There are various different ways for relieving stress. Tobias Esch from the Coburg University of Applied Scientists has been researching meditation as a relaxation technique and the effect that it has on the body.
He discovered that at the start of meditation, the body surprisingly releases stimulating neurotransmitters like dopamine and noradrenalin. Esch believes this is perhaps part of the body's natural survival instinct. Only once it becomes clear that this is a safe time and place to relax are other neurotransmitters released which counteract the stress hormones, resulting in genuine relaxation.