Third, exposure to cold could have a potentiating effect on the adrenaline release evoked by the breathing techniques. In a study of human volunteers, adrenaline levels were increased after 2 hours of sitting in a cold room. Interestingly, in a study during acute exercise in human volunteers, cold exposure prior to exercise was associated with an added immuno-stimulatory effect. Also, cytokineresponse of IL-1beta and IL-6 in ex vivo LPS-stimulated blood was lower in experienced ice-swimmers compared to inexperienced ice-swimmers.