“Humans report a wide range of neurobiological rewards following moderate and intense aerobic activity, popularly referred to as the ‘runner’s high’, which may function to encourage habitual aerobic exercise. Endocannabinoids (eCBs) are endogenous neurotransmitters that appear to play a major role in generating these rewards by activating cannabinoid receptors in brain reward regions during and after exercise…”
Recent work supports direct links between eCB signaling and exercise in humans…
It is possible that neurobiological rewards induced by eCB signaling are an ancient human trait that evolved to encourage aerobic activity, and that the rewards explain the evolution…
The fact that running, and endurance exercise in general, remains an enjoyable and psychologically beneficial recreational activity for tens of millions of humans today suggests that we still may respond to a neurobiological trait that evolved early in our lineage.”
http://jeb.biologists.org/content/215/8/1331.long
“The endocannabinoid system is known to have positive effects on depression partly through its actions on neurotrophins, such as Brain-Derived Neurotrophic Factor (BDNF). As BDNF is also considered the major candidate molecule for exercise-induced brain plasticity, we hypothesized that the endocannabinoid system represents a crucial signaling system mediating the beneficial antidepressant effects of exercise…
These findings provide evidence in humans that acute exercise represents a physiological stressor able to increase peripheral levels of AEA and that BDNF might be a mechanism by which AEA influences the neuroplastic and antidepressant effects of exercise.”
http://www.ncbi.nlm.nih.gov/pubmed/22029953
“Endocannabinoids (eCB) are endogenous ligands for cannabinoid receptors that are densely expressed in brain networks responsible for reward. Recent work shows that exercise activates the eCB system in humans and other mammals, suggesting eCBs are partly responsible for the reported improvements in mood and affect following aerobic exercise in humans.
However, exercise-induced psychological changes reported by runners are known to be dependent on exercise intensity, suggesting that any underlying molecular mechanism should also change with varying levels of exercise intensity.
Here, we examine circulating levels of eCBs following aerobic exercise (treadmill running) in recreationally fit human runners at four different intensities.
We show that eCB signaling is indeed intensity dependent, with significant changes in circulating eCBs observed following moderate intensities only (very high and very low intensity exercises do not significantly alter circulating eCB levels).
Our results are consistent with intensity-dependent psychological state changes with exercise and therefore support the hypothesis that eCB activity is related to neurobiological effects of exercise.
Thus, future studies examining the role of exercise-induced eCB signaling on neurobiology or physiology must take exercise intensity into account.”
“The effects of physical exercise stress on the endocannabinoid system in humans are almost unexplored. In this prospective study, we investigated in a crossover design and under field conditions at different altitudes the effects of physical exercise on the endocannabinoid system (ECS) in 12 trained healthy volunteers…
We conclude that the ECS is activated upon strenuous exercise whereas the combination with hypoxic stress further increases its activity.
In summary, physical exercise activates the endocannabinoid system, whereas the combination with high altitude enhances this activation.”
http://www.ncbi.nlm.nih.gov/pubmed/22101870
“Exercise induces changes in mental status, particularly analgesia, sedation, anxiolysis, and a sense of wellbeing. The mechanisms underlying these changes remain unknown.
Recent findings show that exercise increases serum concentrations of endocannabinoids, suggesting a possible explanation for a number of these changes…
At first glance, it appears that the runner’s high phenomenon is, at present, not a scientific problem because it is built on circumstantial evidence and lacks a plausible mechanistic explanation. However, recent data in our laboratory showed that endurance exercise activates the endocannabinoid system, suggesting a new mechanism underlying exercise induced alterations of mental status.”
http://bjsm.bmj.com/content/38/5/536.long
“Extensive documentation exists showing that exercise induces analgesia and sedation.
…we report here the first evidence that exercise of moderate intensity activates the endocannabinoid system, suggesting a new mechanism for exercise-induced analgesia and possibly other physiological and psychological adaptations to exercise.”
“Recognized as a “disease modifier”, physical activity (PA) is increasingly viewed as a more holistic, cost-saving method for prevention, treatment and management of human disease conditions.
The traditional view that PA engages the monoaminergic and endorphinergic systems has been challenged by the discovery of the endocannabinoid system (ECS), composed of endogenous lipids, their target receptors, and metabolic enzymes.
Indeed, direct and indirect evidence suggests that the ECS might mediate some of the PA-triggered effects throughout the body.
Moreover, it is now emerging that PA itself is able to modulate ECS in different ways.
Against this background, in the present review we shall discuss evidence of the cross-talk between PA and the ECS, ranging from brain to peripheral districts and highlighting how ECS must be tightly regulated during PA, in order to maintain its beneficial effects on cognition, mood, and nociception, while avoiding impaired energy metabolism, oxidative stress, and inflammatory processes.”
“The search for suitable biomarkers of pregnancy outcome is a challenging issue in human reproduction, aimed at identifying molecules with predictive significance of the reproductive potential of male and female gametes.
Among the various candidates, endocannabinoids (eCBs), and in particular anandamide (AEA), represent potential biomarkers of human fertility disturbances…
Based on the available data, we suggest that the AEA tone has the potential to be exploited as a novel diagnostic biomarker of infertility,”
“The endocannabinoid system (ECS) is an evolutionarily conserved master system deeply involved in the central and local control of reproductive functions in both sexes. The tone of these lipid mediators-deeply modulated by the activity of biosynthetic and hydrolyzing machineries-regulates reproductive functions from gonadotropin discharge and steroid biosynthesis to the formation of high quality gametes and successful pregnancy.
This review provides an overview on ECS and reproduction and focuses on the insights in the regulation of endocannabinoid production by steroids, in the regulation of male reproductive activity, and in placentation and parturition.
Taken all together, evidences emerge that the activity of the ECS is crucial for procreation and may represent a target for the therapeutic exploitation of infertility.”