In the current study, Benson and his colleagues studied 52 people, half of whom had meditated for four to 20 years using relaxation techniques and half of whom were novices. Both groups had their blood taken and analyzed before and after a 20 minute relaxation session in which they used a CD for guidance. The new meditaters agreed to participate in two relaxation sessions; in the first, they listened to a CD that provided general health information unrelated to stress, which served as a control. That way, the researchers could compare any molecular changes captured in their blood after they learned deep breathing, mindfulness and mantra practice, which involved focusing their mind on a single repeated word while ignoring distractions.