Group 1 intervention- sauna × 30 min; group 2 intervention-sauna × 45 min
HR, SBP, DBP, tympanic temp, rectal temp, wt; exhaled air analysis for O2 uptake, CO2 exhalation, respiratory quotient; blood analysis for Hb, HCT, calc plasma volume changes, lipid panel, free fatty acids, total free fatty acids – all measured before/after 1st sauna and final sauna
Positive, reduced total cholesterol (), reduced LDL cholesterol ( value unclear), increased HDL cholesterol () claimed (reported numbers do not agree) in group 2 after repeat sauna.
2-group side-by-side clinical interventional study
Healthy men and women/ Germany
41
Finnish
Minimum one month of weekly sauna use in “regular sauna group”
Two groups receive the same 2-session sauna intervention: Group 1:“regular sauna group” before intervention Group 2: “newcomer sauna group” with no prior sauna 3 months before intervention.
TEWL (trans epidermal water loss); stratum corneum hydration; skin erythema; skin surface pH; surface sebum content; ionic concentration of NaCl in sweat
Positive, baseline values (pre-sauna) of forehead sebum level 25% lower in regular sauna group (); sebum levels decreased similarly in both groups; decrease in NaCl sweat concentration in regular sauna group only (~200 mmol/L to ~170 mmol/L, ); skin surface pH lower in regular sauna group but similar elevations with sauna activity.
Group 1 intervention- sauna × 30 min; group 2 intervention-sauna × 45 min
HR, BP, rectal and tympanic temp, body wt; blood Hb; calc plasma volume; serum levels of TSH, T3, T4, human growth hormone, ACTH, cortisol
Positive, increased HR, increased SBP, decreased DBP and reduced plasma volumes after single and repeated sauna sessions in both groups (–). Increased secretions of growth hormone, ACTH, cortisol after single and repeated sauna sessions in both groups (–).
Body mass, HR, Body skinfold thickness, blood lipid profiles and plasma volumes
Positive, reduced total cholesterol (4.50 ± 0.66 mmol/L to 4.18 ± 0.41 mmol/L, ) and LDL levels (2.71 ± 0.47 mmol/L to 2.43 ± 0.35, ) after 10 sessions of sauna over 2 weeks – returned to baseline after 2 weeks without sauna. No significant changes in HDL levels