Fig. 3.

Changes in circulating serum prolactin concentrations during and after passive heat loading. Values are presented as mean±standard deviation. ***P<0.001 vs. previous point. ^###P<0.01, CON vs. CAFF. Pre, −60 min before passive heat loading; Post, immediately after passive heat loading for 30 min; Post-60, after 60 min of resting from the 30-min passive heat loading; Passive heat loading, half immersion to the umbilicus in 42°C hot water (test room temperature, 24.5°C±0.3°C, 50.0%±3.0% relative humidity, and 1-m/sec air velocity); CON, control subjects (n=15, 200 mL of tap water); CAFF, caffeine ingestion subjects (n=15, 3-mg/kg caffeine and 200 mL of tap water).