Anyone who has exercised for a period of time has experienced a ‘high’ from it. The rush of endorphins that occurs during and shortly after activity is an inherent part of the work done and directly related to the level of intensity one can tolerate.
The endocannabinoid system is a group of neuromodulatory ligands and their receptors. They play a role in appetite, pain sensation, mood and memory. Cannabis has clearly been shown to affect these systems. The question becomes what are exercises effects if any? Among other things, animal models of the endocannabinoid system have demonstrated a homeostatic effect on metabolism. Insulin sensitivity, liver function, pancreas function, atherosclerosis, and even intestinal health have been implicated.
Raichlen, et al 2011 decided to test humans, dogs and ferrets on a walking and high intensity running test for plasma levels of anandamide, and 2-arachidonylglcyerol, 2 well known endocannabinoids. 10 fit humans, 8 dogs and 8 ferrets had pre exercise blood drawn for analysis. Heart rate for running averaged at 73% while walking heart rate was 44%.
Humans and dogs showed increases in both markers with a P=0.89 correlation after the run but no change from baseline after the walk. Ferrets showed no change from baseline for either. This tends to indicate that long-distance running at moderate-high intensities cause endocannabinoid responses in mammals which run long distances. Further, this activity helps modulate metabolic activity beyond pure caloric expenditure. This raises the real question of using neurotransmitters to help with therapeutic treatments derived from exercise. Now it is not merely correlation (exercise reduced mil to moderate depression), now mechanisms begin to fall into place and chains of events with the cell and among different systems become more evident. This type of research can really take us into a whole new direction.
Train hard and train safe.