The beneficial health effects of voluntary exposure to cold water – a continuing subject of debate

Abstract

This thesis is a review article based on a detailed multiple database literature survey of published literature in order to try and determine whether voluntary exposure to cold water immersion (CWI) has beneficial health effects. The literature research was deliberately restricted to only include studies in humans within a strict keyword-based framework. After a filtering process the number of studies regarded as being relevant was 92. While many of the studies demonstrated significant effects of CWI on various physiological and biochemical parameters, the question as to whether these changes are actually beneficial for health was difficult to objectively assess. Although some of the studies were based on established winter swimmers, many were performed on subjects with no previous winter swimming experience or in subjects not involving cold water swimming, for example cold water immersion as a post exercise treatment. In addition, clear conclusions from the majority of studies were hampered by the fact that they were carried out in small groups, often of one gender and with differences in exposure temperature and salt composition of the water. Although approached from different angles, CWI seems to have a positive effect on the reduction and/or transformation of body adipose tissue. This may have a protective effect against cardiovascular disease and potentially could have prophylactic effects on health. A further point that is unclear from the literature is as to whether winter swimmers as a group are naturally healthier and that the positive effects they report are not necessarily related to CWI itself but are more associated with the well described positive social aspects of winter swimming. In summary, there is increasing evidence that voluntary exposure to cold water has some beneficial health effects. However, until we have more conclusive studies, the topic will continue to be a subject of debate.