Endocannabinoids are signals that occur within your body that help maintain homeostasis by identifying hunger, pain, disposition and memory. CBD elevates and increases the functionality endocannabinoids by slowing down your metabolism.
The second aspect to this is based on the damage sustained while exercising. Strength training can create microtears in your muscles which is why you feel pain after an intense workout. When your immune cells pick up on the damage, they send signals to repair the tissue. CBD can limit the release of these signals and as a result reducing the pain sensation felt.
The third and final aspect to this involves TrpV1 receptors that act as temperature regulators in the body. When these receptors are activated, they release heat in order to sooth the pain felt. CBD increases the activity of these receptors which results in them getting hot for extended periods of time and desensitising them to the pain felt.