Tae-Wook Kim, Young-Oh Shin, Jeong-Beom Lee, Young-Ki Min, Hun-Mo Yang
Abstract
This study measured caffeine-induced changes in activated sweat gland density (ASGD) and fat oxidation using a randomized crossover design with 10 healthy volunteers given caffeine (Caffe-I, 3 mg/kg ingested 30 min before experiment) and non-caffeine (No-Caff). Subjects were 173.0±3.2 cm in height, 72.5±4.3 kg in weight, and 21.5±2.5 years in age. All experiments were performed in an automated climate chamber (24.0±0.5°C, relative humidity 50±3%, air velocity less than 1 m/sec) between 2–5 p.m. The ASGD on the chest, upper arm, upper back, and lower back were measured (after 30 min running at 60% VO2max), and blood samples were taken (at 40 min before, immediately before and after 30 min running). Activated sweat gland density levels were higher in Caffe-I (Chestp<0.05 and U-Back p<0.01) and free fatty acids (FFA) were higher in Caffe-I compared to No-Caff immediately before (p<0.05) and after running (p<0.01). In summary, caffeine increases ASGD and FFA by stimulating the sympathetic nervous system and increasing of lipolysis.
source: visit here