Intense exercise increases circulating endocannabinoid and BDNF levels in humans--possible implications for reward and depression

Treadmill exercise training inhibits morphine CPP by reversing morphine effects on GABA neurotransmission in D2-MSNs of the accumbens-pallidal pathway in male mice

Relapse is a major challenge in the treatment of drug addiction, and exercise has been shown to decrease relapse to drug seeking in animal models. However, the neural circuitry mechanisms by which exercise inhibits morphine relapse remain unclear. In this study, we report that 4-week treadmill training prevented morphine conditioned place preference (CPP) expression during abstinence by acting through the nucleus accumbens (NAc)-ventral pallidum (VP) pathway. We found that neuronal excitability was reduced in D2-dopamine receptor-expressing medium spiny neurons (D2-MSNs) following repeated exposure to morphine and forced abstinence. Enhancing the excitability of NAc D2-MSNs via treadmill training decreased the expression of morphine CPP. We also found that the effects of treadmill training were mediated by decreasing enkephalin levels and that restoring opioid modulation of GABA neurotransmission in the VP, which increased neurotransmitter release from NAc D2-MSNs to VP, decreased morphine CPP. Our findings suggest the inhibitory effect of exercise on morphine CPP is mediated by reversing morphine-induced neuroadaptations in the NAc-to-VP pathway.

Acute Effects of Ad Libitum Use of Commercially Available Cannabis Products on the Subjective Experience of Aerobic Exercise: A Crossover Study

OBJECTIVE

The present study aimed to examine the acute effects of legal-market cannabis on regular cannabis users' subjective responses to exercise in a controlled laboratory environment.

BACKGROUND

Given the stereotype that cannabis is associated with extreme sedentary behavior, there are concerns that cannabis legalization may exacerbate the US physical inactivity epidemic. However, despite these concerns, recent years have seen considerable public interest in the use of cannabis concurrently with exercise (e.g., running).

METHODS

The present study compared participants' experiences of exercise without cannabis to their experiences of exercise after acute ad libitum use of one of two commercially available cannabis flower products: a Δ9-tetrahydrocannabinol-dominant or a cannabidiol-dominant product. Participants (N = 42) were regular cannabis users between the ages of 21 and 39 years (mean = 30.81 years, standard deviation = 4.72 years).

RESULTS

Although participants reported a more positive affect (p < 0.001), enjoyment (p < 0.001), and runner's high symptoms (p < 0.001) during their cannabis (vs non-cannabis) exercise appointment, they also reported more exertion (p = 0.04). Pain levels were very low and did not differ between appointments (p = 0.45). Effects appeared to depend, in part, on cannabinoid content; there was a larger difference in enjoyment (p = 0.02), and a smaller difference in exertion (p = 0.02), between the cannabis and non-cannabis exercise appointments among participants in the cannabidiol (vs Δ9-tetrahydrocannabinol) condition.

CONCLUSIONS

To our knowledge, this is the first study to investigate the acute effects of commercially available cannabis on subjective responses to exercise in a laboratory environment. Our findings suggest that, among regular cannabis users who use cannabis in combination with exercise, cannabis use prior to exercise may lead to increases in both positive and negative aspects of the subjective exercise experience. Research using diverse samples, exercise modalities, and methodologies (e.g., placebo-controlled trials) is needed to establish the generalizability of these findings.

Cannabinoid type 2 receptor inhibition enhances the antidepressant and proneurogenic effects of physical exercise after chronic stress

Chronic stress is a major risk factor for neuropsychiatric conditions such as depression. Adult hippocampal neurogenesis (AHN) has emerged as a promising target to counteract stress-related disorders given the ability of newborn neurons to facilitate endogenous plasticity. Recent data sheds light on the interaction between cannabinoids and neurotrophic factors underlying the regulation of AHN, with important effects on cognitive plasticity and emotional flexibility. Since physical exercise (PE) is known to enhance neurotrophic factor levels, we hypothesised that PE could engage with cannabinoids to influence AHN and that this would result in beneficial effects under stressful conditions. We therefore investigated the actions of modulating cannabinoid type 2 receptors (CB2R), which are devoid of psychotropic effects, in combination with PE in chronically stressed animals. We found that CB2R inhibition, but not CB2R activation, in combination with PE significantly ameliorated stress-evoked emotional changes and cognitive deficits. Importantly, this combined strategy critically shaped stress-induced changes in AHN dynamics, leading to a significant increase in the rates of cell proliferation and differentiation of newborn neurons, overall reduction in neuroinflammation, and increased hippocampal levels of BDNF. Together, these results show that CB2Rs are crucial regulators of the beneficial effects of PE in countering the effects of chronic stress. Our work emphasises the importance of understanding the mechanisms behind the actions of cannabinoids and PE and provides a framework for future therapeutic strategies to treat stress-related disorders that capitalise on lifestyle interventions complemented with endocannabinoid pharmacomodulation.

Dysfunction in endocannabinoids, palmitoylethanolamide, and degradation of tryptophan into kynurenine in individuals with depressive symptoms

BACKGROUND

The endocannabinoid (eCB) system and the serotonin (5-HT) are both implicated in the severity of the depression. 5-HT is synthesized from the amino acid tryptophan (Trp), which is also a precursor for kynurenine (Kyn) whose production is increased at the expense of 5-HT in depressed patients. No clinical studies have investigated the crosstalk between the eCB system and the Trp/5-HT/Kyn pathways. Here, we hypothesized that the eCB system is associated with an enhanced Kyn production in relation to the severity of depressive symptoms.

METHODS

Eighty-two subjects (51 patients with a diagnosis of depressive disorder (DSM-5) and 31 healthy volunteers), were assessed with the Montgomery-Åsberg Depression Rating Scale (MADRS), Beck Depression Scale, and Global Clinical Impression. Serum concentrations of eCBs (N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG)); structurally related fatty acyl compounds 2-oleoylglycerol (2-OG), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA); Trp, Kyn, Kyn/Trp ratio (an index of Trp degradation into Kyn) and 5-HT were also determined.

RESULTS

Following a principal component analysis including the severity of depression, Kyn and the Kyn/Trp ratio appear to be directly associated with 2-AG, AEA, and PEA. Interestingly, these biomarkers also permitted to distinguish the population into two main clusters: one of individuals having mild/severe depressive symptoms and the other with an absence of depressive symptoms. Using parametric analysis, higher serum levels of 2-AG, Kyn, and the ratio Kyn/Trp and lower levels of Trp and 5-HT were found in individuals with mild/severe depressive symptoms than in those without depressive symptoms. While in asymptomatic people, PEA was directly associated to Trp, and OEA indirectly linked to 5-HT, in individuals with depressive symptoms, these correlations were lost, and instead, positive correlations between AEA and 2-AG, PEA and AEA, and PEA vs 2-AG and OEA concentrations were found.

CONCLUSIONS

Parametric and non-parametric analyses suggest a possible association between eCBs, tryptophan/kynurenine biomarkers, and severity of depression, confirming a likely interplay among inflammation, stress, and depression. The enhanced relationships among the biomarkers of the 2-AG and AEA pathways and related lipids seen in individuals with depressive symptoms, but not in asymptomatics, suggest an altered metabolism of the eCB system in depression.

Quantal size increase induced by the endocannabinoid 2-arachidonoylglycerol requires activation of CGRP receptors in mouse motor synapses

In mouse motor synapses, the exogenous application of the endocannabinoid (EC) 2-arachidonoylglycerol (2-AG) increases acetylcholine (ACh) quantal size due to the activation of CB1 receptors and the stimulation of ACh vesicular uptake. In the present study, microelectrode recordings of miniature endplate potentials (MEPP) revealed that this effect of 2-AG is independent of brain-derived neurotrophic factor (BDNF) signaling but involves the activation of calcitonin gene-related peptide (CGRP) receptors along with CB1 receptors. Potentiation of MEPP amplitude in the presence of 2-AG was prevented by blockers of CGRP receptors and ryanodine receptors (RyR) and by inhibitors of phospholipase C (PLC) and Ca2+ /calmodulin-dependent protein kinase II (CaMKII). Therefore, we suggest a hypothetical chain of events, which starts from the activation of presynaptic CB1 receptors, involves PLC, RyR, and CaMKII, and results in CGRP release with the subsequent activation of presynaptic CGRP receptors. Activation of CGRP receptors is probably a part of a complex molecular cascade leading to the 2-AG-induced increase in ACh quantal size and MEPP amplitude. We propose that the same chain of events may also take place if 2-AG is endogenously produced in mouse motor synapses, because the increase in MEPP amplitude that follows after prolonged tetanic muscle contractions (30 Hz, 2 min) was prevented by the blocking of CB1 receptors. This work may help to unveil the previously unknown aspects of the functional interaction between ECs and peptide modulators aimed at the regulation of quantal size and synaptic transmission.

Health-related behaviors and symptoms of anxiety and depression in Spanish nursing students: an observational study

Background

Symptoms of anxiety and depression are prevalent among young adults and are a significant public health issue. College students are at a higher risk of experiencing poor mental health than other young people due to several factors, including moving away from home, financial pressures, heavy workload, poor time management skills, competitivity, new processes of socialization and insufficient coping mechanisms, among others. In addition, nursing students' mental and physical health may also be affected by unhealthy lifestyle habits and health-related behaviors.

Aim

To determine the prevalence of symptoms of depression and anxiety, and the association between these symptoms and health-related behaviors, in a population of Spanish student nurses.

Methods

Cross-sectional study on a sample of 339 nursing students. We used the Hospital Anxiety and Depression Scale, the International Physical Activity Questionnaire-Short form, the Spanish Healthy Eating Index and an "ad hoc" questionnaire for sociodemographic variables. The association between psychological symptoms and health-related behaviors was analyzed through binary logistic regression models.

Results

The prevalence of symptoms of depression and anxiety was 3.8% and 24.5%, respectively. Negative health-related behaviors were frequent, namely tobacco and alcohol consumption, suboptimal physical activity and diet. Moderate physical activity was associated with a lower probability of experiencing depressive symptoms. Symptoms of anxiety were related to a low level of physical activity, an unhealthy diet and alcohol consumption ≥2 times a week.

Conclusion

Student nurses could benefit from the implementation of both physical and mental health promotion initiatives.

Effectiveness of blood flow restriction versus traditional weight-bearing training in rehabilitation of knee osteoarthritis patients with MASLD: a multicenter randomized controlled trial

To compare the reliability and effectiveness of blood blow restriction resistance training (BFR) versus traditional weight-bearing training (WB) in knee osteoarthritis (KOA) patients with metabolic dysfunction-associated steatotic liver disease (MASLD).

Methods

This multicenter randomized controlled trial was conducted from January 2021 to June 2022 at Shanghai Jiao Tong University affiliated Sixth People's Hospital and The People's Hospital of Mengla County. A total of 120 outpatients were recruited and randomized to perform WB (n=60) or BFR (n=60) resistance training protocols in accordance with standard recommended protocols for 12 weeks. Demographic data and Kellgren and Lawrence grading system scores were collected. Pain, range of motion (ROM), scaled maximal isotonic strength (10RM), self-reported function (KOOS), and 30-s chair sit-to-stand test results were assessed at weeks 1, 4, and 12.

Results

112 patients (57 in the WB group, 55 in the BFR group) completed the training programs and assessments. No significant intergroup demographic differences were noted. ROM and scaled 10RM significantly increased at the 4- and 12-week assessments and differed significantly between groups. The pain, ability of daily living and quality of life subscale in KOOS increased significantly at the 12-week assessment and differed significantly between groups, adjusted for baseline value. Significant and comparable increases in 30-s chair sit-to-stand test results were observed within and between study groups.

Conclusion

BFR training enhanced muscle strength, reduced pain, and improved daily living and sports activities in patients with KOA, compared to WB training alone. BFR should be recommended for rehabilitation in KOA individuals with MASLD.

Clinical trial registration number

ChiCTR2100042872.

Endocannabinoid and psychological responses to acute resistance exercise in trained and untrained adults

INTRODUCTION

This study examined the effects of acute resistance exercise on circulating endocannabinoid (eCB) and mood responses in trained and untrained healthy adults.

METHODS

Thirty-two healthy adults (22.1 ± 2.9 years) were recruited from trained (reporting resistance exercise at least twice per week for ≥ previous three months) and untrained (performing no resistance exercise for ≥ previous three months) groups. Participants (13 male, 19 female) completed three sets of resistance exercise (16 repetitions at 50% 1-repetition max, 12 repetitions at 70% 1-repetition max, 8 repetitions at 80% 1-repetition max). Resistance machines targeted the legs, chest, back, and abdominal muscles. Mood states, affect, and circulating eCB concentrations were evaluated before and after resistance exercise.

RESULTS

There were significant decreases in AEA, PEA, and OEA levels following acute resistance exercise (p <0.05; ds = -0.39, -0.48, -0.65, respectively), with no significant group differences or group by time interactions. 2-AG did not change significantly. Positive affect increased significantly following resistance exercise (p = 0.009), while negative affect decreased (p <0.001). Depressive symptoms, anger, confusion, and total mood disturbance decreased significantly (p <0.05), while vigor increased significantly following resistance exercise (p = 0.005). There were no significant group differences or group by time interactions for any psychological outcomes.

CONCLUSION

These results indicate that acute resistance exercise may reduce eCB and related lipid concentrations, which is opposite to the increase in lipids typically observed with acute aerobic exercise. Furthermore, psychological improvements occur after resistance exercise regardless of decreases in eCBs, supporting the notion that psychological changes with exercise likely occur through a wide variety of biological and environmental mechanisms.

Cannabis Is Not Doping

The World Anti-Doping Agency (WADA) classifies cannabis, all phytocannabinoids, and synthetics as doping, except for CBD. For agency, a method for doping substance must meet two criteria: performance enhancement (ergogenicity), health risk, or violation of the spirit of sports. Cannabis is neither ergogenic nor ergolytic (performance worsens), and the health risks for athletes are overestimated after 20 years of research. The significant problem remains in the complex (and difficult interpretation) definition of the spirit of sports, which transcends the objectives of sports excellence (performance and injury prevention) for moral policing. This perspective presents an evidence-based counterargument recommending the removal of cannabis and phytocannabinoids from the WADA Prohibited List.

Enhancement of peripheral fatty acyl ethanolamide signaling prevents stress-induced social avoidance and anxiety-like behaviors in male rats

RATIONALE

Exposure to traumatic events can lead to alterations in social and anxiety-related behaviors. Emerging evidence suggests that peripheral host-defense processes are implicated in the expression of stress-induced behavioral responses and may be targeted to mitigate the negative sequalae of stress exposure.

OBJECTIVES

In this study, we used the peripherally restricted FAAH inhibitor URB937 to investigate the effects of the fatty acyl ethanolamide (FAE) family of lipid mediators - which include the endocannabinoid anandamide and the endogenous PPAR-α agonists, oleoylethanolamide and palmitoylethanolamide - on behavioral and peripheral biochemical responses to two ethologically distinct rat models of stress.

METHODS

Male adult rats were exposed to acute social defeat, a model of psychological stress (Experiment 1), or to the predator odor 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), a test of innate predator-evoked fear (Experiment 2), and subsequently treated with URB937 (1 or 3 mg/kg, intraperitoneal) or vehicle. Behavioral analyses were conducted 24 h (Experiment 1) or 7 days (Experiment 2) after exposure.

RESULTS

URB937 administration prevented the emergence of both social avoidance behavior after social defeat stress and anxiety-related behaviors after TMT exposure. Further, URB937 administration blocked social defeat-induced transient increase in plasma concentrations of pro-inflammatory cytokines and the elevation in plasma corticosterone levels observed 24 h after social defeat CONCLUSIONS: Enhancement of peripheral FAAH-regulated lipid signaling prevents the emergence of stress-induced social avoidance and anxiety-like behaviors in male rats through mechanisms that may involve an attenuation of peripheral cytokine release induced by stress exposure.

Crosstalk between Exercise-Derived Endocannabinoidome and Kynurenines: Potential Target Therapies for Obesity and Depression Symptoms

The kynurenine pathway (KP) and the endocannabinoid system (ECS) are known to be deregulated in depression and obesity; however, it has been recognized that acute physical exercise has an important modulating role inducing changes in the mobilization of their respective metabolites-endocannabinoids (eCBs) and kynurenines (KYNs)-which overlap at some points, acting as important antidepressant, anti-nociceptive, anti-inflammatory, and antioxidant biomarkers. Therefore, the aim of this review is to analyze and discuss some recently performed studies to investigate the potential interactions between both systems, particularly those related to exercise-derived endocannabinoidome and kynurenine mechanisms, and to elucidate how prescription of physical exercise could represent a new approach for the clinical management of these two conditions.

Hormonal, immune, and oxidative stress responses to blood flow-restricted exercise

INTRODUCTION

Heavy-load free-flow resistance exercise (HL-FFRE) is a widely used training modality. Recently, low-load blood-flow restricted resistance exercise (LL-BFRRE) has gained attention in both athletic and clinical settings as an alternative when conventional HL-FFRE is contraindicated or not tolerated. LL-BFRRE has been shown to result in physiological adaptations in muscle and connective tissue that are comparable to those induced by HL-FFRE. The underlying mechanisms remain unclear; however, evidence suggests that LL-BFRRE involves elevated metabolic stress compared to conventional free-flow resistance exercise (FFRE).

AIM

The aim was to evaluate the initial (<10 min post-exercise), intermediate (10-20 min), and late (>30 min) hormonal, immune, and oxidative stress responses observed following acute sessions of LL-BFRRE compared to FFRE in healthy adults.

METHODS

A systematic literature search of randomized and non-randomized studies was conducted in PubMed, Embase, Cochrane Central, CINAHL, and SPORTDiscus. The Cochrane Risk of Bias (RoB2, ROBINS-1) and TESTEX were used to evaluate risk of bias and study quality. Data extractions were based on mean change within groups.

RESULTS

A total of 12525 hits were identified, of which 29 articles were included. LL-BFRRE demonstrated greater acute increases in growth hormone responses when compared to overall FFRE at intermediate (SMD 2.04; 95% CI 0.87, 3.22) and late (SMD 2.64; 95% CI 1.13, 4.16) post-exercise phases. LL-BFRRE also demonstrated greater increase in testosterone responses compared to late LL-FFRE.

CONCLUSION

These results indicate that LL-BFRRE can induce increased or similar hormone and immune responses compared to LL-FFRE and HL-FFRE along with attenuated oxidative stress responses compared to HL-FFRE.

The Relationship Between Psychological Distress and Physical Activity Is Non-linear and Differs by Domain: a Cross-Sectional Study

BACKGROUND

There is increasing evidence for the relationship between physical activity (PA), sedentary behaviour and mental health. Limited data exists on sex-specific associations. We aimed to identify associations between PA dose and domain and television time with psychological distress, including sex-stratified models.

METHODS

A total of 22,176 adults from the Melbourne Collaborative Cohort Study follow-up 2 cohort (2003-2007) participated in this cross-sectional study. Occupational, household, transport, leisure PA, hours watching television and psychological distress were assessed. Restricted cubic splines were used to examine the relationships between PA domains, television viewing time and psychological distress.

RESULTS

The relationships between PA and psychological distress were non-linear (p < 0.05) and differed by PA domain. There were dose-dependent, inverse associations between distress with transport (B[95% CI] = -0.39[-0.49, -0.30]) and leisure PA (B[95% CI] = -0.35[-0.46, -0.25]). The effect estimates for transport and leisure PA with distress were larger for women. For household domain, a U-shaped curve with an elongated tail was seen. Median PA was associated with lower distress compared with lower quantities (B[95% CI] = -0.12[-0.22, -0.03]); however, this association was not evident with increasing household PA. There were no clear associations between occupational PA and distress. Higher television viewing was associated with higher distress (B[95% CI] = 0.16[0.02, 0.30]).

CONCLUSIONS

Increasing PA and reducing television viewing may contribute to reduced psychological distress, particularly in women. Future interventions should incorporate leisure and transport PA and decrease television viewing to assess the impact on mental health.

Circulating Endocannabinoids and N-Acylethanolamines in Individuals with Cannabis Use Disorder-Preliminary Findings

BACKGROUND

Endocannabinoids and related N-acylethanolamines (NAEs) are bioactive lipids with important physiological functions and putative roles in mental health and addictions. Although chronic cannabis use is associated with endocannabinoid system changes, the status of circulating endocannabinoids and related NAEs in people with cannabis use disorder (CUD) is uncertain.

METHODS

Eleven individuals with CUD and 54 healthy non-cannabis using control participants (HC) provided plasma for measurement by high-performance liquid chromatography-mass spectrometry of endocannabinoids (2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)) and related NAE fatty acids (N-docosahexaenoylethanolamine (DHEA) and N-oleoylethanolamine (OEA)). Participants were genotyped for the functional gene variant of FAAH (rs324420, C385A) which may affect concentrations of AEA as well as other NAEs (OEA, DHEA).

RESULTS

In overnight abstinent CUD, AEA, OEA and DHEA concentrations were significantly higher (31-40%; p < 0.05) and concentrations of the endocannabinoid 2-AG were marginally elevated (55%, p = 0.13) relative to HC. There were no significant correlations between endocannabinoids/NAE concentrations and cannabis analytes, self-reported cannabis use frequency or withdrawal symptoms. DHEA concentration was inversely related with marijuana craving (r = -0.86; p = 0.001). Genotype had no significant effect on plasma endocannabinoids/NAE concentrations.

CONCLUSIONS

Our preliminary findings, requiring replication, might suggest that activity of the endocannabinoid system is elevated in chronic cannabis users. It is unclear whether this elevation is a compensatory response or a predating state. Studies examining endocannabinoids and NAEs during prolonged abstinence as well as the potential role of DHEA in craving are warranted.

Exercise Effect on Mental Health in Isolating or Quarantining Adults

INTRODUCTION: In response to coronavirus disease 2019 (COVID-19), travelers are typically subject to quarantine, which is often associated with poorer mental health (MH). While the protective benefits of community-based exercise are widely recognized, the degree to which this extends to the confined setting is unknown. This systematic review aims to evaluate the effect of exercise on MH in isolating or quarantining adults.METHODS: A literature search of Ovid MEDLINE, APA PsycInfo, and the Cochrane Database of Systematic Reviews limited to January 2019-September 2021 inclusive yielded five eligible studies.RESULTS: Data comprised a total of 2755 college and university students, most of whom were confined. Depending on the scale used, 24.9-76.7% of respondents demonstrated impaired MH, which improved with physical activity (PA), especially when regular and moderate or vigorous. The frequency, duration, and participants of exercise increased as lockdown progressed. One study showed that while sleep, diet, and PA all have an impact on MH, PA was the factor most strongly correlated with MH.DISCUSSION: Physical fitness should be optimized before and maintained during quarantine while exercise space and equipment should be accessible. Importantly, the sustainability of persistent quarantine must be considered given the pervasiveness of COVID-19.Chu V, Newman DG. Exercise effect on mental health in isolating or quarantining adults. Aerosp Med Hum Perform. 2023; 94(9):686-695.

Examining the Interaction between Exercise, Gut Microbiota, and Neurodegeneration: Future Research Directions

Physical activity has been demonstrated to have a significant impact on gut microbial diversity and function. Emerging research has revealed certain aspects of the complex interactions between the gut, exercise, microbiota, and neurodegenerative diseases, suggesting that changes in gut microbial diversity and metabolic function may have an impact on the onset and progression of neurological conditions. This study aimed to review the current literature from several databases until 1 June 2023 (PubMed/MEDLINE, Web of Science, and Google Scholar) on the interplay between the gut, physical exercise, microbiota, and neurodegeneration. We summarized the roles of exercise and gut microbiota on neurodegeneration and identified the ways in which these are all connected. The gut-brain axis is a complex and multifaceted network that has gained considerable attention in recent years. Research indicates that gut microbiota plays vital roles in metabolic shifts during physiological or pathophysiological conditions in neurodegenerative diseases; therefore, they are closely related to maintaining overall health and well-being. Similarly, exercise has shown positive effects on brain health and cognitive function, which may reduce/delay the onset of severe neurological disorders. Exercise has been associated with various neurochemical changes, including alterations in cortisol levels, increased production of endorphins, endocannabinoids like anandamide, as well as higher levels of serotonin and dopamine. These changes have been linked to mood improvements, enhanced sleep quality, better motor control, and cognitive enhancements resulting from exercise-induced effects. However, further clinical research is necessary to evaluate changes in bacteria taxa along with age- and sex-based differences.

Sports-Related Concussion Assessment: A New Physiological, Biomechanical, and Cognitive Methodology Incorporating a Randomized Controlled Trial Study Protocol

BACKGROUND

Taking part in moderate-to-vigorous exercise in contact sports on a regular basis may be linked to an increase in cerebrovascular injury and head trauma. Validated objective measures are lacking in the initial post-event diagnosis of head injury. The exercise style, duration, and intensity may also confound diagnostic indicators. As a result, we propose that the new Interdisciplinary Group in Movement & Performance from Acute & Chronic Head Trauma (IMPACT) analyze a variety of functional (biomechanical and motor control) tests as well as related biochemistry to see how they are affected by contact in sports and head injury. The study's goal will be to look into the performance and physiological changes in rugby players after a game for head trauma and injury.

METHODS

This one-of-a-kind study will use a randomized controlled trial (RCT) utilizing a sport participation group and a non-participation control group. Forty male rugby 7 s players will be recruited for the study and allocated randomly to the experimental groups. The intervention group will participate in three straight rugby matches during a local 7 s rugby event. At the pre-match baseline, demographic and anthropometric data will be collected. This will be followed by the pre-match baseline collection of biochemical, biomechanical, and cognitive-motor task data. After three consecutive matches, the same measures will be taken. During each match, a notational analysis will be undertaken to obtain contact information. All measurements will be taken again 24, 48, and 72 h after the third match.

DISCUSSION

When the number of games increases owing to weariness and/or stressful circumstances, we expect a decline in body movement, coordination, and cognitive-motor tasks. Changes in blood biochemistry are expected to correspond to changes in biomechanics and cognitive-motor processes. This research proposal will generate considerable, ecologically valid data on the occurrence of head trauma events under game conditions, as well as the influence of these events on the biological systems of the performers. This will lead to a greater understanding of how sports participants react to exercise-induced injuries. This study's scope will have far-reaching ramifications for doctors, coaches, managers, scientists, and sports regulatory bodies concerned with the health and well-being of athletic populations at all levels of competition, including all genders and ages.

The influence of aerobic exercise on model-based decision making in women with posttraumatic stress disorder

Individuals with PTSD often exhibit deficits in executive functioning. An unexplored aspect of neurocognitive functions associated with PTSD is the type of learning system engaged in during decision-making. A model-free (MF) system is habitual in nature and involves trial-and-error learning that is often updated based on the most recent experience (e.g., repeat action if rewarded). A model-based (MB) system is goal-directed in nature and involves the development of an abstract representation of the environment to facilitate decisions (e.g., choose sequence of actions according to current contextual state and predicted outcomes). The existing neurocognitive literature on PTSD suggests the hypothesis of greater reliance on MF vs MB learning strategies when navigating their environment. While MF systems may be more cognitively efficient, they do not afford flexibility when making prospective predictions about likely outcomes of different decision-tree branches. Emerging research suggests that an acute bout of aerobic exercise improves certain aspects of neurocognition, and thereby could promote the utilization of MB over MF systems during decision making, although prior research has not yet tested this hypothesis. Accordingly, the current study administered a lab-based two-stage Markov decision-making task capable of discriminating MF vs MB decision making, in order to determine if moderate-intensity aerobic exercise (either shortly after or 30-minutes after the exercise bout has ended) promotes greater engagement in MB behavioral strategies compared to light-intensity aerobic exercise in adult women with and without PTSD (N=61). Results revealed that control women generally displayed higher levels of MB behavior that was further increased following immediate exercise, particularly moderate-intensity exercise. By contrast, the PTSD group generally displayed lower levels of MB behavior, and exhibited greater MB behavior when completing the task following moderate-intensity aerobic exercise compared to light-intensity aerobic exercise regardless of whether there was a short or long delay between exercise and the task. Additionally, women with PTSD demonstrated less impairment in MB decision-making compared to controls following moderate-intensity aerobic exercise. These results suggest that an acute bout of moderate-intensity aerobic exercise boosts MB behavior in women with PTSD, and suggests that aerobic exercise may play an important role in enhancing cognitive outcomes for PTSD.

Psychological distress in nursing students: relationship with screen time, diet and physical activity

OBJECTIVE

to determine the prevalence of anxiety and depression symptoms, as well as their association with screen time, diet and physical activity, in a cohort comprised by nursing students.

METHOD

a descriptive and cross-sectional study conducted with a sample of 648 Nursing students. The instruments used were the Hospital Anxiety and Depression Scale, the short version of the International Physical Activity Questionnaire and the Spanish Healthy Eating Index (Índice de Alimentación Saludable Español, IASE). Different multiple linear regression models were performed to analyze the association between anxiety/depression symptoms and screen time, diet and physical activity.

RESULTS

the prevalence values for anxiety and depression symptoms were 24.1% and 3.7%, respectively. Prolonged screen times (>6 hours a day), low levels of physical activity and inadequate diet were independently and significantly associated with deeper psychological symptoms.

CONCLUSION

Nursing students' mental health might benefit from the implementation of initiatives promoting healthy lifestyles.

Exercise Is Medicine: How Do We Implement It?

Exercise is well known to have beneficial effects on various disease states. In this paper, we broadly describe the fundamental concepts that are shared among various disease states, including obesity, type 2 diabetes (T2D), cardiovascular disease (CVD), heart failure (HF), cancer, and psychological well-being, and the beneficial effects of exercise training within these concepts. We highlight issues involved in implementing exercise recommendations and describe the potential impacts and challenges to medical professionals and patients. Problems are identified and discussed with respect to the future roles of professionals in the current built environment with its limited infrastructure to support current physical activity recommendations.

The Muscle-Gut-Brain Axis and Psychiatric Illness

The microbiota-gut-brain axis (MGBA) has been the subject of much research over the past decade, offering an exciting new paradigm for the treatment of psychiatric disorders. In this review, the MGBA is extended to include skeletal muscle and the potential role of an expanded "muscle-gut-brain axis" (MuGBA) in conditions such as anxiety and depression is discussed. There is evidence, from both preclinical and human studies, of bidirectional links between the gut microbiome and skeletal muscle function and structure. The therapeutic role of exercise in reducing depressive and anxiety symptoms is widely recognised, and the potential role of the gut microbiota-skeletal muscle link is discussed within this context. Potential pathways of communication involved in the MuGBA including the tryptophan-kynurenine pathway, intestinal permeability, immune modulation, and bacterial metabolites such as short-chain-fatty-acids are explored.

Dr Amir Mohammadamini The effect of exercise on suicidal behaviors: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Although exercise may positively impact those with mental or other medical illnesses, there is a lack of understanding on how it influences suicidal ideation or risk.

METHODS

We conducted a PRISMA 2020-compliant systematic review searching MEDLINE, EMBASE, Cochrane, and PsycINFO from inception to June 21, 2022. Randomized controlled trials (RCTs) investigating exercise and suicidal ideation in subject with mental or physical conditions were included. Random-effects meta-analysis was conducted. The primary outcome was suicidal ideation. We assessed bias of studies with risk of bias tool 2.

RESULTS

We identified 17 RCTs encompassing 1021 participants. Depression was the most included condition (71 %, k = 12). Mean follow up was 10.0 weeks (SD = 5.2). Post-intervention suicidal ideation (SMD = -1.09, CI -3.08-0.90, p = 0.20, k = 5) was not significantly different between exercise and control groups. Suicide attempts were significantly reduced in participants randomized to exercise interventions as compared to inactive controls (OR = 0.23, CI 0.09-0.67, p = 0.04, k = 2). Fourteen studies (82 %) were at high risk of bias.

LIMITATIONS

This meta-analysis is limited by few, and underpowered and heterogenous studies.

CONCLUSION

Overall, our meta-analysis did not find a significant decrease in suicidal ideation or mortality between exercise and control groups. However, exercise did significantly decrease suicide attempts. Results should be considered preliminary, and more and larger studies assessing suicidality in RCTs testing exercise are needed.

Regulation of the endocannabinoid system by endurance and resistance exercise in hypoxia in human skeletal muscle

Exercise modulates the circulating levels of the endocannabinoids ligands N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG) and possibly the levels of their receptors and downstream signaling in skeletal muscle. The aim of the present study was to investigate the regulation of the endocannabinoid system by several exercise paradigms in human skeletal muscle. A second aim was to compare endocannabinoid regulation in healthy and prediabetic people in response to an acute endurance exercise. Blood and muscle samples were taken before and after resistance and endurance exercise in normoxia and hypoxia to measure plasma endocannabinoid levels as well as muscle protein expression of CB1, CB2, and downstream signaling. We found that: 1) an acute resistance exercise session decreased plasma 2-AG and N-palmitoylethanolamine (PEA) levels in normoxia; 2) 4 wk resistance training decreased plasma AEA, PEA, and N-oleoylethanolamine (OEA) levels in both normoxia and hypoxia; 3) an acute moderate-intensity endurance exercise increased plasma OEA levels in the healthy and prediabetic groups in normoxia and hypoxia, whereas plasma 2-AG levels increased in the healthy group and AEA in the prediabetic group only in normoxia. The expression of the cannabinoid receptors was only marginally regulated by acute exercise, hypoxia, and prediabetes and downstream signaling did not follow the changes detected in the endocannabinoid ligands. Altogether, our results suggest that resistance and endurance exercise regulate the levels of the endocannabinoid ligands and CB1 expression in opposite ways. The physiological impact of the changes observed in the endocannabinoid ligands in human skeletal muscle after exercise needs further investigation.NEW & NOTEWORTHY We are the first to analyze both endocannabinoids ligands and receptors in response to endurance and resistance exercise. In addition, no study before has compared both exercise paradigms regarding endocannabinoid tone, which is of interest as endocannabinoids regulate energy metabolism, and these are different between endurance and resistance exercise. Furthermore, we investigated whether the endocannabinoid tone was differently regulated in response to acute endurance exercise in prediabetic people. Linking exercise, endocannabinoids and (pre)diabetic people has never been done before.

The Role of Physical Exercise in Opioid Substitution Therapy: Mechanisms of Sequential Effects

It is generally accepted that chronic opioid use is associated with structural and functional changes in the human brain that lead to an enhancement of impulsive behavior for immediate satisfaction. Interestingly, in recent years, physical exercise interventions have been used as an adjunctive treatment for patients with opioid use disorders (OUDs). Indeed, exercise has positive effects on both the biological and psychosocial basis of addiction, modifying neural circuits such as the reward, inhibition, and stress systems, and thus causing behavioral changes. This review focuses on the possible mechanisms that contribute to the beneficial effects of exercise on the treatment of OUDs, with emphasis placed on the description of a sequential consolidation of these mechanisms. Exercise is thought to act initially as a factor of internal activation and self-regulation and eventually as a factor of commitment. This approach suggests a sequential (temporal) consolidation of the functions of exercise in favor of gradual disengagement from addiction. Particularly, the sequence in which the exercise-induced mechanisms are consolidated follows the pattern of internal activation-self-regulation-commitment, eventually resulting in stimulation of the endocannabinoid and endogenous opioid systems. Additionally, this is accompanied by modification of molecular and behavioral aspects of opioid addiction. Overall, the neurobiological actions of exercise in combination with certain psychological mechanisms appear to promote its beneficial effects. Given the positive effects of exercise on both physical and mental health, exercise prescription is recommended as a complement to conventional therapy for patients on opioid maintenance treatment.

Social determinants of health and physical activity are related to pain intensity and mental health in patients with carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy of the upper limb and a frequent cause of disability.

OBJECTIVE

To analyze the association between social determinants of health (SDH) and physical activity with pain intensity and mental health in patients with CTS.

DESIGN

A cross-sectional study was conducted in patients with CTS awaiting surgery in two public hospitals in Chile.

METHODS

The SDH collected included: employment status, educational level and monetary income. The level of physical activity was defined according to compliance with WHO recommendations. Outcome measures included: Pain intensity (Visual Analog Scale), Symptoms of anxiety and depression (Hospital Anxiety and Depression Scale), and catastrophic thinking (Pain Catastrophizing Scale). The adjusted regression coefficient (β) for the association between SDH and physical activity with each outcome was obtained using multivariable linear regression models controlling for age, sex, body mass index and symptom duration.

RESULTS

Eighty-six participants were included (mean age 50.9 ± 10 years, 94% women). A high level of physical activity was associated with a 12.41 mm decrease in pain intensity (β = -12.41, 95%CI: -23.87 to -0.95) and a 3.29 point decrease in depressive symptoms (β = -3.29, 95%CI: -5.52 to -1.06). In addition, being employed was associated with a 2.30 point decrease in anxiety symptoms (β = -2.30; 95%CI: -4.41 to -0.19) and a high educational level was associated with a 7.71 point decrease in catastrophizing (β = -7.71; 95%CI: -14.06 to -1.36).

CONCLUSION

Multidisciplinary care teams should be aware of the association between SDH and physical activity with physical and mental health.

Investigating the Physiological Mechanisms between Resistance Training and Pain Relief in the Cancer Population: A Literature Review

This literature review examines the mechanisms of how exercise, specifically in the form of resistance training, may lead to pain relief in the cancer population. Primary data from three different cancer populations: breast, prostate, and lung, will be examined. A number of experimental studies have been conducted to confirm the effectiveness of resistance training on pain relief as well as the biochemical pathways that relate to this process. In this review, we will examine 5 randomized controlled trials. For the purposes of this review, pain is defined as physical suffering or discomfort associated with illness. Pain is the body's natural signal, bringing attention to damage that has been sustained by tissues. However, chronic pain is common in the cancer population, and often serves no good purpose but instead will negatively impact both physical and mental health. The three types of pain: nociceptive, neuropathic, and inflammatory pathways have been investigated, and the knowledge of pain mechanisms allows for the understanding of how it is associated with pain. The purpose of this exploratory literature review is to give insight on how to maximize pain-relieving effects of resistance training. Research has indicated that resistance training modulates pain pathways by upregulating the release of pain-relieving substances including beta-endorphins, anti-inflammatory cytokines, and endocannabinoids. Understanding of the benefits of resistance training may be useful in relieving cancer pain, and reproducing effects of pain-relieving strategies while minimizing the symptoms related to cancer and its treatment.

Biochemical Markers of Musculoskeletal Health and Aging to be Assessed in Clinical Trials of Drugs Aiming at the Treatment of Sarcopenia: Consensus Paper from an Expert Group Meeting Organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) and the Centre Académique de Recherche et d'Expérimentation en Santé (CARES SPRL), Under the Auspices of the World Health Organization Collaborating Center for the Epidemiology of Musculoskeletal Conditions and Aging

In clinical trials, biochemical markers provide useful information on the drug's mode of action, therapeutic response and side effect monitoring and can act as surrogate endpoints. In pharmacological intervention development for sarcopenia management, there is an urgent need to identify biomarkers to measure in clinical trials and that could be used in the future in clinical practice. The objective of the current consensus paper is to provide a clear list of biochemical markers of musculoskeletal health and aging that can be recommended to be measured in Phase II and Phase III clinical trials evaluating new chemical entities for sarcopenia treatment. A working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) proposed classifying biochemical markers into 2 series: biochemical markers evaluating musculoskeletal status and biochemical markers evaluating causal factors. For series 1, the group agreed on 4 biochemical markers that should be assessed in Phase II or Phase III trials (i.e., Myostatin-Follistatin, Brain Derived Neurotrophic Factor, N-terminal Type III Procollagen and Serum Creatinine to Serum Cystatin C Ratio - or the Sarcopenia Index). For series 2, the group agreed on 6 biochemical markers that should be assessed in Phase II trials (i.e., the hormones insulin-like growth factor-1 (IGF-I), dehydroepiandrosterone sulphate, and cortisol, and the inflammatory markers C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-α), and 2 in Phase III trials (i.e., IGF-I and CRP). The group also proposed optional biochemical markers that may provide insights into the mode of action of pharmacological therapies. Further research and development of new methods for biochemical marker assays may lead to the evolution of these recommendations.

The Endocannabinoid System and Physical Exercise

The endocannabinoid system (ECS) is involved in various processes, including brain plasticity, learning and memory, neuronal development, nociception, inflammation, appetite regulation, digestion, metabolism, energy balance, motility, and regulation of stress and emotions. Physical exercise (PE) is considered a valuable non-pharmacological therapy that is an immediately available and cost-effective method with a lot of health benefits, one of them being the activation of the endogenous cannabinoids. Endocannabinoids (eCBs) are generated as a response to high-intensity activities and can act as short-term circuit breakers, generating antinociceptive responses for a short and variable period of time. A runner's high is an ephemeral feeling some sport practitioners experience during endurance activities, such as running. The release of eCBs during sustained physical exercise appears to be involved in triggering this phenomenon. The last decades have been characterized by an increased interest in this emotional state induced by exercise, as it is believed to alleviate pain, induce mild sedation, increase euphoric levels, and have anxiolytic effects. This review provides information about the current state of knowledge about endocannabinoids and physical effort and also an overview of the studies published in the specialized literature about this subject.

Endocannabinoid signaling in the central nervous system

It is hard to overestimate the influence of the endocannabinoid signaling (ECS) system on central nervous system (CNS) function. In the 40 years since cannabinoids were found to trigger specific cell signaling cascades, studies of the ECS system continue to cause amazement, surprise, and confusion! CB1 cannabinoid receptors are expressed widely in the CNS and regulate cell-cell communication via effects on the release of both neurotransmitters and gliotransmitters. CB2 cannabinoid receptors are difficult to detect in the CNS but seem to "punch above their weight" as compounds targeting these receptors have significant effects on inflammatory state and behavior. Positive and negative allosteric modulators for both receptors have been identified and examined in preclinical studies. Concentrations of the endocannabinoid ligands, N-arachidonoylethanolamine and 2-arachidonoylglycerol (2-AG), are regulated by a combination of enzymatic synthesis and degradation and inhibitors of these processes are available and making their way into clinical trials. Importantly, ECS regulates many essential brain functions, including regulation of reward, anxiety, inflammation, motor control, and cellular development. While the field is on the cusp of preclinical discoveries providing impactful clinical and therapeutic insights into many CNS disorders, there is still much to be learned about this remarkable and versatile modulatory system.

Reward enhances resilience to chronic social defeat stress in mice: Neural ECs and mGluR5 mechanism via neuroprotection in VTA and DRN

INTRODUCTION

Stress often leads to emotional disorders such as depression. The reward might render this effect through the enhancement of stress resilience. However, the effect of reward on stress resilience under different intensities of stress needs more evidence, and its potential neural mechanism has been poorly revealed. It has been reported that the endogenous cannabinoid system (ECs) and downstream metabolic glutamate receptor 5 (mGluR5) are closely related to stress and reward, which might be the potential cerebral mechanism between reward and stress resilience, but there is a lack of direct evidence. This study aims to observe the effect of reward on stress resilience under different intensities of stress and further explore potential cerebral mechanisms underlying this effect.

METHODS

Using the chronic social defeat stress model, we applied reward (accompanied by a female mouse) under different intensities of stress in mice during the modeling process. The impact of reward on stress resilience and the potential cerebral mechanism were observed after modeling through behavioral tests and biomolecules.

RESULTS

The results showed that stronger stress led to higher degrees of depression-like behavior. Reward reduced depression-like behavior and enhanced stress resilience (all p-value <0.05) (more social interaction in the social test, less immobility time in the forced swimming test, etc.), with a stronger effect under the large stress. Furthermore, the mRNA expression levels of CB1 and mGluR5, the protein expression level of mGluR5, and the expression level of 2-AG (2-arachidonoylglycerol) in both ventral tegmental area (VTA) and dorsal raphe nucleus (DRN) were significantly upregulated by reward after modeling (all p-value <0.05). However, the protein expression of CB1 in VTA and DRN and the expression of AEA (anandamide) in VTA did not differ significantly between groups. Intraperitoneal injection of a CB1 agonist (URB-597) during social defeat stress significantly reduced depression-like behavior compared with a CB1 inhibitor (AM251) (all p-value <0.05). Interestingly, in DRN, the expression of AEA in the stress group was lower than that of the control group, with or without reward (all p-value <0.05).

DISCUSSION

These findings demonstrate that combined social and sexual reward has a positive effect on stress resilience during chronic social defeat stress, potentially by influencing the ECs and mGluR5 in VTA and DRN.

Exercise improves depression through positive modulation of brain-derived neurotrophic factor (BDNF). A review based on 100 manuscripts over 20 years

The aim of this review was to explore the relevant neurobiology and the association between peripheral levels of brain-derived neurotrophic factor (BDNF) and acute and short to long-term exercise regimes, as well as its relation to depression and antidepressant treatment. A 20-year literature search was conducted. The screening process resulted in 100 manuscripts. Antidepressants as well as acute exercise, particularly high-intensity, elevates BDNF in healthy humans and clinical populations, as evidenced from aerobic and resistance-based studies. Although exercise is increasingly recognised in the management of depression, acute and short-term exercise studies have failed to establish a relationship between the severity of depression and changes in peripheral BDNF. The latter rapidly returns to baseline, possibly indicating a quick re-uptake by the brain, aiding its neuroplasticity functions. The timescale of administration needed for the antidepressants to stimulate biochemical changes is longer than similar increases with acute exercise.

Targeting mediodorsal thalamic CB1 receptors to inhibit dextromethorphan-induced anxiety/exploratory-related behaviors in rats: The post-weaning effect of exercise and enriched environment on adulthood anxiety

Dextromethorphan (DXM) is an effective over-the-counter antitussive with an alarming increase as an abused drug for recreational purposes. Although reports of the association between DXM administration and anxiety, there are few investigations into the underlying DMX mechanisms of anxiogenic action. Thus, the present study aimed to investigate the role of the mediodorsal thalamus (MD) cannabinoid CB1 receptors (CB1Rs) in DXM-induced anxiety/exploratory-related behaviors in adult male Wistar rats. Animals were bilaterally cannulated in the MD regions. After one week, anxiety and exploratory behaviors were measured using an elevated plus-maze task (EPM) and a hole-board apparatus. Results showed that DXM (3-7 mg/kg, i. p.) dose-dependently increased anxiety-like behaviors. Intra-MD administration of ACPA (2.5-10 ng/rat), a selective CB1 receptor agonist, decreased anxiety-like effects of DXM. The blockade of MD CB1 receptors by AM-251 (40-120 ng/rat) did not affect the EPM task. However, it potentiated the anxiogenic response of an ineffective dose of DXM (3 mg/kg) in the animals. Moreover, the effect of post-weaning treadmill exercise (TEX) and enriched environment (EE) were examined in adulthood anxiety under the drug treatments. Juvenile rats were divided into TEX/EE and control groups. The TEX/EE-juvenile rats were placed on a treadmill and then exposed to EE for five weeks. Interestingly, compared to untreated animals, post-weaning TEX/EE inhibited the anxiety induced by DXM or AM-251/DXM. It can be concluded that the MD endocannabinoid system plays an essential role in the anxiogenic effect of dextromethorphan. Moreover, post-weaning exercise alongside an enriched environment may have an inhibitory effect on adulthood anxiety-like behaviors.

Acute and long-term exercise differently modulate plasma levels of oxylipins, endocannabinoids, and their analogues in young sedentary adults: A sub-study and secondary analyses from the ACTIBATE randomized controlled-trial

BACKGROUND

Fatty acid-derived lipid mediators including oxylipins, endocannabinoids (eCBs), and their analogues, have emerged as key metabolites in the inflammatory and immune response to physiological stressors.

METHODS

This report was based on a sub-study and secondary analyses the ACTIBATE single-center unblinded randomized controlled trial (ClinicalTrials.gov ID: NCT02365129). The study was performed in the Sport and Health University Research Institute and the Virgen de las Nieves University Hospital of the University of Granada. Eligible participants were young, sedentary adults with no chronic diseases. Here, we performed both an acute endurance and resistance exercise sub-studies (n.ß=.ß14 and 17 respectively), and a 24-week supervised exercise intervention, combining endurance and resistance exercise training at moderate-intensity (MOD-EX) or vigorous-intensity (VIG-EX) exercise groups, in young sedentary adults. Randomization was performed by unrestricted randomization. Plasma levels of oxylipins, eCBs, and their analogues were measured using liquid chromatography-tandem mass spectrometry.

FINDINGS

Both endurance and resistance exercise increased by.ß+50% the plasma levels of dihomo-..-linolenic acid and arachidonic acid (AA) omega-6 derived oxylipins, as well as eicosapentaenoic acid and docosahexaenoic acid omega-3 derived after 3 and 120.ßmin of the bout of exercise (all ..².ß....ß0.219 and P.ß..±.ß0.039). These exercise modalities also increased the levels of anandamide and eCBs analogues (+25%). 145 young sedentary adults were assigned to a control (CON, n.ß=.ß54), a MOD-EX (n.ß=.ß48) or a VIG-EX (n.ß=.ß43). 102 participants were included in the final long-term analyses (CON, n.ß=.ß36; MOD-EX, n.ß=.ß33; and VIG-EX, n.ß=.ß33) of the trial. After 24-week of supervised exercise, MOD-EX decreased plasma levels of omega-6 oxylipins, concretely linoleic acid (LA) and adrenic acid derived oxylipins, and the eCBs analogues OEA and LEA in comparison to the CON (all P.ß..±.ß0.021). VIG-EX decreased LA-derived oxylipins and LEA compared to CON. No relevant adverse events were recorded.

INTERPRETATION

Endurance and resistance exercises acutely increased plasma levels of oxylipins, eCBs, and their analogues, whereas 24 weeks of exercise training decreased fasting plasma levels of omega-6 oxylipins, and eCBs analogues in young, sedentary adults.

FUNDING

See Acknowledgments section.

Metabolite patterns associated with individual response to supervised exercise therapy in patients with intermittent claudication

Objective

Supervised exercise therapy (SET) is the first line treatment for intermittent claudication owing to peripheral arterial disease. Despite multiple randomized controlled trials proving the efficacy of SET, there are large differences in individual patient's responses. We used plasma metabolomics to identify potential metabolic influences on the individual response to SET.

Methods

Primary metabolites, complex lipids, and lipid mediators were measured on plasma samples taken at before and after Gardner graded treadmill walking tests that were administered before and after 12 weeks of SET. We used an ensemble modeling approach to identify metabolites or changes in metabolites at specific time points that associated with interindividual variability in the functional response to SET. Specific time points analyzed included baseline metabolite levels before SET, dynamic metabolomics changes before SET, the difference in pre- and post-SET baseline metabolomics, and the difference (pre- and post-SET) of the dynamic (pre- and post-treadmill).

Results

High levels of baseline anandamide levels pre- and post-SET were associated with a worse response to SET. Increased arachidonic acid (AA) and decreased levels of the AA precursor dihomo-γ-linolenic acid across SET were associated with a worse response to SET. Participants who were able to tolerate large increases in AA during acute exercise had longer, or better, walking times both before and after SET.

Conclusions

We identified two pathways of relevance to individual response to SET that warrant further study: anandamide synthesis may activate endocannabinoid receptors, resulting in worse treadmill test performance. SET may train patients to withstand higher levels of AA, and inflammatory signaling, resulting in longer walking times.

Clinical Relevance

This manuscript describes the use of metabolomic techniques to measure the interindividual effects of SET in patients with peripheral artery disease (PAD). We identified high levels of AEA are linked to CB1 signaling and activation of inflammatory pathways. This alters energy expenditure in myoblasts by decreasing glucose uptake and may induce an acquired skeletal muscle myopathy. SET may also help participants tolerate increased levels of AA and inflammation produced during exercise, resulting in longer walking times. This data will enhance understanding of the pathophysiology of PAD and the mechanism by which SET improves walking intolerance.

Pattern of serum brain-derived neurotrophic factor levels after acute interval exercise versus acute continuous exercise in obese adolescent females

Obesity has been linked to lower cognitive function, while exercise is known to be beneficial in enhancing the cognitive function. Exercise is also known to increase brain-derived neurotrophic factor (BDNF), as the biological marker of cognitive function. This study aimed to analyse the pattern of serum BDNF levels after acute interval exercise (MIE) versus acute continuous exercise (MCE) in obese adolescent females. A total of 24 obese females were enrolled in this study and given acute interval exercise and acute continuous exercise with moderate intensity. The serum level of BDNF in all samples was quantified using ELISA. Statistical analysis was performed using two-way repeated measures ANOVA, and LSD post-hoc test with a 5% significance level. The results revealed pre-exercise mean serum BDNF levels of 254.17±86.90 pg/ml (Control), 263.21±79.82 pg/ml (MIE) and 266.01±33.29 pg/ml (MCE) (P=0.948). The mean serum BDNF levels at 10 min post-exercise were 248.84±44.42 pg/ml (Control), 397.00±31.36 pg/ml (MIE), and 582.82±79.24 pg/ml (MCE) (P=0.000). The mean serum BDNF levels at 6 h post-exercise were 250.05±70.44 pg/ml (Control), 344.50±68.84 pg/ml (MIE), and 364.42±100.87 pg/ml (MCE) (P=0.029). The mean serum BDNF levels at 24 h post-exercise were 244.20±48.55 pg/ml (Control), 252.49±89.11 pg/ml (MIE), and 250.99±65.86 pg/ml (MCE) (P=0.986). It was concluded that serum BDNF in obese adolescent females increased but transiently. Serum BDNF levels increased by acute exercise in both MIE and MCE at 10 min and 6 h post-exercise. However, serum BDNF level at 24 h post-exercise decreased close to the pre-exercise serum BDNF level in all groups. Further research is needed studying the effect of chronic exercise on the kinetics of serum BDNF levels in obese adolescent females.

In vivo brain endocannabinoid metabolism is related to hippocampus glutamate and structure - a multimodal imaging study with PET, 1H-MRS, and MRI

Dysregulation of hippocampus glutamatergic neurotransmission and reductions in hippocampal volume have been associated with psychiatric disorders. The endocannabinoid system modulates glutamate neurotransmission and brain development, including hippocampal remodeling. In humans, elevated levels of anandamide and lower activity of its catabolic enzyme fatty acid amide hydrolase (FAAH) are associated with schizophrenia diagnosis and psychotic symptom severity, respectively (Neuropsychopharmacol, 29(11), 2108-2114; Biol. Psychiatry 88 (9), 727-735). Although preclinical studies provide strong evidence linking anandamide and FAAH to hippocampus neurotransmission and structure, these relationships remain poorly understood in humans. We recruited young adults with and without psychotic disorders and measured FAAH activity, hippocampal glutamate and glutamine (Glx), and hippocampal volume using [11C]CURB positron emission tomography (PET), proton magnetic resonance spectroscopy (1H-MRS) and T1-weighted structural MRI, respectively. We hypothesized that higher FAAH activity would be associated with greater hippocampus Glx and lower hippocampus volume, and that these effects would differ in patients with psychotic disorders relative to healthy control participants. After attrition and quality control, a total of 37 participants (62% male) completed [11C]CURB PET and 1H-MRS of the left hippocampus, and 45 (69% male) completed [11C]CURB PET and hippocampal volumetry. Higher FAAH activity was associated with greater concentration of hippocampal Glx (F1,36.36 = 9.17, p = 0.0045; Cohen's f = 0.30, medium effect size) and smaller hippocampal volume (F1,44.70 = 5.94, p = 0.019, Cohen's f = 0.26, medium effect size). These effects did not differ between psychosis and healthy control groups (no group interaction). This multimodal imaging study provides the first in vivo evidence linking hippocampal Glx and hippocampus volume with endocannabinoid metabolism in the human brain.

Severe psychiatric disorders and general medical comorbidities: inflammation-related mechanisms and therapeutic opportunities

Individuals with severe psychiatric disorders, such as mood disorders and schizophrenia, are at increased risk of developing other medical conditions, especially cardiovascular and metabolic diseases. These medical conditions are underdiagnosed and undertreated in these patients contributing to their increased morbidity and mortality. The basis for this increased comorbidity is not well understood, possibly reflecting shared risks factors (e.g. lifestyle risk factors), shared biological mechanisms and/or reciprocal interactions. Among overlapping pathophysiological mechanisms, inflammation and related factors, such as dysbiosis and insulin resistance, stand out. Besides underlying the association between psychiatric disorders and cardiometabolic diseases, these mechanisms provide several potential therapeutic targets.

Effects of a Personalised Physical Exercise Program on University Workers Overall Well-Being: "UAL-Activa" Program

Background and objectives: Regular individualised physical exercise (PE) is a habit that not only has consequences for overall health (physical, emotional, social and mental) but can also have positive effects on organisations and institutions, as it helps workers to improve their personal balance and recover from the effort of their working day, showing higher levels of energy, commitment and productivity. The aim of this study was to understand the relationship between the practice of PE and well-being in personal life and at work, as well as job satisfaction, overall health and the assessment of the personal training service provided by final-year students studying for a degree in Physical Activity and Sport Sciences. Methods: This study used a qualitative research methodology. There were 25 employees of the University of Almeria (UAL) (M = 52.16 ± 9.55 years), divided into two focus groups and participating in the physical exercise program "UAL Activa". Results: The following three main themes, based on the results, emerged: (a) social well-being during PE practice, (b) assessment of the personal training service and (c) physical exercise as an emotional benefit at work. Conclusion. The workers' interventions have shown that participating in a personalised PE program led by a personal trainer can improve overall health and mood, with a very positive influence on the working environment.

A red nucleus-VTA glutamate pathway underlies exercise reward and the therapeutic effect of exercise on cocaine use

Physical exercise is rewarding and protective against drug abuse and addiction. However, the neural mechanisms underlying these actions remain unclear. Here, we report that long-term wheel-running produced a more robust increase in c-fos expression in the red nucleus (RN) than in other brain regions. Anatomic and functional assays demonstrated that most RN magnocellular portion (RNm) neurons are glutamatergic. Wheel-running activates a subset of RNm glutamate neurons that project to ventral tegmental area (VTA) dopamine neurons. Optogenetic stimulation of this pathway was rewarding, as assessed by intracranial self-stimulation and conditioned place preference, whereas optical inhibition blocked wheel-running behavior. Running wheel access decreased cocaine self-administration and cocaine seeking during extinction. Last, optogenetic stimulation of the RNm-to-VTA glutamate pathway inhibited responding to cocaine. Together, these findings indicate that physical exercise activates a specific RNm-to-VTA glutamatergic pathway, producing exercise reward and reducing cocaine intake.

Influence of Nutritional Ketosis Achieved through Various Methods on Plasma Concentrations of Brain Derived Neurotropic Factor

Brain-Derived Neurotropic Factor (BDNF) expression is decreased in conditions associated with cognitive decline as well as metabolic diseases. One potential strategy to improve metabolic health and elevate BDNF is by increasing circulating ketones. Beta-Hydroxybutyrate (BHB) stimulates BDNF expression, but the association of circulating BHB and plasma BDNF in humans has not been widely studied. Here, we present results from three studies that evaluated how various methods of inducing ketosis influenced plasma BDNF in humans. Study 1 determined BDNF responses to a single bout of high-intensity cycling after ingestion of a dose of ketone salts in a group of healthy adults who were habitually consuming either a mixed diet or a ketogenic diet. Study 2 compared how a ketogenic diet versus a mixed diet impacts BDNF levels during a 12-week resistance training program in healthy adults. Study 3 examined the effects of a controlled hypocaloric ketogenic diet, with and without daily use of a ketone-salt, on BDNF levels in overweight/obese adults. We found that (1) fasting plasma BDNF concentrations were lower in keto-adapted versus non keto-adapted individuals, (2) intense cycling exercise was a strong stimulus to rapidly increase plasma BDNF independent of ketosis, and (3) clinically significant weight loss was a strong stimulus to decrease fasting plasma BDNF independent of diet composition or level of ketosis. These results highlight the plasticity of plasma BDNF in response to lifestyle factors but does not support a strong association with temporally matched BHB concentrations.

A Systematic Review and Meta-Analysis on the Effects of Exercise on the Endocannabinoid System

Introduction: The endocannabinoid (eCB) system plays a key role in maintaining homeostasis, including the regulation of metabolism and stress responses. Chronic stress may blunt eCB signaling, and disruptions in eCB signaling have been linked to stress-related psychiatric disorders and physical health conditions, including anxiety, depression, post-traumatic stress disorder (PTSD), diabetes, and obesity. Pharmacological and nonpharmacological behavioral interventions (e.g., exercise) that target the eCB system may be promising therapeutic approaches for the prevention and treatment of stress-related diseases. In this study, we perform a systematic review and the first meta-analysis to examine the impact of exercise on circulating eCB concentrations. Materials and Methods: We performed a review of the MEDLINE (PubMed) database for original articles examining the impact of exercise on eCBs in humans and animal models. A total of 262 articles were screened for initial inclusion. Results: Thirty-three articles (reporting on 57 samples) were included in the systematic review and 10 were included in the meta-analysis. The majority of samples that measured anandamide (AEA) showed a significant increase in AEA concentrations following acute exercise (74.4%), whereas effects on 2-arachidonoylglycerol (2-AG) were inconsistent. The meta-analysis, however, revealed a consistent increase in both AEA and 2-AG following acute exercise across modalities (e.g., running, cycling), species (e.g., humans, mice), and in those with and without pre-existing health conditions (e.g., PTSD, depression). There was substantial heterogeneity in the magnitude of the effect across studies, which may relate to exercise intensity, physical fitness, timing of measurement, and/or fasted state. Effects of chronic exercise were inconsistent. Conclusions: Potential interpretations and implications of exercise-induced mobilization of eCBs are discussed, including refilling of energy stores and mediating analgesic and mood elevating effects of exercise. We also offer recommendations for future work and discuss therapeutic implications for exercise in the prevention and treatment of stress-related psychopathology.

Physical activity before and during pregnancy and maternal mental health: A systematic review and meta-analysis of observational studies

OBJECTIVE

To examine the influence of physical activity before and during pregnancy on maternal mental health outcomes.

METHODS

Ten electronic databases were searched up to May 11, 2021. Studies of all observational designs (except case studies and reviews) were included, which contained information on the relevant population (women before and or during pregnancy), exposures (objective or subjective measures of physical activity), comparator (low or no physical activity), and outcomes (diagnosis and symptom severity of depression or anxiety, quality of life scores, stress and emotions).

RESULTS

Forty-four observational studies (N = 132,399) were included. 'Low' to 'very low' certainty evidence revealed that compared with low levels of PA during pregnancy, high levels of PA were associated with a reduced odds of developing prenatal depression (odds ratio (OR): 0.68, 95% confidence interval (CI): 0.58 to 0.80) and anxiety (OR: 0.67, 95% CI: 0.54 to 0.83). We also found a reduction in the severity of prenatal depressive symptoms (standardized mean difference (SMD): -0.37, 95% CI -0.57 to -0.17), prenatal anxiety symptoms (SMD: -0.45, 95% CI -0.64 to -0.27), and prenatal stress (SMD: -0.33, 95% CI -0.55 to -0.11), concurrent with improved quality of life (SMD: 0.38, 95% CI 0.23 to 0.54). PA before pregnancy did not impact the outcomes of interest.

CONCLUSION

Physical activity during pregnancy is associated with a reduction in the odds and severity of prenatal depression and anxiety, as well as reduced stress and improved quality of life. PROSPERO registration number: CRD42020208469.

Chronic, acute and protocol-dependent effects of exercise on psycho-physiological health during long-term isolation and confinement

Exercise could prevent physical and psychological deteriorations, especially during pandemic times of lock-down scenarios and social isolation. But to meet both, the common exercise protocols require optimization based on holistic investigations and with respect to underlying processes. This study aimed to explore individual chronic and acute effects of continuous and interval running exercise on physical and cognitive performance, mood, and affect and underlying neurophysiological factors during a terrestrial simulated space mission. Six volunteers (three females) were isolated for 120 days. Accompanying exercise training consisted of a continuous and interval running protocol in a cross-over design. Incremental stage tests on a treadmill were done frequently to test physical performance. Actigraphy was used to monitor physical activity level. Cognitive performance, mood (MoodMeter^®), affect (PANAS), brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), vascular-endothelial growth factor (VEGF), and saliva cortisol were investigated prior to, four times during, and after isolation, pre- and post-exercise on two separate days, respectively. As a chronic effect, physical performance increased (and IGF-1 tended) in the course of isolation and training until the end of isolation. Subjective mood and affect state, as well as cognitive performance, basal BDNF and VEGF levels, were well-preserved across the intervention. No acute effects of exercise were detected, besides slower reaction time after exercise in two out of nine cognitive tests, testing sensorimotor speed and memory of complex figures. Consistently higher basal IGF-1 concentrations and faster reaction time in the psychomotor vigilance test were found for the continuous compared to the interval running protocol. The results suggest that 120 days of isolation and confinement can be undergone without cognitive and mental deteriorations. Regular, individual aerobic running training supporting physical fitness is hypothesized to play an important role in this regard. Continuous running exercise seems to trigger higher IGF-1 levels and vigilance compared to interval running. Systematic and prolonged investigations and larger sample size are required to follow up on exercise-protocol specific differences in order to optimize the exercise intervention for long-term psycho-physiological health and well-being.

Dietary PUFAs and Exercise Dynamic Actions on Endocannabinoids in Brain: Consequences for Neural Plasticity and Neuroinflammation

The brain and peripheral nervous system provide oversight to muscle physiology and metabolism. Muscle is the largest organ in the body and critical for glucose sensitivity, prevention of diabetes, and control of obesity. The central nervous system produces endocannabinoids (eCBs) that play a role in brain neurobiology, such as inflammation and pain. Interestingly, studies in humans and rodents show that a moderate duration of exercise increases eCBs in the brain and blood and influences cannabinoid receptors. Cannabinoid actions in the nervous system have advanced our understanding of pain, well-being, and disease. Nutrition is an important aspect of brain and eCB physiology because eCBs are biosynthesized from PUFAs. The primary eCB metabolites are derived from arachidonic acid, a 20:4n-6 (ω-6) PUFA, and the n-3 (ω-3) PUFAs, EPA and DHA. The eCBs bind to cannabinoid receptors CB1 and CB2 to exert a wide range of activities, such as stimulating appetite, influencing energy metabolism, supporting the immune system, and facilitating neuroplasticity. A diet containing different essential n-6 and n-3 PUFAs will dominate the formation of specific eCBs, and subsequently their actions as ligands for CB1 and CB2. The eCBs also function as substrates for cyclooxygenase enzymes, including potential substrates for the oxylipins (OxLs), which can be proinflammatory. Together, the eCBs and OxLs act as modulators of neuroinflammation. Thus, dietary PUFAs have implications for exercise responses via synthesis of eCBs and their effects on neuroinflammation. Neurotrophins also participate in interactions between diet and the eCBs, specifically brain-derived neurotrophic factor (BDNF). BDNF supports neuroplasticity in cooperation with the endocannabinoid system (ECS). This review will describe the role of PUFAs in eCB biosynthesis, discuss the ECS and OxLs in neuroinflammation, highlight the evidence for exercise effects on eCBs, and describe eCB and BDNF actions on neuroplasticity.

Rapid treatments for depression: Endocannabinoid system as a therapeutic target

Current first-line treatments for major depressive disorder (MDD), i.e., antidepressant drugs and psychotherapy, show delayed onset of therapeutic effect as late as 2-3 weeks or more. In the clinic, the speed of beginning of the actions of antidepressant drugs or other interventions is vital for many reasons. Late-onset means that depression, its related disability, and the potential danger of suicide remain a threat for some patients. There are some rapid-acting antidepressant interventions, such as sleep deprivation, ketamine, acute exercise, which induce a significant response, ranging from a few hours to maximally one week, and most of them share a common characteristic that is the activation of the endocannabinoid (eCB) system. Activation of this system, i.e., augmentation of eCB signaling, appears to have anti-depressant-like actions. This article puts the idea forward that the activation of eCB signaling represents a critical mechanism of rapid-acting therapeutic interventions in MDD, and this system might contribute to the development of novel rapid-acting treatments for MDD.

Influence of diet on acute endocannabinoidome mediator levels post exercise in active women, a crossover randomized study

The extended endocannabinoid system, also termed endocannabinoidome, participates in multiple metabolic functions in health and disease. Physical activity can both have an acute and chronic impact on endocannabinoid mediators, as does diet. In this crossover randomized controlled study, we investigated the influence of diet on the peripheral response to acute maximal aerobic exercise in a sample of active adult women (n = 7) with no underlying metabolic conditions. We compared the impact of 7-day standardized Mediterranean diet (MedDiet) and control diet inspired by Canadian macronutrient intake (CanDiet) on endocannabinoidome and short-chain fatty acid metabolites post maximal aerobic exercise. Overall, plasmatic endocannabinoids, their congeners and some polyunsaturated fatty acids increased significantly post maximal aerobic exercise upon cessation of exercise and recovered their initial values within 1 h after exercise. Most N-acylethanolamines and polyunsaturated fatty acids increased directly after exercise when the participants had consumed the MedDiet, but not when they had consumed the CanDiet. This impact was different for monoacylglycerol endocannabinoid congeners, which in most cases reacted similarly to acute exercise while on the MedDiet or the CanDiet. Fecal microbiota was only minimally affected by the diet in this cohort. This study demonstrates that endocannabinoidome mediators respond to acute maximal aerobic exercise in a way that is dependent on the diet consumed in the week prior to exercise.

Modulation of Endocannabinoid System Components in Depression: Pre-Clinical and Clinical Evidence

Depression is characterized by continuous low mood and loss of interest or pleasure in enjoyable activities. First-line medications for mood disorders mostly target the monoaminergic system; however, many patients do not find relief with these medications, and those who do suffer from negative side effects and a discouragingly low rate of remission. Studies suggest that the endocannabinoid system (ECS) may be involved in the etiology of depression and that targeting the ECS has the potential to alleviate depression. ECS components (such as receptors, endocannabinoid ligands, and degrading enzymes) are key neuromodulators in motivation and cognition as well as in the regulation of stress and emotions. Studies in depressed patients and in animal models for depression have reported deficits in ECS components, which is motivating researchers to identify potential diagnostic and therapeutic biomarkers within the ECS. By understanding the effects of cannabinoids on ECS components in depression, we enhance our understanding of which brain targets they hit, what biological processes they alter, and eventually how to use this information to design better therapeutic options. In this article, we discuss the literature on the effects of cannabinoids on ECS components of specific depression-like behaviors and phenotypes in rodents and then describe the findings in depressed patients. A better understanding of the effects of cannabinoids on ECS components in depression may direct future research efforts to enhance diagnosis and treatment.

Molecular Alterations of the Endocannabinoid System in Psychiatric Disorders

The therapeutic benefits of the current medications for patients with psychiatric disorders contrast with a great variety of adverse effects. The endocannabinoid system (ECS) components have gained high interest as potential new targets for treating psychiatry diseases because of their neuromodulator role, which is essential to understanding the regulation of many brain functions. This article reviewed the molecular alterations in ECS occurring in different psychiatric conditions. The methods used to identify alterations in the ECS were also described. We used a translational approach. The animal models reproducing some behavioral and/or neurochemical aspects of psychiatric disorders and the molecular alterations in clinical studies in post-mortem brain tissue or peripheral tissues were analyzed. This article reviewed the most relevant ECS changes in prevalent psychiatric diseases such as mood disorders, schizophrenia, autism, attentional deficit, eating disorders (ED), and addiction. The review concludes that clinical research studies are urgently needed for two different purposes: (1) To identify alterations of the ECS components potentially useful as new biomarkers relating to a specific disease or condition, and (2) to design new therapeutic targets based on the specific alterations found to improve the pharmacological treatment in psychiatry.