The Effects of a Single and a Series of Finnish Sauna Sessions on the Immune Response and Heat Shock Protein Levels in Trained and Untrained Men

The aim of the study was to investigate the effect of a Finnish sauna on the immune status markers. Healthy males (20–25 years old) were divided into gropes: the trained (T; n = 10), and the untrained group (N; n = 10). All participants were subjected to 10 baths (3X15-minute with cooled down for 2 minutes). Blood was collected before the 1st and 10th sauna bath, and 10 minutes after their completion. The levels of: cortisol, Il-6, HSP70, IgA, IgG, IgM and blood cells (WBC), leukocyte populations counts: neutrophils, lymphocytes, eosinophils, monocytes, and basophils were determined. No differences were found in the increase in rectal temperature, cortisol and Ig between groups. In response to the 1st sauna bath, a greater increase in HR was observed in the U group. After the last one, the HR value was lower in the T group. The impact on WBC, CD56+, CD3+, CD8+, IgA, IgG and IgM shows a differences in trained and untrained body responses. It seems that in trained people, the non-specific immune response increases, while in untrained, the specific one. Series of sauna baths can be a way of acclimation to high ambient temperatures for athletes and a solution to improve immune response.