Summary. Acute exercise is a stressful stimulus that may lead to systemic apoptosis. No studies to date address the apoptosis response to caffeine ingestion during acute resistance exercise (RE). The aim of this study was to determine the effects of oral caffeine ingestion on biomarkers of apoptosis including Bax and Bcl-2 during strenuous RE in resistance trained men. In a randomized, double-blind, placebo-controlled, crossover study, fourteen resistance trained men (20.6±2.3 years; 72.8±9.2 kg; 178.7±4.2 cm) ingested caffeine (6 mg/ kg body weight) or placebo one hour before acute RE with 85% of one-repetition maximum (1RM). Blood samples were taken pre- (Pre), immediately post- (IP), and 15 min post- (15P) RE for measurement of serum Bax and Bcl-2 concentrations. Data were analyzed with ANOVA with repeated measures (P<0.05). Bax and percentage change of Bax/Bcl-2 ratio at IP RE were significantly lower in caffeine condition compared to the placebo condition. Moreover, anti-apoptotic Bcl-2 levels were significantly increased at IP in both caffeine and placebo conditions (p=0.041 and 0.01 respectively), but no differences were observed between both conditions at any time point (p>0.05). These results suggest that acute caffeine intake attenuated exerciseinduced apoptosis in resistance trained men, which was confirmed by attenuated percentage change of Bax/ Bcl-2 ratio in the caffeine condition.
