Physiological Function during Exercise and Environmental Stress in Humans-An Integrative View of Body Systems and Homeostasis

The effectiveness of the Copenhagen adduction exercise on improving eccentric hip adduction strength among soccer players with groin injury: a randomized controlled trial

INTRODUCTION

Groin injuries are common in soccer players and often involve adductor muscle strains. The Copenhagen Adduction Exercise (CAE) is a targeted intervention whose effectiveness in rehabilitation for these injuries warrants investigation.

OBJECTIVE

To investigate the impact of a rehabilitation program, which includes the CAE, on eccentric hip adduction (EHAD) strength, hip joint range of motion (ROM), self-reported disability, and pain among soccer players with adductor-related groin pain. It was hypothesized that the addition of CAE to the rehabilitation program would yield greater improvements.

METHODS

Employing a randomized controlled trial with a two-group parallel design, thirty male soccer players with a mean age of 26.4 ± 3.9 years were randomized into an intervention group (IG) including CAE (n = 15) and a control group (CG) without CAE (n = 15), based on a power analysis to ensure 80% power to detect significant differences. Both groups engaged in their respective rehabilitation programs twice a week for eight weeks. The primary outcome measured was EHAD strength, while secondary outcomes included hip joint ROM, self-reported disability measured by the Copenhagen Hip and Groin Outcome Score (HAGOS), and pain levels.

RESULTS

Significant improvements within groups were observed across all measures (p < 0.001). The IG demonstrated a greater increase in EHAD strength (Mean Difference [MD] = 0.49 Nm/kg, 95% Confidence Interval [CI] [0.31, 0.66]), a more pronounced reduction in pain (MD = -1.60, 95% CI [-2.18, -1.02]), and betterment in all HAGOS subscale scores compared to the CG. There were no significant between-group differences in hip joint ROM.

CONCLUSION

Incorporating the CAE into rehabilitation programs significantly improves EHAD strength, decreases pain scores, and reduces self-reported disability in soccer players with adductor-related groin pain.

REGISTRATION

ClinicalTrials.gov identifier: NCT05589623.

The Impact of Starting Positions and Breathing Rhythms on Cardiopulmonary Stress and Post-Exercise Oxygen Consumption after High-Intensity Metabolic Training: A Randomized Crossover Prospective Study

Background: The exploration of optimizing cardiopulmonary function and athletic performance through high-intensity metabolic exercises (HIMEs) is paramount in sports science. Despite the acknowledged efficacy of HIMEs in enhancing cardiopulmonary endurance, the high metabolic stress imposed on the cardiopulmonary system, especially for amateurs, necessitates a scaled approach to training. Objective: The aim of this study is to ascertain whether adjustments in the initiation posture and the adoption of an appropriate breathing strategy can effectively mitigate the cardiopulmonary stress induced by HIMEs without compromising training efficacy. Methods: Twenty-two subjects were recruited into this study. The post-exercise heart rate (PHR) and post-exercise oxygen consumption rate (POCR) were collected within 30 min after exercise. A two-way ANOVA, multi-variable Cox regression, and random survival forest machine learning algorithm were used to conduct the statistical analysis. Results: Under free breathing, only the maximum POCR differed significantly between standing and prone positions, with prone positions showing higher stress (mean difference = 3.15, p < 0.001). In contrast, the regulated breathing rhythm enhanced performance outcomes compared to free breathing regardless of the starting position. Specifically, exercises initiated from prone positions under regulated breathing recorded a significantly higher maximum and average PHR than those from standing positions (maximum PHR: mean difference = 13.40, p < 0.001; average PHR: mean difference = 6.45, p < 0.001). The multi-variable Cox regression highlighted the starting position as a critical factor influencing the PHR and breathing rhythm as a significant factor for the POCR, with respective variable importances confirmed by the random survival forest analysis. These results underscore the importance of controlled breathing and starting positions in optimizing HIME outcomes. Conclusions: Regulated breathing in high-intensity exercises enhances performance and physiological functions, emphasizing the importance of breathing rhythm over starting position. Effective training should balance exercise volume and technique to optimize performance and minimize stress, reducing overtraining and injury risks.

Is Micronutrient Supplementation Helpful in Supporting the Immune System during Prolonged, High-Intensity Physical Training?

It is well known that during prolonged, high-intensity physical training, athletes experience a state of immunosuppression and that balanced nutrition can help maintain immunity. This review summarizes the effects (amplified by virus infection) of high-intensity, long-term exercise on immunity, critically presenting key micronutrients and supplementation strategies that can influence athletes' performance and their immune system. The main conclusion is that micronutrient supplementation with diet could help to protect the immune system from the stress effects induced by intense physical activities. The importance of personalized supplementation has been also recommended.

What stops us and what motivates us? A scoping review and bibliometric analysis of barriers and facilitators to physical activity

INTRODUCTION

Physical inactivity is a major global health concern, contributing to the rising non-communicable disease burden. Elucidating barriers and facilitators influencing participation is critical to promoting activity. This study aimed to synthesize the literature and analyze the extent of research on determinants of physical activity engagement.

METHODS

Scoping review methodology guided the synthesis of 272 publications on factors influencing physical activity. Bibliometric analysis examined publication trends, productivity, influential studies, content themes, and collaboration networks.

RESULTS

Since 2010, the United States has led a significant increase in research output. Highly cited articles identified physiological limitations and psychosocial determinants as key barriers and facilitators. Extensive focus was seen in clinical medicine and exercise science journals. Analysis revealed predominant attention to psychosocial factors, physiological responses, and applications in respiratory disease. Gaps remain regarding policy and environmental factors.

CONCLUSION

This review showed major advances in elucidating determinants while revealing the remaining needs to curb the pandemic of inactivity globally. Expanding international collaboration, contemporary theoretical models, and tailored mixed-methods approaches could promote progress through greater global participation. Addressing knowledge gaps across populations and disciplines should be a priority.

A century of exercise physiology: key concepts in neural control of the circulation

Early in the twentieth century, Walter B. Cannon (1871-1945) introduced his overarching hypothesis of "homeostasis" (Cannon 1932)-the ability to sustain physiological values within a narrow range necessary for life during periods of stress. Physical exercise represents a stress in which motor, respiratory and cardiovascular systems must be integrated across a range of metabolic stress to match oxygen delivery to oxygen need at the cellular level, together with appropriate thermoregulatory control, blood pressure adjustments and energy provision. Of these, blood pressure regulation is a complex but controlled variable, being the function of cardiac output and vascular resistance (or conductance). Key in understanding blood pressure control during exercise is the coordinating role of the autonomic nervous system. A long history outlines the development of these concepts and how they are integrated within the exercise context. This review focuses on the renaissance observations and thinking generated in the first three decades of the twentieth century that opened the doorway to new concepts of inquiry in cardiovascular regulation during exercise. The concepts addressed here include the following: (1) exercise and blood pressure, (2) central command, (3) neurovascular transduction with emphasis on the sympathetic nerve activity and the vascular end organ response, and (4) tonic neurovascular integration.

Impact of stress on male fertility: role of gonadotropin inhibitory hormone

Studies have implicated oxidative stress-sensitive signaling in the pathogenesis of stress-induced male infertility. However, apart from oxidative stress, gonadotropin inhibitory hormone (GnIH) plays a major role. The present study provides a detailed review of the role of GnIH in stress-induced male infertility. Available evidence-based data revealed that GnIH enhances the release of corticosteroids by activating the hypothalamic-pituitary-adrenal axis. GnIH also mediates the inhibition of the conversion of thyroxine (T4) to triiodothyronine (T3) by suppressing the hypothalamic-pituitary-thyroidal axis. In addition, GnIH inhibits gonadotropin-releasing hormone (GnRH), thus suppressing the hypothalamic-pituitary-testicular axis, and by extension testosterone biosynthesis. More so, GnIH inhibits kisspeptin release. These events distort testicular histoarchitecture, impair testicular and adrenal steroidogenesis, lower spermatogenesis, and deteriorate sperm quality and function. In conclusion, GnIH, via multiple mechanisms, plays a key role in stress-induced male infertility. Suppression of GnIH under stressful conditions may thus be a beneficial prophylactic and/or therapeutic strategy.

The healing effects of moderate exercise on acetic acid-induced gastric ulcer in male rats

Aim

This study aimed to evaluate the effect of moderate exercise on the healing of acetic acid-induced gastric ulcers in male rats.

Background

Gastric ulcers include benign mucosal and submucosal lesions of the gastric wall. Exercise regulates a wide range of physiological processes.

Methods

48 male Wistar rats were randomly divided into three experimental groups (n=16 per group) as follows: control, which was left untreated after causing stomach ulcers; experimental group 1, the rats were first exercised and then received acetic acid; experimental group 2, the rats received acetic acid, and then exercised. The ulcer was caused by injecting 0.12 ml of a 60% acetic acid solution after 24 hours of not eating. The rats had a period of moderate treadmill activity either before or after the development of ulcers, lasting for a duration of 30 days. On the seventh and fourteenth days after the experiment, the rats were sacrificed, their stomach was removed, and the wound healing parameters, and wound depth were determined.

Results

Exercise before and after inducing gastric ulcers significantly decreased the depth of gastric ulcers in the experimental groups. The average number of PMN in the control group decreased in comparison to the seventh and fourteenth days following the experiment. Conversely, the number of fibroblasts, epithelialization, and new vessels increased. It seems that exercise before the appearance of ulcers has a greater effect on gastric ulcers compared to exercise after inducing gastric ulcers.

Conclusion

Exercise can prepare the gastric mucosa for forthcoming injuries, and heal gastric ulcers. Moderate aerobic exercise has significant restorative effects on gastric ulcers caused by acetic acid and is recommended.

The heart, a secondary organ in the control of blood circulation

Circulation of the blood is a fundamental physiological function traditionally ascribed to the pressure-generating function of the heart. However, over the past century the 'cardiocentric' view has been challenged by August Krogh, Ernst Starling, Arthur Guyton and others, based on haemodynamic data obtained from isolated heart preparations and organ perfusion. Their research brought forth experimental evidence and phenomenological observations supporting the concept that cardiac output occurs primarily in response to the metabolic demands of the tissues. The basic tenets of Guyton's venous return model are presented and juxtaposed with their critiques. Developmental biology of the cardiovascular system shows that the blood circulates before the heart has achieved functional integrity and that its movement is intricately connected with the metabolic demands of the tissues. Long discovered, but as yet overlooked, negative interstitial pressure may play a role in assisting the flow returning to the heart. Based on these phenomena, an alternative circulation model has been proposed in which the heart functions like a hydraulic ram and maintains a dynamic equilibrium between the arterial (centrifugal) and venous (centripetal) forces which define the blood's circular movement. In this focused review we introduce some of the salient arguments in support of the proposed circulation model. Finally, we present evidence that exercising muscle blood flow is subject to local metabolic control which upholds optimal perfusion in the face of a substantive rise in muscle vascular conductance, thus lending further support to the permissive role of the heart in the overall control of blood circulation.

The Effect of Exercise on Pulsatility Index of Uterine Arteries and Pain in Primary Dysmenorrhea

BACKGROUND

Primary dysmenorrhea (PD) is one of the most common diseases in women of reproductive age. Our aim was to examine whether a twice-weekly thirty-minute exercise intervention could result in a difference in the pulsatility index (PI) of the uterine arteries (UAs) and level of menstrual pain in patients with PD.

METHODS

In our prospective observational trial, the observation period included one spontaneous menstrual cycle and the consecutive time of the next menstruation of all participants, aged 18-44, with no extensive sports experience. In total, 73 volunteers were enrolled: 38 persons in the intervention group (IG) and 35 in the control group (CG). The intervention program was accompanied by music, performed in groups under the supervision of a qualified instructor in Hungary. The primary outcome was the difference between the IG and CG regarding the PI values of UAs at the 1st and the 2nd ultrasound (US) Doppler flowmetry. The secondary outcome was the difference between the IG and CG regarding the PI of UAs and menstrual pain measured by using the Numeric Rating Scale and adherence to the intervention. Statistical tests such as an independent-samples t-test, chi-square test, Mann-Whitney test and analysis of covariance (ANCOVA) were used during the analyses.

RESULTS

Examining the mean of the PI of UAs in the IG and the CG at the 1st and the 2nd US measurement, a significant difference was found in the change in the measured value (Z = -2.545; p = 0.011). The IG showed a significantly higher increase in the mean of the PI of UAs (Median = 0.825) than the CG (Median = 0.130). The difference in the PI of the UAs of the IG and the CG is not related to the level of pain in any group (p = 0.336) and not related to the whole sample (p = 0.354); furthermore, the level of pain did not significantly differ between the two groups.

CONCLUSIONS

Our study is the first to document the significant effects of mild-to-moderate exercise training on the change in the PI of the UAs in individuals with PD. The IG had a reduced blood flow due to circulatory redistribution after exercise. The level of menstrual pain of primary dysmenorrhea patients is independent of the level of blood circulation regarding the PI of the UAs. Randomized controlled studies with more participants and a longer research period are needed to confirm our findings regarding the association between regular exercise and the PI of UAs. The study was registered at clinicaltrials.gov: NCT04618172.

The change of attention network functions and physiological adaptation during high-altitude hypoxia and reoxygenation

Previous studies have not reached a definitive conclusion regarding the effect of high-altitude hypoxia and reoxygenation on attention. To clarify the influence of altitude and exposure time on attention and the relations between physiological activity and attention, we conducted a longitudinal study to track attention network functions in 26 college students. The scores on the attention network test and physiological data, including heart rate, percutaneous arterial oxygen saturation (SpO₂), blood pressure, and vital capacity in pulmonary function measurement, were collected at five time-points: two weeks before arriving at high altitude (baseline), within 3 days after arriving at high altitude (HA3), 21 days after arriving at high altitude (HA21), 7 days after returning to sea level (POST7) and 30 days after returning to sea level (POST30). The alerting scores at POST30 were significantly higher than those at baseline, HA3 and HA21; the orienting scores at HA3 were lower than those at POST7 and POST30; the executive control scores at POST7 were significantly lower than those at baseline, HA3, HA21, and POST30; and the executive control scores at HA3 were significantly higher than those at POST30. The change in SpO₂ during high-altitude acclimatization (from HA3 to HA21) was positively correlated with the orienting score at HA21. Vital capacity changes during acute deacclimatization positively correlated with orienting scores at POST7. Attention network functions at the behavioral level did not decline after acute hypoxia exposure compared with baseline. Attention network functions after returning to sea level were improved compared with those during acute hypoxia; additionally, alerting and executive function scores were improved compared with those at baseline. Thus, the speed of physiological adaptation could facilitate the recovery of orienting function during acclimatization and deacclimatization.

Innate Immunity in Cardiovascular Diseases-Identification of Novel Molecular Players and Targets

During the past few years, unexpected developments have driven studies in the field of clinical immunology. One driver of immense impact was the outbreak of a pandemic caused by the novel virus SARS-CoV-2. Excellent recent reviews address diverse aspects of immunological re-search into cardiovascular diseases. Here, we specifically focus on selected studies taking advantage of advanced state-of-the-art molecular genetic methods ranging from genome-wide epi/transcriptome mapping and variant scanning to optogenetics and chemogenetics. First, we discuss the emerging clinical relevance of advanced diagnostics for cardiovascular diseases, including those associated with COVID-19-with a focus on the role of inflammation in cardiomyopathies and arrhythmias. Second, we consider newly identified immunological interactions at organ and system levels which affect cardiovascular pathogenesis. Thus, studies into immune influences arising from the intestinal system are moving towards therapeutic exploitation. Further, powerful new research tools have enabled novel insight into brain-immune system interactions at unprecedented resolution. This latter line of investigation emphasizes the strength of influence of emotional stress-acting through defined brain regions-upon viral and cardiovascular disorders. Several challenges need to be overcome before the full impact of these far-reaching new findings will hit the clinical arena.

The synergistic effect of physical activity and nutrition to improve the quality of life in breast cancer patients: a systemic review

PURPOSE

Medical recommendations for balanced control of exercise, physical activity, and nutritional intake after breast cancer diagnosis remain unclear. Therefore, this review aims to summarize effective exercise methods and dietary opinions by reviewing clinical trial results.

METHODS

We systematically reviewed studies that evaluated 1) the relationship between exercise methods and quality of life improvement in patients with breast cancer and 2) the recommendations for physical activity, exercise, nutrition, and potential ways to improve life after breast cancer. To conduct this literature review, we searched the PubMed database for articles published until October 1, 2022, using the terms "physical activity OR exercise," "breast cancer," and "nutrition." After a primary review of the retrieved articles, we included clinical trials in this systematic review.

RESULTS

We hypothesized that physical activity improves the quality of life after the onset of breast cancer, suggesting that a balanced approach to aerobic exercise and resistance exercise increases the efficacy of anticancer treatment. From a nutritional point of view, it is recommended that both physical activity and diet management are necessary for patients with breast cancer.

CONCLUSION

Customized exercise and diet can help with weight loss, the reduction of cancer-induced fatigue, the regulation of hormonal changes, the reduction of inflammatory factors, and the improvement of mental health and vitality. Understanding the integrated mechanisms of physical activity and nutritional balance will improve the quality of life of patients with breast cancer. Therefore, it is necessary to continuously advance exercise programs and develop an alimentary balance control program.

Exertional heat stroke: pathophysiology and risk factors

Exertional heat stroke, the third leading cause of mortality in athletes during physical activity, is the most severe manifestation of exertional heat illnesses. Exertional heat stroke is characterised by central nervous system dysfunction in people with hyperthermia during physical activity and can be influenced by environmental factors such as heatwaves, which extend the incidence of exertional heat stroke beyond athletics only. Epidemiological data indicate mortality rates of about 27%, and survivors display long term negative health consequences ranging from neurological to cardiovascular dysfunction. The pathophysiology of exertional heat stroke involves thermoregulatory and cardiovascular overload, resulting in severe hyperthermia and subsequent multiorgan injury due to a systemic inflammatory response syndrome and coagulopathy. Research about risk factors for exertional heat stroke remains limited, but dehydration, sex differences, ageing, body composition, and previous illness are thought to increase risk. Immediate cooling remains the most effective treatment strategy. In this review, we provide an overview of the current literature emphasising the pathophysiology and risk factors of exertional heat stroke, highlighting gaps in knowledge with the objective to stimulate future research.