Endurance training: is it bad for you?

Primary Care Considerations for the Pediatric Endurance Athlete

PURPOSE OF REVIEW

This study aimed to provide an overview of some of the medical concerns surrounding the care of the pediatric endurance athletes and add to the limited literature specific to the pediatric endurance athlete.

RECENT FINDINGS

Endurance athletes are at risk for overtraining, relative energy deficiency in sport (RED-S), overuse injuries, nutritional deficiencies, and sleep dysfunction. Youth runners and female endurance athletes are particularly high-risk populations for RED-S; nutritional deficiencies and their care should involve thoughtful mitigation of modifiable risk factors. The growing endurance athlete may experience slightly different cardiac adaptations than the adult endurance athlete with the long-term implications of these changes still unclear. Endurance sports are common among youth athletes. Multidisciplinary care that includes screening and early intervention for high-risk areas is critical to optimize their care and promote, safe lifelong sport participation.

The acute effects of endurance exercise on epithelial integrity of the airways in athletes and non-athletes: A systematic review and meta-analysis

INTRODUCTION

Acute endurance exercise may induce airway epithelium injury. However, the response of epithelial integrity markers of the airways including club cell secretory protein (CC16) and surfactant protein D (SP-D) to endurance exercise have not been systematically reviewed. Therefore, the aim of this systematic review and meta-analysis was to assess the acute effects of endurance exercise on markers of epithelial integrity of the airways (CC16, SP-D and the CC16/SP-D ratio) in athletes and non-athletes.

METHODS

A systematic search was performed utilizing PubMed/Medline, EMBASE, Web of Science, and hand searching bibliographies of retrieved articles through to September 2022. Based on the inclusion criteria, articles with available data about the acute effects of endurance exercise on serum or plasma concentrations of CC16, SP-D and CC16/SP-D ratio in athletes and non-athletes were included. Quality assessment of studies and statistical analysis were conducted via Review Manager 5.4 software.

RESULTS

The search resulted in 908 publications. Finally, thirteen articles were included in the review. Acute endurance exercise resulted in an increase in CC16 (P = 0.0006, n = 13) and CC16/SP-D ratio (P = 0.005, n = 2) whereas SP-D (P = 0.47, n = 3) did not change significantly. Subgroup analysis revealed that the type (P = 0.003), but not the duration of exercise (P = 0.77) or the environmental temperature (P = 0.06) affected the CC16 response to endurance exercise.

CONCLUSIONS

Acute endurance exercise increases CC16 and the CC16/SP-D ratio, as markers of epithelial integrity, but not SP-D in athletes and non-athletes.

Comparing metabolic profiles between female endurance athletes and non-athletes reveals differences in androgen and corticosteroid levels

Endurance training is associated with physiological changes in elite athletes, but little is known about female-specific effects of endurance training. Despite the significant rise in female sports participation, findings from studies performed on male athletes are largely extrapolated to females without taking into consideration sex-specific differences in metabolism. Subsequently, this study aimed to investigate the steroid hormone profiles of elite female endurance athletes in comparison with their non-athletic counterparts. Untargeted metabolomics-based mass spectroscopy combined with ultra-high-performance liquid chromatography was performed on serum samples from 51 elite female endurance athletes and 197 non-athletic females. The results showed that, compared to non-athletic females, certain androgen, pregnenolone, and progestin steroid hormones were reduced in elite female endurance athletes, while corticosteroids were elevated. The most significantly altered steroid hormones were 5alpha-androstan-3alpha,17alpha-diol monosulfate (FDR = 1.90 × 10^-05), androstenediol (3alpha, 17alpha) monosulfate (FDR = 2.93 × 10^-04), and cortisol (FDR = 2.93 × 10^-04). Conclusively, the present study suggests that elite female endurance athletes have a unique steroid hormone profile with implications on their general health and performance.

Physical Activity, Yoga, and Exercise Prescription for Postpartum and Midlife Weight Management: A Practical Review for Clinicians

This narrative review is aimed to practically review and evaluate the existing evidence and illuminate the effectiveness of physical activity, yoga, and exercise for postpartum and midlife weight management. A comprehensive review was conducted using electronic databases such as PubMed and google scholar using search terms physical activity, exercise, yoga, postpartum, midlife, weight loss, weight reduction, and all the probable terms. This helped in generating evidence-based information and formulating practical physical activity prescriptions to be used by obstetricians, general clinicians, nutritionists, and other allied healthcare personnel. Overweight and obesity in postpartum and midlife women present long-term health risks and complications. Indulging in optimum physical activity comprising exercise and yoga will help in weight management, increasing muscular strength, and endurance thus improving overall health and well-being.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13224-022-01627-w.

The lasting effects of resistance and endurance exercise interventions on breast cancer patient mental wellbeing and physical fitness

Breast cancer is a persisting global burden for health services with cases and deaths projected to rise in future years. Surgery complemented by adjuvant therapy is commonly used to treat breast cancer, however comes with detrimental side effects to physical fitness and mental wellbeing. The aim of this systematic review and meta-analysis is to determine whether resistance and endurance interventions performed during adjuvant treatment can lastingly ameliorate these side effects. A systematic literature search was performed in various electronic databases. Papers were assessed for bias and grouped based on intervention design. RStudio was used to perform the meta-analyses for each group using the ‘meta’ package. Publication bias and power analyses were also conducted. These methods conform to PRISMA guidelines. Combined resistance and endurance interventions elicited significant long-lasting improvements in global fatigue and were beneficial to the remaining side effects. Individually, resistance and endurance interventions non-significantly improved these side effects. Resistance interventions elicited higher benefits overall. Exercise interventions have lasting clinical benefits in ameliorating adjuvant therapy side effects, which negatively impact physical fitness and mental wellbeing. These interventions are of clinical value to enhance adherence rates and avoid comorbidities such as sarcopenia, thus improving disease prognosis.

The protective role of exercise against age-related neurodegeneration

Endurance exercise is a widely accessible, low-cost intervention with a variety of benefits to multiple organ systems. Exercise improves multiple indices of physical performance and stimulates pronounced health benefits reducing a range of pathologies including metabolic, cardiovascular, and neurodegenerative disorders. Endurance exercise delays brain aging, preserves memory and cognition, and improves symptoms of neurodegenerative pathologies like Amyotrophic Lateral Sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and various ataxias. Potential mechanisms underlying the beneficial effects of exercise include neuronal survival and plasticity, neurogenesis, epigenetic modifications, angiogenesis, autophagy, and the synthesis and release of neurotrophins and cytokines. In this review, we discuss shared benefits and molecular pathways driving the protective effects of endurance exercise on various neurodegenerative diseases in animal models and in humans.

Exercise duration modulates upper and lower respiratory fluid cellularity, antiviral activity, and lung gene expression

Exercise has substantial health benefits, but the effects of exercise on immune status and susceptibility to respiratory infections are less clear. Furthermore, there is limited research examining the effects of prolonged exercise on local respiratory immunity and antiviral activity. To assess the upper respiratory tract in response to exercise, we collected nasal lavage fluid (NALF) from human subjects (1) at rest, (2) after 45 min of moderate-intensity exercise, and (3) after 180 min of moderate-intensity exercise. To assess immune responses of the lower respiratory tract, we utilized a murine model to examine the effect of exercise duration on bronchoalveolar lavage (BAL) fluid immune cell content and lung gene expression. NALF cell counts did not change after 45 min of exercise, whereas 180 min significantly increased total cells and leukocytes in NALF. Importantly, fold change in NALF leukocytes correlated with the post-exercise fatigue rating in the 180-min exercise condition. The acellular portion of NALF contained strong antiviral activity against Influenza A in both resting and exercise paradigms. In mice undergoing moderate-intensity exercise, BAL total cells and neutrophils decreased in response to 45 or 90 min of exercise. In lung lobes, increased expression of heat shock proteins suggested that cellular stress occurred in response to exercise. However, a broad upregulation of inflammatory genes was not observed, even at 180 min of exercise. This work demonstrates that exercise duration differentially alters the cellularity of respiratory tract fluids, antiviral activity, and gene expression. These changes in local mucosal immunity may influence resistance to respiratory viruses, including influenza or possibly other pathogens in which nasal mucosa plays a protective role, such as rhinovirus or SARS-CoV-2.

Characterizing Marathon-Induced Metabolic Changes Using 1H-NMR Metabolomics

Although physical activity is a health-promoting, popular global pastime, regular engagement in strenuous exercises, such as long-distance endurance running races, has been associated with a variety of detrimental physiological and immunological health effects. The resulting altered physiological state has previously been associated with fluctuations in various key metabolite concentrations; however, limited literature exists pertaining to the global/holistic metabolic changes that are induced by such. This investigation subsequently aims at elucidating the metabolic changes induced by a marathon by employing an untargeted proton nuclear magnetic resonance (¹H-NMR) spectrometry metabolomics approach. A principal component analysis (PCA) plot revealed a natural differentiation between pre- and post-marathon metabolic profiles of the 30-athlete cohort, where 17 metabolite fluctuations were deemed to be statistically significant. These included reduced concentrations of various amino acids (AA) along with elevated concentrations of ketone bodies, glycolysis, tricarboxylic acid (TCA) cycle, and AA catabolism intermediates. Moreover, elevated concentrations of creatinine and creatine in the post-marathon group supports previous findings of marathon-induced muscle damage. Collectively, the results of this investigation characterize the strenuous metabolic load induced by a marathon and the consequential regulation of main energy-producing pathways to accommodate this, and a better description of the cause of the physiological changes seen after the completion of a marathon.

Effect of Exercise on Fatigue in Multiple Sclerosis Patients: A Network Meta-analysis

Few studies have directly compared the effects of different exercise therapies on reducing fatigue in patients with multiple sclerosis. Thus, we conducted a Frequentist network meta-analysis to analyze and compare the effectiveness of different types of exercise on reducing multiple sclerosis-related fatigue. Relevant randomized controlled trials were searched in PubMed, Web of Science and Cochrane Library databases from the date of their inception up to April 1, 2021. In total, 27 articles involving 1470 participants and 10 types of interventions met the inclusion criteria. The results indicated that aquatic exercise ranked as the most effective among these interventions, and aerobic exercise had small-to-moderate effect sizes. Most of the interventions were shown to be better than the control group, except for climbing. Climbing was the only intervention that ranked worse than the controls. All of these findings merit further investigation in future clinical trials.

Type of Physical Training and Selected Aspects of Psychological Functioning of Women with Obesity: A Randomised Trial

Objective: We conducted a prospective randomised trial to assess whether a specific type of regular physical training performed by women with obesity is related to obtaining specific psychological benefits. Methods: Forty-four women qualified for the study and were divided into two groups. The applied intervention consisted of regular three-month physical exercises in the form of endurance training (group A) or endurance strength training (group B). Initially, and after the completed intervention, we examined anthropometric measurements and the level of: stress (PSS-10), general self-esteem (SES), body self-report (BSQ–34, FRS), and behaviours associated with diet (TFEQ-18). Results: As a result of the intervention, both groups had significantly lower anthropometric parameters and FRS scores with regard to the current figure (gr. A:δ FRS CS −0.90 ± 0.83, p < 0.001; gr. B:δ FRS CS −0.41 ± 0.50, p = 0.01) and BSQ–34 results (gr. A:δ BSQ–34 −14.90 ± 13.5, p = 0.001; gr. B:δ BSQ–34 − 18.64 ± 25.4, p = 0.01). Additionally, an increase in cognitive restraint (δ TFEQ–18 CR1.65 ± 2.06, p = 0.01) and a decrease in emotional eating (δ TFEQ–18 EE −0.82 ± 1.28, p = 0.01) were observed in group B. There were no between-group differences in terms of the magnitude of changes achieved due to the intervention, except for asignificant improvement in the perception of their current figure (FRS) (δ FRSCS −0.90 ± 0.83, p = 0.03) in group A. Conclusions: Regular physical activity over a three-month period by women with obesity promotes the perception of their own body as slimmer and lowers body shape concerns. The change in body shape perception was more pronounced under the influence of endurance training than endurance strength training. Trial registration: ClinicalTrials.gov ID NCT04793451.

The effects of dietary nitrate supplementation on endurance exercise performance and cardiorespiratory measures in healthy adults: a systematic review and meta-analysis

BACKGROUND

Nitrate supplementation is thought to improve performance in endurance sports.

OBJECTIVE

To meta-analyze studies evaluating the effect of nitrate supplementation on endurance sports performance among adults.

DATA SOURCES

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science and CINAHL without language restrictions.

METHODS

We included studies that: 1) compared nitrate supplementation with placebo; 2) enrolled adults engaging in an endurance-based activity; and 3) reported a performance measure or surrogate physiologic outcome. We evaluated risk of bias using the Cochrane Collaboration tool and pooled data with a random-effects model. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to evaluate confidence in estimates.

RESULTS

We included 73 studies (n = 1061). Nitrate supplementation improved power output (MD 4.6 watts, P < 0.0001), time to exhaustion (MD 25.3 s, P < 0.00001), and distance travelled (MD 163.7 m, P = 0.03). We found no significant difference on perceived exertion, time trial performance and work done. Nitrate supplementation decreased VO₂ (MD - 0.04 L/min, P < 0.00001) but had no significant effect on VO_2max or blood lactate levels.

CONCLUSION

The available evidence suggests that dietary nitrate supplementation benefits performance-related outcomes for endurance sports.

Comparison of High-Intensity Training Versus Moderate-Intensity Continuous Training on Cardiorespiratory Fitness and Body Fat Percentage in Persons With Overweight or Obesity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

High-intensity training is comprised of sprint interval training (SIT) and high-intensity interval training (HIIT). This study compared high-intensity training with moderate-intensity continuous training (MICT) on cardiorespiratory fitness (CRF) and body fat percentage for overweight or obese persons.

METHODS

A systematic search of randomized controlled trials using the health science databases occurred up to April, 2020. Twenty-six studies were included for complete analysis. A total of 784 participations were analyzed. The unstandardized mean difference for each outcome measurement was extracted from the studies and pooled with the random effects model.

RESULTS

MICT was significantly better at improving CRF compared with SIT (mean difference = -0.92; 95% confidence interval, -1.63 to -0.21; P = .01; I2 = 10%). Furthermore, there was no significant difference between MICT versus HIIT on CRF (mean difference = -0.52; 95% confidence interval, -1.18 to 0.13; P = .12; I2 = 23%). There was no significant difference in body fat percentage between MICT versus HIIT and MICT versus SIT.

CONCLUSIONS

MICT was significantly better at improving CRF than SIT in overweight or obese persons.

Lower extremity compression garments use by athletes: why, how often, and perceived benefit

Background

Studies on the benefits of lower extremity compression garments (CGs) have focused on their effects on post-exercise recovery and performance improvement. Less is known about why athletes actually use CGs, the frequency with which they use them, and perceived benefits from using CGs. The purpose of this study was to investigate which athletes use CGs, why athletes use CGs, when CGs are worn by athletes, and, in case of an injury or injury prevention, for which injuries CGs are used.

Methods

This cross-sectional study involved 512 athletes who used lower extremity CGs. Athletes completed a questionnaire on the type of CGs they used, and when and why they used them. They also reported their sports participation, past and current sports injuries, and the perceived benefits of using CGs.

Results

88.1% (n=451) of the athletes were endurance athletes and 11.9% (n=61) were non-endurance athletes. Endurance and non-endurance athletes reported running (84.7%, n=382) and obstacle course racing (24.6%, n=15) the most frequently as primary sports, respectively. The most-used CG was the compression sock (59.2%, n=303). In total, 47.5% (n=246) of the athletes used a CG primarily to prevent re-injury and 14.5% (n=74) to reduce symptoms of a current sports injury. Other primary reported aims were primary prevention (13.6%), post-exercise recovery (14.3%), sports performance improvement (8.8%), and to look good (0.2%). The point prevalence of past and current sports injuries among all athletes was 84.2 and 20.2%, respectively. The most common current sports injuries were shin and calf injuries. Many athletes “always” or “often” used their CGs during training (56.8%, n=279) and competitions (72.9%, n=264). Furthermore, almost 90% of the athletes that aimed to prevent re-injury by using CGs reported that CGs contributed to secondary injury prevention.

Conclusion

88% of the CG-users were endurance athletes, of which 85% were runners. All athletes mainly used CGs to prevent injury recurrence, but also to reduce symptoms of a current sports injury. A majority of the athletes reported positive perceived effects from the CGs. CGs were used more during than after sports participation.

Prevalence of disordered eating in athletes categorized by emphasis on leanness and activity type - a systematic review

BACKGROUND

Disordered Eating (DE) shows a strong association with athletics and can lead to several negative mental and physical health effects. Traditionally, sports have been grouped based upon whether or not the sport emphasizes leanness as a competing factor. Due to sociocultural factors, risk for DE may also be associated with the sport type. The aim of this review is to critically analyze the available research and data in this field to consider the relationship between DE and sport type to see which factors influence prevalence among athletes.

METHOD

A systematic review was completed using keywords specific to DE and sport types. Articles were either excluded due to lack of specification of athlete type or failure to use a standardized screening tool or interview for data collection.

RESULTS

6 out of 7 studies found a significant increase in DE rates among lean sport types. When classifying by sport type reports were less consistent, but show non-lean sports also have increased rates of DE.

CONCLUSION

There are variations in prevalence of DE behaviors depending on athlete type. It is important to identify the risk for DE early in athletes so emphasis can be placed on treatment options to nullify progression to an eating disorder, lower negative impacts on an athlete's performance, and prevent other negative health effects. Using sport groups is important to clinical practice as well as research, as certain sports may have a higher risk for development of DE.

Development of Novel Continuous and Interval Exercise Programs by Applying the FITT-VP Principle in Dogs

Although proper exercise training induces positive physiological effects, improper exercise can lead to injury, fatigue, and poor performance. The frequency, intensity, time/duration, type, volume, and progression (FITT-VP) are the essential components of exercise training to maintain or improve physical fitness and health. The purpose of this study was to develop specific exercise programs by applying the FITT-VP principle and to examine the effects on heart rate (HR) and hematological and biochemical parameters in dogs. The healthy male Beagles (n = 4) included in this study performed continuous and interval exercises, comprising 12 protocols. The HR monitoring elicited an affirmative response to activities but varied depending on the protocols. The hematologic parameters (e.g., red blood cell count, white blood cell count, hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration) were within the reference ranges both before and after exercise. The creatine kinase level significantly increased, and the cholesterol level decreased after exercises. In conclusion, the continuous and interval exercise program elicits an appropriate HR reaction, has no adverse effects on the serum parameters, and provides valuable insight for healthcare in dogs.

Health Benefits of Endurance Training: Implications of the Brain-Derived Neurotrophic Factor-A Systematic Review

This article presents a concept that wide expression of brain-derived neurotrophic factor (BDNF) and its receptors (TrkB) in the nervous tissue, evoked by regular endurance training (ET), can cause numerous motor and metabolic adaptations, which are beneficial for human health. The relationships between the training-evoked increase of endogenous BDNF and molecular and/or physiological adaptations in the nervous structures controlling both motor performance and homeostasis of the whole organism have been presented. Due to a very wide range of plastic changes that ET has exerted on various systems of the body, the improvement of motor skills and counteraction of the development of civilization diseases resulting from the posttraining increase of BDNF/TrkB levels have been discussed, as important for people, who undertake ET. Thus, this report presents the influence of endurance exercises on the (1) transformation of motoneuron properties, which are a final element of the motor pathways, (2) reduction of motor deficits evoked by Parkinson disease, and (3) prevention of the metabolic syndrome (MetS). This review suggests that the increase of posttraining levels of BDNF and its TrkB receptors causes simultaneous changes in the activity of the spinal cord, the substantia nigra, and the hypothalamic nuclei neurons, which are responsible for the alteration of the functional properties of motoneurons innervating the skeletal muscles, for the enhancement of dopamine release in the brain, and for the modulation of hormone levels involved in regulating the metabolic processes, responsively. Finally, training-evoked increase of the BDNF/TrkB leads to a change in a manner of regulation of skeletal muscles, causes a reduction of motor deficits observed in the Parkinson disease, and lowers weight, glucose level, and blood pressure, which accompany the MetS. Therefore, BDNF seems to be the molecular factor of pleiotropic activity, important in the modulation processes, underlying adaptations, which result from ET.

Rewiring the Addicted Brain Through a Psychobiological Model of Physical Exercise

Drug addiction is a worldwide public health problem, resulting from multiple phenomena, including those both social and biological. Chronic use of psychoactive substances has been shown to induce structural and functional changes in the brain that impair cognitive control and favor compulsive seeking behavior. Physical exercise has been proven to improve brain function and cognition in both healthy and clinical populations. While some studies have demonstrated the potential benefits of physical exercise in treating and preventing addictive behaviors, few studies have investigated its cognitive and neurobiological contributions to drug-addicted brains. Here, we review studies in humans using cognitive behavioral responses and neuroimaging techniques, which reveal that exercise can be an effective auxiliary treatment for drug addictive disorders. Moreover, we describe the neurobiological mechanisms by which exercise-induced neuroplasticity in the prefrontal cortex improves executive functions and may decrease compulsive behaviors in individuals prone to substance use disorders. Finally, we propose an integrative cognitive-psychobiological model of exercise for use in future research in drug addiction and practical guidance in clinical settings.

Influence of physical exercise on microRNAs in skeletal muscle regeneration, aging and diseases

Skeletal muscle is a dynamic tissue with remarkable plasticity and its growth and regeneration are highly organized, with the activation of specific transcription factors, proliferative pathways and cytokines. The decline of skeletal muscle tissue with age, is one of the most important causes of functional loss of independence in older adults. Maintaining skeletal muscle function throughout the lifespan is a prerequisite for good health and independent living.

Physical activity represents one of the most effective preventive agents for muscle decay in aging.

Several studies have underlined the importance of microRNAs (miRNAs) in the control of myogenesis and of skeletal muscle regeneration and function.

In this review, we reported an overview and recent advances about the role of miRNAs expressed in the skeletal muscle, miRNAs regulation by exercise in skeletal muscle, the consequences of different physical exercise training modalities in the skeletal muscle miRNA profile, their regulation under pathological conditions and the role of miRNAs in age-related muscle wasting.

Specific miRNAs appear to be involved in response to different types of exercise and therefore to play an important role in muscle fiber identity and myofiber gene expression in adults and elder population.

Understanding the roles and regulation of skeletal muscle miRNAs during muscle regeneration may result in new therapeutic approaches in aging or diseases with impaired muscle function or re-growth.