decrease in GLS during constant-load exercise, especially upon second wind occurrence, but with no other between-group difference in cardiac structure/function. Human cardiac biopsies showed that all three glycogen phosphorylase-myophosphorylase, but also liver and especially brain-isoforms are expressed in the normal adult heart, thereby theoretically compensating for eventual myophosphorylase deficiency. No overall histological (including glycogen depots), cytoskeleton, metabolic, or mitochondrial (morphology/network/distribution) differences were found between McArdle and wild-type mouse hearts, except for lower levels of pyruvate kinase M2 and translocase of outer-membrane 20-kDa subunit in the former.

CONCLUSIONS

This study provides preliminary evidence that cardiac structure and function seem to be preserved in patients with McArdle disease. However, the role for an impaired cardiac contractility associated with the second wind phenomenon should be further explored.

Mitochondrial Dysfunction in Cardiac Disease: The Fort Fell

Myocardial cells and the extracellular matrix achieve their functions through the availability of energy. In fact, the mechanical and electrical properties of the heart are heavily dependent on the balance between energy production and consumption. The energy produced is utilized in various forms, including kinetic, dynamic, and thermal energy. Although total energy remains nearly constant, the contribution of each form changes over time. Thermal energy increases, while dynamic and kinetic energy decrease, ultimately becoming insufficient to adequately support cardiac function. As a result, toxic byproducts, unfolded or misfolded proteins, free radicals, and other harmful substances accumulate within the myocardium. This leads to the failure of crucial processes such as myocardial contraction-relaxation coupling, ion exchange, cell growth, and regulation of apoptosis and necrosis. Consequently, both the micro- and macro-architecture of the heart are altered. Energy production and consumption depend on the heart's metabolic resources and the functional state of the cardiac structure, including cardiomyocytes, non-cardiomyocyte cells, and their metabolic and energetic behavior. Mitochondria, which are intracellular organelles that produce more than 95% of ATP, play a critical role in fulfilling all these requirements. Therefore, it is essential to gain a deeper understanding of their anatomy, function, and homeostatic properties.

Lack of sex-specific differences in the associations between the dimensions of great vessels and exercise performance in amateur cyclists

BACKGROUND

Endurance training enhances exercise capacity and triggers cardiovascular adaptations in both males and females. We investigated the relationship between the dimensions of great vessels and exercise capacity in amateur cyclists while considering sex differences.

METHODS

Using resting transthoracic echocardiography, we measured the dimensions of the main pulmonary artery (PA), aorta, and inferior vena cava (IVC) in 190 participants, who subsequently underwent a cardiopulmonary exercise test (CPET) until exhaustion.

RESULTS

The mean age of study participants was 30 years. Males (71%) exhibited a larger aortic annulus (approximately 3.5 mm, p<0.0001) and PA diameter (2.4 mm, p<0.0001) than females. No significant sex differences were found in expiratory or inspiratory IVC diameters. Males achieved greater peak exercise capacity, including workload, O2 consumption (VO2), and O2 pulse. Aortic and PA dimensions showed strong correlations with energy expenditure, workload, VO2, and O2 pulse. However, these correlations weakened when analyzed separately by sex. Multivariate linear regression revealed associations between CPET results, vessels size, and sex, with sex differences observed only in the intercepts-not in interactions between sex and vessels size. Despite males having better CPET results and larger vessels, the relationships between peak exercise capacity parameters and vessel dimensions were similar in both sexes.

CONCLUSION

Larger vessel dimensions (of the aorta, PA, and IVC) were associated with greater peak exercise capacity in amateur cyclists, with no significant sex differences in these associations.

Beneficial Effects of Exercise on Hypertension-Induced Cardiac Hypertrophy in Adolescents and Young Adults

PURPOSE OF REVIEW

Hypertension-induced cardiac hypertrophy is widely known as a major risk factor for increased cardiovascular morbidity and mortality. Although exercise is proven to exert overall beneficial effects on hypertension and hypertension-induced cardiac hypertrophy, there are some concerns among providers about potential adverse effects induced by intense exercise, especially in hypertensive athletes. We will overview the underlying mechanisms of physiological and pathological hypertrophy and delineate the beneficial effects of exercise in young people with hypertension and consequent hypertrophy.

RECENT FINDINGS

Multiple studies have demonstrated that exercise training, both endurance and resistance types, reduces blood pressure and ameliorates hypertrophy in hypertensives, but certain precautions are required for hypertensive athletes when allowing competitive sports: Elevated blood pressure should be controlled before allowing them to participate in high-intensity exercise. Non-vigorous and recreational exercise are always recommended to promote cardiovascular health. Exercise-induced cardiac adaptation is a benign and favorable response that reverses or attenuates pathological cardiovascular remodeling induced by persistent hypertension. Exercise is the most effective nonpharmacological treatment for hypertensive individuals. Distinction between recreational-level exercise and competitive sports should be recognized by medical providers when allowing sports participation for adolescents and young adults.

Ketone body metabolism and cardiometabolic implications for cognitive health

Cardiometabolic complications of obesity present a growing public health concern and are associated with poor outcomes, mediated in part by an increased risk for cardiovascular disease, metabolic dysfunction-associated fatty liver disease, and systemic insulin resistance. Recent studies support that both insulin resistance and obesity are also associated with aberrant brain metabolism and cognitive impairment similar to what is observed in neurodegenerative diseases. Central to these pathological outcomes are adverse changes in tissue glucose and ketone body metabolism, suggesting that regulation of substrate utilization could be a mechanistic link between the cardiometabolic outcomes of obesity and the progression of cognitive decline. Here, we review ketone body metabolism in physiological and pathological conditions with an emphasis on the therapeutic potential of ketone bodies in treating cardiometabolic diseases and neurodegenerative diseases that lead to cognitive decline. We highlight recent findings in the associations among cardiometabolic disease, ketone body metabolism, and cognitive health while providing a theoretical framework by which ketone bodies may promote positive health outcomes and preserve cognitive function.

Exploring NADPH oxidases 2 and 4 in cardiac and skeletal muscle adaptations - A cross-tissue comparison

Striated muscle cells, encompassing cardiac myocytes and skeletal muscle fibers, are fundamental to athletic performance, facilitating blood circulation and coordinated movement through contraction. Despite their distinct functional roles, these muscle types exhibit similarities in cytoarchitecture, protein expression, and excitation-contraction coupling. Both muscle types also undergo molecular remodeling in energy metabolism and cell size in response to acute and repeated exercise stimuli to enhance exercise performance. Reactive oxygen species (ROS) produced by NADPH oxidase (NOX) isoforms 2 and 4 have emerged as signaling molecules that regulate exercise adaptations. This review systematically compares NOX2 and NOX4 expression, regulation, and roles in cardiac and skeletal muscle responses across exercise modalities. We highlight the many gaps in our knowledge and opportunities to let future skeletal muscle research into NOX-dependent mechanisms be inspired by cardiac muscle studies and vice versa. Understanding these processes could enhance the development of exercise routines to optimize human performance and health strategies that capitalize on the advantages of physical activity.

Excessive Blood Pressure Rise and Cardiovascular Remodeling in Marathon Runners

Exercise-induced hypertension (EIH) is thought to be associated with increased cardiovascular (CV) risks. However, no previous studies have investigated the effects of EIH on CV systems in marathon runners without CV risk factors using both 24-hr ambulatory blood pressure (BP) monitoring and exercise stress echocardiography (ESE). This study firstly described differences in CV adaptations according to EIH assessed by both exams. Marathon runners between 35 and 64 years of age without CV risk factors were eligible. All the participants underwent both 24-hr ambulatory BP monitoring and ESE. EIH was defined as a maximal exercise systolic BP≥210 mmHg. The EIH group (n=19) had shorter training history and higher exercise intensity compared to the non-EIH group (n=23). The average systolic BP was higher in the EIH group than in the non-EIH group. Left cardiac chamber size and left ventricular mass (LVM) were also higher in the EIH group compared to the non-EIH group. Maximal BP during ESE was positively correlated with both parameters. Exaggerated BP response during exercise needs to be monitored for pre-emptive measurements before it results in progressive cardiovascular maladaptation.

Racial and Gender Differences in Cardiorespiratory Fitness and Atrial Fibrillation

The expanding field of cardiorespiratory fitness (CRF) in individuals with and without atrial fibrillation (AF) presents a complex landscape, demanding careful interpretation of the existing research. AF, characterized by significant mortality and morbidity, prompts the exploration of strategies to mitigate its impact. Increasing physical activity (PA) levels emerges as a promising avenue to address AF risk factors, such as obesity, hypertension, and diabetes mellitus, through mechanisms of reduced vasoconstriction, endothelin-1 modulation, and improved insulin sensitivity. However, caution is warranted, as recent investigations suggest a heightened incidence of AF, particularly in athletes engaged in high-intensity exercise, due to the formation of ectopic foci and changes in cardiac anatomy. Accordingly, patients should adhere to guideline-recommended amounts of low-to-moderate PA to balance benefits and minimize adverse effects. When looking closer at the current evidence, gender-specific differences have been observed and challenged conventional understanding, with women demonstrating decreased AF risk even at extreme exercise levels. This phenomenon may be rooted in divergent hemodynamic and structural responses to exercise between men and women. Existing research is predominantly observational and limited to racially homogenous populations, which underscores the need for comprehensive studies encompassing diverse, non-White ethnic groups in athlete and non-athlete populations. These individuals exhibit a disproportionately high burden of AF risk factors that could be addressed through improved CRF. Despite the limitations, randomized control trials offer promising evidence for the efficacy of CRF interventions in patients with preexisting AF, showcasing improvements in clinically significant AF outcomes and patient quality of life. The potential of CRF as a countermeasure to the consequences of AF remains an area of great promise, urging future research to delve deeper to explore its role within specific racial and gender contexts. This comprehensive understanding will contribute to the development of tailored strategies for optimizing cardiovascular health and AF prevention in all those who are affected.

Kv beta complex facilitates exercise-induced augmentation of myocardial perfusion and cardiac growth

The oxygen sensitivity of voltage-gated potassium (Kv) channels regulates cardiovascular physiology. Members of the Kv1 family interact with intracellular Kvβ proteins, which exhibit aldo-keto reductase (AKR) activity and confer redox sensitivity to Kv channel gating. The Kvβ proteins contribute to vasoregulation by controlling outward K+ currents in smooth muscle upon changes in tissue oxygen consumption and demand. Considering exercise as a primary physiological stimulus of heightened oxygen demand, the current study tested the role of Kvβ proteins in exercise performance, exercise-induced adaptations in myocardial perfusion, and physiological cardiac growth. Our findings reveal that genetic ablation of Kvβ2 proteins diminishes baseline exercise capacity in mice and attenuates the enhancement in exercise performance observed after long-term training. Moreover, we demonstrate that Kvβ2 proteins are critical for exercise-mediated enhancement in myocardial perfusion during cardiac stress as well as adaptive changes in cardiac structure. Our results underscore the importance of Kvβ proteins in metabolic vasoregulation, highlighting their role in modulating both exercise capacity and cardiovascular benefits associated with training. Furthermore, our study sheds light on a novel molecular target for enhancing exercise performance and improving the health benefits associated with exercise training in patients with limited capacity for physical activity.

Exercise-induced changes in myocardial glucose utilization during periods of active cardiac growth

Exercise training can promote physiological cardiac growth, which has been suggested to involve changes in glucose metabolism to facilitate hypertrophy of cardiomyocytes. In this study, we used a dietary, in vivo isotope labeling approach to examine how exercise training influences the metabolic fate of carbon derived from dietary glucose in the heart during acute, active, and established phases of exercise-induced cardiac growth. Male and female FVB/NJ mice were subjected to treadmill running for up to 4 weeks and cardiac growth was assessed by gravimetry. Cardiac metabolic responses to exercise were assessed via in vivo tracing of [13C6]-glucose via mass spectrometry and nuclear magnetic resonance. We found that the half-maximal cardiac growth response was achieved by approximately 1 week of daily exercise training, with near maximal growth observed in male mice with 2 weeks of training; however, female mice were recalcitrant to exercise-induced cardiac growth and required a higher daily intensity of exercise training to achieve significant, albeit modest, increases in cardiac mass. We also found that increases in the energy charge of adenylate and guanylate nucleotide pools precede exercise-induced changes in cardiac size and were associated with higher glucose tracer enrichment in the TCA pool and in amino acids (aspartate, glutamate) sourced by TCA intermediates. Our data also indicate that the activity of collateral biosynthetic pathways of glucose metabolism may not be markedly altered by exercise. Overall, this study provides evidence that metabolic remodeling in the form of heightened energy charge and increased TCA cycle activity and cataplerosis precedes cardiac growth caused by exercise training in male mice.

Molecular insights into the lipid-carbohydrates metabolism switch under the endurance effort in Arabian horses

BACKGROUND

Recent studies have shown that in Arabian horse muscle, long-term exercise-induced expression of genes related to fatty acid degradation and the downregulation of genes belonging to the glycolysis/gluconeogenesis and insulin signalling pathways. Long-lasting physical exertion may trigger the metabolism to switch the main energy source from carbohydrates to lipids due to higher caloric content.

OBJECTIVES

To describe the metabolism adaptation at the whole transcriptome of blood to endurance effort in Arabian horses.

STUDY DESIGN

In vivo experiment.

METHODS

Venous blood samples from 10 Arabian horses were taken before and after a 120 km long endurance ride to isolate the RNA and perform the high-throughput NGS transcriptome sequencing.

RESULTS

The results, including KEGG (Kyoto Encyclopaedia of Genes and Genomes) and GO (Gene Ontology) analyses, allowed us to describe the most significantly upregulated-ARV1, DGAT2, LIPE, APOA2, MOGAT1, MOGAT2, GYS1, GYS2 and downregulated-ACACA, ACACB, FADS1, FADS2 genes involved in carbohydrate and lipid metabolism. Also, the increased expression of RAF1, KRAS and NRAS genes involved in the Insulin pathway and PI3K-Akt was shown.

MAIN LIMITATIONS

Limited sample size, Arabians used for endurance racing were not compared to Arabians from other equestrian disciplines.

CONCLUSIONS

This general insight into the processes described supports the thesis of the lipid-carbohydrates metabolism switch in endurance Arabian horses and provides the basis for further research.

Cardiac mitochondrial metabolism during pregnancy and the postpartum period

The goal of the present study was to characterize changes in mitochondrial respiration in the maternal heart during pregnancy and after birth. Timed pregnancy studies were performed in 12-wk-old female FVB/NJ mice, and cardiac mitochondria were isolated from the following groups of mice: nonpregnant (NP), midpregnancy (MP), late pregnancy (LP), and 1-wk postbirth (PB). Similar to our previous studies, we observed increased heart size during all stages of pregnancy (e.g., MP and LP) and postbirth (e.g., PB) compared with NP mice. Differential cardiac gene and protein expression analyses revealed changes in several mitochondrial transcripts at LP and PB, including several mitochondrial complex subunits and members of the Slc family, important for mitochondrial substrate transport. Respirometry revealed that pyruvate- and glutamate-supported state 3 respiration was significantly higher in PB vs. LP mitochondria, with respiratory control ratio (RCR) values higher in PB mitochondria. In addition, we found that PB mitochondria respired more avidly when given 3-hydroxybutyrate (3-OHB) than mitochondria from NP, MP, and LP hearts, with no differences in RCR. These increases in respiration in PB hearts occurred independent of changes in mitochondrial yield but were associated with higher abundance of 3-hydroxybutyrate dehydrogenase 1. Collectively, these findings suggest that, after birth, maternal cardiac mitochondria have an increased capacity to use 3-OHB, pyruvate, and glutamate as energy sources; however, increases in mitochondrial efficiency in the postpartum heart appear limited to carbohydrate and amino acid metabolism.NEW & NOTEWORTHY Few studies have detailed the physiological adaptations that occur in the maternal heart. We and others have shown that pregnancy-induced cardiac growth is associated with significant changes in cardiac metabolism. Here, we examined mitochondrial respiration and substrate preference in isolated mitochondria from the maternal heart. We show that following birth, cardiac mitochondria are "primed" to respire on carbohydrate, amino acid, and ketone bodies. However, heightened respiratory efficiency is observed only with carbohydrate and amino acid sources. These results suggest that significant changes in mitochondrial respiration occur in the maternal heart in the postpartum period.

Cardiac macrophage metabolism in health and disease

Cardiac macrophages are essential mediators of cardiac development, tissue homeostasis, and response to injury. Cell-intrinsic shifts in metabolism and availability of metabolites regulate macrophage function. The human and mouse heart contain a heterogeneous compilation of cardiac macrophages that are derived from at least two distinct lineages. In this review, we detail the unique functional roles and metabolic profiles of tissue-resident and monocyte-derived cardiac macrophages during embryonic development and adult tissue homeostasis and in response to pathologic and physiologic stressors. We discuss the metabolic preferences of each macrophage lineage and how metabolism influences monocyte fate specification. Finally, we highlight the contribution of cardiac macrophages and derived metabolites on cell-cell communication, metabolic health, and disease pathogenesis.

Leisure time physical activity is associated with improved diastolic heart function and is partly mediated by unsupervised quantified metabolic health

Objectives

To investigate the association between leisure time physical activity (LTPA) and MRI-based diastolic function and the mediating role of metabolic health.

Methods

This cross-sectional analysis comprised 901 participants (46% women, mean age (SD): 56 (6) years (The Netherlands, 2008-2012)). LTPA was assessed via questionnaire, quantified in metabolic equivalent of tasks (METs)-minutes per week and participants underwent abdominal and cardiovascular MRI. Confirmatory factor analysis was used to construct the metabolic load factor. Piecewise structural equation model with adjustments for confounders was used to determine associations between LTPA and diastolic function and the mediating effect of metabolic load.

Results

Significant differences in mitral early/late peak filling rate (E/A) ratio per SD of LTPA (men=1999, women=1870 MET-min/week) of 0.18, (95% CI= 0.03 to 0.33, p=0.021) were observed in men, but not in women: -0.01 (-0.01 to 0.34, p=0.058). Difference in deceleration time of mitral early filling (E-DT) was 0.13 (0.01 to 0.24, p=0.030) in men and 0.17 (0.05 to 0.28, p=0.005) in women. Metabolic load, including MRI-based visceral and subcutaneous adipose tissue, fasting glucose, high-density lipoprotein cholesterol and triglycerides, mediated these associations as follows: E/A-ratio of 0.030 (0.000 to 0.067, 19% mediated, p=0.047) in men but not in women: 0.058 (0.027 to 0.089, p<0.001) and E-DT not in men 0.004 (-0.012 to 0.021, p=0.602) but did in women 0.044 (0.013 to 0.057, 27% mediated, p=0.006).

Conclusions

A larger amount of LTPA was associated with improved diastolic function where confirmatory factor analysis-based metabolic load partly mediated this effect. Future studies should assess whether improving indicators of metabolic load alongside LTPA will benefit healthy diastolic function even more.

Molecular regulators of exercise-mediated insulin sensitivity in non-obese individuals

Insulin resistance is a significant contributor to the development of type 2 diabetes (T2D) and is associated with obesity, physical inactivity, and low maximal oxygen uptake. While intense and prolonged exercise may have negative effects, physical activity can have a positive influence on cellular metabolism and the immune system. Moderate exercise has been shown to reduce oxidative stress and improve antioxidant status, whereas intense exercise can increase oxidative stress in the short term. The impact of exercise on pro-inflammatory cytokine production is complex and varies depending on intensity and duration. Exercise can also counteract the harmful effects of ageing and inflamm-ageing. This review aims to examine the molecular pathways altered by exercise in non-obese individuals at higher risk of developing T2D, including glucose utilization, lipid metabolism, mitochondrial function, inflammation and oxidative stress, with the potential to improve insulin sensitivity. The focus is on understanding the potential benefits of exercise for improving insulin sensitivity and providing insights for future targeted interventions before onset of disease.

Influence of isometric versus isotonic exercise training on right ventricular morpho-functional parameters in Olympic athletes

BACKGROUND

Cardiovascular adaptations in elite athletes involve both ventricular and atrial changes. Nowadays, limited research exists on right ventricular (RV) remodeling, particularly in female athletes and across different types of exercise training.

METHODS

Our study evaluated 370 athletes (61% males) participated at 2020 Tokyo and 2022 Beijing Olympic Games. Athletes were categorized according to main type of exercise into isometric and isotonic. Comprehensive echocardiographic assessments were conducted to analyze RV morpho-functional parameters, comparing genders and different sporting exercise.

RESULTS

Significant differences in RV parameters were observed based on exercise type and gender. Isotonic athletes showed greater RV remodeling with larger RV outflow tract (15.1 ± 2.1 vs. 14.5 ± 1.7 mm, p < .0001) end-diastolic and end-systolic area (respectively, 24.6 ± 5.5 vs. 21.7 ± 5 mm, p < .000 and 11.7 ± 3.2 vs. 10.1 ± 2.8 mm, p < .0001) and right atrium size (11.7 ± 3.2 vs. 10.2 ± 2.3 mm2 , p = .0001). Functional parameters, such as TDI velocities, were similar between groups. Males showed larger RV area and right atrium size (p < .0001) and lower RV TDI velocities with reduced E' (15.4 ± 2.9 vs. 16.1 ± 3.2 m/s in females, p = .031), resulting in lower E'/A' ratio (1.69 ± .6 vs. 1.84 ± .6 m/s, p = .021), while S' was lower females (14.6 ± 2.3 vs. 14.1 ± 2.4 m/s, p = .041). RV TDI velocities were similar in isotonic and isometric both in male and females.

CONCLUSIONS

In elite athletes, RV morphological changes are influenced by exercise modality but do not translate into functional differences. Female athletes present distinct RV functional profiles, with lower S' velocities and a higher E'/A' ratio. Functional RV TDI parameters are not affected by the typology of exercise practiced.

Exercise and Nutrition Interventions for Prehabilitation in Hepato-Pancreato-Biliary Cancers: A Narrative Review

Gastrointestinal (GI) cancers constitute over 25% of global cancer cases annually, with hepato-pancreato-biliary (HPB) cancers presenting particularly poor prognosis and challenging surgical treatments. While advancements in clinical care have improved post-operative outcomes over time, surgery for HPB cancers remains associated with high morbidity and mortality rates. Patients with HPB cancer are often older, diagnosed at later stages, and have a higher prevalence of co-morbid conditions, leading to reduced life expectancy, suboptimal post-operative recovery, and increased recurrence risk. Exercise and nutrition interventions have emerged as safe non-pharmacological strategies to enhance clinical outcomes among cancer survivors, but their potential in the pre-operative period for patients with HPB cancer remains underexplored. This narrative review evaluates existing evidence on exercise and nutritional interventions during pre-operative prehabilitation for HPB cancer populations, focusing on clinically relevant post-operative outcomes related to frailty and malnutrition. We conducted a literature search in PubMed and Google Scholar databases to identify studies utilizing a prehabilitation intervention in HPB cancer populations with exercise and nutritional components. The currently available evidence suggests that incorporating exercise and nutrition into prehabilitation programs offers a critical opportunity to enhance post-operative outcomes, mitigate the risk of comorbidities, and support overall survivorship among HPB cancer populations. This review underscores the need for further research to optimize the timing, duration, and components of pre-operative prehabilitation programs, emphasizing patient-centered, multidisciplinary approaches in this evolving field.

Social Determinants of Health, Chronic Disease Management, and the Role of the Primary Care Provider-to Include Cardiovascular Disease, Cancer, Diabetes, Major Causes of Morbidity and Mortality as Affected by Social Determinants of Health

Despite advances in health science and medical technology, health outcomes continue to fall behind in certain communities. A recent study linking health outcomes to zip code may explain part of this disparity, social determinants of health. Although well known that patients in resource-poor environments have worse outcomes than patients with advantages, the exact reason for this disparity may not be so well known. This article aims to explore the physiologic basis for worsening disease states in patients with poor social determinants of health, as well as start a discussion surrounding possible screening and interventions that can be performed in a primary care office to promote patient health.

Targeting mitochondrial shape: at the heart of cardioprotection

There remains an unmet need to identify novel therapeutic strategies capable of protecting the myocardium against the detrimental effects of acute ischemia-reperfusion injury (IRI), to reduce myocardial infarct (MI) size and prevent the onset of heart failure (HF) following acute myocardial infarction (AMI). In this regard, perturbations in mitochondrial morphology with an imbalance in mitochondrial fusion and fission can disrupt mitochondrial metabolism, calcium homeostasis, and reactive oxygen species production, factors which are all known to be critical determinants of cardiomyocyte death following acute myocardial IRI. As such, therapeutic approaches directed at preserving the morphology and functionality of mitochondria may provide an important strategy for cardioprotection. In this article, we provide an overview of the alterations in mitochondrial morphology which occur in response to acute myocardial IRI, and highlight the emerging therapeutic strategies for targeting mitochondrial shape to preserve mitochondrial function which have the future therapeutic potential to improve health outcomes in patients presenting with AMI.

Sex-specific cytotoxicity of ostarine in cardiomyocytes

Ostarine is the most popular compound in the selective androgen receptor modulator group (SARMs). Ostarine is used as a physical performance-enhancing agent. The abuse of this agent in higher doses may lead to severe side effects. Here, we evaluate the effects of ostarine on the heart. We utilized a cardiomyocyte H9C2 cell line, isolated primary female and male cardiac fibroblast cells, as well as hearts obtained from rats. Ostarine increased the accumulation of two fibrosis protein markers, αSMA and fibronectin (p < 00.1) in male, but not in female fibroblast cells. Ostarine increased the expression of the cardiomyopathy marker βMhc in the H9C2 cell line (p < 0.05) and in the heart in rats (p < 0.01). The unfavorable changes were observed at high ostarine doses. Moreover, a decrease in viability and an increase in cytotoxicity marker LDH were observed already at lowest dose (1 nmoL/l). Taken together, our results suggest that ostarine is cardiotoxic which may be more relevant in males than in females.

Coordinated Metabolic Responses Facilitate Cardiac Growth in Pregnancy and Exercise

PURPOSE OF REVIEW

Pregnancy and exercise are systemic stressors that promote physiological growth of the heart in response to repetitive volume overload and maintenance of cardiac output. This type of remodeling is distinct from pathological hypertrophy and involves different metabolic mechanisms that facilitate growth; however, it remains unclear how metabolic changes in the heart facilitate growth and if these processes are similar in both pregnancy- and exercise-induced cardiac growth.

RECENT FINDINGS

The ability of the heart to metabolize a myriad of substrates balances cardiac demands for energy provision and anabolism. During pregnancy, coordination of hormonal status with cardiac reductions in glucose oxidation appears important for physiological growth. During exercise, a reduction in cardiac glucose oxidation also appears important for physiological growth, which could facilitate shuttling of glucose-derived carbons into biosynthetic pathways for growth. Understanding the metabolic underpinnings of physiological cardiac growth could provide insight to optimize cardiovascular health and prevent deleterious remodeling, such as that which occurs from postpartum cardiomyopathy and heart failure. This short review highlights the metabolic mechanisms known to facilitate pregnancy-induced and exercise-induced cardiac growth, both of which require changes in cardiac glucose metabolism for the promotion of growth. In addition, we mention important similarities and differences of physiological cardiac growth in these models as well as discuss current limitations in our understanding of metabolic changes that facilitate growth.

Physical Activity Over the Lifecourse and Cardiovascular Disease

Despite improvements in cardiovascular care in recent decades, cardiovascular disease (CVD) remains a leading cause of death worldwide. At its core, CVD is a largely preventable disease with diligent risk factor management and early detection. As highlighted in the American Heart Association's Life's Essential 8, physical activity plays a central role in CVD prevention at an individual and population level. Despite pervasive knowledge of the numerous cardiovascular and noncardiovascular health benefits of physical activity, physical activity has steadily decreased over time and unfavorable changes in physical activity occur throughout people's lives. Here, we use a lifecourse framework to examine the evidence reporting on the association of physical activity with CVD. From in utero to older adults, we review and discuss the evidence detailing how physical activity may prevent incident CVD and mitigate CVD-related morbidity and death across all life stages.

Cardiovascular Disease and Exercise: From Molecular Mechanisms to Clinical Applications

Inactivity is a significant risk factor for cardiovascular disease. Exercise may greatly enhance the metabolism and function of the cardiovascular system, lower several risk factors, and prevent the development and treatment of cardiovascular disease while delivering easy, physical, and emotional enjoyment. Exercise regulates the cardiovascular system by reducing oxidative stress and chronic inflammation, regulating cardiovascular insulin sensitivity and the body's metabolism, promoting stem cell mobilization, strengthening autophagy and myocardial mitochondrial function, and enhancing cardiovascular damage resistance, among other effects. Appropriate exercise intervention has become an essential adjuvant therapy in clinical practice for treating and rehabilitating various cardiovascular diseases. However, the prescription of exercise for preventing and treating cardiovascular diseases, particularly the precise selection of individual exercise techniques and their volume, remains controversial. Using multiomics to explain further the molecular process underlying the positive effects of exercise on cardiovascular health will not only improve our understanding of the effects of exercise on health but also establish a scientific basis and supply new ideas for preventing and treating cardiovascular diseases by activating the endogenous protective mechanisms of the body and suggesting more specific exercise prescriptions for cardiovascular rehabilitation.

A remarkable adaptive paradigm of heart performance and protection emerges in response to marked cardiac-specific overexpression of ADCY8

Adult (3 month) mice with cardiac-specific overexpression of adenylyl cyclase (AC) type VIII (TGAC8) adapt to an increased cAMP-induced cardiac workload (~30% increases in heart rate, ejection fraction and cardiac output) for up to a year without signs of heart failure or excessive mortality. Here, we show classical cardiac hypertrophy markers were absent in TGAC8, and that total left ventricular (LV) mass was not increased: a reduced LV cavity volume in TGAC8 was encased by thicker LV walls harboring an increased number of small cardiac myocytes, and a network of small interstitial proliferative non-cardiac myocytes compared to wild type (WT) littermates; Protein synthesis, proteosome activity, and autophagy were enhanced in TGAC8 vs WT, and Nrf-2, Hsp90α, and ACC2 protein levels were increased. Despite increased energy demands in vivo LV ATP and phosphocreatine levels in TGAC8 did not differ from WT. Unbiased omics analyses identified more than 2,000 transcripts and proteins, comprising a broad array of biological processes across multiple cellular compartments, which differed by genotype; compared to WT, in TGAC8 there was a shift from fatty acid oxidation to aerobic glycolysis in the context of increased utilization of the pentose phosphate shunt and nucleotide synthesis. Thus, marked overexpression of AC8 engages complex, coordinate adaptation "circuity" that has evolved in mammalian cells to defend against stress that threatens health or life (elements of which have already been shown to be central to cardiac ischemic pre-conditioning and exercise endurance cardiac conditioning) that may be of biological significance to allow for proper healing in disease states such as infarction or failure of the heart.

Preoperative exercise and prehabilitation

PURPOSE OF REVIEW

The purpose of this narrative review is to give an overview about the effects of multimodal prehabilitation and current existing and prospectively planned studies. The potential efficacy of exercise in the context of prehabilitation ranges from preoperatively improving patients' functional capacity to inducing cellular mechanisms that affect organ perfusion via endothelial regeneration, anti-inflammatory processes and tumour defense.

RECENT FINDINGS

Current studies show that prehabilitation is capable of reducing certain postoperative complications and length of hospital stay in certain patient populations. These findings are based on small to mid-size trials with large heterogeneity, lacking generalizability and evidence that prehabilitation has positive effects on long term survival.

SUMMARY

The concept of prehabilitation contains the features, namely preoperative exercise, nutritional intervention and psychological support. Preoperative exercise holds potential molecular effects that can be utilized in the perioperative period in order to improve patients' postoperative outcome. Future multimodal prehabilitation trials must specifically clarify the clinical impact of this concept on patients' quality of life after major cancer surgery and cancer-specific survival.

Move more and sit less pilot intervention for individuals with heart failure

BACKGROUND

Higher physical activity (PA) and lower sedentary behavior (SB) have been independently associated with lower risk of Heart Failure (HF). However, few individuals with HF engage in sufficient PA to confer benefits and many engage in high amounts of SB. This this feasibility study was conducted to examine changes in steps/day and SB in response to a tailored move more and sit less intervention.

METHODS

This study used a single group, pre-post study design to assess changes in steps/day, inactive time, and time in moderate- to vigorous-intensity physical activity in individuals with HF stage C and D. Participants completed 1-week baseline assessment and an 11-week intervention. GEE Poisson model was used to evaluate the effect of intervention on change in PA and SB. RESULTS AND TRANSLATIONAL CONCLUSIONS. Thirteen participants with an average age of 69 ± 13 years that had been living with heart failure for 5.5 ± 4.2 years completed this intervention study. Average steps per day increased significantly over the intervention from 4778 steps/day at baseline to 5518 steps/day post-intervention. Time spent sedentary did not change. Move more and sit less interventions that include behavioral change techniques such as immediate feedback on steps can result in changes in walking behavior. Further strategies for reducing SB in this population should be explored.

Influence of biological sex and exercise on murine cardiac metabolism

Although the structural and functional effects of exercise on the heart are well established, the metabolic changes that occur in the heart during and after exercise remain unclear. In this study, we used metabolomics to assess time-dependent changes in the murine cardiac metabolome following 1 session of treadmill exercise. After the exercise bout, we also recorded blood lactate, glucose, and ketone body levels and measured cardiac mitochondrial respiration. In both male and female mice, moderate- and high-intensity exercise acutely increased blood lactate levels. In both sexes, low- and moderate-intensity exercise augmented circulating 3-hydroxybutryrate levels immediately after the exercise bout; however, only in female mice did high-intensity exercise increase 3-hydroxybutyrate levels, with significant increases occurring 1 h after the exercise session. Untargeted metabolomics analyses of sedentary female and male hearts suggest considerable sex-dependent differences in basal cardiac metabolite levels, with female hearts characterized by higher levels of pantothenate, pyridoxamine, homoarginine, tryptophan, and several glycerophospholipid and sphingomyelin species and lower levels of numerous metabolites, including acetyl coenzyme A, glucuronate, gulonate, hydroxyproline, prolyl-hydroxyproline, carnosine, anserine, and carnitinylated and glycinated species, as compared with male hearts. Immediately after a bout of treadmill exercise, both male and female hearts had higher levels of corticosterone; however, female mice showed more extensive exercise-induced changes in the cardiac metabolome, characterized by significant, time-dependent changes in amino acids (e.g., serine, alanine, tyrosine, tryptophan, branched-chain amino acids) and the ketone body 3-hydroxybutyrate. Results from experiments using isolated cardiac mitochondria suggest that high-intensity treadmill exercise does not acutely affect respiration or mitochondrial coupling; however, female cardiac mitochondria demonstrate generally higher adenosine diphosphate sensitivity compared with male cardiac mitochondria. Collectively, these findings in mice reveal key sex-dependent differences in cardiac metabolism and suggest that the metabolic network in the female heart is more responsive to physiological stress caused by exercise.

Metabolic Signatures of Pregnancy-Induced Cardiac Growth

The goal of this study was to develop an atlas of the metabolic, transcriptional, and proteomic changes that occur with pregnancy in the maternal heart. Timed pregnancy studies in FVB/NJ mice revealed significant increases in heart size by day 8 of pregnancy (mid-pregnancy; MP), which was sustained throughout the rest of the term compared with non-pregnant controls. Cardiac hypertrophy and myocyte cross-sectional area were highest 7 d after birth (post-birth; PB) and were associated with significant increases in end-diastolic and end-systolic left ventricular volumes and cardiac output. Metabolomics analyses revealed that, by day 16 of pregnancy (late pregnancy; LP), metabolites associated with nitric oxide production as well as acylcholines, sphingomyelins, and fatty acid species were elevated, which coincided with a lower activation state of phosphofructokinase and higher levels of pyruvate dehydrogenase kinase 4 (Pdk4). In the postpartum period, urea cycle metabolites, polyamines, and phospholipid levels were markedly elevated in the maternal heart. Cardiac transcriptomics in LP revealed significant increases in not only Pdk4, but also genes that regulate glutamate and ketone body oxidation, which were preceded in MP by higher expression of transcripts controlling cell proliferation and angiogenesis. Proteomics analysis of the maternal heart in LP and PB revealed significant reductions in several contractile filaments and mitochondrial complex subunits. Collectively, these findings describe the coordinated molecular changes that occur in the maternal heart during and after pregnancy.

Exercise Enhances Branched-Chain Amino Acid Catabolism and Decreases Cardiac Vulnerability to Myocardial Ischemic Injury

Long-term exercise-induced metabolic adaptations occupy a central position in exercise-afforded cardiac benefits. Emerging evidence suggests that branched-chain amino acid (BCAA) catabolic defect contributes to cardiac dysfunction in multiple cardiometabolic diseases. However, the role of BCAA catabolism in exercise-afforded cardiac benefits remains unknown. Here, we show that exercise improves BCAA catabolism and thus reduce cardiac vulnerability to myocardial ischemic injury. Exercise increased circulating BCAA levels in both humans (male adolescent athletes) and mice (following an 8-week swimming intervention). It increased the expression of mitochondrial localized 2C-type serine-threonine protein phosphatase (PP2Cm), a key enzyme in regulating BCAA catabolism, and decreased BCAA accumulation in mouse hearts, indicating an increase in BCAA catabolism. Pharmacological promotion of BCAA catabolism protected the mouse heart against myocardial infarction (MI) induced by permanent ligation of the left descending coronary artery. Although cardiac-specific PP2Cm knockout showed no significant effects on cardiac structural and functional adaptations to exercise, it blunted the cardioprotective effects of exercise against MI. Mechanistically, exercise alleviated BCAA accumulation and subsequently inactivated the mammalian target of rapamycin in MI hearts. These results showed that exercise elevated BCAA catabolism and protected the heart against myocardial ischemic injury, reinforcing the role of exercise in the promotion of cardiac health.

Lactate modulates cardiac gene expression in mice during acute physical exercise

The aim of the present study was to verify the role of lactate as a signaling molecule in cardiac tissue under physiological conditions. C57BL6/J male mice were submitted to acute running bouts on a treadmill at different exercise intensities (30, 60, and 90% of maximal speed - Smax) under the effect of two doses (0.5 and 5 mM) of α-cyano-4-hydroxycynnamate (CINN), a blocker of lactate transporters. Cardiac lactate levels, activity of the enzymes of glycolytic [hexokinase (HK) and lactate dehydrogenase (LDH)] and oxidative metabolism [citrate synthase (CS)], and expression of genes also related to metabolism [LDH, nuclear factor erythroid 2-related factor 2 (NRF-2), cytochrome oxidase IV (COX-IV), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α)] were evaluated. Elevated cardiac lactate levels were observed after high intensity running at 90% of Smax, which were parallel to increased activity of the HK and CS enzymes and mRNA levels of PGC-1α and COX-IV. No changes were observed in cardiac lactate levels in mice running at lower exercise intensities. Interestingly, prior intraperitoneal administration (15 min) of CINN (0.5 mM) significantly reduced cardiac lactate concentration, activities of HK and CS, and mRNA levels of PGC-1α and COX-IV in mice that ran at 90% of Smax. In addition, cardiac lactate levels were significantly correlated to both PGC-1α and COX-IV cardiac gene expression. The present study provides evidence that cardiac lactate levels are associated to gene transcription during an acute bout of high intensity running exercise.

Exercise Training after Myocardial Infarction Attenuates Dysfunctional Ventricular Remodeling and Promotes Cardiac Recovery

Recent evidences have shown that exercise training not only plays a necessary role in maintaining cardiac homeostasis, but also promotes cardiac repair after myocardial infarction. Post-myocardial infarction, exercise training has been observed to effectively increase the maximum cardiac output, and protect myocardial cells against necrosis and apoptosis, thus leading to an improved quality of life of myocardial infarction patients. In fact, exercise training has received more attention as an adjunct therapeutic strategy for both treatment and prevention of myocardial infarction. This review summarizes the experimental evidence of the effects of exercise training in ventricular remodeling after myocardial infarction, and tries to provide theoretical basis along with suitable references for the exercise prescription aimed at prevention and therapy of myocardial infarction.

State of Knowledge on Molecular Adaptations to Exercise in Humans: Historical Perspectives and Future Directions

For centuries, regular exercise has been acknowledged as a potent stimulus to promote, maintain, and restore healthy functioning of nearly every physiological system of the human body. With advancing understanding of the complexity of human physiology, continually evolving methodological possibilities, and an increasingly dire public health situation, the study of exercise as a preventative or therapeutic treatment has never been more interdisciplinary, or more impactful. During the early stages of the NIH Common Fund Molecular Transducers of Physical Activity Consortium (MoTrPAC) Initiative, the field is well-positioned to build substantially upon the existing understanding of the mechanisms underlying benefits associated with exercise. Thus, we present a comprehensive body of the knowledge detailing the current literature basis surrounding the molecular adaptations to exercise in humans to provide a view of the state of the field at this critical juncture, as well as a resource for scientists bringing external expertise to the field of exercise physiology. In reviewing current literature related to molecular and cellular processes underlying exercise-induced benefits and adaptations, we also draw attention to existing knowledge gaps warranting continued research effort. © 2021 American Physiological Society. Compr Physiol 12:3193-3279, 2022.

The Role of Exercise-Induced Molecular Processes and Vitamin D in Improving Cardiorespiratory Fitness and Cardiac Rehabilitation in Patients With Heart Failure

Heart failure (HF) still affects millions of people worldwide despite great advances in therapeutic approaches in the cardiovascular field. Remarkably, unlike pathological hypertrophy, exercise leads to beneficial cardiac hypertrophy characterized by normal or enhanced contractile function. Exercise-based cardiac rehabilitation improves cardiorespiratory fitness and, as a consequence, ameliorates the quality of life of patients with HF. Particularly, multiple studies demonstrated the improvement in left ventricular ejection fraction (LVEF) among patients with HF due to the various processes in the myocardium triggered by exercise. Exercise stimulates IGF-1/PI3K/Akt pathway activation involved in muscle growth in both the myocardium and skeletal muscle by regulating protein synthesis and catabolism. Also, physical activity stimulates the activation of the mitogen-activated protein kinase (MAPK) pathway which regulates cellular proliferation, differentiation and apoptosis. In addition, emerging data pointed out the anti-inflammatory effects of exercises as well. Therefore, it is of utmost importance for clinicians to accurately evaluate the patient’s condition by performing a cardiopulmonary exercise test and/or a 6-min walking test. Portable devices with the possibility to measure exercise capacity proved to be very useful in this setting as well. The aim of this review is to gather together the molecular processes triggered by the exercise and available therapies in HF settings that could ameliorate heart performance, with a special focus on strategies such as exercise-based cardiac rehabilitation.

Exercise Training Combined with Calanus Oil Supplementation Improves the Central Cardiodynamic Function in Older Women

The aim of this study was to investigate the possible beneficial effects of exercise training (ET) with omega-3/Calanus oil supplementation on cardiorespiratory and adiposity parameters in elderly women. Fifty-five women (BMI: 19–37 kg/m², 62–80 years old) were recruited and randomly assigned to the 4 month intervention with ET and omega-3 supplementation (Calanus oil, ET-Calanus) or ET and the placebo (sunflower oil; ET-Placebo). The body composition was determined by dual-energy X-ray absorptiometry (DXA), and cardiorespiratory parameters were measured using spiroergometry and PhysioFlow hemodynamic testing. Both interventions resulted in an increased lean mass whereas the fat mass was reduced in the leg and trunk as well as the android and gynoid regions. The content of trunk fat (in percent of the total fat) was lower and the content of the leg fat was higher in the ET-Calanus group compared with the ET-Placebo. Although both interventions resulted in similar improvements in cardiorespiratory fitness (VO_2max), it was explained by an increased peripheral oxygen extraction (a-vO₂diff) alone in the ET-Placebo group whereas increased values of both a-vO₂diff and maximal cardiac output (CO_max) were observed in the ET-Calanus group. Changes in CO_max were associated with changes in systemic vascular resistance, circulating free fatty acids, and the omega-3 index. In conclusion, Calanus oil supplementation during a 4 month ET intervention in elderly women improved the cardiorespiratory function, which was due to combined central and peripheral cardiodynamic mechanisms.

Cardiac assessments of bottlenose dolphins (Tursiops truncatus) in the Northern Gulf of Mexico following exposure to Deepwater Horizon oil

The Deepwater Horizon (DWH) oil spill profoundly impacted the health of bottlenose dolphins (Tursiops truncatus) in Barataria Bay, LA (BB). To comprehensively assess the cardiac health of dolphins living within the DWH oil spill footprint, techniques for in-water cardiac evaluation were refined with dolphins cared for by the U.S. Navy Marine Mammal Program in 2018 and applied to free-ranging bottlenose dolphins in BB (n = 34) and Sarasota Bay, Florida (SB) (n = 19), a non-oiled reference population. Cardiac auscultation detected systolic murmurs in the majority of dolphins from both sites (88% BB, 89% SB) and echocardiography showed most of the murmurs were innocent flow murmurs attributed to elevated blood flow velocity [1]. Telemetric six-lead electrocardiography detected arrhythmias in BB dolphins (43%) and SB dolphins (31%), all of which were considered low to moderate risk for adverse cardiac events. Echocardiography showed BB dolphins had thinner left ventricular walls, with significant differences in intraventricular septum thickness at the end of diastole (p = 0.002), and left ventricular posterior wall thickness at the end of diastole (p = 0.033). BB dolphins also had smaller left atrial size (p = 0.004), higher prevalence of tricuspid valve prolapse (p = 0.003), higher prevalence of tricuspid valve thickening (p = 0.033), and higher prevalence of aortic valve thickening (p = 0.008). Two dolphins in BB were diagnosed with pulmonary arterial hypertension based on Doppler echocardiography-derived estimates and supporting echocardiographic findings. Histopathology of dolphins who stranded within the DWH oil spill footprint showed a significantly higher prevalence of myocardial fibrosis (p = 0.003), regardless of age, compared to dolphins outside the oil spill footprint. In conclusion, there were substantial cardiac abnormalities identified in BB dolphins which may be related to DWH oil exposure, however, future work is needed to rule out other hypotheses and further elucidate the connection between oil exposure, pulmonary disease, and the observed cardiac abnormalities.

Exercise improves vascular health: Role of mitochondria

Vascular mitochondria constantly integrate signals from environment and respond accordingly to match vascular function to metabolic requirements of the organ tissues, while mitochondrial dysfunction contributes to vascular aging and pathologies such as atherosclerosis, stenosis, and hypertension. As an effective lifestyle intervention, exercise induces extensive mitochondrial adaptations through vascular mechanical stress and the increased production and release of reactive oxygen species and nitric oxide that activate multiple intracellular signaling pathways, among which peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) plays a critical role. PGC-1α coordinates mitochondrial quality control mechanisms to maintain a healthy mitochondrial pool and promote endothelial nitric oxide synthase activity in vasculature. The mitochondrial adaptations to exercise improve bioenergetics, balance redox status, protect endothelial cells against detrimental insults, increase vascular plasticity, and ameliorate aging-related vascular dysfunction, thus benefiting vascular health. This review highlights recent findings of mitochondria as a central hub integrating exercise-afforded vascular benefits and its underlying mechanisms. A better understanding of the mitochondrial adaptations to exercise will not only shed light on the mechanisms of exercise-induced cardiovascular protection, but may also provide new clues to mitochondria-oriented precise exercise prescriptions for cardiovascular health.

Physical Exercise Promotes a Reduction in Cardiac Fibrosis in the Chronic Indeterminate Form of Experimental Chagas Disease

Chagas disease (CD), caused by the protozoan Trypanosoma cruzi, is a neglected tropical disease and a health problem in Latin America. Etiological treatment has limited effectiveness in chronic CD; thus, new therapeutic strategies are required. The practice of physical exercises has been widely advocated to improve the quality of life of CD patients. The most frequent clinical CD manifestation is the chronic indeterminate form (CIF), and the effect of physical exercises on disease progression remains unknown. Here, in a CIF model, we aimed to evaluate the effect of physical exercises on cardiac histological, parasitological, mitochondrial, and oxidative metabolism, electro and echocardiographic profiles, and immunological features. To establish a CIF model, BALB/c and C57BL/6 mice were infected with 100 and 500 trypomastigotes of the Y T. cruzi strain. At 120 days postinfection (dpi), all mouse groups showed normal PR and corrected QT intervals and QRS complexes. Compared to BALB/c mice, C57BL/6 mice showed a lower parasitemia peak, mortality rate, and less intense myocarditis. Thus, C57BL/6 mice infected with 500 parasites were used for subsequent analyses. At 120 dpi, a decrease in cardiac mitochondrial oxygen consumption and an increase in reactive oxygen species (ROS) were detected. When we increased the number of analyzed mice, a reduced heart rate and slightly prolonged corrected QT intervals were detected, at 120 and 150 dpi, which were then normalized at 180 dpi, thus characterizing the CIF. Y-infected mice were subjected to an exercise program on a treadmill for 4 weeks (from 150 to 180 dpi), five times per week in a 30–60-min daily training session. At 180 dpi, no alterations were detected in cardiac mitochondrial and oxidative metabolism, which were not affected by physical exercises, although ROS production increased. At 120 and 180 dpi, comparing infected and non-infected mice, no differences were observed in the levels of plasma cytokines, indicating that a crucial biomarker of the systemic inflammatory profile was absent and not affected by exercise. Compared with sedentary mice, trained Y-infected mice showed similar parasite loads and inflammatory cells but reduced cardiac fibrosis. Therefore, our data show that physical exercises promote beneficial changes that may prevent CD progression.

Exercise training in heart transplantation

Heart transplantation remains the gold standard in the treatment of end-stage heart failure (HF). Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service. Impaired vascular function and diastolic dysfunction cause lower cardiac output while decreased skeletal muscle oxidative fibers, enzymes and capillarity cause arteriovenous oxygen difference, leading thus to decreased peak oxygen uptake in heart transplant recipients. Exercise training improves exercise capacity, cardiac and vascular endothelial function in heart transplant recipients. Pre-rehabilitation regular aerobic or combined exercise is beneficial for patients with end-stage HF awaiting heart transplantation in order to maintain a higher fitness level and reduce complications afterwards like intensive care unit acquired weakness or cardiac cachexia. All hospitalized patients after heart transplantation should be referred to early mobilization of skeletal muscles through kinesiotherapy of the upper and lower limbs and respiratory physiotherapy in order to prevent infections of the respiratory system prior to hospital discharge. Moreover, all heart transplant recipients after hospital discharge who have not already participated in an early cardiac rehabilitation program should be referred to a rehabilitation center by their health care provider. Although high intensity interval training seems to have more benefits than moderate intensity continuous training, especially in stable transplant patients, individualized training based on the abilities and needs of each patient still remains the most appropriate approach. Cardiac rehabilitation appears to be safe in heart transplant patients. However, long-term follow-up data is incomplete and, therefore, further high quality and adequately-powered studies are needed to demonstrate the long-term benefits of exercise training in this population.