Comparison of the effect of a single bout of aerobic activity and sauna on blood free fatty acids levels

Aerobic exercise breaks down body fat and free fatty acids (FFA) and therefore, plays an important role in cardiovascular health. On the other hand, sauna bath increases FFA levels. The purpose of this study was to compare the effect of a single bout of aerobic activity and sauna bath on blood FFA levels.

Fifteen male college soccer players (age: 24.5 ± 2.5 years, weight: 72 ± 8 kg and Vo2max = 47 ml/kg/min) voluntarily participated in this study. Research protocols performed in two phases. In the first phase, subjects were exposed for 20 min to a sauna bath with 80 °C temperature. Two weeks later (the second phase), the same subjects ran on the treadmill for 20 min till their heart rate reach 120-135 beat/min. Systolic and diastolic pressure, heart rate, and body temperature were measured before and immediately after the phases. Moreover, in order to measure FFA, blood samples were collected before and immediately after the phases. FFA was measured by ELISA method.

Sauna bath significantly increased systolic pressure but decreased diastolic pressure (p < 0.01). Running on treadmill significantly increased both systolic and diastolic pressure (p < 0.01). The changes in systolic and diastolic pressures induced by sauna bath had significant difference with the changes induced by running on treadmill (p < 0.01). Both sauna bath and aerobic activity significantly increased FFA (p < 0.01). However, there was no significant difference between sauna bath and aerobic activity in the increase in FFA (p > 0.05).

Both single bout aerobic activity and sauna bath release FFA into the blood. Since there is no physical activity in sauna bath, FFA released by sauna bath probably go back to the lipid tissue and store.