To examine the effects of 1 week of high volume weightlifting and amino acid supplementation, 28 elite junior male weightlifters received either amino acid (protein) or lactose (placebo) capsules using double-blind procedures. Weightlifting test sessions were performed before and after 7 days of high volume training sessions. Serum concentrations of testosterone (Tes), cortisol (Cort), and growth hormone (GH) as well as whole blood lactate (HLa) were determined from blood draws. Lifting performance was not altered for either group after training, although vertical jump performance was not altered for either group after training, although vertical jump performance decreased for both groups. Both tests elicited significantly elevated exercise-induced hormonal and HLa concentrations. Significant decreases in postexercise hormonal and HLa concentrations from Test 1 to Test 2 were observed for both groups. Tes concentrations at 7 a.m. and preexercise decreased for both groups from Test 1 to Test 2, while the placebo group exhibited a decreased 7 a.m. Tes/Cort. These data suggest that amino acid supplementation does not influence resting or exercise-induced hormonal responses to 1 week of high volume weight training, but endocrine responses did suggest an impending over-training syndrome.